BIOL 319 Part II Flashcards
(635 cards)
1
Q
differences in predator interactions in sandy shore relative to rocky
A
- have to dig/work to get prey
- less restricted by tides
- more partial predation
- seasonal predator intensity
2
Q
why are predators less restricted by tides in sandy/muddy shore
A
more terrestrial predators (marine predators restricted by submersion)
3
Q
seasonal predator intensity, soft sediment shore
A
migratory birds
4
Q
sandy shore infauna predator defense
A
- differential burrowing depth
- differential shell thickness
- anti-predator chemicals
5
Q
bottom-up and top-down predation in sandy shore
A
top-down typically terrestrial like birds
bottom-up typically marine predators - fish, crabs etc
6
Q
burrowing benefit
A
hidden
well-defended
7
Q
sandy shore defense trade-off
A
thin shell bivalves burrow deeper
8
Q
sandy shore anti-predator chemicals
A
polychaetes
bromide-containing aromatic compounds
9
Q
infaunal organisms and predators
A
- infauna typically well protected
- infauna can suffer high mortality due to seasonal predator intensity
- more abundant species suffer highest depletion rates
- predators are specialized to infauna
10
Q
disturbances in soft shore environment
A
- physical
- biological
11
Q
biological disturbance in soft shore environment
A
- predators
- bioturbation
12
Q
physical disturbance, soft shore environment
A
waves
- sediment
- exposure
- shelter
13
Q
waves and sediment
A
impact sediment size, sorting, distribution, permeability, porosity, penetrability
14
Q
waves and exposure
A
high energy, small sediment size, sandy shore
15
Q
waves and shelter
A
low energy, more impacted by tides than waves, small size sediment, clay/mudflat
16
Q
sediment diameter vs water velocity
A
increasing to asymptote (log x)
17
Q
wave impact on beach sediment
A
longshore transport
tides
18
Q
wave exposed, sandy beach infauna
A
dominated by long-lived suspension feeders; bivalves, clams
19
Q
sheltered, muddy beach
A
dominated by short-lived deposit feeders; worms/polychaetes
20
Q
why are bivalves more common in sandy beach
A
suspension feeders - access to currents in sand, and can get clogged by fine particles in mud
21
Q
why worms more abundant in muddy beaches
A
fragile; like calm, sheltered environment
deposit feeders - more OM in mud
22
Q
bioturbation increases
A
- habitat complexity
- sediment oxygen
- sediment sorting
- sediment stickiness
23
Q
impact of bioturbation on other organisms
A
commensalism
amensalim
24
Q
commensalism
A
other species benefit from the activities of bioturbater
25
example of commensalism
mussels sheltering the beach for cockles
26
supply side ecology soft sediment principles
- infauna have larvae
- larvae are delivered by currents (depend on wave exposure)
- variable settlement strategies
- adults are mobile (unlike rocky shore)
27
water table
- natural level of water content
| - approximately at the tide line
28
above water table
very little water in sediments
29
changes in water table
water line moves up/down during day due to tide/currents
30
suspension feeders favour
high energy, coarser sediments
31
amensalism
other species suffers from the activities of bioturbators
32
amensalism example
lugworms exclude other burrowing organisms
33
why do deposit-feeders decrease growth of suspension feeders
sediment reworking re-suspends particles and clogs the filtering organs
34
Importance of larval settlement in sandy shore relative to rocky
not as important in sandy because they can move
35
sandy shore zonation hypotheses
- no zonation
- two zones only (Brown's)
- three zones (Dahl's)
- four zones (Salvant's)
36
sandy shore zonation
- abiotic factors only
- wetness--dryness gradient
- disturbance
37
retention zone
where water goes in to sediment but doesn't stay - waves crash, water enters, water percolates down to water table
38
supralittoral zone
- highest part of beach
- dry vast majority of time
- air breathing organisms, insects
39
littoral zone
- 'true intertidal' zone
- sometimes dry some wet
- mixed species
40
deposit feeders favour
low energy, finer sediments
41
sublittoral zone
lowest intertidal zone
- mostly wet
- lots of infauna
42
Brown's zonation hypothesis
2 zones: air breathers vs water breathers
43
Dahl's zonation hypothesis
3 zones: sub-terrestrial fringe, midlittoral, sublittoral fringe
44
salivates zonation hypothesis
drying, retention, resurgence, saturation
45
beach types that impact zonation
- dissipative beach
- intermediate beach
- reflective beach
46
dissipative beach
- gentle slope (flat)
- wave break before hitting beach, sheltered
- generally wetter, finer sed
- less pronounced wetness gradient
- shallower RPD
47
reflective beach
- steep slope
- waves break on beach - exposed
- intertidal dryer, sediment bigger
- wetness gradient more pronounced
48
zonation in soft sediments
- 2-4 zone depending on beach
- always dry and wet zones, middle ones change
- slope is important
49
true kelp
- (Order Laminaria) brown algae
- large, brown subtidal seaweed
- very strong holdfast
- form dense NA forests
50
kelp zones with depth
top of water column = canopy
middle = understory
benthos = algal turf
51
kelp zones with distance from shore
inshore
kelp canopy
offshore
52
what is "brown algae"
mixed photosynthetic pigments (chl a and chl c)
53
Seaweed morphology pars
holdfast + stipe = thallus
float
blades/fronds
54
characteristics of reflective beach
- large particles
- large physical gradient, flow, moisture
- low chemical gradient
- large importance of waves
- low importance of tides
55
pneumatocyst
seaweed float
56
seaweed difference from terrestrial/vascular plants
seaweed lack 'true' leaves, stems, roots, not plants
57
seaweed blade structures
flat, high SA:V, concentrated w/ chl, maximize nutrient absorption
58
characteristics of dissipative beach
- small particle size
- low physical gradient
- large chemical gradient (O2, Eh)
- low importance of waves
- high importance of tides
59
kelp as photosynthesizers
- very highly productive
- entire body photosynthesizes
- grow fast and large
60
pneumatocyst structure and function
- air/gas filled balls
- grape-volleyball size
- keep blades close to surface
61
why do pneumatocysts want to keep the blades close to the surface
they have the highest concentration of chl - keep close to sunlight for max production
62
pneumatocyst gases
O2, CO2, CO
63
stipe
- strong, flexible, "stem"
- absorbs shock
- photosynthesizes
64
holdfast
"roots"
- anchor
- don't absorb nutrients
- may secrete glue-like substance
65
thallus
whole body
66
convergence in kelp
species evolved to have kelp-like morphology can behave in same way and provide similar fn's to kelp
67
divergence in kelp
species that specialize in different regions may have different morpholgy
68
divergence examples
canopy kelp - long, tall, rise up to 45m
stipulate kelp - only rise ca 2m
prostrate kelp - drape seafloor
69
canopy kelps
-fronds on surface
-giant kelps
-
70
understory kelp
- fronds erect or close to bottom
- middle zone
- stipe dominant
- highest diversity
71
algal turf zone
- short clump, filaments, encrusting
- non-kelp algae
- abundant red algae
72
inshore kelp zone
feather-boa, laminaria
73
canopy conditions
- most light
- most wave action
- not stable environment
74
understory conditions
- less light
- less wave action
- highest diversity
75
why is understory so high in diversity
- stipes = area for attachment
- area between fish to swim
- calm environment
76
algal turf conditions
- least light
- little-no wave influence
- holdfasts = attachment areas, niche space
77
why red algae in algal turf?
low light chl
| flat to maximize absorption
78
organisms associated with understory
stipes: tube-forming polychaetes, byrzoans, sessile organisms
- crustacean feeders
- plankton feeders
- concentrate larvae
79
kelp crustacean feeders
surf perches
80
kelp plankton feeders
topsmelt
| blue rockfish
81
organisms associated with algal turf
holdfast: small inverts, brittle stars, polychaetes, urchins, crabs
- herbivores
- carnivores
82
algal turf herbivores
- adult rockfish
| - kelp bass
83
algal turf carnivores
california sheephead - eat crabs, urchins
84
distribution of kelp forests
- restricted
| - concentrated in mid-high lats., upwelling zones
85
kelp forest restrictions
- hard substrate for attachment
- coastal zone for sunlight
- cool Ts, heat sensitive
- high DIN for high productivity
86
why aren't kelp forests in tropics
- too hot
| - too nutrient poor
87
why aren't kelp forests in polar regions
- growing season too short
- light limitations
- ice scouring
- too harsh of conditions
88
kelp distribution is closer to tropics than might be expected, why?
predominant current direction (S in N, N in S) upwells cool nutrient rich waters and stretches distribution
89
Kelp importance
- high PP, carbon sequestration
- provide food, shelter for many species
- buffer, protect coasts against waves, storms
90
causes of kelp deforestation
- physical condition anomalies
- sea urchins
- storms
91
El Niño deforestation
- more storms, warmer, less nutrient, removal of predators, release herbivores
- upwelling reduced, reversed -warm nutrient poor water - not good for kelp
- kelp often recover from these events
92
urchin deforestation
- urchins normally passively feed on drift kelp
| - when drift limited, urchins experience food limitation - feeding behaviour changes - become destructive
93
drift kelp
free-floating kelp detritus
94
urchin feeding behaviour change
- actively feed on holdfast
- aggregate in big groups
- move through forest as one super kelp eater
- urchin feeding "front"
95
kelp forest with low urchin density
mix of kelp + other turf algae
96
kelp forest with high urchin density
-kelp deforested
crustose
-coralline algae replaces all other species = "urchin barren"
97
urchin barrens and kelp recovery
less likely to recover from this type of deforestation b/c crustose coralline algae prevent kelp from re-rooting
98
Controls on kelp urchins in W NAtl
- single tier (prostrate)
- simple food web
- strong interactions
- cod extirpation -- phase shift to urchin barren -- return to kelp forest
99
Controls on kelp urchins in Aleutians, Alska
- simple food web but multi-tiered
- intermediate diversity
- european settlement-- phase shift-- switched back and forth after that
100
Controls on kelp urchins in Southern California
- multi-tier kelp (3 zones)
- complex food web
- high diversity
- urchin barrens/kelp forests flicker back and forth, short duration
101
What happened to kelp forests in Alaska
otters nearly extirpated-- urchins grow out of control (trophic cascade)-- otter pop's recover, urchins under control-- kelp recovers -- then phase shift again!
102
what caused the second phase shift in Alaska
-increased number of orca kills -- reduced otter pop. -- trophic cascade again by apex predator this time-- 4 level trophic cascade
103
why did orcas start eating more otters
- possibly because their food source is declining (seals)
| - possibly b/c geographical distribution is changing
104
What happened to kelp forest in N Atl
decline in cod allowed urchins to take over-- phase shift -- urchin fisheries opened -- kelp forests re-established
-cod functionally equivalent to sea otters -- trigger same trophic cascade
105
impacts of cod collapse in Nova Scotia (relative to Maine)
following initial phase change from cod collapse -- multiple cycles of urchin disease -- several phase shifts
106
lessons from phase shift studies
- humans are good at triggering phase shifts
- anything that can control urchin populations can trigger the phase shift
- phase shifts can lead to new species interactions
- even in similar regions can have unique triggers/interactions (Maine vs Canada)
107
new interaction following kelp phase shift, N Atl
kelp recover - encourage crabs to migrate into kelp bed-- crabs feed on urchin larvae and diseased adults -- prevent urchin recruitment
108
Details of kelp forest phase shift in Southern California
- more predators, species
- delayed phase shifts (otters removed 150-200ya)
- other predators fed on urchins -- human settlement --functionally equiv. species all under pressure now
- other predators buffered the system from change, provided insurance
109
phase shift
switch between steady states
110
threshold
energy required to switch between steady states
111
when do phase shifts reverse
- when they reach their threshold
| - urchin density is a threshold for urchin barren phase
112
threshold to shift to kelp forest
variable - reducing urchin density not always enough
113
continuous phase shift
"linear"
-path same backwards and forwards
to switch from one system occurs at the same threshold as switching back (e.g. the same urchin density)
114
the points at which a threshold is reached and phase change occurs
tipping point
115
kelp forest hysteresis cause by
feedback mechanisms stabilize the phases
116
kelp state feedbacks
lots of kelp = lots of detritus = lower urchin migration and grazing = lots of kelp
+kelp - +whiplash -- -urchin grazing -- +kelp
+kelp -- +predator abundance -- +urchin mortality -- +kelp
+kelp -- + spore production -- +kelp
117
barren state feedbacks
barren -- +urchin fertilization -- +recruitment -- barren
barren -- +settlement facilitation -- +recruitment -- barren
barren -- -detritus -- -destructive grazing -- kelp recruitment -- barren
barren -- -detritus -- -urchin migration -- barren
barren -- -predator abundance -- -barren state
118
discontinuous phase shift
"non-linear"
switching from one state requires a different threshold than switching back (e.g. lower urchin density to switch back to kelp than to switch to barren)
-harder to predict, reverse
119
another name for discontinuous shift
hysteresis = delay
120
biggest threats to kelp forest ecosystems
- loss of biodiversity
- climate change
- any interference that reduces kelp forest health
- any interference that increases urchin health / destructive behaviour
- nutrient loading and water quality
121
kelp conservation strategies
- maintain biodiv.
- water quality
- restoration
- maintain healthy kelp
122
how to maintain biodiversity
predator recovery
MPAs
responsibly fishery practices
123
how to maintain water quality
sewage and waste management
| runoff management
124
marine foundation species that have evolved from terrestrial ancestors
```
seagrass (meadows)
mangrove (forests)
salt marshes
convergence, similar adaptations
-I will call these SMS ecosystems
```
125
SMS ecosystems have lots in common with
mudflats
| the plants root in soft sediment ecosystems
126
first plant life
precambrian
127
evolution of land plants
Silurian
128
evolution of plants from phytoplankton to seagrass
phytoplankton- red algae -brown algae- green algae- land plants- mangroves- sea grasses
129
adaptations for dealing with life in seawater
- make photosynthesis more efficient
- stability in soft sediment
- deal with anoxic waterlogged sediment
- remove/exclude excess salt
130
why do marine terrestrial plants need to make photosynthesis more efficient
- gas exchange difficult in seawater
- light attenuation with depth
- more energy required for life in seawater
131
why does life require more energy in seawater
need to oxygenate roots -need to photosynthesize more to maintain same growth levels
132
SMS species commonalities
- have above-ground (leaves) and below-ground (roots) components (very different than kelp)
- provide surfaces for epifauna
- interact with infauna
133
SMS sediments share characteristics w/ soft shore ecosystems
- waterlogged sediment (b/c its mud)
- anoxia with depth (RPD)
- similar "chemical layering" as shore sediment
- processed (bioturbated) by a variety of organisms
134
seagrass
- vascular, flowering plant
- monocots
- angiosperms
- not true grasses
- form large meadows (single or multiple species)
- subtidal
135
evolution of marine angiosperms
Cretaceous
136
subtidal
- below mean low tide
| - normally covered by water at all tide levels
137
seagrass distribution
- widely distributed in temperature, tropical coastal systems
- narrow depth restrictions
138
what determines distribution of seagrass
- substrate
- light
- UV
- desiccation
139
substrate and seagrass
- majority require soft substrate
- too much sediment buries them
- not found in rocky substrates
140
light and seagrass
- very high light requirement (photosynthesis inefficient in seawater)
- lower distribution limits set by light availability
- upper limit may be set by UV
- restricted by turbidity (upwelling zones too turbid)
141
seagrass diversity
- ca. 60 species worldwide
- difficult to classify, lots of plasticity
- higher diversity in tropics than temperature latitudes
142
common seagrass genera in North America
- Thalassia: turtle grass, warmer regions, manatees, Florida-Texas
- Zostera: eelgrass, widely distributed along both coasts
- Phyllospadix: on both sides of NP, only genus that attaches to rocks
- Halodule: fresher (lower S) sandy areas, upper eastuaries
143
seagrass morphology
laminate leaf blades, leaf sheath, rhizome, node, simple root
144
seagrass leaf blade
- strap-like
- grow from sheath
- number, height of leaves varies between species
- up to 1m
145
seagrass rhizome
rooting structure that each plant attaches to, connects plant clones together
146
seagrass above-ground:below-ground biomass
ca. 50:50
147
seagrass leaf length
0.5 cm - 5m
148
variability in seagrass leaves
-many shapes and sizes
-single species can have large variability - plasticity
oblong, longitudinal, serrated, folded, cross veined, etc
149
variability in seagrass roots
simple, branched, hairy
150
importance of seagrass characteristics/ morphologies
- some forms can't grow as densely as others
- SA/shape import for organism attachment, feeding
- bushy roots stabilize sediment more
- some forms take more energy to grow resulting in trade-offs
151
seagrass marine adaptations
rhizome - mechanical support, vegetative growth
leaf shape - thin, flexible in high E env.
leaf sheath - provides protection in high E env.
lacunar system - transport O2 below ground to oxygenate roots (depresses RPD)
152
seagrass reproduction
- sexual rare and inefficient
| - vegetative growth (cloning) common but still slow
153
seagrass sexual reproduction
- mostly dioecious
- hydophilous pollination
- flower seasonally w/ high spring tide
- 10% of meadow flowers at a time
- dispersal limited, most seeds drop within m's of parent
- less than 0.00001 probability seedings become new adult
- still important for genetic diversity
154
seagrass asexual reproduction
- rhizomes extend and release new shoots
- recolonization not fast or efficient
- old clone persist
155
importance of seagrass reproduction
- inefficient = long time to recover from disturbance
| - low sexual reproduction = low resilience
156
genotypic diversity =
- lower vulnerability to disturbance, disease
- more productive, abundant
- increased abundance, diversity of epifauna
157
seagrass foodweb
```
PP- seagrass, algae
Epiphytes and fouling animals
Grazers: meso, macro
Suspension feeders: bivalves
Shredders, deposit feeders: shrimp, crabs
Predators: meso, macro
```
158
fouling animals
live on seagrass
| e.g. sponges, bivalves
159
seagrass mesograzers
small inverts
- limpets, amphipods, etc.
- consume algal epiphytes not seagrass unless left unchecked
160
seagrass macropredators
sharks (primarily prey on fish)
161
seagrass mesopredators
medium carnivorous fish
| primarily feed on mesograzers
162
why so many diverse relationships in seagrass
shelter- predators, waves
habitat - attachment sites
food - seagrass, algae, larvae, detritus
163
epiphytic community in seagrass
- important and diverse
- rhodophyta (red algae)
- chlorophyta (green algae)
- phaeophyta (brown algae)
- bacillariophyceae (diatoms)
- older seagrass = more diverse
- 26 species of algae found on 1 species of seagrass
164
seagrass macrograzers
sea cows
| turtes
165
epiphytic algae impact on seagrass community
- inhibit light, nutrient uptake for seagrass
| - nutritious food source for other organisms: higher N:C, easier to digest, no cellulose or lignin, more fatty acids
166
eating seagrass
tough, high in cellulose
- mostly consumed as detritus (microbial breakdown)
- some organisms specialized to consume (sea cow)
167
urchin impacts on seagrass
- live in coral reef (keep them clean)
| - leave reef at night to graze on surrounding grasses = reef halo
168
Green turtle macrograzer
- endangered
- young are omnivores
- older turtles increasingly herbivorous, seagrass specialists
- long guts w/ specialized enzymes to digest
- selective feeders
169
green turtle selective feeding
'gardeners'
- feed on young plants
- physiological selection: more nutritious, easier to digest
- biological selection: stimulates growth of new plants
170
why green turtles are endangered
- human exploitation
- sensitive to land use change, pollution (because of nesting)
- loss of habitat
- accidental kills (bycatch, impacts)
171
sea cow macrograzers
- Order Sirenia (4 species)
- most species feed on marine and fresh plants
- Dugong seagrass specialist
- only herbivorous marine mammal
172
Dugong dugon
- Indo-Pacific
- feed in large herds, leave feeding trail
- massive guts >30m
- selective feeding
- vulnerable
173
Dugong selective feeding
'cultivation feeders'
- prefer Halophila (high N, low fibre)
- pioneer species, grazing it stimulates growth or preferred food
174
surprising species in seagrass meadows
bivalves! (not often found in soft sediments)
| -in the sediment and on seagrass blades
175
seagrass bivalve
Pinna nobilis - endemic to mediterranean seagrass
- gigantic, up to 4ft
- fast growth, fragile shell
- possibly mutualistic w/ seagrass
176
Pinna nobilis mutualism
- seagrass provide food, protection
| - bivalves filter water (make it clear)
177
seagrass burrowers and shredders
- shrimp, crab, feed on seagrass
- some target detritus, others fresh leaves
- some transport detritus into burrows
- rework sediment
- cause bare patches in meadow - open space
178
ecological processes in seagrass communities
- bottom-up forces control diversity, abundance, distribution
- top-down forces control community structure
179
bottom-up seagrass forces
-light
-nutrients
-substrate
seagrasses only distributed and abundant where they factors are
180
top-down forces in seagrass meadow
- mesograzers (if unchecked)
- urchins can cause bare patches
- macrograzers alter composition/abundance
181
what happens to seagrass community if a mesograzer predator is excluded
- mesograzers increase
- reduce algae
- could be positive - more sunlight, nutrients for seagrass
- could eventually run out of algae and feed on seagrass
- could be positive or negative
182
what happens to seagrass community if predator of small fouling animals is removed
- increased fouling animals
- decrease in seagrass
- negative impact
183
mesograzer vs fouling animals
-mesograzers feed on photosynthesizes
attached to seagrass
-fouling animals are attached to seagrass and aren't photsyn.
184
effect to seagrass community if urchin predators are removed
- increase in urchins
- decrease in seagrass
- negative impact
185
mutualistic grazer model, seagrass community
- small inverts. feed on algae (mesograzersm algae)
- algae outcompete seagrass is left unchecked
- small inverts. keep seagrass healthy if controlled by predators
186
top-down linear seagrass trophic cascade
+large predators -- (-)small predators --- +algae grazers --- algae --- seagrasses
187
real trophic cascade in seagrass
- much more complex
- depend on which organisms are targeted
- not always intuitive
188
ecology of fear
non-consumptive trophic cascade
189
example of non-consumptive trophic cascade
-wolf reintroduction in Yellowstone
190
importance of seagrass ecosystem
- increase habitat complexity
- highly productive, CO2 sink, high levels of biodiversity
- provide food
- structural stability, protect shoreline from erosion, waves
- filter pathogens, environmental cleaners
- provide ecosystem services
191
seagrass habitat complexity
- above and below ground
- new niches
- protection
192
seagrasses provide food for
endangered marine animals
- seahorses
- sharks
193
seagrass losses
- 15% lost from 93-2003; 2-5% per year
- 74 species of concern, mostly fish
- foundation species in decline
- organisms that live in seagrass in decline
- water quality in decline
194
threats to seagrass meadow
- human alterations - eutrophication, fishing, land use change
- human recreation - habitat fragmentation
- invasive species (algae)
195
eutrophication and seagrasses
- increased nutrient supply (N, P)
- increased algal growth and take over
- seagrass sensitive to nutrient loading
196
why is eutrophication better for algae
- at high nutrient level seagrass saturates, can't grow any faster
- algae continue to increase and restrict light
- outcompete seagrass
197
Valentine and Duffy hypothesized state shifts in seagrass
seagrass dominated -- algae dominated
low efficiency small predator -overfishing- high efficiency
high abundance mesograzer -pollution- low abundance
low algal biomass -eutrophication- high algal biomass
198
seagrass overfishing example
- 90% decline of cod in sweden (overfishing) -- mesopredators increased -- mesograzes decreased -- algae increased -- seagrass decreased
- 4 level trophic cascade
- overfishing caused seagrass smothering, exacerbated by nutrient pollution
199
boat propeller scars in seagrass
```
-anchors, moorings, propellers
uproot seagrass
fragmentation
increased patchiness
long time to recover (inefficient reproduction)
```
200
studying seagrass processes
ASU - artificial seagrass units
201
major factors affecting seagrass structure
abiotic conditions
herbivory
clonal reproduction
hydrodynamics physical disturbance
202
community impacts from seagrass
```
water flow
particle deposition
associated species abundance and diversity
resource availability
predation success
```
203
seagrass fragmentation
- reduces overall area
- isolates organisms from main population
- edge effects
204
examples of edge effects
- predators more successful on edge (prey can't hide)
| - changes to sediment profile, water physics
205
reported invasive species increasing due to
- ability to detect
| - higher transportation of invasives
206
Caulerpa taxifolia
- invasive algae
- decorative aquarium algae
- one of worlds 100 worst invasive species
- very hardy, likes polluted water, high UV, fast growing, toxic chemicals - grazing resistance
- outcompetes seagrasses, invades damaged beds
207
invasive algae in Mediterranean
introduced in 1980s (possible from ocean institute), almost completely replaced seagrass
208
climate change and seagrass
- T ∆ has negative effect b/c many species live at their limits (foundation species sensitive to T)
- +T = declines in health, changes in species composition
- changes top-down control, rate of consumption
- herbivores may increase activity (metabolic increase w/ T)
209
effect of temperature on interaction strength, seagrass
- depends on species
- strength and direction variable
- hard to predict
210
strategies to protect seagrass
```
MPAs, remove/restrict boating
prevent invasives- promote harvest, regulate ballast water, aquaria trade
fishing regulations
education, promotion, communication
climate change, pollution
```
211
name for a mangrove forest
mangal (entire forest)
| mangrove (single tree)
212
mangrove importance
- biodiversity
- trap sediment, increase water quality outside mangal
- provide shoreline stabilization and protection
213
what are mangals
- tropical, saline, intertidal/estuarine forest
- trees w/ exposed rooting structures in soft sed
- turbid, organic-rich water
214
mangrove distribution
strictly tropical
30ºS - 30ºN
temperatures greater than 20ºC
215
types of mangal habitats
- riverine
- tide-dominated
- basin mangroves
216
Riverine (estuary) mangals
-often river deltas
-large salinity variation
-common in Asia
-seasonal variability high from rainy season
stress = S variability
217
Tide-dominated (open ocean) mangal
-coastal front habitat
-stable salinities, strong tidal cycle
-unstable morphology due to coastal erosion
stress = tide variability
218
basin mangroves (sheltered system)
-inland/fringing mangroves
-little change in tide, no wave action
-often higher S than others (evaporation)
stress = high S
219
mangal plants
- true mangroves
| - mangrove associates
220
mangrove associates
- widely distributed trees/plants
- not restricted to mangal
- peripheral species
221
true mangroves
- adaptations to life in ocean
- 50+ species, 20 genera, 16 families
- up to 16 independent convergent evolution events
- evolved in Cretaceous
- all flowering trees
- viviparous
- prop roots
222
majority of mangrove belong to which families
Avicennicaceae (white mangroves)
| Rhizophoracea (red mangroves)
223
most diverse mangals
Indo-Pacific
| Pacific mangroves much more diverse than All
224
viviparous trees
seeds germinate on parent plant, drop into rooting structures as fully fledged embryos
225
mangrove challenges
- water-logged sed, frequent inundation of saline water
- salinity either variable or high
- highly anoxic sed
- nutrient poor water
226
whats the problem with water-logged sediment
problems for gas exchange
nutrient absorption
stability
227
prop roots
support, nutrient uptake, breathing
| -massive surface area
228
mangrove root parts
pneumatophore
lenticels
aerenchyma
-all to help roots 'breathe'
229
pneumatophore, mangrove root
vertical root structure for air exchange
230
lentils, mangrove root
tiny pores for air exchange
231
mangrove salt tolerance
- filter at uptake (roots)
- storage
- secrete
- dilute
232
salt storage, mangrove
- specialized vacuoles in specific tissues
| eg. bark, stem root
233
salt secretion, mangrove
specialized salt gland
leaves or roots
occasionally shed leaves to remove accumulated salt
234
aerenchyma, mangrove root
tissue for air exchange
235
salt dilution, mangrove
with succulent leaves
236
succulent
thickened and fleshy, usually to retain water in arid climates or soil conditions
237
why is it challenging for a plant to live in saline water
- osmosis -- fighting water loss
| - inhibits transpiration
238
transpiration
water transport from roots to leaves to cool them down`
239
regulating water loss, mangroves
- close stomata
- regulate leaf orientation (angle to maximize light, minimize water loss)
- some species increase root biomass w/ increased S
240
why are mangrove roots so shallow
- estuarine surface water typically less saline than deeper
| - mangrove roots shallow and horizontal to maximize freshwater absorption
241
mangrove reproduction
- vivapary: seed germinates on parent
- trees pollinated by insects or animals
- seeds germinate into propagules and drop in ocean
242
young mangrove propagule
hypocotyl
243
what is a propagule
A structure able to give rise to a new plant
| ex. seed, spore, part of vegetative body capable of independent growth
244
animals that pollinate mangroves
bats
245
propagule dispersal depends on
- tides
| - seed shape
246
tidal impact on mangrove propagule
- dispersal
- saline water, high tide = propagule afloat, dispersal away from parent
- fresh water, low tide = propagule sinks and immediately roots
- note that dropping times may vary and be coordinated w/ tides
247
seed shape impact on mangrove
dart-shaped drops down into mud
248
mangrove propagule success dependent on
- environmental conditions (especially light)
| - predation
249
mangrove propagule predation
- predators like grapsid crabs feed on seeds
| - faster the mangrove roots the more likely it escapes predation
250
most common mangrove species
- Red Mangrove (eg. Rhizophora)
- Black mangrove (e.g.. Avicennia)
- White mangrove (Laguncularia racemosa)
- named for bark colour
251
flowering in the common mangroves
red - all year, max in spring/summer
black- spring/ summer
white - spring/summer
252
propagule shape in common mangroves
red - cigar, green bean
black - oblong/elliptical, lima bean
white - flattened, pea green, sunflower seed
253
propagule length in common mangroves
red - 15cm
black - 2-3cm
white - less than 0.5 cm
254
types of mangrove roots
prop-root
peg-root
knee-root
255
prop-root
- looks like arches above ground
| - look like mini upside-down trees underground, branching, setose = nutritive roots
256
peg-root
- look like many spikes above ground = peg root
- single, linear, bristled nutritive roots on peg root below ground
- 'hairy' roots below peg root = anchoring roots
257
mangal biodiversity
- mix of marine and terrestrial organisms
- numerous infauna phyla
- epifauna on/amongst roots
- epiphytes on trunks, branches
- many insects
258
studying mangal fish provides
examples of evolution in extreme environment - anoxic, sulphidic (euxinic)
259
Rivals marmoratus
- mangrove forest fish
- detects H2S and leaps out of water
- also leaps to avoid predation
- generalized response to avoiding stress
260
degree of vivipary in common mangroves
red - extensive while on tree
black - intermediate
white - semi-viviparous, germinate during dispersal
261
root establishment time in common mangroves
red - 15 days
black - 7 days
white - 5 days
262
knee-root
-'knees' (small bumps) above ground = site of secondary root development
263
unique fish evolution in mangroves
- Rivulus
- mudskipper
- four-eyed fish
264
mudskipper
- bimodal respiration
| - "walking"
265
four-eyed fish
Anableps anableps
- eyes split in two - half emerged, 1/2 submerged
- separate genes to control each half
- each 1/2 adapted uniquely for vision in air or turbid water
266
why are mangals poorly studied
- difficult conditions: heat, humidity, turbid water, difficult to get around
- risks: mosquitos (dengue, malaria), predators (snakes, alligators), politically unsafe
267
area of research focus in mangals
- zonation
- basic ecology
- role as nurseries (fish, shrimp)
- response to threats
268
basic ecological research in mangals
- role of ecosystem engineers
| - island biogeography
269
zonation in mangals
- some clear zonation, some mixed
- environmental stress opposite to rocky/sandy shore (landward less stress)
- hypothesized to be environmental stress driven
270
mangal zonation most common in
areas of high
- tidal variability
- salinity variability
271
mangal zones
- terrestrial
- intermediate
- fringing
272
mangal terrestrial zone
- true terrestrial plants, mangrove associates
| - poor tolerance for low O2, high S
273
mangal intermediate zone
- black/white mangroves (no prop roots)
- least tolerant of salt
- more tolerant of low O2
- many pneumatophores
274
mangal fringing zone
```
red mangroves (prop roots)
-most highly tolerant of salt water
```
275
mangal zonation hypotheses, zonation driven by:
- tidal propagule sorting
- physical condition tolerance
- others: competition, sediment characteristics
276
mangal zonation, tidal propagule sorting
- lighter propagules stranded in upper shores
| - heavier propagule carried to edges
277
IBT
-diversity depends on distance from parent population and island size
278
The Mangrove Experiment
- founding IBT experiments
- naturally fragmented mangrove 'islands'
- fumugated
- monitor
279
The Mangrove Experiment results
- islands closer to source population recovered faster
| - also teaches us about meta community ecology - community connectedness
280
grapsid crabs
- ecosystem engineers
- build burrows
- increase O2 penetration
- decrease sulfide accumulation
281
Mangrove dual stable isotope study
- C, N ratio analyses on PPers
| - find mangrove detritus primary food source of juvenile prawns w/i habitat
282
mangrove isotopic signature
∂13C depleted - (ca. -30 - -26)
| ∂15N depleted (ca. 2-8)
283
river sediment isotopic signature
∂13C depleted - (-28 - -24)
| ∂15N enriched - (18 - 10)
284
eating mangrove leaves
- unplalatable
- high C:N, high salt - unprofitable resource
- Grapsid crab shred leaves encouraging microbial degradation and store in burrows to give degradation time
285
other food sources within mangal
- some species (fiddler crab) rely heavily on algae (odd b/c low in mangal)
- mangal may concentrate other food sources or provide protected env't to feed in
286
removal of grapsids in mangroves
- increased sediment anoxia, sulfide, ammonium concentrations
- decreased # trees
287
mangal ecological interaction study summary
- isotopes useful to study forest interactions
| - good evidence that organisms use mangal for food as well as shelter
288
threats to mangrove forests
- land use change (especially shrimp farming)
- climate change (sea level rise, range shift, T shift)
- lack of knowledge
289
mangrove degradation
UN: 20% of worlds mangrove forests lost 1980-2005
| total losses - 30-40%
290
shrimp farming
- commonly on edge of mangal
- uproot trees to make pens
- high waste, disease, destruction
- pens last 1-5yrs then move on to new spot
- lots of illegal farming
- don't clean up after
291
mangrove forest vs shrimp farm value
-mangal 8-10 higher value than shrimp farm
292
mangal ecosystem goods and services
- forest products
- fishery
- storm protection
293
mangrove rehabitation
- replanting has low success rate especially in converted lands
- restored forest lower complexity, effectiveness
- burden of restoration falls on small poor communities
294
restoration effort
- often very ineffective
| - conservation is a better way to spend time/money
295
sea level rise and mangroves
- more salt water inundation = more stress to higher zones
| - more water logging
296
mangrove distribution shift due to climate change
- poleward in response to lower # extreme cold events -threshold response
- further inland due to sea level rise
297
how will disappearance of manuals affect biodiversity
- reduced habitat complexity likely to reduce biodiversity, abundance
- may result in cascades
- likely impact fisheries
- difficult to predict
298
What are salt marshes
- coastal ecosystem
- flowering grasses, sedges, rushes, rooted in soft sed
- terrestrial plants
- complex topography
- not uniform, interconnected patches
299
salt marsh distribution
- mid to high lats
- coastal zones
- take over from mangroves
- can be displaced from mangrove distribution shift
300
iconic salt marsh plant genus
Spartina (cordgrass)
- looks similar to seagrass
- restricted sexual reproduction
301
Spartina morphology
- aboveground stem and leaves
| - below ground rhizomes
302
Spartina rhizomes
- take up nutrients
- connect clonal pant members
- provide structure and support
- asexual reproduction
303
Spartina sexual reproduction
- flowers
| - seeds and flowers grazed by many animals limiting reproduction
304
Spartina rhizome protection
allow sediment buildup in marsh, supports/protects against disturbance/erosion
305
salt marsh impacts on environment
- trap OM (peat) -- very anoxic (more than other environments)
- fuel bacterial respiration = more anoxic
- change patterns of sediment deposition
306
salt marsh OM
4-20% of sediment mass
307
salt marsh adaptations
- roots, leaves, stems highly vascularized with aerenchyma
| - salt glands
308
aerenchyma
- air channels
- support O2 movement between above/below ground structures
- prevent anoxia in roots
309
spartina salt glands
exudate salt from leaves, stems
310
salt marsh formation
- start as mudflat
- seeds, 'raftings' arrive at mudflat
- new plants root in mud
- vegetative growth
- community builds up and up and up
311
new group of salt marsh plants in mudflat
baffle
| -barrier, trap sediment and peat, build-up ecosystem
312
"rafting"
piece of rhizome w/ shoot
313
salt marsh ecosystem engineers
- one of most extreme forms
- completely change ecosystem, dramatic effect
- alter physical and chemical composition
314
salt marsh impact on sediment deposition
- create heterogeneous landscape
| - considerable depth variations
315
salt marsh heterogeneous landscape
- bare patches
- various channels
- -saltwater trapping in lagoons/puddles
316
salt marsh bare patches
- created by floating wrack accumulation
- smother existing grass = bare patch formation
- evaporation = salt pan (salty and hard to colonize)
317
floating wrack
- detritus
| e. g. dead Spartina
318
salt marsh ecology
- very well studied, especially E USA
- diverse communities and complex habitat-many microhabitats
- many ecological lessons learned here
319
salt marsh ecological interactions well studied
- facilitation
- competition
- grazing
- role of detritus
- upwelling hypothesis
- role of predators
320
salt marsh mussels
semi-infaunal (Geukensia demissa)
- abyssal threads attached to sed grain
- breathe air
- help trap sed. to build up marsh
- supply marsh w/ N-rich material
321
salt marsh crabs
fiddler crab
- aerates sediment, introduces oxygen -- helps plants
- shredding increases fungi growth
322
salt marsh fungi
- mycorhizae
- associated w/ plant roots
- allow plants to gather more nutrients
323
other salt marsh members
- gastropods (grazing snails)
- inverts
- deposit feeders (oligochaetes, polychates)
- predatory crabs (non-fiddlers)
- juvenile fish (nursery)
- birds, rodents
324
differences in salt marsh diversity
generally more diversity on E coast NA (less human impact)
325
salt marsh facilitation
- salt marsh plants are foundation species
- create stable habitat for other organisms
- provide shelter from stress, predators
- trap food, OM
326
detrimental foundation species interactions
Spartina build up sed (+ for many organisms) but exude some sed. organisms (like lugworms)
327
Lugworm vs Spartina
- both ecosystem engineers
- lugworm can't burrow in Spartina zone b/c dense rhizomes
- Spartina does not succeed if lugworms burrow
328
biomechanical warfare paper (lugworms, Spartina)
- success depends on who got there first
- seeding spartina in lugworm habitat not succesful
- transporting lugworms to spartina habitat not successful
- negative ecosystem engineer interaction
- lugworms protect mudflat
329
salt marsh zonation
- environmental stress, competition
| - some have clear zonation, some mixed
330
controls on salt marsh zonation - what areas are more stressful
- opposite to intertidal patterns
- lower intertidal more stressful
- competition more important in upper intertidal
331
sheltered beach salt marsh zonation
-multiple distinct zones of adjacent foundation species
332
wave exposed beach salt marsh zonation
single zone containing nested foundation species
333
why does zonation depend on wave action in salt marsh
- environmental stress prevent single species dominance
- hardiest species colonizes but does not grow quickly, leaving space
- less hardy species takes advantage of buffering from species 1
334
broader implications of salt marsh zonation
-should translate to any system w/ multiple foundation species
335
menge-sutherland w/ facilitation
associational defenses (high in low stress) lowers predation
336
why is salt marsh zonation unique relative to our other ecosystems
b/c it is foundation species zonation - not just zonation of a species - zonation of entire community
337
salt marsh grazing
- tough, rich in cellulose, loaded w/ Si, anti-grazing compounds
- not important source of food, few grazers
- seeds, flowers tasty -limits dispersal
338
Spartina grazers
- Littoraria (periwinkles)
| - grasshoppers, aphids
339
Littoraria
radula scrapes materials off plant, attach to plant by glue-like mucus
340
latitudinal differences in salt marsh grazing
- in NA grazing intensity increases from N --> S
| - causing salt marsh plants to be less palatable in S
341
why are there latitudinal effects on grazing
- more grazers in the S
| - diversity higher in tropical latitudes
342
problems associated with latitudinal grazing differences
-if South species transplanted to North can be problematic (no natural grazer)
343
salt marsh POM
- Spartina leaves turn brown, senesce, fall into water (deciduous)
- microbial decomp.
- detritus also food source for other organisms (oligochaetes)
344
salt marsh detritus importance to other ecosystems
- outwelling hypothesis
- mostly rejected now
- most SM detritus consumed w/i marsh
- can generate DON that fuels PP in other areas
345
Spartina - Littoraria trophic cascade
snail- scrape plant - feeding scar - infection sites for plants
---blue crabs -- (-)snail -- +plant health
346
exclude blue crabs from salt marsh
= more snails = more infected Spartina
347
implications of Spartina/Littoraria interaction
- snails facilitate fungal growth (bad fungi)
| - blue crabs decimated by fisheries = major impact on salt marsh
348
salt marsh importance
- high PP, biodiversity
- nursery
- shore line stabilization, erosion prevention
- nutrient filtering
- sediment trap
349
salt marsh losses
- 92% of NA SMs lost in 200 years
| - largest impact is LUC
350
salt marsh threats
- sea level rise (saline inundation)
- coastal squeeze
- filling, erosion
- eutrophication
351
expected sea level rise
1m
352
coastal squeeze
- coast moving inland from sea level rise
| - humans moving coastward
353
salt marsh filling
many marshes are filled in to create shoreline development - reduces shoreline stability, filtering, increased toxic metal concentration in ocean
354
impact of reduced salt marsh filtering capacity
increased toxic metal concentration in ocean
355
eutrophication and salt marsh
- shifts competitive ability from short plant w/ extensive rhizome to taller
- increase palatability of plant and grazing
356
Spartina invasion
-high tolerance, fast vegetative growth = competitive superiority
-'sterile' plants sometimes transplanted to rebuild habitat, stabilize shores
-if any reproductive species get in can wreak havoc on ecosystem
-Wa, Or, NZ, Aust,
puget sound
357
spartina and puget sound
- destroying oyster industry
- crowding out habitat for shellfish, fish, birds, juveniles
- taken over 15,000 acres of Wilapa Bay
358
Spartina growth rate
ca 17% / year
359
estuary overview
- diverse collection of habitats (encompass sandy/rocky shores, mudflats, marshes, etc)
- incredibly productive, vital for range of animals
- among most degraded habitats on planet
- huge variabilities
360
how do we define and classify estuaries
- salinity
- geomorphology
- sediment patterns
- oxygen
361
types of estuaries based on geomorphology
- glacial fjord estuary
- coastal plain estuary (drowned river valley)
- bar-build estuary
- tectonic estuary
362
geomorphology
stude of landforms and the processes that shape them`
363
Glacial fjord estuary
-common around BC, chile, norway, NZ
-glacier cut U-shaped valley
-long, deep, straight sided, rocky-bottomed
common in higher lats., mt's
-shallow sill at mouth restricting exchange, circulation
364
Costal plain estuary
- Chesapeake Bay
- formed from sea level rise after last ice age flooding river valleys
- funnel-shaped, shallow 30m, river runoff sediments, mud bottom, extensive mudflats
- temperate lats, low sed discharge
365
sea level change due to changes in volume of wter
eustatic (always global)
366
bar-built estuary
- E US, Fl, tropics
- created by offshore deposits forming barrier across bay/inlet w/ river flow
- barrier restricts flow of water in
- commonly tropical
- extensive lagoons
367
glacial ford geomorphology
- boulders, large rocks
| - steep sided
368
drowned river valley geomorphology
lots of soft sediments
369
bar-built estuary geomorphology
calm bay w/ soft sed.
370
bar-built estuary habitats
- seagrass meadow
- mangroves
- mudflats
371
glacial ford habitat
-rocky intertidal epifauna
372
estuary tidal classification
microtidal estuary (less than 2m tidal range)
mesotidal estuary (2-4m)
macro tidal estuary (4-6m)
hyper tidal estuary (greater than 6m)
373
why estuaries have large tidal ranges
topography (constrain water flow)
374
drowned river valley habitats
- mudflats
- seagrass meadows
- mangroves
- salt marshes
375
estuary definition
-where a river meets the ocean
376
estuary limits
-difficult to define, change based on perspective, time
Upper: where tidal influence begins in the river, noticeable tidal movement
Lower: where river 'plume' ends; complex, subjective
377
estuary freshwater/seawater
- determines longitudinal/ vertical salinity variability
| - entire world S range seen w/i estuary
378
estuary geomorphology
determines shape of estuary, habitat availability
379
estuary tidal range
determines emersion/submersion times
380
longitudinal salinity gradient
river -estuary: oligohaline
mid-estuary: mescaline, polyhaline
ocean: euhaline
381
oligohaline
0.5-5 PSU
382
mesohaline
5-18 PSU
383
vertical salinity gradient in estuary with large freshwater input
- S low at surface from freshwater input
- increases through estuary (halocline)
- high and stable S at depth
384
vertical salinity gradient in lagoon or area with high evaporation
- high S at surface
- shorter, shallower, reversed halocline
- relatively stable at depth
385
estuary classification based on salinity gradient
- salt-wedge
- partially-mixed
- well-mixed
386
daily salinity change, estuary
tidal cycle
| -as tide rises saline waters move closer to mouth
387
estuary salinity variability
varies in: space, seasons, day
388
polyhaline
18-30PSU
389
how do organisms deal with salinity variability
- osmoconformity
- osmoregulation
- stenohaline
390
osmoconformity
- maintain internal solutes equal to medium
- eg. inverts
- most tolerant to S ∆'s
391
Euhaline
ca. 30 PSU
| low variability
392
river-driven estuaries have max flow in
summer
393
osmoregulation
- regulate/maintina internal salt levels
- eg. some fish, inverts
- intermediate ∆S tolerance
394
rain driven estuary system, max flow
winter
395
5-18 PSU S zone in estuary
Polyhaline
396
∆S and climate change, estuary
changes to snow packs and rain inputs will alter ∆S's
397
stenohaline
- limited salinity tolerance
- many fish, verts
- cannot tolerate large fluctuations
398
estuary sediments
- rivers (terrestrial)
- tides, currents (marine)
- meet at lowest E
- large particles drop out = sorting
- plume is fine muds, clays
- mid-esutary fine sed rich in OM
399
what do you typically find around mid-estuary
mudflats!
| -only fine sediments remain
400
effect of sediment transport on benthic organisms
- creation, stability of habitats
- water clarity
- food availability
401
sediment transport and water clarity in an estuary
- high sed input = reduced clarity
- clog up filter feeders
- limit light for P
- OM-rich seds fuel bacterial resp., deplete O2, provide food
402
estuaries and geological age
- generally young, majority since last glacial retreat (ca. 20,000ya)
- tropical younger than temperate
- much less time to accumulate diversity than other marine ecosystems
- also ephemeral systems (on geo. timescales)
403
organisms that can tolerate salinity fluctuations
Euryhaline
404
why are estuaries ephemeral
- changes in sea level (ice cap formation, thawing)
- sedimentation (infill estuaries)
- tectonic activity (creates, destroys basins)
405
estuary characteristics that impact benthic communities
- S variabilities
- low O2 conditions (especially fjords)
- tides
- sediment transport
- geological age
406
why low O2 especially problematic in fjords
the sill!
407
estuary diversity
- low compared to other systems
- unique mix of marine, freshwater
- highly productive
- abundance, diversity decline upstream in river
408
controls on estuarine organism distribution
- early models emphasize S
| - recent models emphasize interaction btw S and other processes
409
Remane diagram
number of species vs salinity (river on left - ocean on right)
- species minimum in the estuary
- different types of organisms
- developed in Baltic sea
- assumes S is driving factor
410
problems w/ Remane
- largely qualitative
- variables poorly defined
- extrapolating from Baltic to all estuaries not valied
411
Baltic
- tideless
- marginal sea
- fixed S gradient, consistent btw mouth and inner
- well mixed w/ stark change at ocean in narrow channel
- very highly impacted ecosystem
412
Estuary species hypotheses, Remane, Barnes
Remane- 3 groups: freshwater, brackish-water, marine; attempts to link absolute S w/ organism distr.
Barnes- 2 groups: no brackish species
413
Attrill estuary organism distribution model
-predicts that salinity variability, NOT absolute S, more important for predicting biodiversity
414
important difference btw Remane model and Attrill model
Remane: hypothetical, qualitative model
Attrill: actual testable hypothesis
415
Attrill's salinity experiment
- samples collected along Thames estuary, 4x/year
| - find mean alpha-diversity negatively correlated w/ salinity range (r2 = 0.425)
416
Why did Attrill find only moderate relationship btw diversity and salinity range
- organisms good at dealing w/ S or using behavioural strategies to deal with it
- other physical factors contribute (O2, sediment, light, etc)
- biological factors as well (competition, predation, food)
417
main difference between estuaries and other systems
-lots of animals (secondary production) but very few plants and algae (PP)
418
where do estuarine organisms get all their energy if PP is low
Detritus: allochthonous, autochthonous
419
Allochthonous
produced from ecosystem outside but adjacent to estuary
| eg. salt marsh, mangrove, sea grass, terrestrial detritus
420
using isotopes to assess dietary sources along length of estuary
- shows large variability in food source dependent on estuarine location
- upper estuary = terrestrial source
- lower estuary = marine source
421
marine isotope signature
∂13C enriched
| ∂34S enriched (ca. 10)
422
terrestrial isotope signature
∂13C depleted
| ∂34S enriched (ca. 10)
423
estuary ecological interaction framework
factor #1: salinity
| other smaller factors: turbidity, substrate, ecological interactions, more important on finer scale
424
turbidity impact on estuary
control suspension feeders
425
human distribution
-44% of humans live w/i 150km of coast
426
Halpern et al human impact study
- no area is unaffected by human influence
| - large fraction, 41%, strongly affected by multiple drivers
427
human impacts on estuaries
- habitat destruction, alteration
- introduction of invasives (ballast water)
- climate change, sea level rise
- pollution
- eutrophication, oxygen shortage
428
autochthonous
produced within the system
429
hypoxia
- dissolved seawater oxygen levels below normal (subjective)
- less than 2mg O2/L
- negative response in many taxa
- change in microbial activity
430
anoxia
- oxygen is (almost) completely absent, below detection limit
- subjective
- pretty much nothing around except bacterial mats
431
oxygen measurement units
- most oceanographers use concentration
- physiologists use P_O2
- difficult for communication
432
oxygen concentration of a water mass depends on
- concentration it when last in contact with air
- time since contact with air
- physical impediments to water circulation
- biological activity (respiration)
- temperature
433
OMZ
- oxygen minimum zones
- occur naturally in many regions
- likely in productive regions, especially if circulation restricted
- Arabian sea, Peruvian upwelling zone, SI
434
SI OMZ
- sill in satellite channel restricts flow into estuary
| - natural OMZ at ca. 130m
435
dead zone
- non-natural low oxygen conditions
| - Gulf of Mexico,
436
Why is Gulf of Mexico low O2
- low to begin with
- exacerbated by anthropogenic agriculture
- Mississippi river drains all major US agricultural lands
- lots of fertilizer - high PP - lots of OM -- decreased O2 -- fish kills
437
normal oxygen conditions
normoxia
| >2.4mg O2/L, average 8
438
current state of ocean oxygen
-low oxygen conditions increasing
-existing minima expanding, shallowing
new zones established
-reports growing at exponential rate
439
why are OMZs and dead zones expanding
- directly related in increased fertilizer use
- exacerbated by climate change (increased T, stratification)
- OMZs increasing mostly from global warminng
- DZs increasingly mostly from eutrophication
440
difference between natural OMZ and anthropogenic one
-OMZ are a persistent feature, longer timescales, larger scale, organisms have more time to adapt
441
duration, intensity of hypoxia in dead zones
- in 50%, hypoxia is seasonal
- in 25% hypoxia is periodic
- in 17% its episodic/ infrequent
- in the rest, hypoxia is permanent
442
seasonal hypoxia
spring - summer
- significant negative impacts (fish kills)
- widespread, long-term, organisms can't get away
443
periodic hypoxia
days-weeks
| -higher recovery
444
stages of hypoxia
stage 1. episodically, OM enhanced, hypoxia only when water stratifies
2. periodic, few fish kills
3. critical; seasonal and persistent; 50% of dead zones in this stage
4. permanent; anoxia in bottom water, anaerobic respiration, H2S production (toxic)
445
Animal production in critical stage hypoxia
boom and bust cycles
- reproduce, recolonize when hypoxia absent
- die, bust when hypoxia sets in
446
respiration
OM + O2 -- CO2 + H20
OM + SO4 -- H2S + CO2
OM + NO3 -- N2 + O2
447
anaerobic respiration
- bacterial
- utilize range of oxidants (NO3, SO4, MnO2, Fe2O3, etc)
- may produce toxic byproducts (eg. H2S)
448
episodic hypoxia
-usually early warning sign that system has reached critical level
449
permanent hypoxia
- usually due to persistent, long-term eutrophication
| - eg. Baltic Sea
450
denitrification
using NO3 as oxidant
NO3 - NO3 - NO - N2O - N2
nitrate - nitrite - nitric oxide - nitrous oxide - nitrogen gas
451
hypoxia and sediment
shifts RPD up
452
Pcrit
- critical oxygen threshold for normal physiological processes
- long-term evolutionary adaptation
453
below Pcrit
- organism fails to regulate O2 consumption
- hypoxia, not enough O2 to sustain physiologic processes
- gene expression
- morphology
- behaviour
- death
- reproduction
454
shift in Pcrit value
- change organisms sensitivity to low O2
| - shift right = more sensitive to low O2 (eg. Antarctica organisms)
455
adaptations to low O2
high gill SA, high ventilation rate, blood O2-binding proteins w/ high affinity for O2
456
Pcrit vs minimum environmental P_O2
- positively correlated
| - relationship plateaus
457
molecular hypoxia response
- upregulate processes that improve O2 absorption
eg. hemoglobin synthesis
- upregulate anaerobic metabolism
- downregulate protein synthesis (growth), locomotion, metabolic activity, conserve O2
458
other impacts of hypoxia
- reduced feeding activity
- reduced efficiency of reproduction
- negative impacts on fitness
459
hypoxia and reproduction
- slow/stop gonad development
- impaired fertilization
- decreased hatching success
- increased mortality
460
behavioural response to hypoxia
- most effective in short term
- mobile - move
- surface breathe
- leave burrows
- stretch siphon
461
behavioural hypoxia response trade-offs
many make organisms more vulnerable to predation (e.g. extending siphon higher, air-breathing)
462
morphological response to hypoxia
- phenotypic plasticity
| - longer, thinner gills in low O2 (more SA)
463
hypoxia threshold study
- find that the conventional 2mg O2/L hypoxia definition below sublethal and lethal thresholds for 1/2 species studied
- therefore, # of systems affected by hypoxia is underestimated
- our current threshold is too low
464
different taxa hypoxia tolerance
- crustaceans highest threshold, fastest mean lethal time, most vulnerable
- lots of variability
465
proposed new hypoxia threshold
90 percentile = 4.59 mg O2/L
466
habitat compression
habitat squeeze
- rising sea level + human land use
- hypoxia squeezing marine organisms to surface, limited regions
467
ecosystem changes from a switch from normoxia - hypoxia
```
demersal fish - pelagic
macrobenthos - meiobenthos
suspension feeders - deposit
larger body size - smaller
k-selection - r-selection
longer food chain - shorter
```
468
why would hypoxic environment select for pelagic fish
higher in water column - more O2
469
why would hypoxic environment select for meiobenthos
more tolerant of low O2
470
how hypoxia influences E transfer
normoxia: 25-75% energy transfer
hypoxia: decreased E to mobile predators, increased % to microbes
anoxia: 100% to microbes
471
hypoxia recovery
- more severe hypoxia, more likely to lag in recovery
| - lage = hysteresis
472
NEPTUNE
North-East Pacific Time-series Undersea Network Experiments project
- 6 nodes
- hydrothermal vents, abyssal plain, OMZ, submarine canyon, cold seeps
- cabled observatory, loop, real-time
- convergent and divergent plates
473
JDF plate
itty bitty
| in between caribbean, pacific, cocos
474
cabled observatory advantages
- high-resolution
- long-term
- interdisciplinary monitoring
- variable timescale
- real time connectivity
- online
- limitless power
- automated data QC
- observe episodic processes
- measure multiple variables
- remote control instruments
475
traditional oceanography
- deploy gear from ocean vessel
- trips usually weeks long, expensive, short periods of time
- limited understanding of stochastic, seasonal events
- miss rare species
476
oceanographic sediment sampling
- grabs
- box corer
- multi-core
- benthic trawl
- dredge
477
advantage of manned submersible
- in situ observation
- delicate sampling
- conduct manipulative experiments
- navigate complex topography
478
manned submersible disadvantage
- power limitation (max 12-16hr)
- high costs (100k/day)
- weather limitations
- possible pilot, researcher risks
479
ROV advantage
- longer dives, nearly unlimited power
- versatile sampling
- no pilot, researcher risk
- dexterous manipulator arm
480
cabled seafloor observatory
-observatory linked to land by submarine cables providing power, communication
481
autonomous seafloor observatory
moored-buoys provide power to seafloor instruments, satellite communicates to land
482
multi-instrument platform
- unmanned system at fixed site, connected to land acoustically or via junction box
- instruments, sensors, command module
483
VENUS
Victoria Experimental Network Under the Sea
- 3.5m node
- -instrument platforms
- wet mate connectors (plug in under water)
- real time
- multiple temporal scales
484
cabled observatory limitations
- can't measure everything (reproductive state, physiological condition, metabolism)
- can't sample organisms, genetics
485
NEPTUNE instrumentation
CTD, ADCP, ZAP, Oxygen sensor, Nitrate sensor, pH, pCO2, fluorometer, sediment trap, hydrophone, fixed video camera, seismometers, bottom pressure recorder, vertical profilers
486
ongoing NEPTUNE research projects
- whalebone colonization in submarine canyon w/ OMZ
- zooplankton ontogenetic migration in Barkley canyon
- C export
- vent fauna, diffuse flow dynamics at Endeavour
487
how much data does ONC collect
>400 instruments in the water
>5000 sensors
>8 million measurements/day
>3billion measurements/yr
488
what are coral reefs
- massive biogenic limestone structures deposited by hermatypic
- along w/ other framework builders
489
coral limestone
aragonite
| CaCO3
490
other coral framework builders
- encrusting coralline algae
| - calcareous green algae
491
hermatypic corals
- reef-building
- stony corals
- Order Scleractinia (Class Anthozoa, Subclass Hexacorallia)
- some solitary, majority colonial
492
hermatypic morphology
branched - quicker growing, susceptible to storms
| massive (mound) - slow growing, irregular shaped
493
coral morphology differences are important for
- different protection/response to wave action
| - different growth rate
494
polyp morphology
gastrodermis - nutrient absorption, location of zooxanthellae
tentacles - location of nematocysts
495
zooxanthellae
-densities of millions/polyp
-dinoflagellates but no flagella, no swimming ability
-acquisition unclear
-never obtained from water column
genus Symbiodinium
496
zooxanthellae benefits
- access to sunlight
- stable, protected env't
- receive coral metabolic waste (C_org, NH3, PO4)
497
coral benefits from zooxanthellae
- E-rich carbs, nutrients (from photosynthesis)
- removal of org waste (dont have to worry about toxicity)
- aid CaCO3 deposition (requires high E)
498
hermatypic coral feeding
- heterotrophic feeding: zoop, small organisms at night
- capture w/ namatocysts
- feed for protein, amino acids, waste products for zoox
499
obtaining nutrients in more than one way
polytrophic
500
coral feeding pattern
day: autotrophic, polyps contracted
night: heterotrophic, polyps extend, use tentacles
501
coral secretions
- epidermis mucous
- UV protection
- feeding net to trap bacterioplankton, detritus
502
other PP in coral system
turf algae
sand algae
benthic algae
503
Turf algae
- many species
- small, bushy, close to bottom, 1-10 mm
- often filamentous
504
sand algae
- root in sand
| - relative to Spartina
505
benthic algae
- macroalgae
- hard substrate
- calcareous form
506
coral reef consumers
- sponges (filter water, cleaners)
- molluscs
- echinoderms
- annelids
- crustaceans
- fishes
507
trophic guild
group of organisms that exploit same resource often in similar way
508
fish guilds in coral reef
```
herbivores- wrasse, gobies
coral feeders- parrotfish, puffer
detritus feeder - grey mullet
benthic invert feeder - butterfly fish, grunt
midwater invert feeder - damselfish
small fish feeder- snapper
midwater piscivore- carangids
large piscivore- shark, snapper, barracuda
```
509
herbivorous coral reef fish
- eat algae
- keep coral clean
- remove up to 100% of algae/day - keep standing stocks very low
- prevent phase shift
510
coral-feeding fish
- parrotfish, puffers, filefish, butterfly fish
- feed directly on polyps of fast-growing species
- consume skeleton
- feed on weaker polyps
- increase resilience
511
resilience
ability of an ecosystem to absorb shock, resist phase shift, regenerate after disturbance
512
substratum and coral
- require hard CaCO3 surface for attachment
- may require coralline algae to deposit first
- coralline algae also help hold reef together
513
coral natural resilient
- recover from natural disturbance events like storms
| - sensitive to shocks, e.g. T changes
514
affects coral resilience
- recruitment and survivorship
- water quality
- stable consolidated substratum
- amount of macroalgal cover
- herbivores that remove algae
- animals that remove unhealthy corals
515
magroalgae and coral
- dense mats shade, overgrow corals
| - impede recruitment
516
if herbivorous fish are removed in coral reef
- phase shift to turf algae
- overgrowth of coral by algae
- low ecosystem resilience
- corals very stressed
517
coral herbivore diversity
- indo-pacific: lots of fn redundancy
| - caribbean: less fish, lots of echinoderms (Diadema urchin), low fn redundancy
518
Diadema in Caribbean
- very important algal grazer
| - 95% Caribbean die-off resulted in algal overgrowth - phase shift
519
Diadema in Pacific
- naturan urchin die-off
- shorter phase shift
- other herbivores took over algae grazing role
- high fn redundancy = higher ecosystem resilience
520
coral reef and predators
- maybe strong?
- not clear
- lots of chemical defenses
521
coral reef mutualism
- grouper fish and cleaner fish (spa stations)
- fish, shrimp in same burrow
- clown fish, anemone
522
removal of cleaner fish from reef
- reduced number of species
| - reduced abundance
523
coral reef interaction summary
- highly productive, efficient
- foundation species that support large biodiv.
- fn redundancy important
- role of predators unclear
- mutualism highly prevalent, ecologically important
524
coral zonation
- majority have clear zonation
- more abundant, dense close to shore, sparser w/ depth
- bigger, heartier species in breaker zone
- flat, round, short in deeper zones (better light absorption)
525
elkhorn coral
large antlers grow in direction of current
526
coral competition
- space extremely limited
- outcompete each other by overgrowth, shading (faster growing win?)
- slow growers digest neighbours
527
why is space competition so tight in corals
need shallow depth (light) + hard substrate
528
coral reef threats
- coral bleaching
- disturbance: predators, disease, storms, natural or anthro
- ocean acidification
529
coral bleaching causes
- increaed T
- increased UV
- OA
- turbidity/sedimentation
- coral disease
- ∆S
- exposure
- pollution
530
Mass bleaching events
- 6 since 1979
| - correlated w/ anomalously warm T's (El-Nino)
531
coral reef threats, predators
crown-of-thorn Seastar
- venomous thorn-like spines
- digests (liquifies) entire corals w/ crazy stomach acids
- natural member of reef but sometimes become voracious predators
- leave trails of coral skeletons, rapidly colonized by algae
532
crown-of-thorns predators
- few
| - harlequin sharks, giant triton
533
CoT good?
- promote ecological succession
| - prevent fast-growing corals from overgrowing
534
coral disease
white band disease- bacterial, declines of elk horn
| black band disease- cyanobacteria, sulfide accumulation, toxicity
535
ocean buffering system
CO2g - CO2aq + H2O HCO3- CO3^2- + H+
536
current state of ocean buffering system
pH ca. 8.1-8.2
| bicarbonate ions >> carbonate ions
537
acidification studies
- majority find - response
- all corals show - response
- organisms w/o CaCO3 can also be sensitive to OA
- some taxa were found to increase
538
ocean zones based on light
euphotic (daylight) zone
disphotic (twilight) zone
aphotic (midnight) zone
539
euphotic zone
- epipelagic
| - 200m max, usually much less
540
twilight zone
- mesopelagic zone
- ca. 200-1000m
- max extent of detectable light
- no photosynthesis
541
midnight zone
- bathypelagic (ca 1-4km), abyssopelagic (4-6km), hadalpelagic (>6km)
- below 1000m
- no light
542
seafloor average depth
ca. 3800m
543
deep-sea land features
- abyssal plain
- seamount
- MOR
- trenches
- overlying waters (>1km)
544
deepest trench
Mariana's
| 10.91 km
545
Abyssal plains
- largest ecosystem on E
- deep basins btw continental margins and MORs
- flat, homogenous physical conditions, soft sed, few attachment sites
- mostly unexplored
- cold and salty
546
factors affecting deep-sea life
- light
- temperature
- salinity
- oxygen
- habitat
- pressure
- food
547
light in the deep sea
- decreases w/ depth
- no photosyn
- no light at all below 1km
- animals in total darkness, visual processes highly limited
- difficulties for finding mates, food, E
548
physical characteristics in the deep sea (T, S, O)
- constant, cold and salty
- O2 non-limiting in many regions
- has biggest hypoxic/anoxic zones in ocean
- O2 less homogenous, varies basing to basin
549
deep sea habitats
- mostly soft sediment (abyssal planes)
- some 'oases'
- few attachment sites
550
deep sea and pressure
- 1atm increase per 10m
- up to 1100atm
- average 380atm
551
deep sea and food supply
- very low
- unpredictable
- some 'oases'
552
Deep-sea food sources
- POM from surface PP (marine snow)
- chemosynthesis
- food falls (carcasses)
553
deep sea POM
- surface processes have large impact on deep
- PP mostly above 200m
- amount in deep depends on density in surface, food web
- particles consumed, decomposed before reach deep
- deep POM = moults, fecal pellets, marine snow
- 1-3% reaches deep
554
adaptations to low food availability, deep sea
- conserve E
- enormous mouths
- expandable stomach
- flexible jaw
- unique feeding modes
555
conserving energy in the deep
- watery muscles
- fatty tissues
- weak skeletons
- no scales
- poorly developed respiratory, circulatory, nervous systems
- no migratory behaviour
- dont invest energy in non-essential body parts
- many body parts not necessary w/ that much P
556
Viperfish
- unhinge jaw like snake
| - lure on elongated dorsal fin to attract prey
557
deep-sea feeding modes
- deposit
- suspension
- mucous nets (larvacean)
- predation (fish, tunicate)
- scavenging (hagfish, shrimp)
558
dominant feeding mode in deep
- deposit (soft sed)
| - 80% of fauna
559
deep sea deposit feeders
polychaetes, holthurians, isopods, amphipods, bivalves
560
deep sea suspension feeding
- less common due to low food supply
- sporadic, common in areas w/ high suspension load
- sponges, anemones, barnacles, mussels
561
Larvacean
- feed w/ up to 1m wide mucous net
- found down to 2000m
- net clogs in 1-2 days - discarded - important C sink
- form blooms, important mesozooplankton fraction
562
larvacean discarded nets
'sinkers'
- sink up to 800m/day
- density up to 4/m^2/d
563
Tripod fish
- sit on seafloor facing current
- eat plankton
- use tactile/mechanosensory cues
- mouth at right height to capture zoop, shrimp, small fish swimming by
- take advantage of current, save E not swimming
564
effects of limited food on abyssal ecology
- reduced faunal density
| - size of deep-sea fauna
565
deep-sea fauna density
- food supply too low to supply large numbers
- ca 5-10X fewer organisms in mesopelagic than epipelagic
- ca. 50-100X fewer org. in deep sea than epi.
566
size of deep-sea fauna
- generally small compared to epipelagic, dwarfs
| - but also gigantism
567
examples of deep sea gigantism
isopods, amphipods, spider crab, colossal squid, stingray
568
why gigantism?
- reduced SA:V (less exchange)
- slower growth rate
- slow metabolic rate
- k-selection
569
K-selection characteristics
- few eggs, slow gametogenesis, late reproductive maturity, breed once
- low metabolic rate, activity, small size
- slow growth, high longevity, low pop. density
570
unique deep sea adaptations
- cellular membranes w/ high proportion fatty acids
- bioluminescence
- dark pigmentation
- no schooling
- extreme reproduction
571
high fatty acid membranes
-maintain fluidity at low T, high P
572
bioluminescence function
- attract prey
- attract mates
- repel predators
573
lack of schooling behaviour, deep sea
- increases competition in an already low resource habitat
| - increases predation risk
574
deep-sea exploration
- majority since 1960s
- submersibles, ROVs in 80's helped
- international collaboration to map deep-sea
575
CeDAMar
Census of the Diversity of Abyssal Marine Life
- describe abyssal biodiv
- baseline data
576
CeDAMar major findings
- extreme is normal
| - rare is common (no real dominants)
577
Area hypothesis
- species diversity increases w/ area
- then diversity should be highest in deep-sea
- linear?
578
Area hypothesis drawbacks
- find parabolic pattern, not linear
- highest diversity at mid depth
- other factors involved such as food and location
- hyperbolic in western N Atl, linear in easter N Atl
579
alpha diversity
typically species richness
580
beta diversity
similarity between two communities
581
why is alpha diversity different in western vs eastern Atlantic
- POC flux much large in E vs W
- higher productivity in W (Fe)
- dependent on surface processes
582
deep sea threats`
- deep sea mining
- climate change
- waste deposition
583
manganese nodules
- polymetallic or Mn
- concentric layers of minerals
- microscopic - 20cm
- economically important - Mn, Ni, Cu, Co, Fe
584
climate change in deep sea
- highly dependent on surface processes
- warming may decrease PP
- may select for lighter (lower sinking) organisms
585
hydrothermal vents
- discovered in 1977 by Alvin
- expanded understanding of life limits
- associated w/ tectonics (MORs, volcanic seamounts)
- 690 sites discovered, predict ca. 900 more
- majority at spreading ridges
586
hydrothermal fluid
- geothermally heated (black smokers 350+ ºC)
- acidic, anoxic, sulfide rich, mineral rich
- significant gradients
587
vent biology
- most live in diffused fluids, ca. 2ºC
- some in hotter T, Pompeii worm
- unique adaptations
588
Pompeii worm
Alvinella
- up to 10cm
- burrow in chimneys
- up to 80ºC, most thermotolerant eukaryote known
589
photosynthesis vs chemosynthesis
photo: CO2 + Nut. + H20 -- OM + O2
chemo: CO2 + Nut. + O2 + H2S -- OM + S + H20
- fueled by oxidation
- bacteria, archaea
590
HTV zonation
- based on chemical, T gradient, feeding style (symbiosis, predation)
- Alvinellids, tube worms, bivalves, suspension feeders, periphery
591
animal diversity and distribution at Endeavour
- ca 30% explained by abiotic factors
- facilitation increases in importance toward periphery
- negative interactions important in harsh conditions
592
community succession in East Pacific Rise
- microbial mats grow around new vent extrusion, attract scavengers
- w/i 1yr mats reduced, small tube worms take over
- w/i 2yrs giant tubeworms dominate
- w/i 3yrs mussels appear
- by 4yr mussels colonized tubes, bivalves begin to dominate
593
when HTV stop venting
shift to suspension feeders - hard, raised surfaces
594
HTV puzzle
- different organisms around the world
- some major differences between basins - low exchange
- lower differences within basins
595
HTV gene flow
- limited dispersal capabilities: stepping-stone model
| - long-distance dispersal capabilities: island model
596
vent larvae
- variable
- some can disperse far some can not
- very difficult to study
597
remaining HTV questions
- connectivity: pop. sources/sinks, timescales
- biodiversity: # species, factors that drive distribution, biodiv
- ecosystem services: biogeochemical cycles
598
food falls
- significant nutrient pulse
- fish, whales, other carcasses
- quickly colonized and devoured
- uniques species
- support large # organisms
- last 20-50 years
599
bone-eating worm
Osedax spp.
600
fallen carcasses estimated to provide
0.5g nutrients/m^2 /yr
601
whale fall studies
- purposeful implantations on sea floor
| - repurpose washed-up carcasses
602
whale fall succession
1. mobile-scavenger stage
2. enrichment oppotunist stage
3. sulphophilic stage
603
Mobile-scavenger stage, whale fall
- 0.5-1.5 months after settlement
- 4 months- 1.5 years
- deep-sea necrophages remove soft tissue
- non-specialized scavengers
- eat 40-60kg/day
- short lived, difficult to observe
- eg. hagfish, lithodid crabs, rattails, sleeper shark
604
scavenging rate depens on
carcass weight
605
enrichment opportunist stage, whale tall
- 1-2 years
- organically enriched seds., exposed bone
- 20,000-45,000 ind./m^2
- low diversity
- 1-3m radius around carcass
- proceeds until O2 depletion
606
enrichment opportunist stage biology
- heterotrophic macrobenthos take advantage of enriched sed.
| - opportunistic bone-eating epifauna polychaetes, crustaceans, bacteria, white gastropods, juvenile bivalves
607
Osedax
bone-eating polychaete
- sexual dimorphism (small m lives inside fm)
- morphologically diverse, several lineages, colonize different types of bones
- falls are ephemeral - how are they widely distributed?
608
Osedax morphology
ovisac - rooting structure full of symbiotic bacteria, secretes bone dissolving chemical
- tube
- plume
- oviduct
609
sulphophilic stage
chemoautotrophic
- 2-50yrs
- species-rich, trophically complex, skeleton emits HS from anaerobic breakdown of bone lipid
- >200 microfauna species
- dominated by anaerobic bacteria
- sulphur-oxidizing bacteria
- slowly decrease lipid content over decades
610
whale bones
60% lipid
611
anaerobic decomposition of bone lipid
1. SO4- (sulphate) reduction inside bone by heterotrophic bacteria -- flux HS- from bone
2. HS- (sulphide) oxidizing chemoautotrophic bacteria
612
base of sulphophilic whale fall stage food web
- sulphate-reducing bacteria
- sulphide-oxidizing bacteria
- organisms containing chemoautotrophic symbionts
613
the rest of the sulphophilic whale fall stage food web
- 1º consumers: feeding on chemoautotrophic bacteria
- 2º, 3º consumers, etc.
- scavengers
- including: bacterial mats, isopods, galatheids, polychaetes, limpets, snails
- specialists
614
Whale fall stage 4
hypothesized reef stage
| -sspension feeders take advantage of hard substrates and particulate detritus
615
whale falls provide
- Org, S-rich habitat islands
- hotspots of biodiversity and evolutionary novelty
- unique niches for specialists
616
reduction in whale-falls
- ca. 75% in N Atl
- globally ca. 65% sperm whales
- due to whaling
617
Cold seeps
- hydrocarbons (CH4), suffices, bubble through surface
- much cooler than HTV
- bacteria nutrition, methanotrophic bacteria (free, symbiotic)
- bacteria form carbonates
- less diversity than HTV, last longer
618
cold seep biology
- similar to HTV
- infauna, epifauna
- bivalves, bacteria, tubeworms, etc.
- slower growth rates
619
cold seep succession
-bacteria -- bivalves w/ symbionts -- CaCO3 build up -- tubeworms -- cold seep turns off -- shift to coral reef community
620
cold seep threats
- hydrocarbons - oil exploration
| - knowledge
621
Main themes
1. Ocean contains amazing biodiversity and provides many ecological functions
2. Biodiversity is depleted by anthropogenic activity
3. Biodiversity is important for ecosystem function
4. Much remains unknown
622
Antarctica
- majority is deep, >3km
- majority of studies are shallow
- majority of knowledge on animals, especially crustaceans
- microbial life underrepresented
- low # verts, but lots of experts (big, charismatic)
- knowledge gap
623
polar threats
- fishing, exploitation
- tourism (increased from 7000-35,000 in 15yrs)
- climate ∆- T, ice, acidification
- invasives (?)
624
Caribbean knowledge
- complex current, impacts nutrients
- majority deep, >2km
- focus on shallow
- many species described
- low # microbes studied
- high # crustaceans
- know more than proportional amount about fish
625
Caribbean S-A curves
lot's of work to be done on mollusks, fishes starting to plateau, echinoderms pretty well described
626
Caribbean threats
- coral reef degradation
- increasing human population- coastal development, pollution
- invasives
- climate ∆
- exploitation, over-fishing
627
Canadian marine ecosystems
- longest coastline in world, 243,791 km
- 16% worlds coastline, 17% of worlds oceans
- 3 unique basins
- huge diversity, many ecosystems
628
Canadian marine threats
- climate change
- over-fishing
- shoreline development
- eutrophication
- no biodiversity baseline
629
Canadian Pacific
- cold
- California/Alaska current influence
- seasonal freshwater input
630
Candian Atlantic
- cold
- driven by Labrador current, Gulf stream
- seasonal freshwater
- seasonal ice coverage
- Bay of Fundy, unique
631
Canadian Arctic
- ice most of yer
| - influenced by Labrador current, Beaufort Gyre, freshwater discharge
632
Canadian marine biodiversity
- min 16,000 species
- 9500 microbes (up to 54,500)
- 1650 phyto
- 900 fish
- 52 marine mammals
- only 48% of organisms described named and classified
633
comparing Canadian basins
Arctic- more phyto and crustaceans than the others, SA curve steep
- W Canada more diverse than E
- E better studied, closest to flat SA curve
- W richest seaweed flora in world (650spp)
634
CoML
Census of Marine Life
- 2000-2010 investigation of diversity, distribution, abundance of marine life
- 540 expeditions, 2700 scientists, 80 countries
- 6000 potentially new species
- first list of global marine species
- 90% or marine life is microbial
635
common marine ecology challenges
- learn more about small taxa: phytoplankton, microbes
- increase sampling in under-sampled habitats
- train new generation of taxonomists
