Energy Capture and Allocation

Question 1

Primary Production

Answer 1

The formation of organic matter through the trapping of light energy and assimilation of inorganic elements

Question 2

Mangroves, Salt Marsh, and Seagrass Coverage

Answer 2

These ecosystems cover less than 0.5% of the marine area yet account for between 50 and 71% of carbon storage in marine sediments

Question 3

Primary Producers of the Ocean

Answer 3

Seaweeds (macro-algae), seagrasses, and microscopic algae (phytoplankton) and bacteria

Question 4

Algal Bloom

Answer 4

When phytoplankton rapidly proliferate under proper light and nutrient conditions

Question 5

Needs of Photosynthetic Organisms

Answer 5

Light, carbon dioxide, oxygen, macro-nutrients (phosphate, nitrate, silicate)

Question 6

Oligotrophic

Answer 6

Low concentrations of nutrients for algal blooms and low primary productivity (<100 g carbon m-2 per year)

Question 7

Eutrophic

Answer 7

High concentrations of essential nutrients for algal blooms and high primary productivity (300 to 500 g carbon m-2 per year)

Question 7

Mesotrophic

Answer 7

In between eutrophic and oligotrophic waters (100 to 300 g carbon m-2 per year)

Question 8

Eutrophication

Answer 8

Rapid increase in the primary productivity of an area, often caused by a rise in an essential inorganic nutrient like nitrogen or phosphorus

Question 9

Biomass-Limiting

Answer 9

The nutrients are so exhausted that no more mass can be produced

Question 10

Rate-Limiting

Answer 10

The nutrients limit the rate of new biomass production by their rate of supply

Question 11

Diffusive Boundary Layer

Answer 11

Surrounds each cell or surface in water and restricts the molecular diffusion and the movement of water // Smaller cells have a thinner/lower DBL and have a physiological advantage in low nutrient waters

Question 12

HNLC Areas

Answer 12

High nutrient, Low-chlorophyll areas are potentially limited by light or depletion of standing stocks, yet more likely by the absence of iron (a necessary micro-nutrient for primary production)

Question 13

Succession of Phytoplankton Species

Answer 13

Controlled by a complex mosaic of factors, like temperature, irradiance, growth rates, and nutrient supply

Question 14

Governing Factors of Marine Primary Production

Answer 14

Light, nutrients, stability, and mixing

Question 15

Tropical and Subtropical Areas (PP)

Answer 15

Normally have permanent thermal stratification and less mixing, so more nutrient-limiting, resulting in lower levels of productivity that are fairly consistent

Question 16

Polar Areas (PP)

Answer 16

Significant mixing which brings good nutrient concentrations, yet more light-limiting through irradiance, and limited times of production

Question 17

Temperate Waters (PP)

Answer 17

Seasonal fluctuation of primary productivity due to the complex range of factors, so low in the summer/winter and higher in the spring/summer

Question 18

Coriolis Effect

Answer 18

Deflects currents northwards in the northern hemisphere and southwards in the southern hemisphere, drawing surface waters away from the equator and allowing for upwelling to occur there

Question 19

Coastal Waters // Continental Shelf Waters (PP)

Answer 19

These waters have the highest primary productivity, shallow enough for good light and receive nutrients from river sources

Question 20

Marine and Terrestrial Primary Production

Answer 20

Roughly the same, at 50 Pg of carbon each per year

Question 21

Primary Production

Answer 21

Usually defined by the amount of bacterial, algal, or plant biomass built up through the process of photosynthesis over time

Question 22

Net Primary Production

Answer 22

The total photosynthetic carbon assimilation minus respiration carbon losses

Question 23

Mass Balance

Answer 23

There is a net input of around 20 Tmol carbon per year to the oceans, and the oceans are probably net heterotrophic, with respiration exceeding photosynthesis by about 0.2%

Question 24

Redfield Ratio

Answer 24

A 7:1 relative proportion of nitrogen and phosphorus needed by phytoplankton

Question 25

Trophic Levels

Answer 25

Producers (autotrophs) - Primary Consumers (heterotrophs, for all following levels) - Secondary Consumers - Tertiary Consumers - Quaternary Consumers (also Decomposers)

Question 26

Food Chains

Answer 26

Show a relationship from primary producers to quaternary consumers, via the energy flows and loss of energy upwards (linear model)

Question 27

Food Webs

Answer 27

In addition to showing connections of energy, includes all the relationships, including decomposers, detritivores, scavengers as well

Question 28

Quantitative Measures in Food Webs

Answer 28

Connectance, linkage density, and chain length (and mean)

Question 29

Connectance

Answer 29

The measure of the proportion of links in a food web (the number of observed links divided by the total number of species squared)

Question 30

Linkage Density

Answer 30

The number of observed links divided by the number of total species (basically gives you the average number of links)

Question 31

Chain Length

Answer 31

The number of trophic levels in each chain (can add up these numbers and then divide by the number of chains)

Question 32

Continual Input of Small Nutrient Doses

Answer 32

Competitive species are favored, domination by a very few species, relatively constant biomass

Question 33

Occasional Input of Large Nutrient Doses

Answer 33

Biomass may fluctuate widely, continually altering species composition

Question 34

Dietary Guilds

Answer 34

A way of classifying species in each trophic level by their dietary habits

Question 35

Dead Zones

Answer 35

Occur because of eutrophication which may lead to algae blooms where the end result is low O2 areas (hypoxia) or no O2 areas (anoxia) because the bacteria use up all the oxygen during decomposition

Question 36

Causes of Increasing Eutrophication

Answer 36

Increased nutrient pollution, sea surface warming, ocean acidification, and reduced water flow

Question 37

Grazing

Answer 37

Phytoplankton are often consumed by a range of grazing zooplankton // this can lead to “clear-water phases” when they eat all of the algae

Question 38

Detritus

Answer 38

Most phytoplankton biomass settles to lake or sea beds

Question 39

Diadromous Fish

Answer 39

Fish that spend part of their lives in freshwater and part of their lives in marine waters; anadromous if mostly salt [salmon], catadromous if mostly fresh [herring]

Question 40

Potadromous Fish

Answer 40

Migration takes place entirely in freshwater systems, e.g. catfish

Question 41

Oceanodromous Fish

Answer 41

Migration takes place entirely in the sea, e.g. bluefin tuna

Question 42

Tidal Migrations

Answer 42

Smaller scale movements over shorter periods in up-shore or down-shore directions, for food, to minimize predation risk, for reproduction // Can be intertidal migration or selective tidal-stream transport

Question 43

Primary Producers of the Ocean

Answer 43

Seaweeds (which are macro-algae, not flowering plants), seagrasses, microscopic algae and bacteria, mangroves, etc

Question 44

Phytoplankton Cells

Answer 44

Micro-algae that generate most of the primary production in the oceans

Question 45

Prokaryotic Photosynthetic Organisms

Answer 45

Much smaller than microphytoplankton, and include organisms like cyano-bacteria and pelagic prochlorophytes

Question 46

Picoplankton

Answer 46

Very small, from 0.2 to 2.0 um // thus the prokaryotic photosynthetic organisms fit into this

Question 47

Photoautotrophs

Answer 47

Algae (micro- and macro-) and cyanobacteria // Use light for their energy source and carbon dioxide (in various forms) to produce new organic matter

Question 48

Anticyclonic Gyres

Answer 48

CW in northern hemisphere, CCW in southern // regions of low primary production because the thermocline is deepened, with water moving toward the center of the gyre

Question 49

Cyclonic Gyres

Answer 49

CCW in northern hemisphere, CW in southern // mix water below the thermocline into surface waters, so support higher rates of primary production

Question 50

Marine Snow

Answer 50

Zooplankton are a vector for transport of organic material from the surface to the depths, and detritus that falls out of the euphotic zone is “marine snow”

Question 51

Species of Oligotrophic Waters

Answer 51

Small phytoplankton species that have a greater surface area:volume ratio, enabling more molecular diffusion crucial for the resupply of nutrients

Question 52

Diffusion-Limitation

Answer 52

For organisms >100 um in diameter, movement through water can lower the DBL and increase nutrient diffusion // For macro-algae and seagrasses, ridges and ruffled blades increase the motion of water around the DBL

Question 53

Main Growth-Limiting Nutrients (marine)

Answer 53

Nitrogen and phosphorus

Question 54

Main Growth-Limiting Nutrients (freshwater)

Answer 54

Nitrogen and phosphorus, yet mostly phosphorus