ROCKY SHORE ORGANISMS

Question 1

phytoplankton and zooplankton

Answer 1

plentiful in the nutrient-rich coastal seas.

Question 2

Seaweed (e.g., Kelp)
● Description: Large, brown algae that require constant submersion in
water. They grow quickly and attach to rocks with holdfasts. Usually
found in the low intertidal to subtidal zones where water flow is
consistent.

Answer 2

● Description: Large, brown algae that require constant submersion in
water. They grow quickly and attach to rocks with holdfasts. Usually
found in the low intertidal to subtidal zones where water flow is
consistent.

Question 3

Mussel

Answer 3

● Description: Bivalve mollusks that attach to rocks using byssal threads. They
thrive in the mid-intertidal zone, where they are submerged and exposed
periodically but can withstand some desiccation.

Question 4

Crab

Answer 4

● Description: Mobile scavengers that move across different zones. They
are commonly found in the mid-intertidal zone but will move to higher or
lower areas depending on food availability and tidal conditions.

Question 5

Sea Anemone

Answer 5

● Description: Soft-bodied, tentacled creatures that attach to rocks and feed
on passing prey. Typically found in the mid to low intertidal zone, they
prefer being submerged most of the time.

Question 6

Limpet

Answer 6

Limpet
● Description: Cone-shaped mollusks that cling tightly to rocks to avoid
being dislodged by waves. Found in the high to mid-intertidal zone where
they can tolerate drying out during low tide.

Question 7

Erect Coralline Algae

Answer 7

Erect Coralline Algae
● Description: A type of red algae that forms hard, calcareous structures. It
is found in the low intertidal to subtidal zone where it is continuously
submerged and receives plenty of light. This algae contributes to the
structure of the rocky shore and provides a habitat for small marine
creatures.

Question 9

Starfish (Sea Star)

Answer 9

Starfish (Sea Star)
● Description: Predatory echinoderms that feed on mollusks and other small
organisms. Found in the low intertidal to subtidal zone where they are constantly
submerged.

Question 11

GREEN seaweed

Answer 11

Intestine Weed, Sea lettuce,Sea Emerald,Bryopsis sp.,
Brancing velvet weed,Sea Rimu, encrusting velvet weed,

Question 12

BROWN seaweed

Answer 12

Bull Kelp, Sargassum, zig-zag weed, Ecklonia
Ecklonia radiata, strap weed, dead man’s fingers, Carpophyllum plumosum, Neptune’s necklace :)

Question 13

major source of physiological stress;

Answer 13

As most intertidal species are marine, large variations
in these abiotic factors are a major source of physiological stress;

Question 14

The intertidal zone alternates between:

Answer 14

terrestrial and marine conditions each
day as the tide rises and falls.

Question 15

THE ABIOTIC ENVIRONMENT

Answer 15

Abiotic or physical factors like temperature, salinity, pH and dissolved oxygen

Question 16

widely changing abiotic conditions.

Answer 16

One of the most significant factors in creating a large number of ecological niches in
the intertidal zone is the:
widely changing abiotic conditions.

Question 17

Rock surfaces provide:

Answer 17

a relatively permanent, stable platform for animals and algae
to attach to or shelter beneath in a dynamic environment exposed to strong water
currents and wave action

Question 18

The rock

Answer 18

provides a stable anchorage for many sessile
organisms and allows them to grow to a large size without being dislodged.

Question 19

As temperature increases, the risk of .

Answer 19

desiccation also increases

Question 20

High air
temperatures coupled with low humidity and coastal breezes mean

Answer 20

that the
evaporation rate is high.

Question 21

Salinity is a measure of :

Answer 21

the amount of dissolved minerals or ‘salts’ in water.

Question 22

Oxygen dissolved in the sea results from:

Answer 22

photosynthesis of marine producers like
phytoplankton and macroalgae and diffusion between the air and the sea at the
water surface.

Question 23

Organisms in standing water in tide pools organisms breathe by:

Answer 23

respiration by simple diffusion.

Question 24

Important nutrients for algal growth:

Answer 24

like iron, magnesium, nitrate and phosphate
are dissolved in seawater.

Question 25

wave action

Answer 25

Another effect of wave action is to create a mechanical stress on intertidal organisms.

Question 26

interspecific competition

Answer 26

Competition between different species increases down the shore with increasing biodiversity.

Question 27

Like plants, algae are photoautotrophic:

Answer 27

they obtain their nutrition by photosynthesis.

Question 28

Predation

Answer 28

The high shore therefore acts as habitat prey refuge from marine predators for sessile species such as mussels and barnacles, where the total mortality due to predation is lower than it would be lower down the shore.

Question 29

Food availability

Answer 29

Filter-feeding animals can only feed when they are submerged so it stands to reason that they will be more numerous in the lower shore where they spend longer periods covered by seawater.

Question 30

Zonation

Answer 30

Biological zonation is the distribution of species into visible bands or zones along (perpendicular to) an environmental gradient.

Question 31

Tolerance range Optimum range

Answer 31

An organism will have an upper and a lower tolerance limit for different abiotic factors and these determine the tolerance range.

Question 32

Gause’s Principal of Competitive Exclusion.

Answer 32

No two species can occupy the same ecological niche indefinitely; interspecific competition will ultimately result in the exclusion of the poorer-adapted species from that niche i.e. one species’ population will decline as the others’ grows:

Question 33

Fundamental niche

Answer 33

The potential niche a species could occupy in the absence of better-adapted competitor is known as its fundamental niche.

Question 34

ADAPTATIONS TO LIFE IN THE INTERTIDAL ZONE:

Answer 34

COPING WITH STRESS

Question 35

Heat & Dessication

Answer 35

drastic changes in temperature can occur rapidly if influences of the tide, time of day and sea temperature are considered together.

Question 35

Intertidal organisms are ectothermic:

Answer 35

they lack any physiological mechanisms to generate body heat.

Question 36

High temperatures also disrupt:

Answer 36

the organisation, stability and structure of delicate molecules in cells, such as membrane lipids, enzymes, DNA and RNA.

Question 37

eurythermal

Answer 37

Many intertidal species are eurythermal: they can tolerate much higher environmental temperatures than their non-intertidal relatives. Their physiological processes have adapted to function at higher temperatures.

Question 38

Example of physiological adaptation to high temperatures

Answer 38

A physiological adaptation to potentially damaging high environmental temperatures is the production of heat shock proteins during periods of thermal stress. The proteins function is to help maintain metabolic function by stabilising and repairing important enzymes and protecting them from heat damage.

Question 39

behaviours known as phototaxis and geotaxis.

Answer 39

Chitons respond to both light and gravity and tend to move downward towards dark crevices when exposed to the air,

Question 40

aerobic respiration

Answer 40

With the exception of the high-shore pulmonate limpets12, most intertidal animals rely directly on water for dissolved oxygen for aerobic respiration.

Question 41

anaerobic respiration;

Answer 41

The most common physiological adaptation is to reduce the oxygen demand and rate of carbon dioxide production by lowering the metabolic (and therefore respiration) rate, and fuelling essential life processes by anaerobic respiration; the lactic acid build up is then reversed during re-submergence as the tide rises.