Lecture 21 - Chapter 24 - Marine systems

Question 1

Define an estuary

Answer 1

interface/mixing of freshwater rivers and saltwater ocean
- sediments (nutrient rich) from upriver are deposited here

Question 2

Define salt marshes and mangroves

Answer 2

1. Salt marshes are found in temperate zones
2. mangroves found in tropical zones
3. in coastal areas, protected from wave action
4. both are areas of low diversity

Question 3

Why are salt marshes and mangroves areas of low diveristy?

Answer 3

1. Flooding,
2. exposure to salt water
3. Unstable surfaces like sand and mud
   cause stress to primary producers (plants)

Question 4

In mangrove areas, how do plants manage said stress?

Answer 4

1. pneumatophores (specialized in gas exchange stick up from the ground)
2. aerial prop roots (provide extra support)

Question 5

What are 4 zones of the ocean?

Answer 5

1. intertidal zone
2. benthic environment
3. neritic province
4. oceanic province

Question 6

Define the intertidal zone

Answer 6

area of the shore between low and high tide

Question 7

Define the benthic env.

Answer 7

ocean floor from the edge of the intertidal zone to deep ocean trenches

Question 8

define neritic province

Answer 8

surface ocean waters from 0 to 200 m (656 feet) deep

Question 9

Define the oceanic province

Answer 9

deep sea all ocean water > 200 m deep and away from the shore

Question 10

What are the sources of stress in the intertidal zone?

Answer 10

1. temperature fluctuation
2. exposure to air
3. human activity
4. movement of waves (animals need to be stable)

Question 11

List the 4 zones in the rocky intertidal

Answer 11

1. spray zone
2. high zone
3. mid zone
4. low zone

Question 12

What kind of surfaces can be found in intertidal zones?

Answer 12

1. rocky
2. sandy and muddy

Question 13

Define the spray zone

Answer 13

-submerged only during very high spring tides or storms
- often wet from waves and windblown spray

Question 14

Define the high zone

Answer 14

• flooded only at the peak of spring tides

Question 15

Define the mid zone

Answer 15

-submerged much of the time
- zone is between average high and low tide

Question 16

define the low zone

Answer 16

• exposed only rarely during very low spring tides

Question 17

Out of the 4 rocky zones, which one is most stressful and why?

Answer 17

Spray zone because its dry, hot, and less submerging

Question 18

Out of the 4 rocky zones, where would diversity be high and low?

Answer 18

Highest - down close the ocean- mid zone
low - spray zone

Question 19

How do animals live in the stressful rocky intertidal environments? (adaptations)

Answer 19

1. snails secrete mucus (under foot)
2. algae (slimy) - prevents it from drying out since it floats on top
3. crabs - super mobile so can move if too hot, dry, hunt, hide
4. barnacles - open and close their shells according to tides

Question 20

Describe the sandy & muddy intertidal zones

Answer 20

1. detrital food webs tend to be dominate - inputs from dead algae, animals, fecal material
2. most organisms live beneath the surface such as bacteria, sand dollars, starfish
3. fish and birds are important predators here
4. below the line there is predatory snails and crabs

Question 21

What is another name for neritic provinces?

Answer 21

continental shelves

Question 22

What are continental shelves home too?

Answer 22

coral reefs
shallow waters
rich with diversity

Question 23

Why do coral reefs thrive in the neritic province?

Answer 23

1. they require access to light so this shelf provides it
2. allows a symbiotic relationship between algae called zooxanthellae

Question 24

Who are the dominant primary producers in the neritic zone?

Answer 24

Phytoplankton

Question 25

What forms the base of the food web in the benthic environment?

Answer 25

dead organic material !

Question 26

Who lives in the benthic zone?

Answer 26

1. lots of worms
2. fish with their own lights
3. crustaceans
4. bacteria