Deck 16: Coastal Seas and Continental Shelves

Question 1

What impact fishing has had on the benthic and pelagic organisms of coastal seas?

Answer 1

Commercial fishing of cod and lobsters has had a great and detrimental effect on the benthic and pelagic organisms that rely on the kelps of the coastal seas. These commercial commodities are natural predators of the sea urchins that graze the kelp. When the cod and lobsters are removed from the community the urchin population explodes and can completely decimate the kelp growth, in turn decimating many species that rely on the kelp community for food and shelter.

Question 2

What are two ecological roles for plankton in the neritic zone

Answer 2

Plankton in the neritic zone play important ecological roles. The phytoplankton, which is the basis of the continental oceanic food chain, are so dense in the neritic zone, that in only 10% of the ocean's total volume, 90% of commercially harvested fish and shellfish are supported by the phyto and zooplankton. Not only do the plankton provide nutrients for such a dense population of marine organisms, the zooplankton krill that feed on the diatoms become the basis of the food chain of large populations of birds. More than 100 million tons of krill is consumed by fish in the southern ocean alone; in Antarctica, 15% more than that becomes almost 80% of the diet of large populations of birds. Krill is also being consumed by humans. From the bottom to the top of the food chain is a very short distance solely because of the productivity of plankton.

Question 3

The uneven distribution of bottom organisms and sediment type on the continental shelf is referred to as

A) reticulation
B) patchiness
C) diversity
D) sediment selection
E) benthic orientation

Answer 3

A

Question 4

Name two important functions of bottom currents in benthic communities.

Question 5

In colder waters, ___ dominate the phytoplankton.

A) krill
B) copepods
C) diatoms
D) dinoflagellates
E) kelp

Question 6

Coastal waters receive nutrient runoff from the land and upwellings bring nutrients from deeper water to the surface. The heavy concentration of nutrients combined with large amounts of sunlight support large populations of phytoplankton which in turn support large numbers of zooplankton and fish.

Question 7

Explain how the types of bottom sediments influence the diversity of life on the floor of the continental shelf.

Question 8

Most of the world's harvest of commercial fish comes from

A) estuaries
B) bays
C) coastal seas
D) the open ocean
E) benthic regions

Question 9

The most abundant members of the zooplankton are

A) krill
B) copepods
C) jellyfish
D) diatoms
E) dinoflagellates

Question 10

What are the main sources of nutrient input into coastal seas

Question 11

List three explanations for the patchy distribution of organisms in soft-bottom communities.

Question 12

Currently there is concern about climate change caused by the greenhouse effect. How might this affect the productivity of coastal seas

Question 13

Nutrients produced by bacteria in the bottom sediments are returned to the surface waters by

A) gyres
B) upwellings
C) thermoclines
D) Eckman spirals
E) the Coriolis effect

Question 14

Hard bottom sediments such as rock support seaweeds and a variety of sessile and sedentary filter feeders. Soft bottom sediments such as sand and mud support many burrowing organisms.

Question 15

Explain how decreases in the size of lobster and cod populations have affected North Atlantic kelp beds.

Question 16

Burrowing organisms would more likely be found where

A) sediments are predominantly gravel
B) the sediments are sand, and the water currents are fast
C) the sediments are silt, and the water currents are slow
D) the sediments are silt, and the water currents are fast
E) landslides frequently disrupt the bottom

Question 17

In soft-bottom communities, suspension feeders and deposit feeders are usually not found in the same areas because

A) they compete with each other for food
B) they compete with each other for space
C) deposit feeders prey on suspension feeders
D) the suspended silt in regions inhabited by deposit feeders clogs the feeding structures of suspension feeders
E) the type of sediments inhabited by deposit feeders will not support suspension feeders

Question 18

What factors affect the size of plankton populations

Question 19

Why are kelp beds frequently compared to terrestrial rainforests

Question 20

Why do so many species of small fish found in coastal seas travel in large schools

Question 21

The world's most productive upwelling area is located off the coast of

A) California
B) Peru
C) China
D) South Africa
E) Europe

Question 22

Kelp communities are important because they provide a complex three-dimensional habitat for hundreds of species as well as a food source for many species.

Question 23

Why is the neritic zone such a productive area

Question 24

Sedentary and sessile filter feeders and suspension feeders are better adapted to

A) hard bottoms
B) soft bottoms

Question 25

The dominant alga in southern California kelp forests is

A) Fucus
B) Laminaria
C) Eisenia
D) Sargassum
E) Macrocystis

Question 26

How do waves and currents affect the types of benthic organisms found on the continental shelf

Question 27

Diagram a simple food web for the continental shelf.

Question 28

Why do disturbances such as landslides have a greater impact on invertebrate populations than on algal populations

Question 29

Describe the process of succession that occurs in soft-bottom communities that are disturbed.