Chapter 9

Question 1

List oceanic ecosystem in order from bottom to top

Answer 1

• Primary producers (oxygen producing, 203 absorbing, phytoplankton, seaweed)
• Herbivorous consumers (zooplankton, cockles)
• 1st level carnivorous consumers (juvenile fish, jellyfish, crustaceans)
• 2nd level carnivorous consumers (larger fish)
• 3rd level carnivorous consumers (squid)
• Top carnivores (shark, dolphin, albatross)

Question 2

What is thermohaline circulation?

Answer 2

Carbon saturated water moving around the globe like a carbon-salt conveyer belt. Result of different water densities

Question 3

How does thermohaline work?

Answer 3

High salinity water cools and sinks in North Atlantic
Deep water returns to surface in Indian and pacific oceans through upwelling
(Sheds energy/carbon, moves nutrients, salt, heat)

Question 4

Where are the most important fishing grounds?

Answer 4

On and along continental shelves less than 200 nautical miles of shore

Question 5

How much of worlds protein supply do fish supply?

Answer 5

20%

Question 6

What is happening to the fish?

Answer 6

Declining numbers
Smaller than those caught in the past

Question 7

What is a shifting baseline?

Answer 7

Using current or recent degraded state as baseline rather than historical data

Question 8

What is prey switching?

Answer 8

predator shifts target species after theirs gets depleted or not available
Continues to move down the food line

Question 9

What is serial depletion?

Answer 9

One stock after another becomes depleted as result of prey switching

Question 10

Point source vs non point source

Answer 10

Point source –> can point to a source of pollution (pulp mill, factory)
Non point source –> total of multiple sources (agriculture)

Question 11

Why is the ocean so polluted?

Answer 11

If receives all of the water flowing off land as well airborne contaminants

Question 12

What are the two forms of chemical pollutants?

Answer 12

Toxic
Nutrients

Question 13

What is endocrine disruption?

Answer 13

Interference of normal bodily proccesses (sex, metabolism, growth) by chemicals in soaps, detergents, that are released into ecosystem. Can cause feminization in some aquatic species.

Question 14

What effect does nutrient enrichment have on the ocean?

Answer 14

Can cause oxygen depletion leads to large dead areas
Threatening certain species by creating higher number of male fish to female

Question 15

What is an oxygen deficient area called?

Answer 15

Dead areas are called hypoxic.

Question 16

How much would surface temperature have to increase to cause global destruction of coral reef ecosytems?

Answer 16

1 degree c

Question 17

What is the most sensitive indicator of global climate change?

Answer 17

The arctic Ocean

Question 18

How does heat cause sea levels to rise?

Answer 18

When water warms molecules are moving faster causing water to take up more space. (Thermal expansion effect)

Melting of ice sheets and glaciers

Question 19

How many zettajoules of energy has the earth absorbed between 1865 and 1997

Answer 19

150 Zettajoules –> equivalent to 2.4 billion atomic bombs (heat, not radiation energy)

Question 20

Why are BC shellfish struggling to survive?

Answer 20

Oceans becoming more acidic

Question 21

What year did the United Nations Convention on the Law (UNCLOS) form?

Answer 21

1994
Ratified by Canada in 2003

Question 22

What was the most important provision enacted by UNCLOS

Answer 22

Exclusive economic zones (EEZs): Special rights regarding exploration and use of marine resources (water and wind energy)

Stretches 200 nautical miles
establishes 45% of seabed as common property

Question 23

What is the fastest way to create change in fishing methods?

Answer 23

End subsidies that support commercial fisheries

Question 24

What is a marine protected area?

Answer 24

underwater reserve set aside and protected from human exploitation because of fragility, rarity or valued biodiversity of ecosystem

Question 25

What are the 5 marine ecozones?

Answer 25

• pacific marine
• arctic basin
• arctic archipelago
• northwest atlantic
• atlantic

Question 26

What is the fisheries act?

Answer 26

Federal legislation established to manage / protect Canada’s fishery resources

Outdated, new act formulated but not yet approved by parliament

Question 27

What were the effects of the cod industry collapsing?

Answer 27

loss of about 50,000 jobs in quebec and the maritime provinces

Question 28

What led to the collapse of the cod fisheries?

Answer 28

Overfishing
Imperfect science and management
Inappropriate incentives for processing plants and fish workers
Changing environmental conditions
Predators