CH 13 Marine Ecosystems

Question 1

2 Key factors that shape ocean ecosystems?

Answer 1

1. Depth of the water column
   (affects temperature because of varying sunlight available at different depths)
2. Proximity to shore
   (the closer to land and rivers that empty into ocean, the more nutrient rich and productive the area)

Question 2

What are the 4 ocean zones? (top to bottom)

Answer 2

1. Epipelagic zone
2. Meso & Bathypelagic zone
3. Abyssopelagic zone
4. Hadal Zone (deep trenches)

Question 3

What is an estuary?

Answer 3

Low lying area at the most of a river, they can take the form of: tidal flats, salt marshes, mangrove swamps, wetlands

Question 4

What services do Oceans provide ecosystems?

Answer 4

• Temperature moderation
• Nutrient cycling
• Support for commercial fisheries
• Storm protection for coastal areas
• Recreational Opportunities
• Source of medicines

Question 5

What is a coral reef?

Answer 5

ocean ecosystems formed by coral colonies that build reef landforms as they accumulate.
Found in shallow, nutrient-poor water in tropical regions

Question 6

What allows Coral to live in nutrient poor marine waters?

Answer 6

The corals mutualistic relationship with photosynthetic zooxanthellae enables them to live in nutrient poor marine waters. Zooxanthellae line the epidermal tissue of the coral and provides energy for them through their photosynthesis

Question 7

What % of ocean species liver in coral reefs (even if temporarily)?

Answer 7

25 % of all ocean species

Question 8

What human actives are threatening ocean life (and reefs)?

Answer 8

• Fishing pressures
• Pollution
• Invasive species

Question 9

Biggest threat to coral reefs?

Answer 9

Overfishing

Question 10

Biggest threat to oceans?

Answer 10

Fossil Fuel Combustion

Question 11

How much of all C02 released by human activities over the last 2 centuries has been absorbed by the ocean?

Answer 11

30% of all C02 released in the last two centuries has been absorbed by the ocean…leading to acidification

Question 12

What acid is formed from C02 that is a huge threat to ocean ecosystems

Answer 12

Carbonic acid

Question 13

What are some consequences of Ocean Acidification

Answer 13

• Decline in availability of key nutrients like nitrogen and iron
• Less plankton as a result
• Less nitrogen fixing by bacteria
• shells dissolve in acid waters
• reduce water’s ability to absorb low frequency sounds, affecting mammals ability to communicate

Question 14

How does carbonic acid enter water?

Answer 14

C02 enters the ocean from the atmosphere; fossil fuel burning provides extra C02, increasing the amount.

• C02 is converted to carbonic acid (H2C03), which then dissociates to release H)
• If more H is present (acid conditions) it binds to the carbonate needed to make shells
• H causes shells to dissolve, releasing CA2+ and HC03.

Question 15

Process of Coral bleaching

Answer 15

1. Atmospheric warming
2. Ocean warming
3. Thermal stress on zooxanthellae
4. Decreased photosynthesis
5. Ejection by host coral

Question 16

Strategies for protecting marine ecosystems?

Answer 16

• Designate vulnerable areas as marine protected areas
• Reduce use of fossil fuel
• Limit development in vulnerable areas
• Prohibit bottom trawling for fish in vulnerable areas and reduce overfishing in general
• Reduce pollution