Chapter 8- oceans and fisheries Flashcards

1
Q

coral reefs

A

really struggling will be the canary in the coal mine for climate change

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2
Q

Ocean ecosystems

A
  • 72% of Earth’s surface
  • up to 9000m (no O2 when really deep)
  • costal zones & continental shelves= most productive (in top 100m) (find estuaries)
  • Nutrient availability, temperatures, and light=major ecological factors
  • large bodies of water have a higher specific heat capacity
  • can regulate temperatures around land masses
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3
Q

Land

A

limiting factor=water

  • productivity increases from poles to tropics
  • biotic pyramids- reduced at each trophic level
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4
Q

Ocean

A

limiting factor= nutrients
some most productive areas in Canada
-rapid turnover at 1st trophic level
-some areas in arctic are most productive due to interplay between ocean & land

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5
Q

Nutrients in the Ocean

A
  • concentrations increase with depth
  • most productive area=costal zones and areas of upwellings
  • can be held for long periods of time due to low oxygen and bacterial influence
  • Hope to Vancouver estuary= VERY diverse
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6
Q

Carbon sequestration

A

All carbon stored in dead animals in the ocean sink to the bottom of ocean and deompose there
1/4 to 1/3 of human CO2 emissions are absorbed creating carbonic acid= change in pH
-potential way to combat climate change

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7
Q

Carbon in the ocean

A
  • oceans key in absorbing CO2
  • carbon moved out of surface water to deeper ocean
  • stored in dead organisms, ocean sediments, coral reefs
  • takes up 2 billion tonnes of carbon/year
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8
Q

Coral Reefs

A
  • regulation of environmental disturbances (due to biodiversity)
  • treatment of organic waste too much= death of coral reef
  • food production
  • recreational opportunities
  • high biodiversity= higher resilience
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9
Q

Coral Bleaching

A

happens when exposed to higher acidity

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10
Q

Coral and Global Warming

A

CaCO3 + COOH= erosion/dissolve
zooxanthellae produce CHO that feed corals, helps with photosynthesis
increased temperatures=expelling zooanthellae so coral leaching occurs

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11
Q

Coral

A

individual polyps and calcium carbonate skeletons

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12
Q

Dead coral

A

white due to absence of algae

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13
Q

Marine food webs

A

HUGE biodiversity
complex=resilient
global warming=negative implications

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14
Q

Marine Food Webs cold water

A
  • simple in colder waters

- cannot afford to lose a lot of species

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15
Q

Thermocline

A

line where temperature in ocean gets colder

  • sharp transition in temperature between warm surface waters and cool deeper waters
  • colder water below thermocline due to carbon being absorbed and sinking
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16
Q

Thermocline Circulation

A
  1. Cooled water sinks into deeper basin with water close to 0C (not frozen due to salt)
  2. High salt content critical (increases water density)
  3. Dense water sinks and carries carbon with it
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17
Q

Implications of Global warming on thermocline circulation

A
  1. Ocean temperature increases therfore changing water density
  2. Freshwater glaciers melting males seas water less salty which changes the salt:fresh water ratio
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18
Q

Management Challenges

A

The real problem is that we do not undersatnd our ocean ecosystems and we have yet to learn they cannot be managed

  • need to learn about them before we can manage them well
  • deep sea vents 50 to 100 years behind general natural history because they are really hard to explore
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19
Q

Costal Development

A

half of world’s costal wetlands destoryed to support development
-lose estuary ecosystem and interface between terrestrial and ocean world just so we can have an inner harbour
-Canada= bad
US=worse

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20
Q

How much of the world’s population lives in costal zones?

A

60%

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21
Q

Implications of Costal Development

A

lots of flooding
no way to absorb storms *hurricane Katrina
loss of biodiversity with loss of land/water interface (waves hit a wall and head back out to sea)

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22
Q

Fisheries

A
  • 1950s saw onset of industrial fisheries *almost to death
  • resource base now less than 10% for entire communities of large fish species
  • eating ourselves our of an ocean ecosystem
23
Q

Global Fisheries

A

Major source of protein (too many people reliant on fish

  • total catch grew, now stabalizing (but declining per capita amount of fish being caught)
  • major employer (many towns dependant)
  • high revenues (but many subsidies) help buy fishing boat
24
Q

Global Fisheries Harvest

A

aquaculture=13% of worlds fish harvest

fish farming or salmon & oyster

25
Q

Top marine and Inland Fisheries

A

=China
many countries highly dependent on fish
then Peru, USA, indonesia, Japan, Chilie, India, Russia, Thailand, Norway

26
Q

Depleting Fisheries

A
  • 1/3 of fisheries are over-exploited
  • 70% of species used at or above sustainable levels
  • now fishing down the food chain (good for good stuff until it runs out then we catch the next most desirable thing)
  • equivalent to prey switching
27
Q

By-catch

A

non targeted fish

28
Q

Aquaculture

A
=farming of aquatic organisms (fish, shellfish, plants, in controlled environments 
-BC and NB dominant 
-Atlantic salmon is leading export 
Effects: 
-fish disease
-genetically modified fish 
-impacts on wild species 
(too many nutrients with dead zone due to overabundance of salmon feces
29
Q

What is the limiting factor in terrestrial ecosystems?

A

water

30
Q

What is the most common limiting factor in marine ecosystems?

A

nutrients

31
Q

Fisheries and Marine mammals

A
  • manages by fisheries and oceans
  • many whales now hunted to extinction
  • Northern Right Whale (one of most rare)
  • get 160,000L of oil from 1 whale
  • whale populations declining
  • accumulates biotoxins
32
Q

Fishing Methods

A
  1. Seine Fishing
  2. Bottom-Trawling
  3. Trawling
  4. Longline Fishing
  5. Trolling
  6. Dredging
33
Q

Seine Fishing

A

using a large fishing net with weights along the net’s bottom and floats along the top

  • encircle school of fish
  • dolphins may get caught
34
Q

Bottom Trawling

A

heavy nets dragged along ocean floor- ground fish and cod, squid, halibut, rockfish

  • lots of by-catch
  • incidental damage to ocean floor
35
Q

Drift netting

A

=illegal (hang line out for kms and leave it)

36
Q

Trawling

A

pulling a large fishing net behind more than 1 boat

-midwater trawling=anchovies, shrimp, mackerel, tuna

37
Q

Longline FIshing

A

uses 100s or 1000s of baited hooks hanging from a single line (swordfish, tuna, halibut, sablefish)

38
Q

Trolling

A

one or more fishing lines baited with lure or bait fish are drawn through the water behind a moving boat (makerel, kingfish, tuna, marlin)
-go slowly through the water

39
Q

Pollution

A

oceans are a sink for many pollutants *agriculture, industry, urbanization, waste disposal
-Chemical pollutants
-toxic materials
-nutriends
-endocrine disrupter (DDT) fish and polar bears
rain goes into ocean and takes all the stuff from the street with it

40
Q

Bioaccumulation

A

accumulation of toxins in higher trophic level species

41
Q

Dredging

A

towing a dredge along the ocean bottom (scallops, oysters, sea cucumbers)
-pull along productive zone of ecosystem

42
Q

Worst method of fishing

A

drift nets, illegal

catch whales, sea turtles, dolphins as by-catch)

43
Q

Oil and Gas development

A

60% of world’s global oil production is from sedimentary basins under the ocean

44
Q

Canada’s oceans

A

-longest coastline in the world
-Management
fisheries and marine species (department of fisheries and Oceans)
sea birds=Environment Canada
shoreline=provinces and municipalities
-silo effect when they don’t meet and talk
-lots of overlap but can also cause administrative difficulties

45
Q

200 mile limit

A

set limit that is ours to manage

46
Q

Pacific Ocean

A
  • sea temperatures higher than Arctic
  • important for waterfowl, seasbirds, and shoreline
  • seas lions seals, whales
47
Q

Threats to Pacific Ocean

A
  • pollution
  • habitat loss
  • overfishing
  • aquaculture
48
Q

Arctic Ocean

A
  • often covered by permanent pack ice
  • biological and productivity generally low (poynas=high)
  • bowhead, beluga, narwhal aka northern right whale floats when killed)
49
Q

Threats to Arctic Ocean

A
  • increase oil and gas activities
  • habitat loss (melting)
  • climate change
  • political disputes
50
Q

Atlantic Ocean

A

20C warmer than arctic

  • highly productive
  • abundant marine life
  • 22 species of whales and 6 species of seals
  • cod fishery collapse (federal gov allowed this to happen)
51
Q

Threats to Atlantic Ocean

A
  • oil and gas activities
  • over harvesting
  • political disputes
52
Q

Aboriginal Uses of Resources

A

treaty rights to subsistence fishing

-conflicts court cases cooperation

53
Q

Ocean’s Act

A
  1. Sustainable development
  2. Integrated Management
  3. Precautionary Principle
54
Q

Marine Protected Areas

A
Sagunenay St. Lawrence NMP 
Fathom 5 NMP 
Lake Superior NMP 
Endeavour Hydropthermal Vents MPA 
(managed by Parks Canada)