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Marine Diversity

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Marine Diversity Ocean Structure and Biodiversity – PowerPoint PPT presentation

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Title: Marine Diversity


1
Marine Diversity
  • Ocean Structure and Biodiversity

2
Oceans cover most of the Earths surface
  • The oceans influence global climate, team with
    biodiversity, facilitate transportation and
    commerce, and provide resources for us
  • They cover 71 of Earths surface and contain 97
    of Earths surface water
  • Oceans influence the atmosphere, lithosphere, and
    biosphere

3
The oceans contain more than water
  • Ocean water is 96.5 water
  • Plus, ions of dissolved salts
  • Evaporation removes pure water and leaves a
    higher concentration of salt
  • Nutrients (nitrogen and phosphorus)
  • Dissolved gas
  • Oxygen is added by plants, bacteria, and
    atmospheric diffusion

4
Ocean water is vertically structured
  • Temperature declines with depth
  • Heavier (colder saltier) water sinks
  • Light (warmer and less salty) water remains near
    the surface
  • Temperatures are more stable than land
    temperatures
  • Waters high heat capacity
  • It takes much more heat to warm water than air
  • Oceans regulate the earths climate
  • They absorb and release heat
  • Oceans surface circulation

5
Ocean water flows horizontally in currents
  • Currents are continuous, directed movements of
    ocean water generated by the forces acting upon
    it and they carry nutrients, heat and gasses.
  • Surface currents are driven by wind
  • Deep water currents are driven by density
    differences, heating and cooling, gravity, and
    wind
  • Pole-moving currents are warm water currents that
    move from the equator toward the north or south
    pole

6
Major Currents
7
Surface winds and heating create vertical
currents
  • Upwelling winds blow away from the coast and
    draws the vertical flow of cold, deep, nutrient
    rich water towards the surface
  • High primary productivity and lucrative fisheries
  • Downwellings winds blow and push warm water
    toward the coast colder, more dense water sinks

8
Salinity
  • The ocean is approximately 3-4 saline
  • 30-40 parts per trillion (ppt)
  • 1/1,000,000,000,000
  • 30 to 40 ng / 1 L
  • Saline indicates the presence of ions including
    both mono- and polyatomic
  • Chloride, sodium, sulfate, magnesium, calcium,
    potassium and bicarbonate

9
Global Salinity
10
Fishing Practices Regulations
  • Here fishy, fishy, fishy!

11
Economic Importance of Aquatic Ecosystems
  • The economic importance of aquatic diversity is
    the estimate of the value of their ecological
    services which is 21 trillion a year.
  • At least 3.5 billion people depend on the seas
    for their primary source of food this number
    could double to 7 billion in 2025.

12
  • Driftnets for schools of herring, sardines,
    mackerel, sharks
  • Longline fishing for tuna and swordfish
  • Trawling for pelagic fish and groundfish

13
Trawling
  • Bottom-trawling destroys communities
  • Likened to clear-cutting and strip mining

14
Fishing has industrialized
  • Factory fishing highly industrialized, huge
    vessels use powerful technologies to capture fish
    in huge volumes
  • Even process and freeze their catches while at
    sea

15
Fishing practices kill nontarget animals
  • By-catch the accidental capture of animals
  • Driftnetting drowns dolphins, turtles, and seals
  • Fish die from air exposure on deck
  • Banned or restricted by many nations
  • Longline fishing kills turtles, sharks, and
    albatrosses
  • 300,000 seabirds die each year

16
Emptying the oceans
  • We are placing unprecedented pressure on marine
    resources
  • Half the worlds marine fish populations are
    fully exploited
  • 25 of fish population are overexploited and
    heading to extinction
  • Total fisheries catch leveled off after 1998,
    despite increased fishing effort
  • It is predicted that populations of all ocean
    species we fish for today will collapse by the
    year 2048

17
We have long overfished
  • People began depleting sea life centuries ago
  • Some species hunted to extinction Stellers sea
    cow, Atlantic gray whale, Caribbean monk seal
  • Overharvesting of Chesapeake Bay oyster beds led
    to the collapse of its fishery, eutrophication,
    and hypoxia
  • Decreased sea turtle populations causes
    overgrowth of sea grass and can cause sea grass
    wasting disease

18
The total global fisheries catch has increased
19
Industrialized fishing depletes populations
  • Catch rates drop precipitously with
    industrialized fishing
  • 90 of large-bodied fish and sharks are
    eliminated within 10 years
  • Populations stabilize at 10 of their former
    levels
  • Marine communities may have been very different
    before industrial fishing
  • Removing animals at higher trophic levels allows
    prey to proliferate and change communities

20
Modern fishing fleets deplete marine life rapidly
  • Grand Banks cod have been fished for centuries
  • Catches more than doubled with immense industrial
    trawlers
  • Record-high catches lasted only 10 years

21
  • Oceans today contain only one-tenth of the
    large-bodied animals they once did

22
Several factors mask declines
  • Industrialized fishing has depleted stocks,
    global catch has remained stable for the past 20
    years
  • Fishing fleets travel longer distances to reach
    less-fished portions of the ocean
  • Fleets spend more time fishing and have been
    setting out more nets and lines, increasing
    effort to catch the same number of fish
  • Improved technologies faster ships, sonar
    mapping, satellite navigation, thermal sensing,
    aerial spotting
  • Data supplied to international monitoring
    agencies may be false

23
We are fishing down the food chain
  • Figures on total global catch do not relate the
    species, age, and size of fish harvested
  • As fishing increases, the size and age of fish
    caught decline
  • 10-year-old cod, once common, are now rare
  • As species become too rare to fish, fleets target
    other species
  • Shifting from large, desirable species to
    smaller, less desirable ones
  • Entails catching species at lower trophic levels

24
Consumer choices influence fishing practices
  • Buy ecolabeled seafood
  • Dolphin-safe tuna
  • Consumers dont know how their seafood was caught
  • Nonprofit organizations have devised guides for
    consumers
  • Best choices farmed catfish and caviar,
    sardines, Canadian snow crab
  • Avoid Atlantic cod, wild-caught caviar, sharks,
    farmed salmon

25
Central Case collapse of the cod fisheries
  • No fish has more impact on human civilization
    than the Atlantic cod
  • Eastern Canadians and U.S. fishermen have fished
    for cod for centuries
  • Large ships and technology have destroyed the cod
    fishery
  • Even protected stocks are not recovering

26
Cod are groundfish
  • They live or feed along the bottom
  • Halibut, pollock, flounder
  • Cod eat small fish and invertebrates
  • They grow to 60-70 cm long and can live 20 years
  • Inhabit cool waters on both sides of the Atlantic
  • There are 24 stocks (populations) of cod

27
To Protect and Serve
  • We can protect and sustain marine biodiversity by
    using laws, international treaties, and
    education.
  • First identify and protect species that are
    endangered and/or threatened.
  • Clean up aquatic environments

28
Why is it so hard?
  • 1. Our human footprint is so large and is
    growing exponentially
  • 2. Damage to the ocean is not usually visible to
    the naked eye
  • 3. People view the ocean as an in-exhaustable
    resource
  • 4. The ocean is outside the legal jurisdiction
    of any one country.

29
We can protect areas in the ocean
  • Marine protected areas (MPAs) established along
    the coastlines of developed countries
  • Still allow fishing or other extractive
    activities
  • Marine reserves areas where fishing is
    prohibited (less than 0.3 of the ocean)
  • Leave ecosystems intact, without human
    interference
  • Improve fisheries, because young fish will
    disperse into surrounding areas

30
Reserves work for both fish and fisheries
  • Found that reserves do work as win-win solutions
  • Overall benefits included
  • Boosting fish biomass
  • Boosting total catch
  • Increasing fish size
  • Benefits inside reserve boundaries included
  • Rapid and long-term increases in marine organisms
    and decrease mortality and habitat destruction

31
How should reserves be designed?
  • 20-50 of the ocean should be protected in
    no-take reserves
  • How large?
  • How many?
  • Where?
  • Involving fishers is crucial fisheries in coming
    with these answers

32
Areas outside reserves also benefit
  • Benefits included
  • A spillover effect when individuals of
    protected species spread outside reserves
  • Larvae of species protected within reserves seed
    the seas outside reserves
  • Improved fishing and ecotourism

33
Marine Management
  • There are a number of ways to manage marine
    fisheries more sustainably and protect marine
    biodiversity.
  • A country has jurisdiction over the ocean up to
    200 miles from its coast.
  • Rather than protecting the marine environment,
    countries tend to promote fishing.

34
Integrated Coastal Management
  • Integrated Coastal Management (ICM) is an idea or
    management policy based on a community approach.
  • Private sector as well as the public sector work
    together to identify problems and share the
    burden of restoration or management.

35
Managing Fisheries
  • Fishery Regulations
  • set catch limits well beyond maximum sustainable
    yield
  • improve monitoring and enforcement
  • Economic Approach
  • reduce or eliminate subsidies
  • charge fees for harvesting fish and shellfish
    from public areas
  • certify sustainable fisheries

36
More Management
  • Protected Areas
  • establish no-fishing zones
  • establish more reserves
  • rely on integrated coastal management
  • Consumer Education
  • label sustainably harvested fish
  • educate about overfished and endangered species

37
Management (cont.)
  • Bycatch
  • streamline fishing techniques and tools
  • Aquaculture
  • restrict coastal locations for fish farms
  • control pollution (CWA)
  • depend on herbivorous fish species
  • Non-native Invasions
  • kill organisms in ship ballast water, filter
    ballast water or dump in open sea

38
Legislation Each group will discuss the event
and the impact
  • 1946 - International Convention of the Regulation
    of Whaling
  • 1970 - US ban on whaling and importation of whale
    products
  • 1972 - US Marine Mammel Protection Act
  • 1973 - US Endangered Species Act
  • 1975 - Convention on International Trade in
    Endangered Species (CITES)
  • 1979 - Global Treaty on Migratory Species

39
Revamping Ocean Policy
  • Two recent studies called for an overhaul of U.S.
    ocean policy and management.
  • Develop unified national policy.
  • Double federal budget for ocean research.
  • Centralize the National Oceans Agency.
  • Set up network of marine reserves.
  • Reorient fisheries management towards ecosystem
    function.
  • Increase public awareness.

40
MANAGING AND SUSTAINING MARINE FISHERIES
  • There are a number of ways to manage marine
    fisheries more sustainably and protect marine
    biodiversity.
  • Some fishing communities regulate fish harvests
    on their own and others work with the government
    to regulate them.
  • Modern fisheries have weakened the ability of
    many coastal communities to regulate their own
    fisheries.

41
Solutions
Managing Fisheries
Fishery Regulations Set catch limits well below
the maximum sustainable yield Improve monitoring
and enforcement of regulations
Bycatch Use wide-meshed nets to allow escape of
smaller fish Use net escape devices for sea
birds and sea turtles Ban throwing edible and
marketable fish back into the sea
Economic Approaches Sharply reduce or eliminate
fishing subsidies Charge fees for harvesting
fish and shellfish from publicly owned offshore
waters Certify sustainable fisheries
Aquaculture Restrict coastal locations for fish
farms Control pollution more strictly Depend
more on herbivorous fish species
Protected Areas Establish no-fishing
areas Establish more marine protected
areas Rely more on integrated coastal management
Nonnative Invasions Kill organisms in ship
ballast water Filter organisms from ship ballast
water Dump ballast water far at sea and replace
with deep-sea water
Consumer Information Label sustainably harvested
fish Publicize overfished and threatened species
Fig. 12-7, p. 261
42
The graph to the right shows the decline in the
catch of groundfish (such as cod, haddock, and
flounder) from Georges Bank from 1965 to 1995.
This decline in the fish harvest resulted in the
closure of large portions of the fishery.
  1. Identify the five-year period during which the
    greatest rate of decline in the fish harvest took
    place. For that five-year period, calculate the
    rate of decline in the fish harvest, in metric
    tons per year. Show clearly how you determined
    your answer.

43
  • Choose any TWO commercial fishing practices from
    the list below. For each of your choices,
    describe the practice and explain the role it
    plays in the depletion of marine organisms.
  •  Bottom trawling
  • Long-line fishing
  • Using drift nets/gill nets/purse seines
  • Using sonar
  •  Identify one international regulation or United
    States federal law that applies to the harvesting
    of marine food resources and explain how that
    regulation or law helps to manage marine species.
  •  The oceans of the world are often referred to as
    a commons. Give an example of one other such
    commons, explain how human activities affect that
    commons, and suggest one practical method for
    managing that commons.

44
Using the APES Rubric
  • Lets score your response
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