De Hoop Nature Reserve Western Cape, South Africa. Shell midden that is over 100,000 years old

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1 Humans & the Sea

2 De Hoop Nature Reserve Western Cape, South Africa Shell midden that is over 100,000 years old

3 Shell fish hooks of South Coastal Californians (3000 BC-AD 900)

4 7 billion Human Population

5 NASA composite satellite image showing lights at night around the world (November 27, 2000). Notice the abundance of lights along coastal areas, especially eastern Australia, the Saudi Arabian peninsula and the Americas. Source: StormCenter Communications

6 U. S. Coastal population growth continues to outpace non-coastal growth. Source: StormCenter Communications

7 Food From The Sea / Fisheries Majority of harvest consist of fishes (finfish) = 84% = 16% of animal protein consumed worldwide Also harvest molluscs & crustaceans (shellfish)

8 Worldwide Catches Then & Now

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12 Human Effects on Environment

13 Human Impact on Marine Environments

14 Habitat Destruction Estuaries & Salt Marshes Dredging, landfilling, damming, marinas & harbors 1/3 of all U.S. estuaries are gone 67% in CA are gone

15 Habitat Destruction Mangroves Dredging, landfilling, damming, development, shrimp farms Mangroves once covered 75% of tropical coastlines, ½ have been destroyed

16 Shrimp Farm in Mangrove Forest

17 Habitat Destruction Coral Reefs Pollution, overfishing, sedimentation, global warming More than ¼ of the world s coral reefs have been lost high risk

18 Threats to Coral Reefs

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20 Human Effects on Environment

21 Biotic Pollution introduction of foreign or exotic species that do not naturally occur in an area How Do Exotic Species Become Introduced? Transported in ballast water, with seafood (oysters), aquarium trade

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24 Biotic Pollution introduction of foreign or exotic species that do not naturally occur in an area Why can they be so harmful to ecosystems? - Often upsets balance among native organisms - May compete with native organisms for food, habitat, etc - May prey upon natives

25 Caulerpa taxifolia

26 Human Effects on Environment

27 Pollution Increased nutrients from sewage, fertilizers, etc.

28 Pollution oil, toxic chemicals & metals (pesticides, mercury) = biological magnification

29 The L.A. River carries enough trash each year to fill the Rose Bowl two stories deep

30 Human Effects on Environment

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32 Factory Ships processed & frozen on ship

33 Global Climate Change

34 Global Climate Change Affects temp. & UV sensitive organisms Decrease in phytoplankton (base of the food chain) Phytoplankton levels in the Northern Pacific Ocean dropped more than 30% since the 1980s.

35 Coral Bleaching occurs when corals expel zooxanthellae

36 Many marine organisms are made up of limestone shells and skeletons!

37 Different species of coccolithophores that have been exposed to differing level of acidity. The top row shows normal sea water ph levels, the bottom row shows development in lower than normal ph levels. Scale bars are 1 µm. Adapted by permission from Macmillan Publishers Ltd: Nature Publishing Group, Riebesell, U., et

38 Different species of coccolithophores that have been exposed to differing level of acidity. The top row shows normal sea water ph levels, the bottom row shows development in lower than normal ph levels. Scale bars are 1 µm. Adapted by permission from Macmillan Publishers Ltd: Nature Publishing Group, Riebesell, U., et

39 What could happen to marine food webs and ecosystems?

40 What activities release a lot of carbon dioxide (CO 2 )? What can you do to stop ocean acidification?

41 Aquaculture the rearing of aquatic organisms (fresh and marine waters) - U.S. aquaculture = $900 mil/year industry - World aquaculture production in 1996 = 26.5 mill tons. Growing % / year - 1 out of every 4 fish destined for human consumption comes from fish farms

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43 Human Effects on Environment

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