Sustaining Aquatic BiodiversityCh. 11, part 1

Biodiversity is highest at: Coral reefs, estuaries, and deep

ocean Near coast since more producers

there At bottom since more food and

habitats

Threats to Aquatic Biodiversity

HIPPCO

H = habitat loss & degradation Mostly in coral reefs and

mangroves used by humans

Damage done by trawling

51% of freshwater species threatened with extinction - the most of any group

I - invasive species 84% of coastal

waters invaded Causes 2/3 of

all fish extinctions

Cost USA ~$14 million/year

Often arrive in ballast waterWater

hyacinth in Lake Victoria

P = population growth By 2020 - 80% of world’s people

will live in coastal cities

Lebanon

Rio de Janeiro

P = pollution Just 4% of world’s oceans

unaffected by pollution Most pollution comes from

land activities Pesticides/fertilizers Plastics Oil

C = climate change Causes sea levels to rise

CO2 “sinks” coral reefs, swamps, wetlandsStore CO2 – out of air

Puts coastal cities underwater

O = overfishing Industrialized fishing

depletes populations quickly

Fishprint - area of ocean needed to sustain our fish consumption Currently at 157% Commercial

extinction - no longer profitable to fish since so few left

Bycatch

Fig. 11-7, p. 256

Fish farming in cage

Spotter airplaneTrawler fishing

Sonar Purse-seine fishing

Long line fishing

lines with hooks

Deep sea aquaculture cage

Drift-net fishing

Float Buoy

Fish caught by gills

Stepped Art

The numbers 35% of marine species 71% of freshwater species May go extinct in our lifetime The MOST AFFECTED GROUP of

all species by humans

Dolphin and whale slaughter by Japan

Shark finning

What we can do to help Laws and treaties

Difficult to enforce Most of ocean is not owned by

anyone - tragedy of the commons Economic Incentives - tourism

Long term gain vs. short term profit

Some laws/treaties you should know

CITES - 1975 - trade in endangered species Global Treaty on Migratory Species - 1979 US Marine Mammal Protection Act - 1972 US Endangered Species Act - 1973 US Whale Conservation and Protection Act

- 1976 International Convention on Biological

Diversity - 1995

Who owns the seas? A country owns from its coast to

200 miles out Beyond is the high seas -

international laws and treaties apply here - but who enforces them?

Marine Sanctuaries & Marine Protected Areas (MPAs)

4000 worldwide; 200 in US waters

Offer only partial protection Most still allow dredging,

trawler fishing, drilling, etc CA is leading

Most extensive network of MPAs with most restrictions

The Ecosystem Approach Establish marine reserves all over, especially

coastal areas They work! - in 2-4 years see marked

improvement Increase tourism Help fishing industry

Only .1% of ocean is protected (so we have reserved 99.9% for us)

Costs $12-14 billion/year to make reserves

What can you do? Purchase only sustainably

harvested seafood (WalMart) Support businesses that develop

and use resources sustainably Ecotourism NO Shell shops

thanks

Fisheries Management Step 1: figure out what we have out there! Step 2: switch from old model - Max.

sustained yield - to new model - optimum sustained yield (take species interactions into account)

Step 3: don’t forget the Precautionary Principle

What’s actually happening1. Comanagement - local

communities regulate coastal fishing, government regulates offshore

2. Government subsidies - gov’t (i.e. taxes) support fisheries to keep them in business; encourage expansion (uh…)

3. Individual transfer rights (ITRs) Gov’t gives each vessel of % of the total allowable catch

for the year; companies can trade with each other Problems:

Fishing co. “owns” waters, but public still responsible for cleaning up messes

Harder for small operations to compete Too many ITRs given out - so still overfishing

Successes 1995, Alaskan halibut, fishing season went from 2 days to

260

End part 1