Chapter 11: Sustaining Aquatic Biodiversity
Lake Victoria
 1980 – 500 cichlid species
o Small; eats detritus, algae, zooplankton
 Nile perch introduced (large predatory)
o Large scale fishing wipes out small fisherman
o Forests cut for firewood to smoke perch
 Algal blooms
o Deforestation, nutrient & sewage runoff
o 200 cichlid extinct (more algae)
Aquatic Biodiversity
 Biodiversity higher
o Near coast (vs. open sea)
o In bottom region of ocean (vs. surface region)
 Highest biodiversity
o Coral reefs
o Estuaries
o Deep-ocean floor
Habitat Loss & Degradation
 90% oceanic fish spawn in reefs, coastal wetlands, & rivers
o Disappear 2-10x faster than tropical forest
 Ocean bottom trawling
o Move across 150x more ocean floor than clear cut forests
 Dams on rivers
o Slows water flow, sediments, fish runs, change water temps
 Freshwater withdrawal
o Mostly for agriculture
 51% freshwater fishes threatened
Invasive Species
 84% coastal waters colonized by invasives
 Water hyacinth – blocks sunlight & lowers oxygen
 Asian swamp eel – came to Florida from aquarium dumping
 Purple loosestrife – from European wetlands; can make 2.5 mil. seeds/yr
Population & Pollution
 2020 – predicted 80% world’s pop. will live near/along coast
 ~4% of ocean unaffected
o Humans have doubled N going into oceans; same w/ P
o Pacific trash vortex
o Urban & industrial toxic runoff
Climate Change
 Average sea level up 4-8 in over past 100 yrs (1-5 ft by 2100)
o Melting glaciers & ice caps
o Thermal expansion of water
 Destroys reefs, islands, coastal wetlands, FL, LA, NYC
 Increases acidity & GHGs
Overexploitation
 Atlantic cod fisheries devastated from trawling
o Cod fishing closed
o 99% large sharks gone
o Rays & skates boom; now no scallops
 90% large predatory fish gone
 Fishing Methods
o Trawling – Net size = 12 jumbo jets
o Longline fishing – 80 mile long lines
o Drift-net fishing – 50 feet deep; 40 miles long
Protective Laws
 CITES – Convention in International Trade in Endangered Species
 ESA – Endangered Species Act
 CBD – Convention on Biological Diversity
o U.S. – signed; not ratified
 Conservation of Migratory Species (CMS)
o 1979 Global Treaty on Migratory Species
o Aims to conserve terrestrial, marine, & avian migratory species throughout their range
 U.S. Marine Mammal Protection Act (MMPA) of 1972
o Prohibits taking, importing, exporting, & selling of marine mammals (or parts)
 U.S. Whale Conservation & Protection Act of 1976
o Work to protect & conserve whales
o Study whale’s & habitats to learn how better to help
o Order Cetacea
 Whales, dolphins, & porpoises
 Toothed whale – teeth for biting & chewing prey
 Baleen whale – has baleen (whalebone) to filter plankton
Marine Protected Areas
 Ocean areas partially protected from human activities
o 4,000 in world; 200 in U.S.
o Most allow trawling, dredging, mining
 Marine Reserves
o Ocean areas put off-limits to human activities
 Core area – no human disturbance
 Outer area – less harmful recreation & shipping
o Score One for the Bush man!
 2006 – 2nd largest protected reserve; Northwest of Hawaii; Size of Montana
 Supports…
 7,000 marine species
 Hawaiian Monk Seal
 Green Sea Turtle
 Protection Works
o Full protection; w/in 2-4 yrs…
 Populations double
 Fish size grows by a third
 Reproduction triples
 Biodiversity up a fourth
 Helps nearby areas as fish larvae spread
Marine Solutions
 Fishing Regulations
o Set catch limits below maximum sustainable yield
o Improve monitoring & enforcement
 Economic Approaches
o Get rid of fishing subsidies
o Certify sustainable fisheries
o Charge fees for harvesting marine life from offshore waters
 Bycatch
o Wide-meshed nets (small fish)
o Net escape devices (turtles)
o Ban dumping of marketable fish
 Aquaculture
o Restrict fish farm locations
o Control pollution more strictly
o Depend on herbivorous fish

Consumer Info
o Label sustainable harvested fish
o Publicize overfished & threatened
 Nonnative Invasions
o Kill or filter ballast water organisms
o Dump ballast water in deep sea
Wetlands
 Highly productive, flood & erosion control, natural filter (water quality)
 U.S. – ½ of orig. wetlands
o Drained & filled for crops, cities, roads, less disease minerals, oil, natural gas
 Mitigation Banking
o Destroy wetlands if you create or restore equal area of same type
 Fail to meet standards
 Don’t do same eco services
 Not monitored
o Build first; then destroy
 Precautionary Principle?
 Florida Everglades
o aka River of Grass
o 60 miles wide & knee deep
o Lake Okeechobee to FL Bay
 Now – less than ½ size
o Water diversion
 Glades dried out
 FL Bay saltier
o Comprehensive Everglades Restoration Plan (CERP)
 Restore curving flow of Kissimmee River
 Remove many canals & levees to allow Lake Okeechobee to feed south
 Flood 240 sq. km farmland to create artificial marshes
 Create reservoirs & underground water storage areas
 Great Lakes
o Combined; largest fresh water body
o Invaded by 162 nonnatives
 Sea Lamprey
 Zebra Mussel
 Cost U.S./Canada $140 mil./yr
 Quagga Mussel
 Asian Carp? (Mississippi River)
 Sea Lamprey
 Columbia River
o Runs thru Canada, Wash, Oreg
o 14 major hydroelectric dams
 200+ in basin
o Wild Salmon
 Down 94%
 9 species threatened/endangered
 Since 1980; $3 bil. spent
Freshwater Protection
 Save watershed areas
 Remove dams to restore current
 Protected by law…
o Wild River – inaccessible
o Scenic River – great scenic value
o No widening, straightening, dredging, filling, & damming