Main biodiverse places 1. Coral reefs, estuaries, and deep-ocean floor 2. Biodiversity is greatest nearest coastal areas—more producers and habitats here (estuaries, mangroves, salt water marshes) 3. Bottom is more diverse than surface b/c of variety of habitats

Why is aquatic ecosystems important? Provides: Recreation, food (economic) Cycles nutrients for aquatic/terrestrial species Reduces forces of storms (mangroves, barrier islands, marshes)

Greatest threats to biodiversity HIPPCO Habitat destruction Invasive species Pollution Population/resource use growth Climate change Overexploitation THE SINGLE GREATEST THREAT: Habitat destruction

Trawlers Huge source of habitat destruction –coral reefs and other sea bottom habitats Huge nets carried by weighted chains and steel plates Like underwater bulldozers Trawling Video: Bottom TrawlingBottom Trawling

Trawling

Fresh Water problems Dams and water withdrawl (usually for agriculture) Disrupts natural water flow and kills biodiversity Stops flows of natural sediments—corrosion Natural migration of animals hindered

HIPPCO-- Invasives Cause extinction of native species by outcompeting them for resources—food, habitat No natural predators/competitors Blamed for 2/3 fish extinctions from Many come from ballast water from large container ships

HIPPCO (Invasives)— Nile perch Algal blooms caused increase of population of cichlids in Lake Victoria

Nile perch purposely introduced to stimulate fishing industry Cichlid pop. boomed– so did perch Some 200 species of fish now eradicated from lake b/c of perch

Snakeheads dyn/content/video/2007/07/06/VI htm l dyn/content/video/2007/07/06/VI htm l Sport fishing video

HIPPCO Population growth By % of worlds pop live ON/NEAR coastal waterways This increases pollution run-off Destroys habitat

HIPPCO Pollution 80% of all ocean pollution comes from land based activities Run-off on nitrogen, phosphorus cause eutrophication of marine/freshwater ecoystems Leads to algal blooms, fish die-off, ecosystem collapses Physical plastic waste, dumping, litter—animals can eat such particles, become entangled in, become poisoned/killed

Sea turtles Staple to sea turtles’ diet— jelly fish……. Looks strikingly similar to a plastic bag

Great Pacific Garbage Patch

Albatross

Litter from beach kills some 1 million birds and 100,000 mammals/sea turtles

HIPPCO Climate change Will cause sea-level to rise—as high as 5 feet by 2100 Cause flooding of prime coastal wetlands—very important biodiverse ecosystems Mangroves, estuaries, wetlands…….

Mangrove video Slideshow on Mangroves

HIPPCO Overexploitation (overfishing) Human demand for seafood—WAY ABOVE sustainable levels of natural fisheries All these fish are connected—over fishing one species will impact on ENTIRE ECOSYSTEM Case Study– Newfoundland– over fished Atlantic Cod Fishery collapsed and closed 20,000 fisherman/factory workers lost jobs People began fishing sharks—collapsed shark fishery Skates/rays once eaten by sharks now boomed in population Wiped out nearly all bay scallops

34% of marine fish, 71% of freshwater fish face extinction IN OUR LIFETIMES Fisherman only fish a few species of profitable fish, but modern day fishing techniques kill huuggeeee numbers of other species Bycatch– any species of animal not targeting for fishing (i.e.– rays, sharks, turtles, dolphins)

Overfishing Techniques 1. Bottom trawling 2. Long-lining 3. Driftnets

Longlining

Albatross

Longline clip Long lining Coral reef overfishing Japanese Fish market BBC

Trawling

ig. 12-A, p. 255 Fish farming in cage Trawler fishing Spotter airplane Sonar Trawl flap Trawl lines Purse-seine fishing Trawl bag Fish school Drift-net fishing Long line fishing Lines with hooks Fish caught by gills Deep sea aquaculture cage Float Buoy

Numbers to KNOW 50% of current fisheries are exploited 20% nearly overexploited 10% depleted ALL DUE TO OVERFISHING

How do we stop losing this biodiversity (from overfishing) Aquaculture- fish “farming” Raising fish in underwater cages/ponds for harvest commercially Concerns that if fish escape cages, could lead to introduce new diseases to native gene pool

Set laws, boundaries, limits International laws/treaties have helped cut down on overfishing, illegally pirating of fish/whales/turtles/dolphin But, not enough to maintain sustainable levels

Different approaches Laws/treaties International Whale Commission Anadromous Fish Conservation Act (1965) Marine Mammal Protection Act (1976) Endangered Species Act (1972) Magnuson Fishery Conservation and Management Act (1973) International The United Nations Agreement for the Implementation of the Provisions of the United Nations Conventions on the Law of the Sea (1982) CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora) Economic incentives

Economic Incentives Some places make more money through tourism of sea life (turtles, whales, etc) rather than illegal poaching

Create ecosystem sustainability Some countries using ecosystem approach to sustain marine life Plan is to protect entire area/ecosystem rather than just one species of animal

How can we maintain fisheries? Community cooperation Some fisheries (Norwegian cod) have been maintained through communication with fisherman/coastal community But, becoming harder and harder due to international fishing fleets Consumer choice Some fish species are more sustainable than others Some companies indicate where fish was caught

How can we sustain wetlands? US lost half of coastal wetlands since 1900– think about GoogleEarth photo from previous slide Destroyed for roads, cities, buildings Filled in, covered for agriculture Wetlands are natural filters and home to many different animals

Laws can be used…… US law allows any wetland destroyed or covered, as long as area of wetlands same size is restored/created

How can we sustain fresh water ecosystems? HIPPCO has taken a verrrry severe toll on freshwater ecosystems Why?

Great Lakes Attacked by 162 invasive species– zebra mussel, sea lamprey are the worst Cost of controlling invasives is huge! US/Canada spends $15 million a year to spray chemicals on lamprey breeding grounds Zebra mussel—clogs pipes, drains to powerplants and city water supplies Cost--$140 million

Protect Watersheds! Through laws, economic incentives, restoration efforts! Prevent overfishing, encourage land conservation (designation of parks/reserves).