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Chapter 13 Sustaining Aquatic Biodiversity

Chapter 13 Sustaining Aquatic Biodiversity. What we get from aquatic ecosystems. Ecosystem services – list? Economic benefits – list?. Percent of various groups of organisms that are threatened with premature extinction due to human activities. 34% (51% of freshwater species). Fish. 24%.

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Chapter 13 Sustaining Aquatic Biodiversity

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  1. Chapter 13Sustaining Aquatic Biodiversity

  2. What we get from aquatic ecosystems Ecosystem services – list? Economic benefits – list?

  3. Percent of various groups of organisms that are threatened with premature extinction due to human activities 34% (51% of freshwater species) Fish 24% Mammals 20% Reptiles 14% Plants 12% Birds

  4. Freshwater threats • Overfishing • Pollution • Loss of wetlands • Dams • Invasive species • Overuse of water – reduction in flow or supply

  5. Freshwater Conservation • Need to protect wetlands from development – federal permit required to fill or destroy wetlands of at least 3 acres • Mitigation banking – destruction of existing wetlands is allowed as long as an equal area of the same type of wetland is created or restored, used as a last resort;

  6. Artificial wetlands How well do you think this works compared to leaving the wetlands intact?

  7. Freshwater Conservation • Salmon fisheries • Fish hatcheries cultivate and release young salmon • Undoing the dam-age – • removing some dams, providing fish ladders

  8. Human capture Fish change form Salmon processing plant Fish enter rivers and head for spawning areas To hatchery In the fall spawning salmon deposit eggs in gravel nests and die Modified Life Cycle Eggs are taken from adult females and fertilized with sperm “milked” from males Grow to maturity in Pacific Ocean in 1-2 years Fry hatch in the spring... Normal Life Cycle Eggs and young are cared for in the hatchery And grow in the stream for 1-2 years Grow to smolt and enter the ocean... Fingerlings are released into river Fingerlings migrate downstream

  9. Sipsey Fork of the Black Warrior River Freshwater Conservation Government intervention • Clean Water Act (Chapter 22) • Wild and Scenic Rivers Act, 1968 • In AL, Sipsey Fork of the Black Warrior River

  10. Freshwater Conservation Private intervention – example: • Freshwater Land Trust – nonprofit organization • Their mission is “the acquisition and stewardship of lands that enhance water quality and preserve open space” • http://www.freshwaterlandtrust.org/

  11. Freshwater Conservation: A Case Study • Florida Everglades – threatened due to development that diverted and polluted water that maintained the wetlands • Large urban areas developed on the Atlantic coast (Miami) • Kissimmee River was converted into a straight channel in 1960s by U.S. Army Corps of Engineers, canals built from Lake Okeechobee to get water to cities • Sugar cane and other crops are grown where wetlands used to be, runoff of phosphorus a problem

  12. Canals have diverted flow of freshwater from its natural course to the cities

  13. Freshwater Conservation: A Case Study • Solutions? • Established the Florida Everglades as a National Park – but the “plumbing” upstream was already compromised • Huge restoration project has been negotiated to restore portions of the Kissimmee River, remove levees and canals, return farmlands to wetlands, reduce diversion of water for urban areas, capture water that would go out to sea and return it to the Everglades by huge pumping systems • Too little, too late?

  14. Marine Ecosystems Threats • Overharvesting of fish, shellfish, oysters, whales • Incidental loss of species due to industrialized fishing techniques • Pollution – sediment, chemicals, nutrients, garbage (Chapter 22) • Urban development on coasts threatens estuaries, coral reefs

  15. Using marine resources: Jurisdiction? International law: • Country’s sovereignty extends 12 miles off coast • Exclusive Economic Zone (EEZ) out to 200 miles • Nations of the world have jurisdiction over 36% of ocean’s surface and 90% of its fish stocks • Many countries have not used these laws to protect their resources and many have declined • Outside of these areas, anyone can fish (remember tragedy of the commons?)

  16. U.S. EEZ

  17. Loss of ocean fisheries • We are placing unprecedented pressure on marine resources • Half the world’s 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

  18. Quote from William Herrington Transactions of the American Fisheries Society "It is only in the last few years when the fishing fleet has suffered from a marked scarcity of haddock that the folly of (the) belief in the inexhaustibility of nature has become potent". Date: 1932 People have been overharvesting for a long time! We shift from one species to another as one is depleted.

  19. The total global fisheries catch has increased

  20. 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

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

  22. Decline of ocean fisheries: cod • No fish has had 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 • Prey may now be competing with, and eating, young cod

  23. 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

  24. Industrialized fishing changes fish communities • 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

  25. Oceans today contain only one-tenth of the large-bodied animals they once did

  26. Fishing down the food chain • 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 • Example: cod  haddock  pollock (fish sticks) • Entails catching species at lower trophic levels

  27. Global marine 3.5 3.4 3.3 3.2 3.1 Mean trophic level 3.0 2.9 2.8 2.7 2.6 2.5 1950 1960 1970 1980 1990 Year

  28. Global freshwater 3.5 3.4 3.3 3.2 3.1 Back to freshwater fish for one slide: Drop in mean trophic level even more pronounced in populations of freshwater fish 3.0 Mean trophic level 2.9 2.8 2.7 2.6 2.5 1950 1960 1970 1980 1990 Year

  29. 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 • Bottom-trawling destroys communities • Likened to clear-cutting and strip mining

  30. Conservation efforts: ecosystem approach • Shift away from species and toward the larger ecosystem • Consider the impacts of fishing on habitat and species interactions • Set aside areas of oceans free from human interference

  31. Conservation efforts: ecosystem approach • IUCN – establishes Marine Protected Areas (MPA) • There are 1300 worldwide • Areas are protected but fishing and other resource extraction may still be allowed • Levels of protection • Uniform Multiple-Use • Zoned Multiple-Use • Zoned Multiple-Use With No-Take Area(s) • No-Take • No Impact • No Access

  32. Conservation efforts: ecosystem approach • Marine reserves = areas where fishing is prohibited • Leave ecosystems intact, without human interference • Improve fisheries, because young fish will disperse into surrounding areas • Many commercial, recreation fishers, and businesses do not support reserves

  33. Conservation efforts: ecosystem approach • 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 • Decrease mortality and habitat destruction • Lessen the likelihood of extirpation of species

  34. Conservation efforts: ecosystem approach • Benefits outside the marine reserve 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

  35. Conservation efforts: ecosystem approach Integrated coastal management Definition: “process for the management of the coast using an integrated approach, regarding all aspects of the coastal zone, including geographical and political boundaries, in an attempt to achieve sustainability” (Wikipedia)

  36. Conservation efforts: ecosystem approach Integrated coastal management – what needs to be integrated? • Different levels of government • Land and water zones • Economic sectors that operate there (fisheries, tourism, port companies) • Nations • Disciplines (scientific, cultural, political, etc.)

  37. Conservation efforts: ecosystem approach US Marine Mammal Protection Act, 1972 – first legislation to call for an ecosystem approach to species protection

  38. Conservation: Species approach Laws/Treaties: • CITES • Endangered Species Act

  39. Conservation: Species approach Case Study: Whaling People have used whales for food and oil since 3000 BC Whales’ large size, slow reproduction have made them vulnerable to extinction

  40. 1946 International Whaling Commission was started to regulate whaling worldwide, membership is voluntary 1986 IWC banned commercial whaling – allows it for scientific research and native people Some countries continue to carry out whaling: Japan, Norway, Iceland

  41. Conservation: Species approach Sea turtles – all species are endangered or threatened • TED www.youtube.com/watch?v=j9olIycYg0c • Protection of nesting areas on the beach • On AL coasts, top to bottom pictures: Loggerhead, Green, and Kemp’s Ridley

  42. Conservation: Marketplace Approach Summer flounder – quotas were set for commercial and recreational fishing; has been successful in increasing population of adult fish

  43. Conservation: Marketplace Approach • Individual transfer quotas – fishermen are allowed a total allowable catch (TAC) which may be traded; usually species-specific; has been done in New Zealand, Canada and the Netherlands; one study shows it has been helpful in promoting sustainability

  44. Conservation: Marketplace Approach Use optimum sustainable yield instead of maximum sustainable yield • MSY was used in the past to determine how much fish to catch • Definition: maximum number of fish that could be harvested annually without causing a population drop • Has not worked“However, [MSY] has been widely criticized as ignoring several key factors involved in fisheries management and has led to the devastating collapse of many fisheries. As a simple calculation, it ignores the size and age of the animal being taken, its reproductive status, and it focuses solely on the species in question, ignoring the damage to the ecosystem caused by the designated level of exploitation and the issue of bycatch. Among conservation biologists it is widely regarded as dangerous and misused.” • Better to use optimum sustainable yield – lower amount harvested than with MSY

  45. Conservation: marketplace approach Educate the consumer • Buy ecolabeled seafood • Dolphin-safe tuna • Consumers don’t 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

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