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Objectives Describe HIPPCO List the threats to aquatic life Agenda Warm-up – 5 HIPPCO notes – 10 Strange Days – 10 HIPPCO Notes – 10 Computer Lab. Warm-up What is the epilimnion ? Hypolimnion ? How does the temperature of each change with season?. APES Chapter 11: Day 1. Homework:
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Objectives Describe HIPPCO List the threats to aquatic life Agenda Warm-up – 5 HIPPCO notes – 10 Strange Days – 10 HIPPCO Notes – 10 Computer Lab Warm-up What is the epilimnion? Hypolimnion? How does the temperature of each change with season? APES Chapter 11: Day 1 Homework: Chapter 11 Objectives
Sustaining Aquatic Biodiversity Chapter 11
Core Case Study: A Biological Roller Coaster Ride in Lake Victoria • Shallow lake in East Africa • 500 species of fish found nowhere else • Nile perch: deliberately introduced • Loss of biodiversity and cichlids (“SIK-lids”) • Increased poverty and malnutrition • Depleted forests (to preserve fish oil)
Core Case Study: A Biological Roller Coaster Ride in Lake Victoria • Frequent algal blooms • Nutrient runoff • Spills of untreated sewage • Less algae-eating cichlids
11.1 What are the major threats to aquatic biodiversity?
We Have Much to Learn about Aquatic Biodiversity • Greatest marine biodiversity • Coral reefs • Estuaries • Deep-ocean floor • Biodiversity is higher • Near the coast than in the open sea • In the bottom region of the ocean than the surface region We have explored 5% of the global ocean!
Human Activities Are Destroying and Degrading Aquatic Habitats • Habitat loss and degradation • Marine • Coastal pollution and tourism • Ocean floor: effect of trawlers • Freshwater • Dams • Excessive water withdrawal H I PPCO
Science Focus: Protecting and Restoring Mangroves • Protect and restore mangroves • Reduce the impact of rising sea levels • Protect against tropical storms and tsunamis • Cheaper than building concrete sea walls • Mangrove forests in Indonesia
Natural Capital Degradation: Area of Ocean Bottom Before and After a Trawler
Invasive Species Are Degrading Aquatic Biodiversity • Invasive species • Threaten native species • Disrupt and degrade whole ecosystems • 84% of world’s coasts are being colonized by invasive species H I PPCO
Invasive Species Are Degrading Aquatic Biodiversity • Three examples • Water hyacinth: Lake Victoria (East Africa) • Asian swamp eel: waterways of south Florida • Purple loosestrife: indigenous to Europe • Treating with natural predators—a weevil species and a leaf-eating beetle—Will it work? H I PPCO
Science Focus: How Carp Have Muddied Some Waters • Lake Wingra, Wisconsin (U.S.): eutrophic • Contains invasive species • Purple loosestrife and the common carp increase turbidity • Dr. Richard Lathrop • Removed carp from an area of the lake • This area appeared to recover • More photosynthesis
Population Growth and Pollution Can Reduce Aquatic Biodiversity • Nitrates and phosphates mainly from fertilizers enter water • Leads to eutrophication • Toxic pollutants from industrial and urban areas H I PPCO
Population Growth and Pollution Can Reduce Aquatic Biodiversity • Nitrates and phosphates mainly from fertilizers enter water • Leads to eutrophication • Toxic pollutants from industrial and urban areas H I PPCO
Climate Change Is a Growing Threat • Global warming: sea levels will rise and aquatic biodiversity is threatened • Coral reefs • Swamp some low-lying islands • Drown many highly productive coastal wetlands • New Orleans, Louisiana, and New York City H I PPCO
Video Clip • Strange Days on Planet Earth – Dirty Secrets • Bleaching the Reef
Overfishing and Extinction: Gone Fishing, Fish Gone • Marine and freshwater fish • Threatened with extinction by human activities more than any other group of species • Modern industry can cause 80% depletion of target species in 10-15 years • Commercial extinction – occurs when it is no longer profitable to continue fishing an affected species H I PPCO
Overfishing and Extinction: Gone Fishing, Fish Gone • Bycatch – nontarget species caught in fishing • Comprises almost 1/3 of world’s annual fish catch H I PPCO
Case Study: Industrial Fish Harvesting Methods • Trawler fishing • Dragging funnel shaped nets held open at the neck along ocean bottom • Weighted down with chains or metal plates • Newer nets are large enough to swallow 12 jumbo jet planes! • Catch shrimp, cod, flounder, and scallops
Case Study: Industrial Fish Harvesting Methods • Purse-seine fishing • Spotter plane locates school of fish • Vessel encloses it with large net • Catch surface dwelling species (tuna, mackerel, anchovies, and herring) • Dolphins frequent bycatch
Case Study: Industrial Fish Harvesting Methods • Longlining • Putting out lines up to 80 miles long with baited hooks • Adjustable depths • Frequent bycatch (sea turtles and seabirds)
Case Study: Industrial Fish Harvesting Methods • Drift-net fishing • Fish caught by huge drifting nets • Hang as deep as 50 feet below surface • Extend 40 miles long • 1992 UN ban on use of nets longer than 1.6 miles
Major Commercial Fishing Methods Used to Harvest Various Marine Species
11-2 How Can We Protect and Sustain Marine Biodiversity? • Concept 11-2 We can help to sustain marine biodiversity by using laws and economic incentives to protect species, setting aside marine reserves to protect ecosystems, and using community-based integrated coastal management.
Legal Protection of Some Endangered and Threatened Marine Species • Why is it hard to protect marine biodiversity? • Human ecological footprint and fishprint are expanding • Much of the damage in the ocean is not visible • The oceans are incorrectly viewed as an inexhaustible resource • Most of the ocean lies outside the legal jurisdiction of any country
Case Study: Protecting Whales: A Success Story… So Far • Cetaceans: Toothed whales and baleen whales • Bite and chew food vs. filter feeders • 1970: U.S. • Stopped all commercial whaling • Banned all imports of whale products • 1986: moratorium on commercial whaling • Pros? Cons? Tourism…
Individuals Matter: Creating an Artificial Coral Reef in Israel • Reuven Yosef, Red Sea Star Restaurant • Coral reef restoration • Reconciliation ecology • Treatment of broken coral with antibiotics
Case Study: Holding Out Hope for Marine Turtles • Carl Safina, Voyage of the Turtle • Studies of the leatherback turtle • Threats to the leatherbacks • Trawlers • Pollution • Climate change • Communities protecting the turtles
Marine Sanctuaries Protect Ecosystems and Species • Offshore fishing • A country’s offshore fishing zone extends 20 statute miles from its shores • Exclusive economic zones – foreign ships may extend into foreign waters when given governmental permission • High seas – free for all! • Law of the Sea Treaty – coastal nations have jurisdiction over 36% of ocean surface and 90% fish stocks
Marine Sanctuaries Protect Ecosystems and Species • Marine Protected Areas (MPAs) – areas of ocean partially protected from human activities • 4, 000 nationwide • 200 US • Only partially protected • Harmful human activities still illegally occur
Establishing a Global Network of Marine Reserves: An Ecosystem Approach • Marine reserves – fully protected! • Closed to • Commercial fishing • Dredging • Mining and waste disposal • Core zone • No human activity allowed • Less harmful activities allowed • E.g., recreational boating and shipping
Establishing a Global Network of Marine Reserves: An Ecosystem Approach • Fully protected marine reserves work fast • Fish populations double • Fish size grows • Reproduction triples • Species diversity increase by almost one-fourth
11-3 How Should We Manage and Sustain Marine Fisheries? • Concept 11-3 Sustaining marine fisheries will require improved monitoring of fish populations, cooperative fisheries management among communities and nations, reduction of fishing subsidies, and careful consumer choices in seafood markets.
Estimating and Monitoring Fishery Populations Is the First Step • Maximum sustained yield (MSY): traditional approach; maximum amount of fish that can be harvested annually without causing a population drop • Difficult to estimate population size and growth rate • Optimum sustained yield (OSY): takes into account interactions among species
Estimating and Monitoring Fishery Populations Is the First Step • Multispecies management: also incorporates competitive and predator-prey interactions • Large marine systems:using large complex computer models • **Precautionary principle: sharply reducing fish harvest and closing some overfished areas until they recover • Need more information about what levels of fishing can be sustained
Government Subsidies Can Encourage Overfishing • 2007: World Trade Organization, U.S. • Proposed a ban on fishing subsidies • Reduce illegal fishing on the high seas and in coastal waters • Close ports and markets to such fishers • Check authenticity of ship flags • Prosecution of offenders
Some Countries Use the Marketplace to Control Overfishing • Individual transfer rights (ITRs) • Control access to fisheries • Government gives each fishing vessel owner a specified percentage of total allowable catch (TAC) for a give year • New Zealand and Iceland • Difficult to enforce • Problems with the ITR approach • Illegally exceeding quotas • Difficult to enforce
Consumer Choices Can Help to Sustain Fisheries and Aquatic Biodiversity • 1997: Marine Stewardship Council (MSC), London • Supports sustainable fishing • Certifies sustainably produced seafood • Manage global fisheries more sustainably • Individuals • Organizations • Governments
Video Clip • Strange Days on Planet Earth: Baboons
11-4 How Should We Protect and Sustain Wetlands? • Concept 11-4 To maintain the ecological and economic services of wetlands, we must maximize preservation of remaining wetlands and restoration of degraded and destroyed wetlands.