Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
13 Marine and Coastal Systems and Fisheries PowerPoint® Slides prepared by Stephen Turnbul Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-1 Housekeeping Items • For a short video on the role of plastic in relation to marine birds, see http://www.youtube.com/watch?v=pUM58LIU2Lo. • I will get the mid-term assignments back as soon as possible, but I am swamped with work at the moment. • Some more tidbits related to what we’ve been talking about: Burrowing owls are becoming scarce on the prairies and one teacher is taking her high school students out to study their numbers, and even try to boost their population; Wild boars are becoming a huge pest in Texas and, now, starting on the prairies. © 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. Housekeeping Items The federal government is importing an Asian wasp to try to kill of the ash borer, which in turn is killing millions of ash trees. This is an example of a bio-control (let’s hope it goes OK); Bird numbers are drastically down in many parts of Canada, especially species such as bank swallows and purple martins (down by 95%). Scientists are trying to figure out why; Dogs are being trained to locate endangered species, such as frogs, which are otherwise almost impossible to detect; Imperial Mines, notorious for the Mt. Polley disaster has been authorized to open the Red Chris mine in the Stikine, despite protests from Alaskan fishers’ groups; I saw an item (will try to find more) about a mining company that is endangering an indigenous group in Mexico that still practices peyote rituals. Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada Upon successfully completing this chapter, you will be able to • Identify physical, geographical, chemical, and biological aspects of the marine environment • Describe major types of marine ecosystems • Outline historic and current human uses of marine resources • Assess human impacts on marine environments • Review the current state of ocean fisheries and reasons for their decline • Evaluate marine protected areas and reserves as innovative solutions • If you get a chance, watch “Blue Planet” on your own, since we won’t have time to watch it in class. Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-4 Central Case: Lesson learned: The Collapse of the Cod Fisheries • No fish has more impact on human civilization than the Atlantic cod • Eastern Canadian and New England fishermen have fished for cod for generations • Large ships and technology have destroyed the cod fishery • Even protected stocks are not recovering or recovering only very slowly Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-5 Cod are groundfish and inhabit the Grand and Georges Bank • Groundfish = fish that live or feed along the bottom - Halibut, pollock, flounder • Cod eat small fish and invertebrates • They grow to 60-70 cm long and can live 20 years • There are 24 stocks of cod • Exclusive Economic Zone = legal right to waters 200 nautical miles from shore Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-6 The Ocean Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-7 Ocean cover most of Earth’s surface • The oceans influence global climate, teem with biodiversity, facilitate transportation and commerce, and provide resources for us • Oceans influence the atmosphere, lithosphere, and biosphere Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-8 The oceans contain more than water • 96.5% water • Ions of dissolved salts • Nutrients (e.g. nitrogen and phosphorus) • Dissolved gas - Oxygen is added by plants, bacteria, and atmospheric diffusion Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-9 Ocean water is vertically structured • Temperature declines with depth • Heavier (colder saltier) water sinks • Temperatures are more stable than land temperatures - Water’s high heat capacity - It takes much more heat to warm water than air • Oceans regulate the earth’s climate - They absorb and release heat - Ocean’s surface circulation Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-10 Ocean water is vertically structured (cont’d) • Thermocline = below surface water, temperature decreases rapidly with depth • Halocline = salinity changes with increasing depth • Pycnocline = below the surface zone - Density increases rapidly with depth • Deep Zone = below the pycnocline - Dense, sluggish water - Unaffected by winds, storms, sunlight, and temperature Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-11 Ocean water flows vertically and horizontally, influencing climate • Upwelling = the vertical flow of cold, deep water towards the surface - High primary productivity and lucrative fisheries - Where winds blow away from, or parallel to, coastlines • Downwelling = oxygen-rich water sinks where surface currents come together Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-12 Upwelling Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-13 The upper waters of the oceans flow horizontally in currents (cont’d) • Thermohaline circulation = global oceanic circulation system of upwelling and downwelling currents • Ocean water flows horizontally – wind systems and air pressure • Gyre = an oceanic current that flows in a circular motion - Coriolis force = artifact of Earth’s rotation • There is concern that climate change might disrupt both the thermohaline circulation and gyres/ currents (such as the Gulf Stream that keeps the UK temperate) Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-14 The upper waters of the oceans flow horizontally in currents Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-15 Great Pacific Garbage Continent Leah submitted some information about some new technology developed to start to process this plastic. Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada La Niña and El Niño demonstrate the atmosphere-ocean connection • El Niño - Equatorial winds weaken - Warm water flows eastward and suppresses upwellings - Alter weather worldwide - Canada abnormally warm and dry • La Niña - Opposite to El Niño - Weather: Canada abnormally cool and wet Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-17 Seafloor topography can be rugged and complex • The seafloor consists of: - Volcanoes - Steep canyons - Mountain range - The planet’s longest range is under water - Mounds of debris - Trenches - Some flat areas - And fault lines! Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-18 Seafloor topography can be rugged and complex (cont’d) • Bathymetry = the measurement of ocean depths • Topography = the physical geography or the shape and arrangement of landforms • Continental shelves = gently sloping areas that underlie the shallow waters bordering continents • Continental slope = connects the continental shelf to the ocean floor • Abyssal plain = flat bottom of the deep ocean Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-19 A stylized bathymetric profile of the ocean Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-20 Marine and Coastal Ecosystems Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-21 Marine and coastal ecosystems • Some zones support more life than others • Photic zone = well-lit top layer that supports high primary productivity • Pelagic = habitats and ecosystems occurring between the ocean’s surface and floor • Benthic = habitats and ecosystems occurring on the ocean floor Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-22 Open-ocean systems vary in their biological diversity • Phytoplankton constitute the base of the marine food chain in the pelagic zone; they are being affected by increasing ocean acidity • Zooplankton feed on them • Fish, jellyfish, whales, feed on zooplankton • Predators at higher trophic levels include larger fish, sea turtles, sharks, and fisheating birds Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-23 Open-ocean systems vary in their biological diversity (cont’d) • Animals adapt to extreme water pressure and the absence of light - Scavenge carcasses or organic detritus - Some are predators, others have mutualistic relationships with bacteria - Some carry bacteria that produce light chemically by bioluminescence • Hydrothermal vents support chemosynthetic species Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-24 Shallow-water systems are highly productive • Kelp = large, dense, brown algae growing from the floor of continental shelves • Dense strands provide shelter and food for organisms • Underwater forests • Absorbs wave energy and protects shorelines from erosion • Alginates serve as thickeners in cosmetics, paints, paper, and soaps Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-25 Shallow-water systems are highly productive (cont’d) • Coral reef = a mass of calcium carbonate composed of the skeletons of corals • Located in shallow subtropical and tropical waters - Consists of millions of densely packed individuals - Protect shorelines by absorbing waves - Innumerable invertebrates and fish species find food and shelter in reef nooks and crannies - Are in real trouble because of climate change Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-26 Shallow-water systems are highly productive (cont’d) • Corals = tiny colonial marine organisms - Related to sea anemones and jellyfish - Remain attached to rock or existing reef - Capture passing food with stinging tentacles - Derive nourishment from symbiotic algae, zooxanthallae Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-27 Shallow-water systems are highly productive (cont’d) • Coral bleaching = occurs when zooxanthellae leave the coral - Coral die, leaving white patches • Nutrient pollution causes algal growth, which covers coral • Divers damage reefs by using cyanide to capture fish • Acidification of oceans deprives corals of carbonate ions Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-28 Intertidal zones undergo constant change • Intertidal (littoral) ecosystems = where the ocean meets the land - between the uppermost reach of the high tide and the lowest limit of the low tide • Tides = periodic rising and falling of the ocean’s height due to the gravitational pull of the sun and moon - Intertidal organisms spend part of their time submerged in water and part of their time exposed to sun and wind Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-29 Some of you included in your midterm assignment. A typical intertidal zone Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-30 Coastal ecosystems protect shorelines • Salt marsh = occur along coasts at temperate latitude (small vestiges remain in Victoria and Esquimalt) - Tides wash over gently sloping, sandy, silty substrates - High primary productivity - Critical habitat for birds and commercial fish and shellfish species - Filter pollution - Stabilize shorelines against storm surges Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-31 Coastal ecosystems protect shorelines (cont’d) • Mangroves = trees with unique roots - Curve up for oxygen - Curve down for support • Nurseries for commercial fish and shellfish • Nesting areas for birds • Food, medicine, tools, construction materials Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-32 Coastal ecosystems protect shorelines (cont’d) • Mangroves are threatened: - Threatened by development and shrimp farming - Half the world’s mangrove forests are gone - Once destroyed, coastal areas no longer… - Slow runoff - Filter pollutants - Retain soil - Protect communities against storm surges • We are protecting only 1% of remaining mangroves Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-33 Freshwater meets saltwater in estuaries • Estuaries = water bodies where rivers flow into the ocean - Wide fluctuations in salinity • Critical habitat for shorebirds and shellfish • Transitional zone for anadromous (spawn in freshwater, mature in salt water) fishes – e.g. salmon • Affected by development, pollution, habitat alteration, and overfishing • Anyone know what has compromised the health of the Nanaimo Estuary? Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-34 Human Use and Impact Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-35 Oceans provide transportation routes • Humans have interacted with oceans for thousands of years - Moving people and products over vast distances - Accelerated global reach of cultures • Has substantial impact on the environment - Moves resources around the world - Ballast water transplants organisms, which may become invasive Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-36 We extract energy and minerals • Crude oil and natural gas - Oil spills damage fisheries • Methane hydrate = a potential energy source - Ice-like solid methane embedded in water crystals - A vast supply, but research needs to be done • Renewable energy sources, such as waves, tides, heat Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-37 We extract energy and minerals (cont’d) • Minerals such as sand, gravel, sulfur, calcium carbonate, and silica • Rich deposits of copper, zinc, silver, and gold • Manganese nodules are scattered along the ocean’s floor - But, they are too hard to currently mine Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-38 Marine pollution threatens resources and marine life • Even into the mid-20th century, coastal U.S. cities dumped trash and untreated sewage along their shores • Oil, plastic, chemicals, excess nutrients make their way from land into oceans • Raw sewage and trash from cruise ships • Abandoned fishing gear from fishing boats In their 25th annual cleanup, Ocean Conservancy’s International Coastal Cleanup, almost 500,000 volunteers from more than 100 nations, picked up 16 million kg of trash Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-39 Marine pollution threatens resources and marine life (cont’d) • Plastic dumped into the sea harms wildlife - Mistake floating plastic debris for food • Most plastic is nonbiodegradable - Drifts for decades • Marine debris affects people - Equipment damage © 2010 Pearson Education Canada See Chris Jordan’s trailer for his new film, Midway, at http://www.midwayfilm.com/. Copyright © 2013 Pearson Canada Inc. 13-40 Marine pollution threatens resources and marine life (cont’d) • Ocean acidification - Decrease in acidity (pH) of ocean water - Caused by uptake of atmospheric carbon dioxide - Corals and other marine organisms that build their shells are at risk Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-41 Oil pollution comes from many sources • Major oils spills (i.e., the Exxon Valdez, BP Deepwater Horizon) make headlines and cause serious environmental problems • Most pollution comes from small sources - Boat leakage and runoff from land - Naturally occurring leaks from the seabed • Oil spills coat and poison wildlife Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-42 Pollutants can contaminate seafood • Mercury contamination - From coal combustion and other sources - Bioaccumulates and biomagnifies - Dangerous to young children and pregnant or nursing mothers - Avoid eating fish and shellfish at high trophic levels - Avoid seafood from areas where health advisories have been issued Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-43 Excess nutrients cause algal blooms • Algal blooms = nutrients increase populations of algae that produce powerful toxins • Red tide = blooms of algal species that produce reddish pigments and discolor water - Illness and death to wildlife and humans - Economic losses to fishing industries and beach tourism • Reduce runoff and prevent consumption of affected organisms Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-44 Emptying the Ocean Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-45 Emptying the oceans • 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 • 2006 study in Science: - Predicted that populations of all ocean species we fish for today will collapse by the year 2048 Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-46 We have long overfished • Some species hunted to extinction: Steller’s sea cow, Atlantic gray whale, Caribbean monk seal • Overharvesting of Chesapeake Bay oyster beds led to the collapse of its fishery. Currently, numbers stand at less than 1% of historic numbers. • People never imagined that groundfish could be depleted - New approaches or technologies increased catch rates Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-47 Fishing has become industrialized • Driftnets for schools of herring, sardines, mackerel, sharks • Longline fishing for tuna and swordfish • Bottom-trawling for pelagic fish and groundfish Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-48 Some fishing practices kill nontarget animals and damage ecosystems • By-catch = the accidental capture of animals • Driftnetting drowns dolphins, turtles, and seals - 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 Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-49 Modern fishing fleets deplete marine life Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-50 Some fishing practices kill non-target animals and damage ecosystems (cont’d) • 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 Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-51 Oceans today contain only one-tenth of the large-bodied animals Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-52 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 lessfished portions of the ocean - Fleets spend more time fishing - Fishing in deeper water - Improved technologies: faster ships, sonar mapping, satellite navigation, thermal sensing, aerial spotting - Data supplied to international monitoring agencies may be false Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-53 We are “fishing down the food chain” • Figures on total global catch do not relate the species, age, and size of fish harvested • 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 - Entails catching species at lower trophic levels Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-54 Aquaculture has benefits and drawbacks • Aquaculture = farm fisheries - 30% of the world’s fish production - Canada is fourth-largest producer of farmed salmon in the world - Freshwater fish and shellfish (clams, oysters, mussels) - Canada is now authorizing the production of GM salmon Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-55 Aquaculture has benefits and drawbacks (cont’d) • Benefits - Improves food security, though still uses wild fish - Reduces pressure on wild stocks - 10 to 1000 times more energy-efficient • Drawbacks - Increased disease causes antibiotic use - High-density fishery causes more waste - Can damage landscape - Can spread sea lice to wild populations © 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. 13-56 Consumer choice can influence marine harvest practices • Buy eco-labeled seafood - Dolphin-safe or, better yet, pole and line, tuna • Use consumer guides - SeaChoice or Seafood Watch seafood guides - Some best choices: farmed catfish and caviar, sardines, Canadian snow crab, Pacific halibut, trap-caught shrimp - Some to avoid: Atlantic cod and halibut, wild caviar, imported King crab, shark, farmed shrimp - See also http://www.davidsuzuki.org/what-you-cando/food-and-our-planet/suzukis-top-10-sustainableseafood-picks/ Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-57 weighing the issues Eating Seafood After reading this chapter, •Do you plan to alter your decisions about eating seafood in any way? If so, how? If not, why not? •Do you think consumer buying choices can exert an influence on fishing practices? On mercury contamination in seafood? Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-58 Marine biodiversity loss erodes ecosystem services • 2006 study in Science, showed effects of biodiversity loss on ecosystems - Less primary and secondary production - Less able to withstand disturbance - Reduced habitats for fish and shellfish - Reduced filtering and detoxification Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-59 Marine Conservation Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-60 Fisheries management has been based on maximum sustainable yield • Maximum sustainable yield = Maximal harvest while keeping fish available for the future • Despite management, stocks have plummeted • Ecosystem-based management - 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 Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-61 We can protect areas in the ocean • Marine protected areas (MPAs) = established along the coastlines of developed countries - Still allow fishing or other extractive activities • 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 Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-62 Reserves can work for both fish and fishers • Found that reserves do work as win-win solutions • In 2001 census by marine scientists stated, that in addition to boosting fish biomass, total catch, and record-sized fish, marine reserves: - Within reserve boundaries - Produce rapid and long-term abundance, diversity, and productivity - Decrease mortality and habitat destruction - Lessen the likelihood of extirpation Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-63 Reserves can work for both fish and fishers (cont’d) • Marine reserves: - Outside reserve boundaries - “Spillover effect” = protected species spread outside reserve - Larvae of protected species “seed the sea” outside the reserve - Improved fishing and ecotourism Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-64 How should reserves be designed? • 20-50% of the ocean should be protected in no-take reserves - How large? - How many? - Where? • Involving fishers is crucial fisheries in coming with these answers Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-65 Another Model: Alaska Fisheries • Pre-statehood, the US government managed the Alaskan fishery. In 1938: there was a harvest of 120 million fish. In 1958, a harvest of 20 million. • A year later, Alaska became a state. • For a variety of reasons, by 1972 the harvest was even lower. · • It was decided to take action in the form of limiting the entry of new fishing vessels; rebuilding wild stocks; constructing hatcheries; improving stock enhancement, and initiating ‘ocean ranching.’ · · · · Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada Alaska Fisheries • With ocean ranching one strips the eggs from the brood stock, rears them in a hatchery, then places them in ocean nets for 3-4 weeks offshore away from wild stock migration routes, after which they are turned loose. • Meanwhile, they have spent enough time to become imprinted on the area of the ocean nets to return and are thus easy to scoop up, rather than having to be chased. Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada Alaska Fisheries • In Oregon, where ocean ranching was initiated, it was taken over by Weyerhauser. • In Alaska, the key focus for debate was the hatcheries. There was strong pressure for them to be corporate-controlled on the argument that governments are inherently inefficient, but the fishers resisted. They didn’t want to see the privatization of the commons. Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada Alaska Fisheries • The state government responded by bringing all the players together to come up with a strategic plan, of which the ranching was a key component. • Initially, government took over the hatchery program and made a hash of it (harvests declined to 4 million fish). All gear groups were united in the nature of their critique. • By 1976, Regional Aquaculture Associations had been formed representing fishers and other stakeholders in partnership with the state. One particularly successful one has been the Northern Southeast Regional Aquaculture Association (NSRAA). Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada Alaska Fisheries • The organization has achieved its goal of having 85% of fish produced in the area being harvested as a common resource. • The hatcheries, now operated by non-profit organizations, are costly to run, as are the rest of the management and decision-making activities. • Conventional banks would not look at them, so Alaska set up a State Fisheries Enhancement Loan Fund to extend long-term loans with holidays on the interest and principal. However, this was inadequate, so the fishers demanded that they be subjected to a 2-3% tax on all landed fish to further contribute to the shared infrastructure. • By 1980, the NSRAA had paid off its original loan. Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada Alaska Fisheries Model • The benefits of the model: It seems to protect and enhance the fish stocks. The benefits stay mostly with fishers and their communities. It avoids the ‘tragedy of the commons’ (actually open access systems that Garrett Hardin mistook for the commons), and It keeps control largely in the hands of those most affected. Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada Conclusion • Oceans cover most of our planet and contains diverse topography and ecosystems • We are learning about the oceans and coastal environments, intensifying our use of their resources and causing more severe impacts • Setting aside protected areas of the ocean can serve to maintain natural systems and enhance fisheries • Look beyond simply making fisheries stable and instead consider restoring the ecological systems that once flourished in our waters Copyright © 2013 Pearson Canada Inc. © 2010 Pearson Education Canada 13-73