What conclusion can you draw from this graph?

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

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 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

The total global fisheries catch has increased

(kilograms per person) World Fish Catch Per Person Per Capita Fish Catch 25 20 15 10 5 1950 1970 1960 2000 1990 1980 (kilograms per person) Per capita catch Year World Fish Catch Per Person

(thousands of metric tons) Fish Population Estimates 800 600 400 200 1960 1970 1980 1990 2000 Year 80 70 60 50 40 30 20 (thousands of metric tons) Harvest (kilograms/tow) Abundance 10

We have long overfished People began depleting sea life centuries ago 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, eutrophication, and hypoxia Decreased sea turtle populations causes overgrowth of sea grass and can cause sea grass wasting disease People never imagined that groundfish could be depleted New approaches or technologies increased catch rates

A Systems View

Sonar Uses sound waves that allow fishermen to quickly locate fish and/or see the bottom Targets specific species Image: http://www.marinesonic.com

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

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

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

Industrialized fishing depletes populations 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

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

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

Consumer choices influence fishing practices 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

The Big Question Fish Populations are declining The Human Population is increasing exponentially What can be done to sustain fish as a viable food resource for the human population? What YOU can do: Choose to eat sustainably harvested seafood

Aquaculture Methods Is Aquaculture the Answer? Trade-Offs Aquaculture Highly efficient High yield in small volume of water Increased yields through cross- breeding and genetic engineering Can reduce over- harvesting of conventional fisheries Little use of fuel Profit not tied to price of oil High profits Advantages Large inputs of land, feed, And water needed Produces large and concentrated outputs of waste Destroys mangrove forests Increased grain production needed to feed some species Fish can be killed by pesticide runoff from nearby cropland Dense populations vulnerable to disease Tanks too contaminated to use after about 5 years Disadvantages Trade-Offs Aquaculture Aquaculture Methods Is Aquaculture the Answer?

More Sustainable Aquaculture Reduce use of fishmeal as a feed to reduce depletion of other fish Improve pollution management of aquaculture wastes Reduce escape of aquaculture species into the wild Restrict location of fish farms to reduce loss of mangrove forests and other threatened areas Farm some aquaculture species (such as salmon and cobia) in deeply submerged cages to protect them from wave action and predators and allow dilution of wastes into the ocean Set up a system for certifying sustainable forms of aquaculture Solutions More Sustainable Aquaculture

Relevant Laws UN Law of the Seas Magnuson-Stevens Fisheries Management and Conservation Act (Magnuson Act) Marine Sanctuaries Act Oceans Act of 2000 Endangered Species Act (ESA) Convention on International Trade in Endangered Species (CITES) Lacey Act of 1900

Laws Related to Fishery Management Magnuson Act Establishes 200 mile fishing area Set up regional councils that Set quotas Set size limits Set seasons Protects habitat Minimizes bycatch Rebuilds overfished stocks UN Law of the Seas Nations have jurisdiction over Exclusive Economic Zones (200 Miles) Sea Floor sovereignty up to 12 miles offshore Allows for Individual Transferable Quotas which can be sold to others

Fisheries management Based on maximum sustained yield Maximal harvest while keeping fish available for the future Managers may limit the harvested or restrict gear used Despite management, stocks have plummeted It is time to rethink fisheries management 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

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

Reserves work for both fish and fisheries 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

Areas outside reserves also benefit Benefits 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

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

Laws Related to Habitat Protection Oceans Act of 2000 Established Presidential Commission to Examine Federal Ocean Policy Promote protection of marine environments Prevent marine pollution Marine Sanctuaries Act Protects habitat of marine organisms Protects animals from being harvested in that area

Laws Related to Species Protection ESA Identifies and lists endangered species Prohibits the harm or harvesting of listed species Protects habitat CITES Identifies and lists endangered species Prohibits international trade in listed species Lacey Act of 1900 Prohibits sale of illegally harvested species Forces legal methods

Conclusion Oceans cover most of our planet and contain diverse topography and ecosystems We are learning about the oceans and coastal environments, intensifying our use their resources and causing severe impacts Setting aside protected areas of the ocean can serve to maintain natural systems and enhance fisheries We may once again attain the ecological systems that once flourished in our waters

QUESTION: Review Which of the following does not mask the decline of fisheries? Fishing fleets travel longer distances Fishing fleets spend more time fishing Fishing fleets use traditional methods of fishing Data supplied to monitoring agencies may be false Answer: c

QUESTION: Review Marine reserves have all the following benefits except: Fishing increases in the reserve The size of fish increases Larvae can “seed” areas outside the reserve Decreased mortality and habitat destruction Answer: a

QUESTION: Interpreting Graphs and Data What does this graph show about the future of global fisheries catch? China will be a major player in applying fishing pressure China will be player a smaller role in applying fishing pressure The world will decrease its fishing pressure The U.S. is not included in this graph Answer: b

QUESTION: Interpreting Graphs and Data Which conclusion can you draw from this graph? Oceans today contain far fewer fish Oceans today contain far more fish It is easier to find fish today There is little correlation between fishing and fish stocks Answer: b

QUESTION: Viewpoints If a developer wants to build a community on an estuary, providing jobs but eliminating the marsh, what should be done? Let the developer build; we need the jobs Let the developer build, but make him/her pay for any damage from storms Let the surrounding landowners vote whether to let the developer build Prevent the development; the potential damage is too great Answer: any

QUESTION: Viewpoints Do you plan to alter your decisions about eating seafood? Yes; I will be more selective about what I eat No; I will continue to eat the same type and amount of seafood as always Answer: any

Fishing Methods Bycatch: Spotter airplane Fish farming in cage Trawler fishing Purse-seine sonar trawl flap trawl lines trawl bag Long line fishing lines with hooks Drift-net fishing fish caught by gills float buoy fish school Bycatch: Different types of fishing practices result in different animal/species being killed as bycatch: Nets kill dolphins, porpoises and whales Longline fishing kills birds, and Bottom trawling devastates marine ecosystems.