© 2011 Pearson Education, Inc. AP Environmental Science Mr. Grant Lesson 79 Emptying the Oceans & Marine Conservation

© 2014 Pearson Education, Inc. Mastery Check Describe three ways plastics affect marine life.

© 2011 Pearson Education, Inc. Objectives: Define the term marine reserve. Review the current state of ocean fisheries and reasons for their decline. Evaluate marine protected areas and reserves as innovative solutions. TED - Legendary ocean researcher Sylvia Earle shares astonishing images of the ocean -- and shocking stats about its rapid decline -- as she makes her TED Prize wish: that we will join her in protecting the vital blue heart of the planet.

© 2011 Pearson Education, Inc. Marine Reserve: A marine protected area that is highly protected, and is effective as a complete sanctuary; no extractive uses are permitted, and very few (or no) other human uses (including scientific research) are permitted. Define the term marine reserve.

© 2011 Pearson Education, Inc. Review the current state of ocean fisheries and reasons for their decline. Over half the world’s marine fish populations are fully exploited, 28% are overexploited, and only 20% can yield more without declining. Global fish catches have stopped growing since the late 1980’s, despite increased fishing effort and improved technologies. People began depleting marine resources long ago, but impacts have intensified in recent decades. Commercial fishing practices include drift netting, long-line fishing, and trawling, all of which capture non-target organisms, called bycatch. Non-target species are killed when they are captured as bycatch while fishing for commercially-valuable species. Today’s oceans hold only one-tenth as many large animals that they did before industrialized commercial fishing.

© 2011 Pearson Education, Inc. Review the current state of ocean fisheries and reasons for their decline. As fishing intensity increases, fish become smaller and fishermen switch to less-desirable species. Consumers can encourage good fishery practices by shopping for sustainable seafood. Marine biodiversity loss affects ecosystem services. Traditional fisheries management has not stopped declines, so many scientists feel that ecosystem-based management is needed.

© 2014 Pearson Education, Inc. Emptying the Oceans  Overharvesting is the worst marine problem  We are putting unprecedented pressure on marine resources  Half the world’s marine fish populations are fully exploited and can’t be fished more intensively  28% of fish population are overexploited and heading to extinction  Total fisheries catch leveled off after 1988 despite increased fishing effort  The maximum wild fisheries potential has been reached

© 2011 Pearson Education, Inc. Emptying the oceans

© 2011 Pearson Education, Inc. The global fisheries catch has increased It is predicted that populations of all ocean species we fish for today will collapse by 2048

© 2014 Pearson Education, Inc. Emptying the Oceans  If current trends continue, it is predicted that populations of all ocean species we fish for today will collapse by 2048  If fisheries collapse as predicted, we will lose their ecosystem services  Productivity will decline, and they will become more sensitive to disturbance  Filtering of water will decline, causing more harmful algal blooms and beach closures  Aquaculture is relieving some of the pressure on wild stocks, b ut it has its own set of environmental problems

© 2014 Pearson Education, Inc. We have long overfished  People began depleting sea life centuries ago  Species have been hunted to extinction: Caribbean monk seal, Steller’s sea cow, Atlantic gray whale  Decreased sea turtle populations cause overgrowth of sea grass and can cause sea grass wasting disease  Overharvesting nearly exterminated many whale species  People never thought groundfish could be depleted  Local populations dwindled as far back as the 19th century  New approaches or technologies were needed to increase catch rates

© 2014 Pearson Education, Inc. Fishing has industrialized  Factory fishing  huge vessels use powerful technologies to capture fish in huge volumes  Driftnets  transparent nylon mesh nets that drift with the current  Used for herring, sardines, mackerel, sharks, shrimp  Longline fishing  extremely long (up to 80 km or 50 mi) lines with several thousand baited hooks  Used for tuna and swordfish

© 2014 Pearson Education, Inc. Fishing has industrialized  Trawling  using cone shaped nets with weights at the bottom and floats at the top to catch pellagic fish  Bottom trawling  using weighted nets that drag across the seafloor to catch groundfish or scallops

© 2014 Pearson Education, Inc. Fishing practices kill nontarget animals and damage ecosystems  Bycatch  the accidental capture of animals  A 2011 report found that 17% of all commercially harvested fish were captured unintentionally  Driftnetting drowns dolphins, turtles, and seals  Fish die on deck  Banned in international waters  But is still used in national waters  Longline fishing kills turtles, sharks, and over 300,000 seabirds/year  Methods (e.g., flags) are being developed to limit bycatch

© 2011 Pearson Education, Inc. Fishing practices kill nontarget animals Fisheries bycatch is one of the biggest problems facing the world's oceans

© 2014 Pearson Education, Inc.

Fishing practices kill nontarget animals and damage ecosystems  Dolphins are trapped in nets used to catch tuna  Hundreds of thousands of dolphins were killed  The 1972 Marine Mammal Protection Act forced fleets to try to free dolphins  Bycatch dropped dramatically  Other nations fished for tuna, and bycatch increased  The U.S. government required that nations exporting tuna to the United States minimize dolphin bycatch  “Dolphin-safe” tuna uses methods to avoid bycatch  Other species (sharks) are still being caught  Dolphin populations have not yet recovered

© 2011 Pearson Education, Inc. Dolphin deaths have declined, but …

© 2014 Pearson Education, Inc. Fishing practices kill nontarget animals and damage ecosystems  Bottom trawling causes bycatch and harms entire ecosystems  Heavy nets crush organisms and damage sea bottoms  Especially destructive to complex areas (e.g., reefs)  It equals clear-cutting and strip mining  The average spot of the sea floor in the Georges Bank has been trawled three times, d estroying young cod as bycatch  Bycatch of cod while fishing for other species in the Grand Banks nearly doubled from 2006 to 2009

© 2011 Pearson Education, Inc. Bottom-trawling destroys ecosystems

© 2014 Pearson Education, Inc. Modern fishing fleets deplete marine life rapidly  Grand Banks cod have been fished for centuries  Catches more than doubled with industrial trawlers  Record-high catches lasted only 10 years  Georges Bank cod fishery also collapsed

© 2014 Pearson Education, Inc. Modern fishing fleets deplete marine life rapidly  Worldwide, industrialized fishing is depleting marine populations with astonishing speed  90% of large-bodied fish and sharks are eliminated within 10 years after fishing begins  Populations stabilize at 10% of their former levels  Communities were very different before modern fishing  Removing animals at higher trophic levels allows prey to proliferate and change communities

© 2011 Pearson Education, Inc. Industrialized fishing is destroying fisheries Oceans today contain only one- tenth of the large- bodied animals they once did

© 2011 Pearson Education, Inc. Modern fleets deplete marine life rapidly

© 2014 Pearson Education, Inc. Several factors mask declines  Industrialized fishing has depleted stocks  But global catch has remained stable for the past 20 years  How can stability mask population declines?  Fishing fleets travel farther to reach less-fished areas  Fleets fish in deeper waters (now at 250 m)  Fleets spend more time fishing and set more nets  Improved technologies: faster ships, sonar mapping, satellite navigation, thermal sensing, aerial spotting  Fleets expend more effort to catch the same number of fish  At some point, there will not be enough fish left

© 2014 Pearson Education, Inc. We are “fishing down the food chain”  Figures on total global catch do not tell the whole story  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 more abundant species  Shift from large, desirable species to smaller, less desirable ones  This entails catching species at lower trophic levels  “Image makeovers” renamed formerly undesirable fish  “Orange roughy” was once called “slimehead”

© 2011 Pearson Education, Inc. We are “fishing down the food chain”

© 2011 Pearson Education, Inc. Purchasing choices influence fishing practices Best choices: farmed catfish, mussels, oysters, tilapia

© 2014 Pearson Education, Inc.

Marine biodiversity loss erodes ecosystem services  Factors that deplete biodiversity threaten ecosystem services we get from the oceans  Systems with reduced species or genetic diversity show less primary and secondary production  They are less able to withstand disturbance  Biodiversity loss reduces habitat for nurseries for fish and shellfish  Less diversity leads to reduced filtering and detoxification, resulting in algal blooms, dead zones, fish kills, beach closures

© 2011 Pearson Education, Inc. Diversity loss erodes ecosystem services Accelerating Loss of Ocean Species Threatens Human Well- Being.

© 2014 Pearson Education, Inc. Fisheries management has been based on maximum sustainable yield  Maximizes harvest while maintaining fish for the future  Managers may limit the harvest or restrict gear used  Despite management, stocks have plummeted  Requires accurate measurement of fish numbers  Overestimates have resulted in overharvesting  Ecosystem-based management shifts away from species and toward the larger ecosystem  Considers the impacts of fishing on habitat quality, species interactions, and long-term effects  Sets aside areas of oceans free from human interference

© 2011 Pearson Education, Inc. Fisheries management Successful management of summer flounder has resulted in an increase in adult fish stock.

© 2011 Pearson Education, Inc. Evaluate marine protected areas and reserves as innovative solutions. We have established fewer protected areas in the oceans than we have on land, and most marine protected areas allow many extractive activities. No-take marine reserves can protect ecosystems while also boosting fish populations and making fisheries sustainable.

© 2014 Pearson Education, Inc. We can protect areas in the ocean  Marine protected areas (MPAs)  most are along the coastlines of developed countries  They 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 and recreational fishers and businesses do not support reserves  To be successful, establishment needs to be sensitive to concerns of local residents

© 2011 Pearson Education, Inc. We can protect areas in the ocean

© 2014 Pearson Education, Inc. Reserves can work for both fish and fishers  A 2001 review showed that after just one to two years of establishment, marine reserves:  Increased densities of organisms by 91%  Increased biomass by 192%  Increased organism size by 31%  Increased species diversity by 23%  Benefits inside reserve boundaries include:  Rapid and long-term increases in abundance, diversity, and productivity of marine organisms  Decreased mortality and habitat destruction  Decreased likelihood of extirpation of species

© 2011 Pearson Education, Inc. Reserves work for both fish and fisheries

© 2014 Pearson Education, Inc. Reserves can work for both fish and fishers  Areas outside reserves also benefit  A “spillover effect” occurs when individuals of protected species spread outside reserves  Larvae of species protected within reserves “seed the seas” outside reserves  Improved fishing and ecotourism

© 2011 Pearson Education, Inc. Areas outside reserves also benefit

© 2014 Pearson Education, Inc. Reserves can work for both fish and fishers  Local residents who were opposed changed to supporting reserves once they saw their benefits  Once commercial trawling was stopped on Georges Bank:  Populations of organisms began to recover  Fishing in adjacent waters increased

© 2014 Pearson Education, Inc. How should reserves be designed?  Reserves should be able to  Protect ecosystems  Sustain fisheries  Include people  Most studies suggest that 20–50% of the ocean should be protected in no-take reserves  How large should the reserves be?  How many should we have?  Where should they be located?  Involving fishers is crucial in coming up with answers

© 2011 Pearson Education, Inc. How should reserves be designed?

© 2011 Pearson Education, Inc. TED Video Sylvia Earle has been at the frontier of deep ocean exploration for four decades. She's led more than 50 undersea expeditions, and she's been an equally tireless advocate for our oceans and the creatures who live in them. " We've got to somehow stabilize our connection to nature so that in 50 years from now, 500 years, 5,000 years from now there will still be a wild system and respect for what it takes to sustain us." Sylvia Earle Sylvia Earle's TED Prize wish to protect our oceans (18:16)