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
OCN331 Our Objective: Insights for Your Lifetime OCN331 • How do the oceans make fish? • How do we extract fish from the oceans? • What other living resources do the world’s oceans hold? • Why do we care? Social Concerns Information Quality Natural Variability Some Wind and Current Fundamentals I. Effect of Differential Heating on Atmospheric Circulation II. The Coriolis Effect III. Trade Winds and Westerlies IV. Air-Sea Interactions V. El Niño Some effects of atmospheric circulation cells Dry climate and high pressure in the vicinity of 30o latitude Wet climate and low pressure in the vicinity of the equator and 60o latitude Bermuda: 32.3 N Honolulu: 21.3 N There are five major coastal upwelling regions in the world, along the coasts of California, Namibia, Mauritania, and Somalia. Effects of Walker Cell circulation Wet climate and low pressure at the western margin of the ocean basin near the equator Dry climate and high pressure at the eastern margin of the ocean basin near the equator. Things to Remember I. High atmospheric pressure at 30° N and 30° S latitude governs major wind patterns II. The Coriolis Effect deflects winds and currents to the RIGHT in the Northern Hemisphere and to the LEFT in the Southern Hemisphere III. These wind and current phenomena generate coastal UPWELLING of deep ocean water IV. Variations in the strength of these winds and currents can lead to conditions (EL NIÑO) that disrupt upwelling Hugo Grotius Mare Liberum 1609 • • • • • Whales Norwegian herring Japanese sardine Peruvian anchovy Can. N. Atlantic cod • • • • • • • Technology Capital Investment Fisheries Information Politics Social Issues Tragedy of commons Population Total Global Fisheries Harvest ~160Mt • • • • • • Year 2002 2003 2004 2005 2006 CAP 94.5 91.8 96 95.5 93.1 AQ 52 55.2 60 63.3 66.7 • Capture Fisheries are constant at ~90-95Mt • Aquaculture is steadily increasing Disposition of the total aquatic catch for 2002 Use % of total (by weight) Human consumption 75.8 Fresh 39.7 Frozen 20.0 Cured 7.3 Canned 8.7 Reduction 19.0 miscellaneous 5.3 Why Do We Care? • Calories • High Quality Protein • Essential Amino Acids • Essential Fatty Acids (PUFA’s) EPA & DHA Content of Fish • • • • • • • • • Cod Flounder Mackerel Pollock Salmon, farmed Shrimp Trout Tuna, bluefin Tuna, canned • • • • • • • • • 0.13 0.43 1.57 0.46 1.83 0.27 0.80 1.28 0.73 ω3 Fatty Acids & Fetus Health • “Fish is Brainfood” • EPA & DHA (from week 20) • Important for Infants’ – Nerve, Visual, Immune system development – DHA Supplements Breast Milk & Formulas Important for Infants’ Intellect -IQ-fish consumption correlation How the Oceans Make Fish • Primary Production Commercial Fish • 3 Types of Ocean Areas – Open Ocean – Coastal Areas – Upwelling Areas Open Ocean Area • • • • • Deep Low inputs Mostly Regen. Nutrs. Stable Temporally Nutrient Limited • Small Phytoplankton • Long Food Chains • Low Comm.Fish Yield Coastal Areas • • • • Shallow Seasonal Inputs Seasonal Variability ~50% New Nutrients • Larger Phytoplankton • Shorter Food Chains • Benthic Food Chains • Gadoid fishes • High Comm. Fish Yield Upwelling Areas • • • • Shallow Seasonal Inputs Seasonally Steady Mostly New Nutrients • Larger Phytoplankton • Short Food Chains • Clupeid fish • High Comm. Fish Yield Harvesting • How it’s done • What’s caught • Changes over time Old & New Methods • Spear • Hook-n-line • Traps • • • • • • • • Exploding harpoon Trolling Trolling-n-chumming Demersal Trawl line Pelagic Trawl line 2000 hooks; 3-4% Traps FADs Nets • Gill Nets • Floats & weights • Drift nets – – – – – Efficiency Fiber advances Bycatch 33000km—80% Banned in 1992 • • • • • • • • Trawl Nets demersal & pelagic Power needed Beam beam Otter 10-100m opening Echo-sounder sonar Table 2.2 Major species of fish caught with otter trawls Species Major fishing countries Areas fished Alaska pollock Russia, Japan, South Korea Northwestern Pacific USA Northeastern Pacific Atlantic cod Iceland, Norway, Russia Northeastern Atlantic Blue whiting Norway, Iceland, Russia, Faeroe Islands Northeastern Atlantic Largehead hairtail China, South Korea Northwestern Pacific Purse Seines • • • • • • Globally, most fish catch…by far Catch fish schooling near surface 100km x 100m Fish must aggregate in large schools Powerful means to deploy & retrieve Dories (50’s) to power block Catch Amount by type • Purse Seine ~50% – Herring,sardine,anchovies,tuna,mackerel • Otter Trawl ~17% – Pollock, cod,whiting • Lines ~ 9% – Tunas,swordfish,cod,halibut,haddock,etc • Pound/trap nets – Lobsters,crabs • Gill Nets ~6% – Squid,salmon,billfish ~8% OVERVIEW OF WORLD FISHERIES I. Reporting and Measurement Issues II. Major Fisheries - By Fish III.Major Fisheries - By Nation IV.Major Fisheries - By Ocean V. Economic Values II. Major Fisheries - by Fish THE FIRST TIER • Peruvian Anchovy • Alaskan Pollock • Skipjack Tuna • Capelin Peruvian Anchovy • Not heavily fished until the 1950s • By 1970, the largest fishery in the world • Susceptible to disruptions by ENSOs • Lessons may have been learned Alaskan Pollock • Not heavily fished until the 1960s • Improvements in processing ability were important • Overfishing a real concern • Monitoring and managing techniques may be improving Skipjack Tuna • Another recently developed fishery • Catches are trending upwards • This resource may be underutilized • Monitoring and managing techniques are a challenge III. Major Fisheries - by Nation THE FIRST TIER • China • Peru • United States • Indonesia III. Major Fisheries - by Nation THE SECOND TIER • Japan • Chile • India • Russia IV. Major Fisheries - by Ocean Atlantic 25.6% Pacific 62.6% Indian 10% Other 1.7 Percentages of global marine capture fishery production accounted by regions of the ocean Fishing area Atlantic % global capture production 25.6 Northwest 2.4 West central 2.1 Southwest 2.7 Northeast 12.7 East central 4.1 Southeast 1.6 Pacific 62.6 Northwest 26.9 West central 11.5 Southwest 0.9 Northeast 2.9 East central 2.0 Southeast Indian 18.4 10.0 East 5.5 West 4.5 V. Economic Values Fish eaten by humans have high market value Fish used for reduction have low market value Reasons to Fish Below the MSY I. Inaccurate Information A. I Fish Therefore I Lie (Schaefer Model) B. Not Enough Biological Data (Beverton-Holt Model) II. Variable Recruitment III. Resource Mismatch IV. Presence of Competitors V. Stock Stability VI. Economics (Law of Diminishing Returns) I. T Schaeffer Model Requirements: Measurement of Fish Caught Measurement of Fishing Effort Beaverton-Holt Model Requirements: Measurement of Fish Caught Knowledge of Fish Biology Population Size (Tagging) Age (Otoliths) Reproductive Biology OTOLITHS: Information that can be obtained from the analysis of otolith biomineralization patterns Age Spawn Date Hatch Date Metamorphosis Growth History Beverton-Holt Model: Application to a Resource-Limited Population Mortality declines with fishing because: 1. Caught fish don’t die a natural death; F 2. A fished population is a younger population, with a lower death rate; 3. Individuals in a fished population have access to more resources, so they are healthier and have a lower death rate. The Canadian Cod Example: Fished to Commercial Extinction Before Establishment of a Moratorium: No Recovery of the Stock, No Recovery of the Fishery Social Concerns Information Quality Natural Variability Characteristics of r-selected and K-selected populations parameter r-selected K-selected Environment variable and/or unpredictable constant and/or predictable Lifespan short long Growth rate fast slow Fecundity high low Natural mortality high low Population dynamics unstable stable HOW MANY FISH SHOULD WE CATCH? SUBSTANTIALLY LESS THAN THE MAXIMUM SUSTAINABLE YIELD THAT IS CALCULATED Clupeid & Gadoid Fisheries r – Selected Species ~1/3 Global Fisheries Instability Management Challenges Commercial catch of Japanese pilchards Migration routes of the Norwegian springspawning herring during the period 1963-1966. The location of the nine major populations of British Columbia herring. Commercial catches of cod in the North Sea (A) Catch of North Sea Herring and (B) spawning stock biomass of the autumn spawning herring. The dashed line in panel B is the target spawning stock of 1.3 Mt recommended by the ICES. Harvest of sexually immature fish Over Habitat Recruitm’t Closure of Capitlizat’n destruction overfishing fishery Japanese Pilchards Norwegian springspawning Herring Canadian Pacific Herring Canadian Atlantic Cod N. Sea Cod N. Sea Herring TUNA TALES TUNA I The World’s Tuna Fisheries TUNA II A Fishery Management Case Study: Yellowfin Tuna and Dolphins in the Eastern Tropical Pacific TUNA III The Mighty Bluefin Pertinent information on commercially important tuna species Species Length (cm) Weight (kg) Age of sexual maturity (years) Lifespan (years) Albacore 60-90 10-20 5 10 Bigeye 80-180 15-20 4 10 Skipjack 30-80 8-10 2 12 Yellowfin 40-180 5-20 3 10 Atlantic bluefin 45-450 135-680 4-8 15-30 Pacific bluefin 150-300 300-555 6 30 200 200 8-12 40 Southern bluefin Skipjack information Most catch occurs in the Pacific (70%) and Indian (24%) oceans. Smallest of the commercially important tunas Tendency to school Most skipjack are caught with purse seines. Diet includes clupeids, crustaceans, and mollusks Major market for skipjack tuna is canned tuna Yellowfin information Geographical distribution and spawning behavior similar to skipjack. Tend to associate with dolphins more than any other species. Pacific (67%) and Indian Ocean (22%) account for most of the catch. Much of the fishing is done with purse seines. Canned tuna (light tuna) is again the primary market. Albacore information Temperate water fish, and stocks in the N and S hemisphere are disjoint. The principal fishing areas are the western and central Pacific Caught with pole-and-line, surface trolling, or long lines, no purse seine The principal market for albacore is canned tuna… “white tuna”. Japan and Taiwan dominate the catch. Atlantic Bluefin information Atlantic Bluefin found only in the N. Atlantic, Mediterranean, Black Sea. Bluefin in the South Atlantic are S. Bluefin. Atlantic bluefin are the largest of the tunas Two spawning areas: Gulf of Mexico and Mediterranean Sea Controversy over whether the stocks should be considered separately these tuna definitely make trans-Atlantic migrations. <1970 ~$0.10/kg….Now$20-70/kg Increasing demand to supply the Japanese sushi and sashimi markets development of air freight in the early 1970s Management: International Commission for the Conservation of Atlantic Tunas (ICCAT) formed in 1969. Pacific Bluefin information The only unregulated Bluefin fishery in the world. Japan accounts ~64% of catch, most from NW Pacific. Unlike the Atlantic Bluefin…only one stock of Pacific Bluefin tuna. Caught on a variety of gear…bycatch….often juveniles Almost all taken in the eastern Pacific are sexually immature Southern Bluefin information Overexploited. Only one known breeding ground (Indian Ocean) The fishery is dominated by Japan and Australia. As with other Bluefins, surface gear takes sexually immature fish. Since1980… victim of recruitment overfishing Commission for the Conservation of Southern Bluefin Tuna (CCSBT) set catch quotas...no evidence that the spawning stock is recovering …further reductions in the catch quotas will be needed to give the stock a chance to recover. The long time to reach sexual maturity makes this species particularly vulnerable to overfishing. Marine Mammal Protection Act – 1972 NMFS Implementation of MMPA with respect to dolphin stocks Early 1980s – U.S. wants to put observers on all tuna boats. Observers on fewer than 50% of U.S. boats and only a handful of foreign boat-trips. Early 1980s – U.S. wants to ban sundown sets Tuna boats start to drop out of U.S. fleet Late 1980s – dolphin kills start to increase Lessons Learned? Pluses Consumers, via their government, pushed effectively for the implementation of management Benefits to the fishery from accepting the management plan 1. Main markets didn’t want to buy dead dolphin 2. Spared dolphins live to help find tuna again Minuses Expenses to the industry have forced much of the fishing fleet to jurisdictions where the management plan can be evaded Peruvian Anchoveta Fishery I. The Physical Setting II. The Upwelling Ecosystem III. Anchoveta Ecology IV.History of the Anchoveta Fishery The Upwelling Ecosystem I. Nutrient-rich waters from beneath the nutricline fertilize the euphotic zone with nitrate and phosphate II. High nitrate and phosphate enables high primary productivity by phytoplankton II. Anchoveta graze this nutritional resource III. Anchoveta are then eaten by mackerel (from below) and guano birds (from above) Anchoveta Ecology I. Population is confined to the Peru Coastal Current system II. Feed low on the food chain III. 4-year lifespan IV. Spawning year-round, with peaks in Sept-Oct and Feb-Mar V. Recruited to the fishery at 5 months of age Anchoveta Ecology V. Recruited to the fishery at 5 months of age VI. Sexual maturity at 12 months of age VII. Very high fecundity: 15,000 eggs/spawn, 24 spawns/year VIII. Very high mortality prior to recruitment: > 99% IX. After recruitment, mortality is ~ 16% X. A modest drop in population size enhances recruitment Effects of El Niño on Anchoveta Catch Impact of El Niño on Peruvian anchovies Possible impacts: anchovies starve poor recruitment changes in predation Response of anchovies concentrate in cold water nearer the coastline move into deeper water and disperse Ecological Summary Advantages: • An Extraordinary Combination of Nutritional Resources and an r-Selected Fish • Short Food Chain • “Simple” Sources of Mortality Problems: • Complex Biological-Meteorological Interactions • Variable Recruitment Management Summary Advantages: • An Extraordinary Combination of Nutritional Resources and an r-Selected Fish • Fishery within the Peruvian EEZ • National and International Fisheries Scientists Involved Problems: • Complex Biological-Meteorological Interactions • Harvesting Prior to Sexual Maturity • Overcapitalization and Socio-Political Pressures • MSY as a target Tragedy of Freedom in a Commons Pasture Example (the village green) Grazing Example (the wide open west) “Inexhaustible” Resources of the Ocean National Parks Tragedy of Freedom in a Commons Oceans Example (fisheries) What are the benefits and costs to me of taking yet more fish from a stressed population? Benefit: I get all the biomass generated by those fish. Costs: The fish population is further degraded, but that degradation is shared by all my competitors. Recognition of Necessity The Commons is justifiable only under conditions of low population density Injustice is preferably to total ruin Freedom is the recognition of necessity The Ingredients for Avoiding a Tragedy of the Commons: Elinor Ostrom 1. The nature of the resource 2. Recognition of resource depletion 3. Nature of the community: “Small and stable populations with a thick social network and social norms promoting conservation do better” The Bermuda Fisheries: A Tragedy of the Commons Averted? Background: 1. A Problem Perceived 2. A Study Undertaken 3. A Policy Changed Prior to 1970: Resource was in excess of the demand. A “Commons” use of the resource seemed OK. Policy was to increase fisheries activity. In 1975: Policy was to “exploit the harvestable resources to their maximum sustainable levels 1980 and 1984 attempts to regulate the use of fish pots, but problems remained: Pots were too indiscriminately efficient Pot fishery was too difficult to police Fishermen used more pots than they were allotted and tagged their illegal pots with other fisher’s names! Fishermen took other fisher’s pots 1980s: A growth in the use of the resource by other economic interests. Tourism: Scuba, Snorkel, Glass-Bottom Boat Charter fishermen found their interests aligned more with tourism than with commercial fishing The Bermuda Example of Averting a “Tragedy of the Commons” Made possible by a fortuitous set of circumstances: A. Affluence B. Isolation C. Changing Economic Interests D. An Advantageous Political Environment Important events in the history of Hawaiian commercial fisheries 1976 – Congress passes the Fisheries Management and Conservation Act 1984 – closure of Hawaiian Tuna Packers cannery 1987 – beginning of buildup of longline fleet 1990 – amendments to FMCA recognize need for management of highly migratory species 2000 – recognition that swordfish longline fishery is taking turtles 2000 – President Clinton creates northwestern Hawaiian Islands coral reef ecosystem reserve 2006 – President Bush makes NWHI a marine national monument; closes bottomfishing Hawaiian commercial pelagic fish catch by weight (A) and value (B) Commercial landings of skipjack tuna What are precious corals? Colonial coelenterates living below the euphotic zone. Valuable as a source of raw material for jewelry. Main production centers at the present time are Taiwan and Japan. Value of 1980 fishery is about $50 million [~50X stony coral imports] Most precious corals live at depths of hundreds of meters, making harvest by other than remote methods impractical. Precious corals are very much K-selected. Skeletons are made of calcium carbonate, protein, or a mixture of the two. Color due to organic matter in skeleton. Management of Precious Corals • Susceptible to Over-exploitation • Historical Attempts – Total Ban – Reserves – Limited Entry – Benign Neglect – Size & Weight Quotas Problems with Marine Debris Wildlife Entanglement Entanglement/Injury Ingestion/Starvation Both can lead to death Navigational Hazards that may cause Vessel Damage Large accumulations of derelict fishing gear can: Damage a vessel Entangle the propellor Result in a navigational hazard Result in a safety risk for those onboard The Sea & Human Evolution • Context • Dr. Michael Crawford – Director, Institute for Brain Chemistry and Nutrition, London Metropolitan Museum – Author, “The Driving Force: Food, Evolution and the Future” – Seafood & Human Health 2005 – Honoring the Omega-3 Pioneers – The Role of Seafood in Human Evolution The Sea & Human Evolution • Savannah scenario: big brain via fierce competition with big carnivores (Lamarcian) • Fish: LIPIDS >> Se,Fe,Cu,Zn,I >> Protein • Brain size: (1y) ≈ (mother) = PRIORITY! • Brain Size: 2% sm animals, %↓ and size↑ – Except humans • Humans: good sources of preformed DHA The Sea & Human Evolution • Humans exploiting coastal foods: 150,000y • Savannah hypothesis: male-centric – females make the next generation • Life centers: Euphrates, Ganges, Nile, Tiber • DHA conveys advantage to coastal dwellers over inland meat-eaters • 70% energy to fetus brain development Health • Rimm et al. (Harvard School of Public Health) • J. American Medical Association • “The health benefits of eating fish greatly outweigh the possible risks” – Heart health –Omega 3 fatty acids – Fish >= Twice/week Ciguatera Fish Poisoning • Occurs in tropical and subtropical regions • Vector is exclusively reef fish • Affects hundreds of thousands of people annually • Underreported; misdiagnosed Ciguatera Sequence Environmental conditions Gambierdiscus Gambierdiscus Macroalgae Herbivorous Fish Carnivorous Fish Fishing Pressure Fish Humans Mercury in Fish: hazard or hype? John Kaneko MS, DVM PacMar Inc. and Hawaii Seafood Project NOAA Take Home Message • There are no confirmed cases of mercury poisoning from eating tuna or open ocean fish. • “Dose makes the poison”, mercury may be toxic at high levels, but not at low levels. • Yellowfin tuna protects against mercury poisoning because it contains more selenium than mercury. • Pilot whales are mammals, not fish! Advisory is NOT for the General Consumer • There are no advisories for the general consumer • Vast majority of consumers can benefit by eating more fish • Caution: avoiding fish may increase risk of heart disease Babies need fish oils The benefits of healthy fish oils for brain development are known and widely-accepted. The potential harmful effects of low levels of mercury from open ocean fish are uncertain, undocumented and hypothetical. Pregnant women should eat fish! • October 5, 2007 Announcement from National Healthy Mothers Healthy Babies Coalition (w/150 member organizations) • Recommends women eat at least 2 meals of fish (12 oz) per week. • To get enough omega-3 fatty acids for their baby’s brain development. • Recognized that selenium appears to protect against toxic effects of mercury. http://www.sciencedaily.com/releases/2007/10/071004133313.htm Has mercury poisoning ever happened from eating Open Ocean Fish? • NO • There has never been a case of mercury poisoning from eating pelagic fish, including tuna, swordfish and others. Selenium Health Benefits • Essential antioxidant effects (ex. glutathione peroxidase) • Anti-cancer effects (ex. prostate, breast) • Promote immune system function • Metal detoxification (ex. mercury) Results: Hg & Se µmole/kg 40 = selenium 35 = mercury µM . 30 25 20 15 10 5 0 YF MM SJ SF WH AL BE MC SM BM OP ES TS SW MS PW YF=Yellowfin; MM=Mahimahi; SJ=Skipjack; SF=Spearfish; WH=Wahoo; AL=Albacore; BE=Bigeye; MC=Monchong; SM=Striped Marlin; BM=Blue Marlin; OP=Opah; ES=Escolar; TS=Thresher shark; SW=Swordfish; MS=Mako Shark; PW=Pilot whale Kaneko, JJ and NVC Ralston 2007. Selenium and Mercury in Pelagic Fish in the Central North Pacific Ocean near Hawaii. Biological Trace Element Research 119 (3): 242-254. (NOAA Award No. NA05NMF4521112) Conclusion • Pelagic fish are generally rich in selenium, therefore, they are far more likely to prevent mercury toxicity than to contribute to causing it. • Pilot whale meat is high in mercury, but not in selenium and may contribute to mercury toxicity. John Kaneko and Nick Ralston, PacMar Inc., Hawaii Seafood Project (NOAA Award No. NA05NMF4521112).