Fishing Practices

1. Fishing Practices

2. Commercial fishing: • 500 species regularly caught • Employs 200 million people worldwide • In 2002 the world fishing fleet numbered about four million vessels. • In 2005: • 100 million tons taken • $70 billion

3. Global Fish Catch

4. 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

5. Fish Population Estimates 800 80 Abundance 70 Harvest 600 60 Harvest (thousands of metric tons) Abundance (kilograms/tow) 50 400 40 30 200 20 10 0 1960 1970 1980 1990 2000 Year

6. 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

7. Fishing Techniques

8. Fishing Methods • Harpoon - whales, swordfish, bluefin tuna • Pole and line - mahi-mahi and used for tuna extensively in the 50‘s • Longline - swordfish, tuna (pelagic); cod, halibut (bottom) • Trolling - salmon, albacore, mahi-mahi • Drift (gill) netting - various pelagic fish • Trawl - anchovies (pelagic); cod, halibut (bottom) • Purse seine - sardines, herring, mackerel • Traps and Pots - Crabs, lobster, rock fish

9. Gillnetting Uses curtains of netting suspended by a system of floats and weights Either anchored to sea floor or float at the sea surface Netting is almost invisible, fish swim right into it; and their gills get caught net size: 20 m x 65 km

10. Drift Netting Driftnets have earned the nickname “walls of death.” • Large floating nets • Unbreakable and invisible to most sea species • likely to entangle large pelagic species:dolphins, whales, sharks, turtles, and rays.

11. Longlining • Longlines are horizontal sets of fishing hooks • Set on the ocean floor: demersal longlines • Set near the surface: pelagic longlines • Longlines can be tens of kilometres long • Can carry thousands of hooks • Baited hooks are attached to the longline by short lines called snoods that hang off the mainline.

12. Not anchored; set to drift near the surface of the ocean • Attached radio beacon tracks line to haul in catch • Usually used to catch large tuna and billfish species.

13. Anchored to the sea floor. • Buoys mark line • Same as Pelagic longline in all other respects

14. Purse seine • Uses large wall of netting to encircle schools of fish • Drawstring pulls bottom of netting closed, like a purse • Herds schools of fish into center • Some purse seines can unintentionally catch other animals (dolphin caught when fishing for tuna) Animation

15. Trawl bottom midwater http://www.youtube.com/watch?v=bUHcD_jTgVA

16. Effects of Trawling on Coral Reefs http://www.eea.europa.eu/publications/report_2002_0524_154909/regional-seas-around-europe/page111.html

17. Trawl from space Gulf of Mexico, near Louisiana coast. Individual vessels can be seen as bright spots at end of sediment trails. Other bright spots are fixed oil and gas production platforms. One sediment trail can be traced for 27 km. Assuming a standard trawling speed of 2.5 knots, sediment from this trawl is visibly persistent for nearly 6 hours. Water depth <20m. Large, indistinct bright blue patches at lower left and upper right are cloud/haze. (Credit: Landsat)

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

19. Factory Ship Courtesy of Wikipedia Commons • Can haul in LARGE quantities of fish • Can process and freeze fish onboard • Up to 60 - 70 meters long • Can be at sea for six weeks at a time with a crew of over 35 people. • Types: demersal (weighted bottom trawling) • pelagic (mid-water trawling) • pair trawling, two vessels, 500 metres apart, both pull huge net with a mouth circumference of 900 meters

20. Pole / Troll • Uses fishing pole and bait to target fish • Environmentally responsible; alternative to longlining • pole/troll fishermen have very low bycatch rates.

21. Fisheries Problems & Solutions

22. Fisheries mismanagement • Overfishing • Commercial extinction • Bycatch (27 million metric tons annually) • Targeting smaller species on the low end of the food chain

23. Fisheries Problems & Solutions • Maximum sustainable yield: maximum amount of fish that can be harvested without depleting future stocks • World‘s maximum sustainable yield estimated at 100 to 135 million metric tons • Present harvests are at about 100 million metric tons • For fisheries where numbers available, estimated that 45% are currently over-fished • A number of fisheries have already collapsed (Anchovy fishery off Peru, Cod fishery in the N. Atlantic)

24. Fisheries Problems & Solutions F. Bycatch (or bykill): animals unintentionally killed during harvest of the target species Trawling: Bycatch in shrimp trawling is very high (125 to 830% of the catch is discarded as bycatch), turtles often caught in trawls. SOLUTION: trawls with trap doors to let turtles escape

25. Allows smaller fish to be caught • Allows turtles to escape • Lowers incidence of bycatch

26. Same concept as TEDs • Hatch kept open with inflatables

27. 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

28. Bycatch by Gear Type for 2002/2003

29. Purse seine: Tuna known to hang out under pods of dolphins, nets set around pods of dolphins would result in many drowning. SOLUTIONS: Nets not set around dolphin pods and/or employ — “backing down”, a technique that lowers upper edge of net letting dolphins escape Dolphins caught in tuna net

30. Fisheries Problems & Solutions Driftnets: indiscriminate entangling of many sorts of marine animals SOLUTION: banned in oceanic fisheries (but some countries still using them)

31. Fisheries Problems & Solutions • Long lining: Many albatross drown trying to snatch bait from long lines being deployed. snagged on hooks and pulled under. • SOLUTION: deploy in the dark or with special rig to let line out under water.

32. Global swordfish catch Ave. wt. in lbs http://www.pifsc.noaa.gov/wpacfin/hi/dar/Pages/hi_fish_2.php year

33. Artificial Reefs • Improve the local marine bio-density • attract schools of fish • providing habitats for the colonization of commercially valuable species • improve the local inshore marine harvest May wash up on beaches construction rubble tires ship wrecks

34. AquaCulture

35. Aquaculture (marine agriculture)- farming finfish, shellfish and algae under favorable conditions

36. One of every four fish eaten today was raised in either a fw or sw fish farm.

37. Aquaculture also produces: • Bait fish • Ornamental or aquarium fish • Aquatic animals used to augment natural populations • Algae for chemical extraction • Pearl oysters

38. History: • 2000 years ago in Egypt, Rome, China • <2000 years in Hawaii • 600 years ago France developed mussel aquaculture • 500 years ago Europe developed the idea of using pond fertilizer to promote plankton growth • 400 years ago China discovered that oysters would grow on bamboo stakes • 1960’s- Europe and U.S. catfish and salmon

39. Criteria for selecting species for farming: - inexpensive to grow - grows quickly - high sales price - resistant to disease and parasites

41. Hawaii open ocean aquaculture Mio, big eye tuna, yellow tail $34.7 million in 2008

42. 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

43. 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

44. 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

45. 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

46. 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

47. Trade-Offs Aquaculture Advantages Disadvantages 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 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 Aquaculture Methods Is Aquaculture the Answer?

48. Solutions 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

49. 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

50. MagnusonAct Establishes 200 mile fishing area Set up regional councils that Set quotas Set size limits Set seasons Protects habitat Minimizes bycatch Rebuilds overfished stocks Laws Related to Fishery Management • 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