Fisheries 017

Fisheries

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http://www.pbs.org/emptyoceans/

• Traditional food production and distribution practices are unable to feed the world’s 6.3+ billion people

• Will resources in the sea be able to provide enough food to alleviate future problems of malnutrition and starvation ?

Most valuable living marine resources:• Demersal fish• Pelagic fish• Crustaceans• Mollusks• Marine mammals

Location of the world’s major commercial fisheries

upwellingcoastal areas

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

Global Fish Catch

World Commercial Catch of Marine Fishes, Crustaceans, and Mollusks (1995) cod

Species Group Millions of Metric Tons, Live Wt.Herrings, sardines, anchovies 22.0Jacks, mullets, sauries 11.2Mollusks 11.0Cods, hake, haddock 10.6 Redfish, basses, conger eels 7.0Crustaceans 4.8Tunas, bonitos, billfish 4.7Mackerel, snooks, cutlass fishes 4.7Flounders, halibut, soles 0.9Miscellaneous marine fishes 17.7Total (excluding marine mammals) 94.6

Non-Food Products from the Sea

• Bioactive Compounds

• Algin & Agar: products from seaweed

• Whales: Oil for lubrication, in cosmetics, bones for fertilizer

• Seals and sea lions: furs

Food from the Sea

• Seaweeds

• Invertebrates (e.g., oysters, clams, crabs, lobster, squid, etc.)

• Fish (herring, mackerel, haddock, cod, tuna, mahi-mahi, etc.)

• Whales

Fisheries management• Fisheries management

seeks to maintain a long-term fishery by: – Assessing ecosystem health– Determining fish stocks– Analyzing fishing practices– Enforcing catch limits

• Fisheries management does not regulate the number of fishing vessels

Fisheries Mismanagement

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

the food chain

Bycatch by Gear Type for 2002/2003

Peru Anchovy Fishery

Peru Anchovy Fishery

• Upwelling zone off Peru

• Fishery began 1950

• Greatest fish catches for any single species

• Fish exported for domestic animal feed

• Fishery collapsed due to El Niño and overfishing

= El Niño19571965197219761982-83

Peru Anchovy Fishery

Peru Anchovy Fishery

Normal Year

El Niño Year

Collapse of New England Fisheries

• Cod, haddock, ocean perch, herring, mackerel, blue fin tuna

• George’s Bank- highly productive, nutrient rich environment

• Prior to 1976, Russia, Japan, Norway, & West Germany fished in Georges Bank

Collapse of New England Fisheries

Magnuson Act passed & prevented foreigners from fishing in U.S. waters

Fishery technology intensified and resulted in overfishing

Harvests were beyond the max. sustainable yield

Georges Bank closes after collapseSome fish stocks begin to rebound

Fisheries Management Council

The Magnuson Act created 8 regional fisheries management councils for U.S. waters and regions:

North Pacific FMC

(Anchorage, AK)

Pacific FMC

(Portland, OR)

Western Pacific FMC

(Honolulu, HI)

New England FMC

(Saugus, MA)

Mid-Atlantic FMC

(Dover, DE)

South Atlantic

(Charleston, SC)

Gulf of Mexico FMC

(Tampa, FL)

Caribbean

(San Juan, PR)

Fisheries Management Plans

Congress directed the Councils to manage federal fisheries by creating

Fisheries Management Plans or “FMPs” by:

1. Identifying fish species that need management

2. Analyzing the biological, environmental, economic and social factors that affect the fishery

3. Preparing (and modifying, as necessary) an FMP to protect fishery resources while maintaining opportunities for domestic commercial and recreational fishing

Salmon• Anadromous fish that

migrate from sw to fw to spawn

• Spawning grounds affected by dam construction

• Aquaculture and restocking efforts

Fish Ladders

Alaska Fisheries

• Halibut and sablefish • IFQ• Limited entry c1930’s

Shark Overfishing

• Slow growth• Low reproductive rate• Late sexual maturity

Orange Roughy

• Distribution: world wide, high concentrations in New Zealand

• Found: 700-1000m depth• Life span: slow-growing, long-lived, ~150 years• Size: 30-40 cm• Diet: prawns, fish, & squid• Reproductive age: 25-30 years old

Fishing Techniques

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

Drift Net

net size: 20 m x 65 km

Longlining

Gill net

Bottom-dwelling fish

Purse seine

Trawl

midwater

bottom

http://www.youtube.com/watch?v=bUHcD_jTgVA

Before trawl

After trawl

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)

Fisheries Problems & Solutions A. Maximum sustainable yield: maximum amount of

fish that can be harvested without depleting future stocks

B. World‘s maximum sustainable yield estimated at 100 to 135 million metric tons

C. Present harvests are at about 100 million metric tons

D. For fisheries where numbers available, estimated that 45% are currently over-fished

E. A number of fisheries have already collapsed (Anchovy fishery off Peru, Cod fishery in the N. Atlantic)

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

Dolphins caught in tuna net

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

Fisheries Problems & Solutions

Driftnets: indiscriminate entangling of many sorts of marine animals SOLUTION: banned in oceanic fisheries (but some countries still using them)

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.

Global swordfish catch

http://www.pifsc.noaa.gov/wpacfin/hi/dar/Pages/hi_fish_2.php

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N. AtlanticSwordfish

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Mariculture or Aquaculture (marine agriculture)- farming finfish, shellfish and algae under favorable conditions

Big Island, Kona, Tilapia

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

84% of the 6 million to 7 million tons of seafood consumed each year in the U.S. is imported . About ½ comes from aquaculture. H. Jones, Time, 2011.

Aquaculture also produces:• Bait fish• Ornamental or aquarium fish• Aquatic animals used to

augment natural populations• Algae for chemical extraction• Pearl oysters

• 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

History:

TheAhupua‘a

TheAhupua‘a

Molokai: South Coast• The pond’s walls were made from lava

boulders and coral.• Walls keep the fish inside while allowing the

sea water to ebb in and out.

Types of fish raised in ponds:

• ulua (papio)

• owama (goatfish)

• kahala (amberjack)

• manini (convict tang)

• palani (surgeon)

• oio (bonefish)

• uhu (parrotfish)

These fish were kept in a separate pond to breed and raised so they could easily be harvested by hand.

Criteria for selecting species for farming:

- inexpensive to grow

- grows quickly

- high sales price

- resistant to disease and parasites

tilapia barramundi catfish

Problems associated with Mariculture:

• Won’t make a dent in the shortfall in food supply

• Fish food- fish meal • Pollution • Escapees• Loss of natural habitat• Loss of genetic diversity• High stress overcrowding pens• High concentration of

pathogens/parasites

Overcrowded Pens

Salmon with lice

Parasites & Disease

Pollution Under a salmon farm cage

Fish Vaccination

Integrated Aquaculture

Aquaponics

Hawaii open ocean aquaculture

Mio, big eye tuna, yellow tail

$34.7 million in 2008

Artificial ReefsImprove the local marine bio-density

1. attract schools of fish 2. providing habitats for the colonization

of commercially valuable species3. improve the local inshore marine

harvest

May wash up on beaches

tires ship wrecks construction rubble

T

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Papahānaumokuākea Marine National Monument

http://www.mbayaq.org/cr/cr_seafoodwatch/download.asp

HawaiiSeafood Guide

2007

Barramundi (U.S. farmed)Clams (farmed)Crab, dungenessHalibut (Pacific)Salmon(wild)Swordfish (Hawaii)Tilapia (farmed)Skip-jack tuna (troll/poll, handline)

HawaiiSeafood Guide

2007

Chilean SeabassCod, AtlanticMahi mahi (imported longline)Salmon (farmed)SharksShrimp (imported)Swordfish (imported)Orange roughyTuna, Albacore (worldwide except Hawaii)Tuna Bige Eye (longline)Tuna bluefin

Catfish (farmed imported)Crab, KonaGroupers (NWHI)Lobster (American/Maine)Octopus (Hawaii)SquidTrevally/Jack (Hawaii)Tuna, cannedTuna, Skipjack (Hawaii longline)

Inquiry

1. What problems are associated with aquaculture?

2. What does fisheries sustainability mean?

3. What occurred shortly after the Magnuson Act was passed?

4. Define the EEZ.5. What contributed to the demise of the

Peru anchovy fishery?6. Discuss technology changes in the

fishing industry in the last 100 years.