Fisheries

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Fisheries
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http//www.pbs.org/emptyoceans/
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• Traditional food production and distribution
  practices are unable to feed the worlds 6.3
  billion people
• Will resources in the sea be able to provide
  enough food to alleviate future problems of
  malnutrition and starvation ?

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

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Location of the worlds major commercial fisheries
coastal areas
upwelling
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• 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

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Global Fish Catch
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World Commercial Catch of Marine Fishes,
Crustaceans, and Mollusks (1995)
cod
Species Group Millions of Metric Tons, Live
Wt. Herrings, sardines, anchovies 22.0 Jacks,
mullets, sauries 11.2 Mollusks 11.0 Cods,
hake, haddock 10.6 Redfish, basses, conger
eels 7.0 Crustaceans 4.8 Tunas, bonitos,
billfish 4.7 Mackerel, snooks, cutlass
fishes 4.7 Flounders, halibut, soles
0.9 Miscellaneous marine fishes 17.7 Total
(excluding marine mammals) 94.6
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Food Non-Food Products
from the Sea
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• 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

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• Food from the Sea
• Seaweeds
• Invertebrates (e.g., oysters, clams, crabs,
  lobster, squid, etc.)
• Fish (herring, mackerel, haddock, cod, tuna,
  mahi-mahi, etc.)
• Whales

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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

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Fisheries Mismanagement
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Fisheries mismanagement

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

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Bycatch by Gear Type for 2002/2003
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Euphausia superba
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Who eats Krill?
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Krill the Antarctic Food Web
Critical components of Antarctic food webs
Killer whales
Sperm whales
Penguins winged birds
Pelagic fishes
Seals
Baleen whales
Carnivorous zooplankton
Squid
Krill
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• Krill Fishery
• Annual consumption by natural predators 470
  million MT
• 1972 Japan and Russia began harvesting krill

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Krill Fishery

• Potential harvest 25-30 million MT/yr
• Economic cost of fishery high
• Patchy distribution complicates location
• Depths may be 150-200m
• Single net haul may collect 10 MT
• Ecological consequences of removal poorly
  understood

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Peru Anchovy Fishery
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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

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Peru Anchovy Fishery
El Niño 1957 1965 1972 1976 1982-83
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Peru Anchovy Fishery
Normal Year
El Niño Year
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• Collapse of New England Fisheries
• Cod, haddock, ocean perch, herring, mackerel,
  blue fin tuna
• Georges Bank- highly productive, nutrient rich
  environment
• Prior to 1976, Russia, Japan, Norway, West
  Germany fished in Georges Bank

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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
collapse Some fish stocks begin to rebound
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Fisheries Management Council
The Magnuson Act created 8 regional fisheries
management councils for U.S. waters and regions
New England FMC (Saugus, MA) Mid-Atlantic
FMC (Dover, DE) South Atlantic (Charleston,
SC) Gulf of Mexico FMC (Tampa,
FL) Caribbean (San Juan, PR)
North Pacific FMC (Anchorage, AK) Pacific
FMC (Portland, OR) Western Pacific
FMC (Honolulu, HI)
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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
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Salmon

• Anadromous fish that migrate from sw to fw to
  spawn
• Spawning grounds affected by dam construction
• Aquaculture and restocking efforts

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Fish Ladders
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Alaska Fisheries

• Halibut and sablefish
• IFQ
• Limited entry

c1930s
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Shark Overfishing

• Slow growth
• Low reproductive rate
• Late sexual maturity

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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

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Fishing Techniques
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• Fishing Methods
• Harpoon - whales, swordfish, bluefin tuna
• Pole and line - mahi-mahi and used for tuna
  extensively in the 50s
• 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

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Drift Net
net size 20 m x 65 km
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Longlining
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Gill net
Bottom-dwelling fish
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Purse seine
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Trawl
bottom
midwater
http//www.youtube.com/watch?vbUHcD_jTgVA
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Before trawl
After trawl
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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 lt20m. Large, indistinct bright blue
patches at lower left and upper right are
cloud/haze. (Credit Landsat)
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Laws of the Sea Treaty
Allow nations to claim jurisdiction over their
territorial seas (contiguous sea beds and their
waters that extend off shore by 12 nautical miles)

• Exclusive Economic Zone (EEZ)
• 200 nautical miles
• under direct control of the country that owns the
  nearest land

• Regulates continental shelf resources
• Fishing
• Mineral exploration
• Scientific research

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Exclusive Economic Zone of the United States
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Fisheries Problems
Solutions
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• Fisheries Problems Solutions
• Maximum sustainable yield maximum amount of fish
  that can be harvested without depleting future
  stocks
• Worlds 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)

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

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Global swordfish catch
Ave. wt. in lbs
http//www.pifsc.noaa.gov/wpacfin/hi/dar/Pages/hi_
fish_2.php
year
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Mariculture
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Mariculture or Aquaculture (marine
agriculture)- farming finfish, shellfish and
algae under favorable conditions
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One of every four fish eaten today was raised
in either a fw or sw fish farm.
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• Aquaculture also produces
• Bait fish
• Ornamental or aquarium fish
• Aquatic animals used to augment natural
  populations
• Algae for chemical extraction
• Pearl oysters

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• History
• 2000 years ago in Egypt, Rome, China
• lt2000 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
• 1960s- Europe and U.S. catfish and salmon

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Criteria for selecting species for
farming - inexpensive to grow - grows
quickly - high sales price - resistant to
disease and parasites
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• Problems associated with Mariculture
• Wont 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

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Hawaii open ocean aquaculture
Mio, big eye tuna, yellow tail
34.7 million in 2008
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Hawaiian Fish Ponds
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TheAhupuaa
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• Molokai South Coast
• The ponds walls were made from lava boulders and
  coral.
• Walls keep the fish inside while allowing the sea
  water to ebb in and out.

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• 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.

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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
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Papahanaumokuakea Marine National Monument
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Hawaii Seafood Guide 2007
http//www.mbayaq.org/cr/cr_seafoodwatch/download.
asp
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Hawaii Seafood Guide 2007
Catfish (farmed imported) Crab, Kona Groupers
(NWHI) Lobster (American/Maine) Octopus
(Hawaii) Squid Trevally/Jack (Hawaii) Tuna,
canned Tuna, Skipjack (Hawaii longline)
Chilean Seabass Cod, Atlantic Mahi mahi (imported
longline) Salmon (farmed) Sharks Shrimp
(imported) Swordfish (imported) Orange
roughy Tuna, Albacore (worldwide except
Hawaii) Tuna Bige Eye (longline) Tuna bluefin
Barramundi (U.S. farmed) Clams (farmed) Crab,
dungeness Halibut (Pacific) Salmon(wild) Swordfish
(Hawaii) Tilapia (farmed) Skip-jack tuna
(troll/poll, handline)
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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.