Download Non-Food Products from the Sea

• Traditional food production and
distribution practices are unable
to feed the world’s 7+ 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 (bottom dwellers)
• Pelagic fish (free-swimming mid/upper
dwellers)
• Crustaceans
• Mollusks
• Marine mammals
Location of the world’s major commercial fisheries
coastal areas
upwelling
Non-Food Products from the Sea
• Bioactive Compounds (drugs and
insecticides)
• Algin & Agar: products from seaweed
use for promoting gel formation
• 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 – international moratorium imposed in
1987; no commercial whaling permitted since
with limited exceptions
Case Study: Peru Anchovy Fishery
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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
and has NEVER recovered
Peru Anchovy Fishery
= El Niño
1957
1965
1972
1976
1982-83
Peru Anchovy Fishery
Peru Anchovy Fishery
Normal Year
El Niño Year
Case Study: 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-Stevens Act of 1976 prevented
foreigners from fishing in U.S. waters
• Fishery technology intensified and resulted
in overfishing – yields well beyond
sustainable levels
• Georges Bank closed indefinitely after
collapse in ~1994
• Some fish stocks have begun to rebound
Fisheries Management Council
The revised Magnuson Act in 2007 created 8 regional
fisheries management councils.
Overfished stocks as of 2010
Fisheries Management Plans
Congress directed the Councils to create Fisheries
Management Plans or “FMPs” for each species
•
Primarily concerned with balancing growth of stocks
with commercial needs
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Established annual catch limits or acceptable biological
catch
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Attempted to end overfishing and help stocks recover
Major critics say that the fisheries are still about to crash
and that the Councils are mismanaged and ineffective
• Heavily revised in 2010 to be community-based
initiatives and saw increased prices with less but more
responsible catches as a result in experimental areas
Fishing Techniques
Fishing Methods
• Longline – baited hooks (100’s to many
thousands) along a long line; used for swordfish, tuna
(pelagic); cod, halibut (bottom)
• Trolling – many lines with single hooks slowly
dragged through the water; use for salmon, albacore,
mahi-mahi
Fishing Methods
• Drift (gill) netting – vertical nets hung in the
water to trap passing fish
• highly controversial!
• banned by UN, US limits length to ~1.7 miles
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used to catch various pelagic fish
Drift Net
net size:
20 m x 65 km
Fishing Methods
• Trawl – large “pouch” dragged through
water/across bottom; used for anchovies (pelagic); cod,
halibut (bottom)
• Purse seine – net is wrapped around a school
of surfacing or near surfacing fish; used for sardines,
herring, mackerel, tends to accidentally snare any predators like
dolphins
Trawl
bottom
midwater
Before trawl
After trawl
Fishing Methods
• Traps and Pots - Crabs, lobster, rock fish
• Main problem with most methods is “bycatch” –
nontarget species caught and usually killed
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)
1. 200 nautical miles (230 land miles)
2. under direct control of the country that owns the
nearest land
Regulates continental shelf resources:
• Fishing
• Mineral exploration
• Scientific research
Exclusive Economic Zone of the United States
Mariculture or Aquaculture
(marine agriculture)- farming
finfish, shellfish and algae under
favorable conditions
Big Island, Kona, Tilapia
Aquaculture also produces:
• Bait fish
• Ornamental or aquarium fish
• Aquatic animals used to
augment natural populations
• Algae for chemical extraction
• Pearl oysters
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
• High stress overcrowding pens
• High concentration of pathogens/parasites
Overcrowded Pens