OVERFISHING &

AQUACULTURE

WHERE DO WE GET THE FISH

AND SHELLFISH WE EAT?

Oceans and Fish Farms

7% of the global food supply comes from marine

organisms.

55% (3.8%) of our annual catch comes from the

oceans.

45% (3.2%) of our annual catch comes from

aquaculture.

Demersal

(mostly bottom dwelling)

Hake

Haddock

Cod

Pelagic

(surface dwelling)

Crustaceans Mollusks

Sardine Anchovy

Herring

Mackerel

Tuna

Krill

Shrimp

Lobster

Crab

Oyster Clam

Octopus

Squid

Fish Shellfish

Major Commercial Marine Speices

WHAT IS THE STATE OF

GLOBAL FISHERIES TODAY?

Dire Prediction for the Futurehttp://www.npr.org/templates/story/story.php?storyId=6469061

100

80

60

40

20

0

1950 1960 1970 1980 19902000

Year

Total World Fish Catch

Catc

h(m

illio

ns o

f m

etr

ic t

on

s)

Trend Toward Overfishing

WHAT ARE THE MAJOR FISHING

STRATEGIES USED?

Spotter airplane

Fish farmingin cage

Trawlerfishing

Purse-seinefishing

sonartrawl flap

trawl

lines

trawl bag

Long line fishing

lines with

hooks

Drift-net fishing

Fish caughtby gills

float buoy

fish school

Fishing Strategies

WHAT OTHER TECHNOLOGY

IS USED IN COMMERCIAL

FISHING?

Sonar Unit Used for Fishing

Scientists Use Satellites to Track Fishhttp://www.sfgate.com/cgi-bin/article.cgi?file=/chronicle/archive/1998/08/05/MN82865.DTL

Microwave Telemetryhttp://microwavetelemetry.com/Fish_PTTs/index.php

Monitoring Variables

Storage Capacity of Device

Signal Transmission Strength

Size of Device

Type of Monitor

WHAT PROBLEMS ARISE

FROM THESE FISHING

METHODS?

Bycatch

Refers to fish and

other marine life

caught "incidentally"

in the pursuit of

another species.

Results from use of

fishing gear and

practices that are not

selective.

Common Bycatch Organisms

Turtles

Starfish

Sponges

Skates

Bycatch Variables

Species

Size

Sex

Quality

WHAT LAWS GOVERN

GLOBAL FISHING?

Magnuson-Stevens Fishery Conservation and Management Act (1976)

http://www.mms.gov/eppd/compliance/fcma/index.htm

Law Variables

specify a time frame in which to end overfishing

and rebuild overfished stocks that is as short as

possible

the biology of the stock

the needs of fishing communities

recommendations by international organizations

the interaction of the overfished stock within the

marine ecosystem.

WHAT ORGANIZATIONS ARE

WORKING TO RESTORE

GLOBAL FISHING?

Marine Stewardship Councilhttp://www.msc.org/html/content_458.htm

CAN ARTIFICIAL REEFS HELP

RESTORE MARINE

ECOSYSTEMS?

Artificial Reefs

Concrete blocks

Acres of old cars

Drug transport vessels

Oil Rigs

Artificial Reefs Help Dolphinshttp://archives.cnn.com/2000/NATURE/05/16/hong.kong.dolphins.enn/

Artificial Reefs - Cons

Represent an inexpensive way to throw out trash

Cause damage to natural habitats during their

construction

Can displace naturally occurring species and

habitats

Tend to concentrate fish unnaturally, making them

more vulnerable to overfishing

CAN AQUACULTURE HELP

RESTORE FISH POPULATIONS?

Types of Aquaculture

Fish Farming

Fish Ranching

Norway’s Fish Farms in Dangerhttp://www.npr.org/templates/story/story.php?storyId=17638050