Marine Biology 1060            Chapter 16                Study Guide

Selected topics from Resources from the sea

Terms:

fin fish            shellfish                fish protein         fish meal        bycatch        fish oil        renewable resources
maximum sustainable yield        fishing effort        exclusive economic zone (EEZ)            mariculture
salmon ranching                        shrimp farming

Concepts:

I. General
    A. Some important numbers to know:
        1. 6 billion people on earth
        2. Total world marine catch is currently about 150 million metric tons
        3. 15% of all protein eaten by humans globally comes from marine food sources
        4. as populations have increased, the per capita catch has gone down by 7% since it's peak in 1989
        5. Americans consume as average of 42 lb. per capita/year of seafood
        6. Most industrialized fishing nations have experienced a reduction in catch since 1989
        7. $16-21 billion dollars in subsidy are paid to fishing industries worldwide each year
        8. only about 1/3 of the by-catch is ever utilized - most is simply discarded dead

II. Examples of fisheries that are experiencing reduction or collapse of fisheries
    A. Grand Banks and George's Banks both have collapsed cod fisheries since 1994 - complete fishing ban
    B. Southeast Pacific Sardine fisheries collapsed in the 1940's
    C. Swordfish are close to commercial extinction - populations have fallen by 70% since 1960 and today,
            88% caught are juveniles too young to have reproduced
    D. Blue fin Tuna populations are currently only 10 % of their original sizes ( Goes as high as $350 lb. in Japanese markets)
    E. All major fishery species are showing declines largely due to over fishing

III. Management of marine fisheries:
    A. United Nations Convention on the Law of the Sea - 1989 - allowed the establishment of a
            200 mile offshore Exclusive Economic Zone
            1. allows nations to regulate fishing and marine resource use within the 200 mile EEZ
            2. first time that marine resources could be managed for the exclusive utilization of one nation
    B. Many marine fisheries are managed using a Maximum Sustainable Yield Model
        1. adult organisms are removed from the population to a level that will leave just enough
            individuals to breed and replenish the population
        2. this model does not appear to have prevented declines nor crashes to many fisheries populations
            a. usually based on counts of alone
            b. too many variables to use a simple model such as this for prediction
            c. many species appear to have a critical lower limit beyond which they simply do not recover
                1. example : Newfoundland Grand Banks Cod fisheries have not recovered even though all
                    fishing has been banned for many years
        3. new, dynamic models for conservation an management are needed
    C. Some new directions
        1. mariculture of: shrimp, salmon, lobster, flounder, oyster, scallop
        2. development of new fisheries ; Krill in particular as a protein source
        3. required utilization of most by-catch