MPA- Again

John McManus jmcmanus at
Wed Mar 13 12:27:57 EST 2002

I think you may be asking for something that is either ten years away or not
even possible. In the papers you have seen cited, there are several examples
in which the increases in fish biomass were documented and others in which
the total fisheries return was compared with and without the reserve. If you
put a no-take zone in amidst heavy overfishing, the chances are very high
that you will get more fish biomass in the reserve over time. As far as how
much fisheries production you will get -- that is a very site specific and
depends on many variables. I think in 5 or 10 years, the new agent-based
modeling approaches many of us are working on may be able to give a crude
idea of what that production might or might not be given specifics from your
situation. However, you are talking about a complex ecological problem that
is always likely to have a high degree of uncertainty in the "numbers". I
agree that we need to do a lot more work in support of management
decision-making. However, we certainly have enough information now on which
to take action.

Note that this is not much different than making predictions on the stock
market (where the same new modeling approach is increasingly used). If we
expect to make management decisions in the absence of uncertainty, we may
have an infinite wait.




John W. McManus, PhD
Director, National Center for Caribbean Coral Reef Research (NCORE)
Rosenstiel School of Marine and Atmospheric Sciences (RSMAS)
University of Miami, 4600 Rickenbacker Causeway
Miami, Florida 33149.
jmcmanus at
Tel. (305) 361-4814
Fax (305) 361-4600

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