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P.L. Colin
9.5 Additional Information on Methods: Biological, Physical
and Sociological
The previous section was intended to provide only brief descriptions of available
techniques, but not include detailed information on any particular technique.
Additional information on some techniques is provided in the following section.
Most are techniques the author believes hold promise for high quality data return
with acceptable levels of effort and skills required.
9.5.1 Discovery of Aggregations
Most spawning aggregations were revealed to researchers through interviews with
fi shers as “traditional, or local, knowledge” passed down orally through generations
of fi shers, or as relatively new knowledge gained recently by commercial fi shers.
Traditional knowledge is common in Pacifi c Island cultures (Johannes 1981 ; Aswani
and Hamilton 2004 ) and to a lesser degree in some Caribbean cultures (Craig 1966 ) .
Active programmes are recording and verifying this information. Techniques for
interviews of fi shers are discussed in Chap. 10 . Older commercial fi shers from
“non-traditional” societies are often important sources of additional information.
For example, the discovery of spawning aggregations of mutton snapper, Lutjanus
analis , off the Dry Tortugas, Florida, USA, was made by commercial fi shers, who
shared their proprietary knowledge with scientists and managers (Burton et al. 2005 ) .
Seldom do researchers actually encounter unknown or undocumented aggregations, but this can occur, particularly for species of limited commercial importance
that are not searched for by fi shers (Randall and Randall 1963 ) . It may also happen
in the case of dive guides who spend a lot of time in the water. The chances of success in locating unknown aggregations can be increased by searching during periods
when many species are aggregating, such as the month and the lunar phase for
aggregation by a given species in the region, examination of market samples to
identify spawning periods, or searching in types of habitats known to harbour aggregations elsewhere. Visiting shelf edge Caribbean reefs around the full moon of
December through May, for example, might reveal new aggregations of species
already known to aggregate at such times and locations in the region. In Palau the
humphead wrasse, Cheilinus undulatus , spawns on outer reef faces, both along
straight sections of reefs and near promontories (Colin 2010 ) and several new aggregations were located in Palau by searching at times when aggregation and spawning
were occurring at known sites. Towing a diver or snorkeler behind a boat might be
productive as much more area can be covered compared to a normal SCUBA dive.
This approach is useful for species that can vary somewhat in their aggregation
area between years, such as the red hind (e.g. Kadison et al. 2006 ) . Gathering new
information about species already known to aggregate somewhere else is valuable,
and helps improve the overall perspective of what aggregations mean biologically,
P.L. Colin
9.5 Additional Information on Methods: Biological, Physical
and Sociological
The previous section was intended to provide only brief descriptions of available
techniques, but not include detailed information on any particular technique.
Additional information on some techniques is provided in the following section.
Most are techniques the author believes hold promise for high quality data return
with acceptable levels of effort and skills required.
9.5.1 Discovery of Aggregations
Most spawning aggregations were revealed to researchers through interviews with
fi shers as “traditional, or local, knowledge” passed down orally through generations
of fi shers, or as relatively new knowledge gained recently by commercial fi shers.
Traditional knowledge is common in Pacifi c Island cultures (Johannes 1981 ; Aswani
and Hamilton 2004 ) and to a lesser degree in some Caribbean cultures (Craig 1966 ) .
Active programmes are recording and verifying this information. Techniques for
interviews of fi shers are discussed in Chap. 10 . Older commercial fi shers from
“non-traditional” societies are often important sources of additional information.
For example, the discovery of spawning aggregations of mutton snapper, Lutjanus
analis , off the Dry Tortugas, Florida, USA, was made by commercial fi shers, who
shared their proprietary knowledge with scientists and managers (Burton et al. 2005 ) .
Seldom do researchers actually encounter unknown or undocumented aggregations, but this can occur, particularly for species of limited commercial importance
that are not searched for by fi shers (Randall and Randall 1963 ) . It may also happen
in the case of dive guides who spend a lot of time in the water. The chances of success in locating unknown aggregations can be increased by searching during periods
when many species are aggregating, such as the month and the lunar phase for
aggregation by a given species in the region, examination of market samples to
identify spawning periods, or searching in types of habitats known to harbour aggregations elsewhere. Visiting shelf edge Caribbean reefs around the full moon of
December through May, for example, might reveal new aggregations of species
already known to aggregate at such times and locations in the region. In Palau the
humphead wrasse, Cheilinus undulatus , spawns on outer reef faces, both along
straight sections of reefs and near promontories (Colin 2010 ) and several new aggregations were located in Palau by searching at times when aggregation and spawning
were occurring at known sites. Towing a diver or snorkeler behind a boat might be
productive as much more area can be covered compared to a normal SCUBA dive.
This approach is useful for species that can vary somewhat in their aggregation
area between years, such as the red hind (e.g. Kadison et al. 2006 ) . Gathering new
information about species already known to aggregate somewhere else is valuable,
and helps improve the overall perspective of what aggregations mean biologically,