From
the Editor
This special issue of the bulletin is devoted to the topic of reef fish
aggregations. Spawning aggregations are a fascinating phenomenon, and they are
of critical importance when it comes to the challenge of managing reef fish
resources effectively. This issue was compiled in recognition of that
importance. Its intent is to provide a focus on the topic of reef fish
aggregations, especially as they relate to fisheries for live fish, and to
highlight recent
progress in aggregation research and management.
The following articles document recent efforts to study and manage
spawning aggregations in Papua New Guinea, Solomon
Islands, Pohnpei and Palau, and they focus on the grouper
species that dominate the trade in live reef food fish. The articles
pay particular attention to the three groupers that are among the
most valuable species in the trade and whose spawning aggregations
in the Indo-Pacific tend to share the same sites and times.
These three species, which make up Yvonne Sadovy’s “trysting
trio” in the article that follows, are Epinephelus fuscoguttatus,
E. polyphekadion and Plectropomus areolatus (with some region-specific
substitutions and additions — see the articles by Sadovy
and by Hamilton and coauthors).
Richard Hamilton and coauthors share some of the rich local
knowledge of aggregation sites and patterns held by fishing
communities in Papua New Guinea and Solomon Islands. The
authors’ interviews with fishers in four study areas reveal
detailed information about the dynamics and status of aggregations
at no less than 50 grouper aggregation sites.
Kevin Rhodes and coauthors summarize the results from four
years of underwater surveys of a grouper-trio aggregation site in
Pohnpei and discuss how the results can be used to devise more effective
conservation measures for aggregating fish populations.
Yvonne Sadovy and coauthors discuss various ways to track the status of
aggregations over time, focusing on underwater monitoring methods. They
highlight the difficulties — in terms of both survey design and practice — that
must be overcome in order to obtain information that is truly valuable for
management.
Finally, Terry Donaldson summarizes the ongoing aggregation studies
in Micronesia, Melanesia and Asia conducted by the University of Guam Marine
Laboratory and its partners.
All these articles deal with the effects of fishing on aggregations and on
fish populations that aggregate. A common theme, not surprisingly, is that many
aggregating populations are in trouble from fishing, and not just from live food
fish fisheries. Hamilton and coauthors find that “What is more startling [than
the effects of the live reef food fish trade] is the dramatic impact that recent
artisanal night-time spearfishing appears to be having on [grouper aggregation
sites] throughout Melanesia.” The assessment of management options provided by
Rhodes and coauthors for the case of Pohnpei takes into account a similar
finding: “the removal of reproductively active fish for subsistence use may
equal or exceed that of commercial catch….”
In 1999, Bob Johannes and coauthors commented that “Researchers and fisheries
managers in the western Atlantic have a substantial lead over those elsewhere in
their employment of management measures focusing on spawning aggregations.”(1) The
articles in this bulletin are evidence that this lead is eroding. Although this
small collection does not represent all the recent progress in the Indo-Pacific,
it reflects the growing momentum in documenting and monitoring aggregations and
the increasing efforts to use the resulting information to effectively manage
the region’s reef fish resources (efforts that I’m sure these authors would say
are not yet enough).
Tom Graham
1. Johannes R.E., Squire L., Graham T., Sadovy Y. and Renguul H. 1999.
Spawning aggregations of groupers (Serranidae) in Palau. Marine Research Series
Publication No. 1. The Nature Conservancy.
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