579
13 Conclusion
(i.e. farming of marine species). Both depend on proper management being in place
and that usually involves some control on fi shing effort. Moreover, restocking may
not be effective for the recovery of much depleted aggregating species if information
on aggregation location is traditionally transmitted. Moreover, while mariculture is
an additional means of production, it is not a solution to overfi shing unless directly
linked i.e. unless 1 tonne produced by mariculture reduces fi shing pressure by 1 tonne.
To our knowledge this does not occur in practice.
13.4 Key Scientifi c Data Gaps for Aggregating Species
A number of fundamental gaps in knowledge impede our ability to effectively
manage aggregation-based fi sheries and to protect threatened and endangered
species that form aggregations. From the work presented in this book, we identify
13 key areas that call for greater attention and suggest possible means and approaches
for addressing them.
Hypothesis testing on why aggregation sites and times are important. Such ques•
tions have bearing on their long-term persistence, the need to manage them, the
risks of losing them, etc.
There remains a need for empirical data on the effects of reduced aggregation
•
sizes on reproductive activity to determine whether minimum threshold sizes
exist below which spawning ceases in small aggregations. Related to this is the
question of whether extirpated aggregations can reform after protection. Also
relevant is a better understanding of how population abundance and density levels
affect aggregation formation and mating behaviour.
There is a dearth of information on the biological and socioeconomic effects of
•
different management policies on aggregations and the fi sheries of aggregating
species at both aggregating and non-aggregating times.
More effort is needed to directly survey and monitor known aggregations, since
•
fi sheries data may not refl ect the status of aggregations (i.e. due to hyperstability).
New technologies to survey aggregations at locations where diver surveys may or
may not be possible need careful ground-truthing. Hydroacoustic surveys are
perhaps the best example of the need for independent ground-truthing. New
video and photographic techniques, with sophisticated image-processing, hold
much promise for quantifying aggregations. Methods for counting fi sh in large
three-dimensional groupings, such as some snappers and the Nassau grouper,
need to be developed.
Justifi cations for the management or protection of aggregation sites are
•
needed, based on economic analyses of aggregation fi sheries, alternative use
activities, assessments of the importance of their fi shery and ecosystem value,
and consideration of aggregation sites for inclusion as important biodiversity areas,
ecosystem-based management, and ecotourism, etc. The long-term economic
benefi ts of the complete protection of aggregations, as sources of young for
exploitation in the non-reproductive season, need serious consideration.
13 Conclusion
(i.e. farming of marine species). Both depend on proper management being in place
and that usually involves some control on fi shing effort. Moreover, restocking may
not be effective for the recovery of much depleted aggregating species if information
on aggregation location is traditionally transmitted. Moreover, while mariculture is
an additional means of production, it is not a solution to overfi shing unless directly
linked i.e. unless 1 tonne produced by mariculture reduces fi shing pressure by 1 tonne.
To our knowledge this does not occur in practice.
13.4 Key Scientifi c Data Gaps for Aggregating Species
A number of fundamental gaps in knowledge impede our ability to effectively
manage aggregation-based fi sheries and to protect threatened and endangered
species that form aggregations. From the work presented in this book, we identify
13 key areas that call for greater attention and suggest possible means and approaches
for addressing them.
Hypothesis testing on why aggregation sites and times are important. Such ques•
tions have bearing on their long-term persistence, the need to manage them, the
risks of losing them, etc.
There remains a need for empirical data on the effects of reduced aggregation
•
sizes on reproductive activity to determine whether minimum threshold sizes
exist below which spawning ceases in small aggregations. Related to this is the
question of whether extirpated aggregations can reform after protection. Also
relevant is a better understanding of how population abundance and density levels
affect aggregation formation and mating behaviour.
There is a dearth of information on the biological and socioeconomic effects of
•
different management policies on aggregations and the fi sheries of aggregating
species at both aggregating and non-aggregating times.
More effort is needed to directly survey and monitor known aggregations, since
•
fi sheries data may not refl ect the status of aggregations (i.e. due to hyperstability).
New technologies to survey aggregations at locations where diver surveys may or
may not be possible need careful ground-truthing. Hydroacoustic surveys are
perhaps the best example of the need for independent ground-truthing. New
video and photographic techniques, with sophisticated image-processing, hold
much promise for quantifying aggregations. Methods for counting fi sh in large
three-dimensional groupings, such as some snappers and the Nassau grouper,
need to be developed.
Justifi cations for the management or protection of aggregation sites are
•
needed, based on economic analyses of aggregation fi sheries, alternative use
activities, assessments of the importance of their fi shery and ecosystem value,
and consideration of aggregation sites for inclusion as important biodiversity areas,
ecosystem-based management, and ecotourism, etc. The long-term economic
benefi ts of the complete protection of aggregations, as sources of young for
exploitation in the non-reproductive season, need serious consideration.