273
8 Fishery and Biological Implications of Fishing Spawning Aggregations…
numbers, sizes and catchment areas of aggregating fi sh, market prices of fi sh, biological impacts of overexploitation of reproductive fi sh on the overall fi shery, basic
fi shery parameters and percentage of annual catch from aggregations, fi shing costs,
profi tability, general market conditions of supply and demand under different scenarios, and differences in catchability between spawning and non-spawning periods. The value and characteristics of the non-aggregation fi shery component with or
without aggregation management also need assessment.
8.7.5 Advantages of Fully Protected Aggregations
and Implications
If certain aggregation sites are closed to fi shing, other human use activities will
usually need to be implemented to mitigate economic losses from fi shing restrictions. These may include the introduction of diving charts to view aggregations or
training for catch-and-release sportfi shing of aggregations. Before such activities
can be offered as alternative uses, however, it must be considered whether the
alternatives could themselves potentially have negative impacts on reproductive
activity requiring specifi c management steps. Therefore, studies which focus on
understanding how the presence of divers, the use of various fi shing gears, and
catch-and-release fi shing activities affect mating behaviour or survivorship are
needed. While divers can evidently approach some species without apparent impact
(as in the case of spawning cubera snapper in Belize), or species may be habituated
to divers, little attention has been paid to this subject to date. In the case of the
humphead wrasse (or Napoleon fi sh) Cheilinus undulatus , for example, the presence of divers interrupts courtship and spawning (Patrick Colin personal observation). Wider implications of protection also warrant examination, such as the
impacts of shifting fi shing effort from aggregations to other reef resources during
periods of aggregation protection.
8.7.6 Information on Importance of Aggregations
to Fisheries and Ecosystem Health
Due to widespread declines in harvested fi sh populations and the pervasive degradation of marine ecosystems worldwide over the past several decades, fi sheries management is undergoing a theoretical and sometime actual shift away from single-species
management and towards more ecosystem-based management approaches. To integrate spawning aggregations into this new management framework, their role(s) in
ecosystem trophic and community structure, food web dynamics, and other ecosystem processes and parameters need to be appreciated (Chap. 2 ).
8 Fishery and Biological Implications of Fishing Spawning Aggregations…
numbers, sizes and catchment areas of aggregating fi sh, market prices of fi sh, biological impacts of overexploitation of reproductive fi sh on the overall fi shery, basic
fi shery parameters and percentage of annual catch from aggregations, fi shing costs,
profi tability, general market conditions of supply and demand under different scenarios, and differences in catchability between spawning and non-spawning periods. The value and characteristics of the non-aggregation fi shery component with or
without aggregation management also need assessment.
8.7.5 Advantages of Fully Protected Aggregations
and Implications
If certain aggregation sites are closed to fi shing, other human use activities will
usually need to be implemented to mitigate economic losses from fi shing restrictions. These may include the introduction of diving charts to view aggregations or
training for catch-and-release sportfi shing of aggregations. Before such activities
can be offered as alternative uses, however, it must be considered whether the
alternatives could themselves potentially have negative impacts on reproductive
activity requiring specifi c management steps. Therefore, studies which focus on
understanding how the presence of divers, the use of various fi shing gears, and
catch-and-release fi shing activities affect mating behaviour or survivorship are
needed. While divers can evidently approach some species without apparent impact
(as in the case of spawning cubera snapper in Belize), or species may be habituated
to divers, little attention has been paid to this subject to date. In the case of the
humphead wrasse (or Napoleon fi sh) Cheilinus undulatus , for example, the presence of divers interrupts courtship and spawning (Patrick Colin personal observation). Wider implications of protection also warrant examination, such as the
impacts of shifting fi shing effort from aggregations to other reef resources during
periods of aggregation protection.
8.7.6 Information on Importance of Aggregations
to Fisheries and Ecosystem Health
Due to widespread declines in harvested fi sh populations and the pervasive degradation of marine ecosystems worldwide over the past several decades, fi sheries management is undergoing a theoretical and sometime actual shift away from single-species
management and towards more ecosystem-based management approaches. To integrate spawning aggregations into this new management framework, their role(s) in
ecosystem trophic and community structure, food web dynamics, and other ecosystem processes and parameters need to be appreciated (Chap. 2 ).