264
Y. Sadovy de Mitcheson and B. Erisman
important in those species comprised of multiple age groups, providing the opportunity for social transmission of migration routes (Dodson 1988 ) . The removal of
older, larger adults may therefore affect spawning and aggregation-formation indirectly through loss of knowledge of spawning site locations and migration routes
and could seriously compromise recovery initiatives such as restocking using hatchery-produced fi sh in such species.
8.5 Socioeconomic Importance of Aggregation-Fishing
and Aggregating Species
From a commercial perspective, aggregations represent excellent sources of large
numbers of fi sh that can be taken quickly, predictably and effi ciently, thereby saving
both time and operation costs. These qualities, conversely, make them particularly
challenging to manage. For valuable and high volume niche fi sheries, such as those
for live fi sh (e.g. groupers) and roe (e.g. mullet), and for species only accessible at
aggregations, these are especially appealing, and, indeed, possibly the only (in the
case of roe), time to quickly obtain high catches. Aggregations are also economically attractive for recreational fi sheries, providing the opportunity for private-boat
fi shers to reach high catch limits in single trips, or, in the case of tourist fi shers,
allowing them to maximize the number of fi sh caught during daily fi shing charters.
They can also be very appealing to sports divers for viewing. We explore the
socioeconomic implications of aggregation protection and exploitation.
8.5.1 Gluts, Prices, and Fisher Behaviour
The economics of having large gluts of fi sh fi lling local markets over a short spawning season and the potential for fi sh wastage have received little attention but likely
offset some of the more obvious advantages associated with the commercial exploitation of aggregations. The fl ooding of a large number of fi sh into a limited market,
i.e. where supply temporarily and massively exceeds demand, can result in the price
per unit weight declining such that fi shers get less cash per fi sh than at other times.
In extreme cases, fi sh are wasted because there are too many for small local markets, or because they cannot be stored until market prices improve. During the peak
fi shing periods for Gulf corvina in the northern Gulf of California, Mexico, as much
as 1,000 tonnes of fi sh may be caught and sold to local buyers over just 3–4 days.
This fl ood of fi sh causes market prices to plummet, often over the course of hours.
When the supply of fi sh exceeds the capacity of local processing and export
plants, buyers close their markets completely, and several hundred tonnes of fi sh
meat may be abandoned on the beach or thrown into the local dump by fi shermen
who can no longer sell their catch (Brad Erisman unpublished data) (Fig. 8.13 ).
Y. Sadovy de Mitcheson and B. Erisman
important in those species comprised of multiple age groups, providing the opportunity for social transmission of migration routes (Dodson 1988 ) . The removal of
older, larger adults may therefore affect spawning and aggregation-formation indirectly through loss of knowledge of spawning site locations and migration routes
and could seriously compromise recovery initiatives such as restocking using hatchery-produced fi sh in such species.
8.5 Socioeconomic Importance of Aggregation-Fishing
and Aggregating Species
From a commercial perspective, aggregations represent excellent sources of large
numbers of fi sh that can be taken quickly, predictably and effi ciently, thereby saving
both time and operation costs. These qualities, conversely, make them particularly
challenging to manage. For valuable and high volume niche fi sheries, such as those
for live fi sh (e.g. groupers) and roe (e.g. mullet), and for species only accessible at
aggregations, these are especially appealing, and, indeed, possibly the only (in the
case of roe), time to quickly obtain high catches. Aggregations are also economically attractive for recreational fi sheries, providing the opportunity for private-boat
fi shers to reach high catch limits in single trips, or, in the case of tourist fi shers,
allowing them to maximize the number of fi sh caught during daily fi shing charters.
They can also be very appealing to sports divers for viewing. We explore the
socioeconomic implications of aggregation protection and exploitation.
8.5.1 Gluts, Prices, and Fisher Behaviour
The economics of having large gluts of fi sh fi lling local markets over a short spawning season and the potential for fi sh wastage have received little attention but likely
offset some of the more obvious advantages associated with the commercial exploitation of aggregations. The fl ooding of a large number of fi sh into a limited market,
i.e. where supply temporarily and massively exceeds demand, can result in the price
per unit weight declining such that fi shers get less cash per fi sh than at other times.
In extreme cases, fi sh are wasted because there are too many for small local markets, or because they cannot be stored until market prices improve. During the peak
fi shing periods for Gulf corvina in the northern Gulf of California, Mexico, as much
as 1,000 tonnes of fi sh may be caught and sold to local buyers over just 3–4 days.
This fl ood of fi sh causes market prices to plummet, often over the course of hours.
When the supply of fi sh exceeds the capacity of local processing and export
plants, buyers close their markets completely, and several hundred tonnes of fi sh
meat may be abandoned on the beach or thrown into the local dump by fi shermen
who can no longer sell their catch (Brad Erisman unpublished data) (Fig. 8.13 ).