Discouraging Trophy Fishing For Threatened Species
Researchers from North America came together to investigate whether trophy fishing, as promoted by the International Game Fish Association (IGFA), inherently compromises conservation of endangered species. It is well known that overfishing is one of the greatest threats to marine biodiversity. Selective fishing on a mass scale lead to declines in marine fish population size and body size.
Trophy fishing is a form of hobby fishing when the largest individuals of a species are targeted. The goal here is to catch record-sized specimens. Previous studies have shown that the capture of a trophy sized fish is the driving factor in satisfaction of fishermen and thus is often a very strong motivator. The need for confirmation of a record catch often renders catch-and-release impossible as the captured fish has to be taken to a standardized scale on land. Nevertheless, the researchers point out that catch and release is not necessarily any better for the fish: many (depending on gear, angler behaviour, environmental conditions, etc.) end up suffering post-release mortality.
Surely, recreational trophy fishing cannot be as threatening as commercial fishing? As it turns out, fecundity (i.e. reproductive capacity), larval quality and offspring survival correlate strongly with size in fishes. This, combined with the fact that the number of eggs a female fish can produce is greatly dependent on the volume of the individual, reveals the true danger of trophy fishing. The practice can have a disproportionately large negative effect on population dynamics of a given species even if just several individuals are removed from the population. This is especially true in cases of species that exhibit low rates of reproduction or ones which already have experienced dramatic population declines. The researchers warn that the prestigious trophy fishing awards given out to people present a unique social and biological challenge where a potentially destructive behaviour is rewarded and looked up to.
The investigation into the matter was carried out by analysing the IGFA 2011 world record guide book. Then, for each of the 1222 fish species in the IGFA guide book, International Union for Conservation of Nature (IUCN) Red List status was determined using the online database.
The results were worrying. Eighty-five species (6.95%) from the IGFA trophy guide are listed as ‘Threatened with extinction’ (i.e. Vulnerable, Endangered, or Critically Endangered). Interestingly, out of the 52 species highlighted on the cover of the 2011 IGFA World Record book, 5 are ‘Threatened with extinction’ according to IUCN. Apparently, threatened species make up a significantly higher proportion of the largest fish size class, whereas the least threatened species are typically smaller in size. This confirms the concerns trophy fishing poses by targeting the biggest individuals. The largest IGFA trophy fish certified record, for instance, belongs to the threatened great white shark Carcharodon carcharias (1208 kg).
It is therefore the researchers’ strict recommendation that the IGFA issue a declaration that world record certifications would no longer be offered for species identified by the IUCN Red List as ‘Threatened with extinction.’ The scientists also find that regional considerations are of importance as the global population status of a given species might differ significantly from its local equivalent.