An abundant harvest typically indicates a fruitful crop, which is a desirable thing. However, that isn’t always the case in fisheries. Fish taken outside the target stock are frequent catches in both freshwater and saltwater fishing. However, overfishing can have a long-term negative impact on the stability and health of species.
Bycatch, or fish that are accidentally taken, is “one of the most pervasive and disabling concerns in global fisheries” and the focus of Alan Hastings’ research. This work adds to the ongoing discussions about the issue of bycatch and approaches to reviving the health of fisheries. “Although this problem has been well known for at least 50 years, it nonetheless remains one of the most important challenges in fisheries,” the team writes.
When trawling or huge nets are used in commercial fishing operations, bycatch occurs. In a broader sense, bycatch can also refer to other marine animals like dolphins, turtles, or even seabirds. Bycatch species that are long-lived or have low fecundity and can’t replenish their population as quickly as the target fish can pose a threat to a species’ well-being and potentially result in its extinction.
Normal protection tactics for these endangered species involve limiting fish harvests in the hopes that the weaker stock will strengthen. Alternately, funds may be used to create a harvesting system that enables the threatened fish population to evade capture. However, the fishing business is under financial pressure from both solutions.
If there was another option, the research team questioned. They created a model that was centered on a situation that managers and fishermen could relate to: the harvest of a target species is in jeopardy because a poor stock of a bycatch species has been driven to dangerously low levels. How could they preserve the imperiled species’ future while still catching other tasty fish?
Marine reserves were recommended as a solution by the idealized model. The purpose of a marine reserve is to prevent ecosystems from being disturbed so that fish can achieve and sustain healthy population levels. Fishing is prohibited in marine reserves. This approach and studies are distinctive since they incorporate marine reserves rather than fully stopping harvests. The team pondered if reserves, with their commitment to conservation, could assist managers in bringing fish populations back to safe, healthy levels.
Examining the model revealed that marine reserves will support population recovery when the poor stock is a slower-reproducing, longer-lived species. Although it might appear like a very unique case, the bycatch issue that fisheries frequently deal with is represented by it.
The researchers note that “for a wide range of life history combinations, maximum yields are not compromised by spatial closures [reserves] that guarantee the persistence of weak stocks,” but they do believe that their findings contribute to the discussion on the minimization of the negative effects of bycatch. Of course, there are many other characteristics and behaviors of fish to take into account in other scenarios.
Bycatch may already have an answer in the ocean. The authors come to the following conclusion: “Marine reserves may be a solution that benefits both fishermen and conservation.”