About 20 years ago, consumers were introduced to the problem of “bycatch” in fisheries. Back then, images of dolphins caught in tuna nets prompted the establishment of “dolphin-safe” products. Now, most cans of tuna sport Flipper-friendly labels.

Bycatch has been associated with large industrial-scale fishing. But a recent study, led by researchers from the University of California at Santa Cruz, has found that even small manual fishing operations can have devastating side effects. And this time, it is endangered loggerhead turtles that are the victims.

Off the coast of Baja California in Mexico, modest fishing fleets work waters that are both abundant in fish and sea turtles. The favoured method is a combination of nets plus hooks tied to a string (“longlines”), targeting bottom-dwelling fish. Where sea turtles are congregated, they can be caught accidentally.

As with all sea turtle species, loggerheads are long-lived and slow-growing. Most protection has focused on the breeding grounds - nesting beaches are closed off in many countries. However, once hatched, loggerheads spend years feeding at sea before they reach maturity. And losing a large part of the juvenile population will have major impact on future numbers. The turtles in Mexico are part of the North Pacific population, which nests in Japan. Nesting beach records have shown a dramatic decline in breeding females over the past ten years.

Ironically, larger commercial fisheries have been stopped sporadically due to their impact on loggerheads in other areas. Small fisheries have been overlooked, as they are difficult to track and their fishing equipment is limited. As a result, minimal bycatch problems have been assumed. But this smaller-scale fishing is found across the world at subsistence levels, making it a potential powder keg for bycatch issues.

Fortunately, once the problem was described for local fishermen in Baja California, positive measures have been taken. The Mexican conservation group Grupo Tortuguero is involved. Other fishing methods are being explored. And information is disseminated in various creative ways, from comics to murals. A voluntary turtle reserve has been created, with the possibility of federal protection in the near future. Where a small-scale operation was creating a big problem, the local scale has also enabled a rapid response, serving as an optimistic example of effective grassroots conservation.