Use of biodegradable gillnets for resource and marine environment conservation: assessing the potential application in Northeast Arctic cod (Gadus morhua) fisheries

Biodegradable plastic materials are being tested in different fisheries for reducing marine plastic pollution and continuous capture by abandoned, lost, or otherwise discarded (ALD) gillnets. These earlier trials have shown varying results regarding the catch efficiency of new biodegradable gillnets. This study aimed at exploring the fishing efficiency of gillnets made of biodegradable polybutylene succinate-co-adipate (PBSA) material at different time points during sea trials in the Northeast Arctic cod (Gadus morhua) fishery. The results, based on study with 5210 cod, showed that the PBSA gillnet catch efficiency was clearly length-dependent, where PBSA gillnets retained less of larger sized cod (> around 95 cm), while having similar or higher catch rates of smaller cod (around < 95 cm). The reduction in catch efficiency of cod for the PBSA gillnets increased when they were used over the fishing season compared to the initial performance (first six deployments). This displayed a potential reduction in overall revenue for the industry from nylon gillnet catch value; however, this result differed among the deployments. These results show that improvements in long-term catch efficiency and durability are still needed for a commercial application of PBSA gillnets.