Department of Fisheries Technology, SINTEF Ocean, Trondheim, Norway.
Department of Fisheries Technology, SINTEF Ocean, Hirtshals, Denmark.
PLoS One. 2020 Sep 24;15(9):e0234224. doi: 10.1371/journal.pone.0234224. eCollection 2020.
Gillnets made of the biodegradable resin polybutylene succinate co-adipate-co-terephthalate were tested under commercial fishing conditions to compare their fishing performance with that of conventional nylon polyamide (PA) gillnets. Both types of gillnets were made of 0.55 mm Ø monofilaments. However, since the biodegradable nets are weaker than nylon PA nets when using the same monofilament diameter, we also used biodegradable nets made of 0.60 mm Ø monofilament that had a similar tensile strength to the 0.55 mm Ø nylon PA nets. The relative catch efficiency of the different gillnet types was evaluated over the 2018 autumn fishing season for saithe and cod in northern Norway. For cod, both biodegradable gillnets (0.55 and 0.60 mm) had a significantly lower catch efficiency compared to the traditional nylon PA net (0.55 mm) with estimated catch efficiencies of 62.38% (CI: 50.55-74.04) and 54.96% (CI: 35.42-73.52) compared with the nylon PA net, respectively. Similarly for saithe, both biodegradable gillnets (0.55 and 0.60 mm) had a lower estimated catch efficiency compared to the traditional nylon PA net (0.55 mm) with estimated catch efficiencies of 83.40% (71.34-94.86) and 83.87% (66.36-104.92), compared with the nylon PA net, respectively. Tensile strength does not explain the differences in catch efficiency between the two gillnet types, since increasing the twine diameter of the biodegradable gillnets (to match the strength of nylon PA gillnets) did not yield similar catch efficiencies. However, the elasticity and stiffness of the materials may be responsible for the differences in catch efficiency between the nylon PA and biodegradable gillnets.
我们在商业捕捞条件下测试了由可生物降解树脂聚丁二酸丁二醇酯共对苯二甲酸酯制成的刺网，以比较其捕捞性能与传统尼龙聚酰胺（PA）刺网的性能。两种类型的刺网均由 0.55 毫米 Ø 的单丝制成。然而，由于可生物降解网在使用相同单丝直径时比尼龙 PA 网弱，我们还使用了由 0.60 毫米 Ø 的单丝制成的可生物降解网，其拉伸强度与 0.55 毫米 Ø 的尼龙 PA 网相似。2018 年秋季，在挪威北部对鳕鱼和黑线鳕进行了不同刺网类型的相对捕捞效率评估。对于鳕鱼，与传统的尼龙 PA 网（0.55 毫米）相比，两种可生物降解刺网（0.55 和 0.60 毫米）的捕捞效率均显著降低，估计的捕捞效率分别为 62.38%（CI：50.55-74.04）和 54.96%（CI：35.42-73.52）。同样，对于黑线鳕，与传统的尼龙 PA 网（0.55 毫米）相比，两种可生物降解刺网（0.55 和 0.60 毫米）的估计捕捞效率均较低，分别为 83.40%（71.34-94.86）和 83.87%（66.36-104.92）。拉伸强度并不能解释两种刺网类型之间捕捞效率的差异，因为增加可生物降解刺网的线径（以匹配尼龙 PA 刺网的强度）并不能产生相似的捕捞效率。然而，材料的弹性和刚性可能是导致尼龙 PA 和可生物降解刺网之间捕捞效率差异的原因。
