Centro para el Estudio de Sistemas Marinos (CESIMAR), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Edificio CCT CONICET - CENPAT, Puerto Madryn, Chubut, Argentina.
Instituto de Investigación de Hidrobiología, Facultad de Ciencias Naturales y Ciencias de la Salud, Universidad Nacional de la Patagonia San Juan Bosco, Trelew, Chubut, Argentina.
J Fish Biol. 2021 Nov;99(5):1650-1667. doi: 10.1111/jfb.14873. Epub 2021 Sep 6.
The relationship between fish functional diversity and fishing levels at which its baselines shift is important to identify the consequences of fishing in ecosystem functioning. For the first time, the authors of this study implemented a trait-based approach in the Argentine Patagonian Sea to identify the vulnerability and spatiotemporal changes in functional diversity of fish assemblages incidentally captured by a trawling fleet targeting the Argentine red shrimp Pleoticus muelleri (Spence Bate, 1888) between 2003 and 2014. The authors coupled seven fish trophic traits to a reconstructed fish assemblage for the study area and by-catch and evaluated changes in fish species richness and four complementary functional diversity measures (functional richness, redundancy, dispersion and community trait values) along with fishing intensity, temporal use, latitudinal location and depth of fishing grounds, and vessel length. Resident fishes larger than 30 cm in length, with depressed and fusiform bodies, intermediate to high trophic levels, and feeding in benthic, demersal and midwater areas were vulnerable to by-catch. In addition, fish assemblages exhibited a low functional trait redundancy, likely related to species influxes in a biogeographic ecotone with tropicalisation signs. Significant increases in fish trait richness and dispersion poleward and deep suggested new functional roles in these grounds, matching trends in community body size, reproductive load, maximum depth and trophic level. Finally, a temporal increase in fish species and functional trait removal in fishing grounds led to trait homogenisation since 2003. The authors identified that tipping points in temperate fish functional trait diversity showed the importance of trait-based approaches within ecosystem-based fisheries management.
鱼类功能多样性与基线转移捕捞水平之间的关系对于确定捕捞对生态系统功能的影响至关重要。本研究首次在阿根廷巴塔哥尼亚海域采用基于特征的方法，确定了在 2003 年至 2014 年期间，针对阿根廷红虾 Pleoticus muelleri（Spence Bate，1888）的拖网船队偶然捕捞的鱼类群落的脆弱性和功能多样性的时空变化。作者将七个鱼类营养特征与研究区域的重建鱼类群落和副渔获物相关联，并评估了鱼类物种丰富度以及四个补充功能多样性指标（功能丰富度、冗余度、分散度和群落特征值）的变化，同时评估了捕捞强度、时间利用、纬度位置和捕捞深度以及船只长度的变化。大于 30 厘米长、身体扁平、纺锤形、中等到高营养级、在底栖、底栖和中层水域觅食的定居鱼类容易被副渔获物捕获。此外，鱼类群落表现出低的功能特征冗余度，这可能与具有热带化迹象的生物地理生态过渡区的物种流入有关。鱼类特征丰富度和分散度向极地方向和深处的显著增加表明在这些海域中出现了新的功能角色，与群落体型、生殖负荷、最大深度和营养级的趋势相匹配。最后，由于 2003 年以来，在渔业水域中鱼类物种和功能特征的去除导致了特征同质化。作者确定了温带鱼类功能特征多样性的临界点，表明了基于特征的方法在基于生态系统的渔业管理中的重要性。
