Bandara Tharindu, Brugel Sonia, Andersson Agneta, Lau Danny Chun Pong
Department of Ecology and Environmental Science Umeå University Umeå Sweden.
Department of Animal Science, Faculty of Animal Science and Export Agriculture Uva Wellassa University Badulla Sri Lanka.
Ecol Evol. 2023 Jun 1;13(6):e10158. doi: 10.1002/ece3.10158. eCollection 2023 Jun.
Algae-produced long-chain polyunsaturated fatty acids (LC-PUFA; with ≥20 carbon atoms) are key biomolecules for consumer production and animal health. They are transferred to higher trophic levels and accumulated in food chains. However, LC-PUFA accumulation in consumers and their trophic transfer vary with the diet quality and the physiological demand for LC-PUFA of consumers. The goal of this study was to investigate spatial and taxonomic differences in LC-PUFA retention of coastal fish predators that potentially differ in their habitat use (benthic versus pelagic) and prey quality. We analyzed the fatty acid (FA) composition of common fish species, namely roach and European perch, as well as their potential prey from benthic and pelagic habitats in three bays of the northern Baltic Sea. We then assessed whether the fish LC-PUFA retention differed between species and among the study bays with different diet quality, that is, LC-PUFA availability. Our data indicated taxon-specific differences in the retention of LC-PUFA and their precursor FA in fish (i.e., short-chain PUFA with <20 carbon atoms). Perch did not show any spatial variation in the retention of all these FA, while roach showed spatial differences in the retention of docosahexaenoic acid (DHA) and their precursor FA, but not eicosapentaenoic acid (EPA). Data suggest that diet quality and trophic reliance on benthic prey underlay the DHA retention differences in roach. Although the PUFA supply might differ among sites, the low spatial variation in LC-PUFA content of perch and roach indicates that both fishes were able to selectively retain dietary LC-PUFA. Climate change together with other existing human-caused environmental stressors are expected to alter the algal assemblages and lower their LC-PUFA supply for aquatic food webs. Our findings imply that these stressors will pose heterogeneous impacts on different fish predators. We advocate further investigations on how environmental changes would affect the nutritional quality of the basal trophic level, and their subsequent impacts on LC-PUFA retention, trophic ecology, and performance of individual fish species.
藻类产生的长链多不饱和脂肪酸（LC-PUFA；碳原子数≥20）是消费者生产和动物健康的关键生物分子。它们被转移到更高的营养级并在食物链中积累。然而，消费者体内LC-PUFA的积累及其营养传递会因饮食质量和消费者对LC-PUFA的生理需求而有所不同。本研究的目的是调查沿海鱼类捕食者在LC-PUFA保留方面的空间和分类差异，这些捕食者在栖息地利用（底栖与浮游）和猎物质量方面可能存在差异。我们分析了波罗的海北部三个海湾中常见鱼类物种（即拟鲤和欧洲鲈）及其来自底栖和浮游栖息地的潜在猎物的脂肪酸（FA）组成。然后，我们评估了鱼类LC-PUFA保留在不同物种之间以及在具有不同饮食质量（即LC-PUFA可利用性）的研究海湾之间是否存在差异。我们的数据表明，鱼类在LC-PUFA及其前体FA（即碳原子数<20的短链PUFA）的保留方面存在分类群特异性差异。鲈鱼在所有这些FA的保留方面没有表现出任何空间变化，而拟鲤在二十二碳六烯酸（DHA）及其前体FA的保留方面表现出空间差异，但在二十碳五烯酸（EPA）方面没有。数据表明，饮食质量和对底栖猎物的营养依赖是拟鲤DHA保留差异的基础。尽管不同地点的PUFA供应可能不同，但鲈鱼和拟鲤LC-PUFA含量的低空间变化表明，这两种鱼都能够选择性地保留饮食中的LC-PUFA。预计气候变化与其他现有的人为环境压力源将改变藻类群落，并降低其对水生食物网的LC-PUFA供应。我们的研究结果表明，这些压力源将对不同的鱼类捕食者产生不同的影响。我们主张进一步研究环境变化将如何影响基础营养级的营养质量，以及它们随后对LC-PUFA保留、营养生态学和单个鱼类物种性能的影响。
