CIIMAR-Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Matosinhos, Portugal.
Department of Biology, UA-University of Aveiro, Campus Universitário de Santiago, Aveiro, Portugal.
PLoS One. 2024 Oct 16;19(10):e0300992. doi: 10.1371/journal.pone.0300992. eCollection 2024.
The use of environmental DNA (eDNA) to assess the presence of biological communities has emerged as a promising monitoring tool in the marine conservation landscape. Moreover, advances in Next-Generation Sequencing techniques, such as DNA metabarcoding, enable multi-species detection in mixed samples, allowing the study of complex ecosystems such as oceanic ones. We aimed at using these molecular-based techniques to characterize cetacean communities, as well as potential prey on the northern coast of Mainland Portugal. During four seasonal campaigns (summer 2021 to winter 2022/2023), seawater samples were collected along with visual records of cetacean occurrence. The eDNA isolated from 64 environmental samples was sequenced in an Illumina platform, with universal primers targeting marine vertebrates. Five cetacean species were identified by molecular detection: common dolphin (Delphinus delphis), bottlenose dolphin (Tursiops truncatus), Risso's dolphin (Grampus griseus), harbor porpoise (Phocoena phocoena) and fin whale (Balaenoptera physalus). Overall, except for the latter (not sighted during the campaigns), this cetacean community composition was similar to that obtained through visual monitoring, and the complementary results suggest their presence in the region all year round. In addition, the positive molecular detections of Balaenoptera physalus are of special relevance since there are no records of this species reported on scientific bibliography in the area. The detection of multiple known prey of the identified dolphins indicates an overlap between predator and prey in the study area, which suggests that these animals may use this coastal area for feeding purposes. While this methodological approach remains in a development stage, the present work highlights the benefits of using eDNA to study marine communities, with specific applications for research on cetacean distribution and feeding ecology.
利用环境 DNA（eDNA）评估生物群落的存在，已成为海洋保护领域中一种有前途的监测工具。此外，下一代测序技术（如 DNA 代谢组学）的进步，使得在混合样本中能够进行多物种检测，从而能够研究海洋等复杂生态系统。我们旨在利用这些基于分子的技术来描述葡萄牙大陆北部沿海的鲸目动物群落以及潜在的猎物。在四个季节性的考察期间（2021 年夏季至 2022/2023 年冬季），我们采集了海水样本，并记录了鲸目动物的出现情况。从 64 个环境样本中提取的 eDNA 在 Illumina 平台上进行测序，使用针对海洋脊椎动物的通用引物。通过分子检测，我们鉴定了 5 种鲸目动物：宽吻海豚（Delphinus delphis）、瓶鼻海豚（Tursiops truncatus）、灰海豚（Grampus griseus）、港湾鼠海豚（Phocoena phocoena）和长须鲸（Balaenoptera physalus）。总的来说，除了后者（在考察期间没有观察到），这个鲸目动物群落的组成与通过视觉监测获得的结果相似，补充的结果表明它们全年都在该地区存在。此外，长须鲸的阳性分子检测结果特别重要，因为该地区的科学文献中没有报道过这种物种的记录。鉴定出的海豚的多种已知猎物的阳性检测结果表明，研究区域内捕食者和猎物之间存在重叠，这表明这些动物可能将该沿海地区用于觅食目的。虽然这种方法仍处于发展阶段，但本研究强调了利用 eDNA 研究海洋群落的好处，特别是在鲸目动物分布和摄食生态学研究方面。
