Laboratorio de Ciencias del Mar (UNDECIMAR), Facultad de Ciencias, Universidad de la República, Iguá 4225, 11400, Montevideo, Uruguay.
College of Earth and Atmospheric Sciences, Oregon State University, Corvallis, OR, 7331- 5503, USA.
Mar Environ Res. 2022 Apr;176:105591. doi: 10.1016/j.marenvres.2022.105591. Epub 2022 Mar 1.
The yellow clam Mesodesma mactroides is a cool-water species that typifies sandy beaches of the Southwestern Atlantic Ocean (SAO), which embraces one of the strongest ocean warming hotspots. The region is influenced by the Rio de la Plata (RdlP), which represents a zoogeographic barrier that restricts its larval exchange. We investigated yellow clam larval connectivity patterns using an individual based model (IBM). The IBM combined outputs from a 3D hydrodynamic model with a clam submodel that considered salinity- and temperature-dependent mortality for the planktonic larvae. Connectivity across the RdlP estuary occurred only for larvae released in spring during a strong La Niña event. Mortality due to freshwater precluded larval transport across the RdlP, whereas larval mortality induced by warmer waters reduced connectivity, leading to self-recruitment in most areas. Warming acceleration in this hotspot could further restrict larval connectivity between populations in the SAO, with conservation implications for this threatened species.
黄蚬 Mesodesma mactroides 是一种冷水种，典型地栖息于西南大西洋（SAO）的沙滩上，该地区是世界上海洋变暖最强烈的热点之一。该地区受拉普拉塔河（RdlP）的影响，拉普拉塔河是一个动物地理屏障，限制了其幼虫的交换。我们使用基于个体的模型（IBM）研究了黄蚬幼虫的连通模式。IBM 将三维水动力模型的输出与蚬子模型相结合，该模型考虑了浮游幼虫的盐度和温度相关死亡率。仅在春季拉尼娜事件期间释放的幼虫才能跨越拉普拉塔河口进行连通。由于淡水导致的死亡率使幼虫无法跨越拉普拉塔河进行运输，而温暖水域导致的幼虫死亡率降低了连通性，导致大多数地区出现自我补充。该热点地区的加速变暖可能会进一步限制 SAO 中种群之间的幼虫连通性，这对这种受到威胁的物种具有保护意义。
