Marine fronts are oceanographic drivers for marine species dispersal, especially for their pelagic organisms like the larvae. Larvae can aggregate at the front and consequently have a limited dispersal, which in turn reduces the connectivity between marine populations. Due to the high variations in the ocean, the fronts also have annual changes (i.e., its formation period, gradient, and position), which have poorly-documented effects on larval retention. In the northwestern Mediterranean Sea, a surface density front is localized across a continental margin which is also indented by submarine canyons. There, an abundant population of the commercial deep-sea blue and red shrimp Aristeus antennatus (Crustacea: Decapoda: Dendrobranchiata: Aristeidae) inhabits the seafloor. Each summer, the shrimp offspring are released in pelagic deep-sea and access the superficial waters divided by the density front. In this study, we focused on the interannual variability of the density front influence on the larval transport of shrimps and its repercussions on the potential connectivity between shrimp populations at each front side. A particle-tracking model simulated the larval transport of A. antennatus in hydrodynamics of the northwestern Mediterranean Sea between the years 2006 and 2016. Larval drift distance and seawater density were correlated by 98%. Over the years 2006–2016, the front region retained 86% of larvae, but this rate yearly varied due to changes in density gradient and position of the front. For example, in 2010, 48% of larvae connected to zones south of the front when the density gradient was relatively low. In 2015, 99.2% of larvae were retained in the front region when the latitudinal front position and density gradient were relatively high. Interannual variability of the front position was potentially related to the strength and position of mesoscale circulation patterns. Our findings suggest that the larval retention on habitats favored by canyon productivity because of the front could explain the persistent abundance of A. antennatus population. This information is important to set or improve the fisheries management in zones with strong interannual hydrodynamic variability.

海洋前沿是海洋物种扩散的海洋学驱动力，特别是对于它们的浮游生物（如幼体）而言。幼虫可以聚集在前部，因此散布程度有限，从而降低了海洋种群之间的连通性。由于海洋的高度变化，这些锋面还具有年度变化（即，其形成时期，梯度和位置），这对幼虫的滞留影响文献记载很少。在地中海西北部，地表密度前沿位于大陆边缘，也被海底峡谷压入。那里有大量的商业深海蓝虾和红虾触角虾（甲壳纲：十足目：Dendrobranchiata：纤毛科）栖息于海底。每年夏天，虾的后代都会在深海中游，并进入表层水域除以密度前沿。在这项研究中，我们集中于密度前沿对虾幼体运输的年际变化及其对虾正面各对虾种群之间潜在连通性的影响。粒子跟踪模型模拟触角拟南芥的幼虫运输在2006年至2016年之间，西北地中海的水动力变化。幼虫的漂移距离和海水密度之间的相关性为98％。在2006–2016年间，前部区域保留了86％的幼体，但是由于密度梯度和前部位置的变化，这一比率每年变化。例如，在2010年，当密度梯度相对较低时，有48％的幼虫连接到锋面以南的区域。2015年，当纬度的前部位置和密度梯度较高时，幼虫保留在前部区域的比例为99.2％。前部位置的年际变化可能与中尺度循环模式的强度和位置有关。我们的发现表明，由于前缘，幼体在峡谷生产力所支持的栖息地上的存留可以解释其持续存在的原因。A.触角种群。该信息对于设置或改善年际水动力变化较大的区域的渔业管理非常重要。