Data from: Monitoring spawning activity in a southern California marine protected area using molecular identification of fish eggs

In order to protect the diverse ecosystems of coastal California, a series of marine protected areas (MPAs) have been established. The ability of these MPAs to preserve and potentially enhance marine resources can only be assessed if these habitats are monitored through time. This study establishes a baseline for monitoring the spawning activity of fish in the MPAs adjacent to Scripps Institution of Oceanography (La Jolla, CA, USA) by sampling fish eggs from the plankton. Using vertical plankton net tows, 266 collections were made from the Scripps Pier between 23 August 2012 and 28 August 2014; a total of 21,269 eggs were obtained. Eggs were identified using DNA barcoding: the COI or 16S rRNA gene was amplified from individual eggs and sequenced. All eggs that were successfully sequenced could be identified from a database of molecular barcodes of California fish species, resulting in species-level identification of 13,249 eggs. Additionally, a surface transport model of coastal circulation driven by current maps from high frequency radar was used to construct probability maps that estimate spawning locations that gave rise to the collected eggs. These maps indicated that currents usually come from the north but water parcels tend to be retained within the MPA; eggs sampled at the Scripps Pier have a high probability of having been spawned within the MPA. The surface transport model also suggests that although larvae have a high probability of being retained within the MPA, there is also significant spillover into nearby areas outside the MPA. This study provides an important baseline for addressing the extent to which spawning patterns of coastal California species may be affected by future changes in the ocean environment.

为保护加利福尼亚沿海多样的生态系统，当地已设立一系列海洋保护区（marine protected areas, MPAs）。唯有对这些栖息地开展长期监测，方能评估此类海洋保护区保护乃至潜在增益海洋资源的能力。本研究通过对浮游生物中的鱼卵进行采样，为毗邻美国加利福尼亚州拉霍亚斯克里普斯海洋研究所的海洋保护区内鱼类产卵活动的监测建立了基线。2012年8月23日至2014年8月28日期间，研究团队在斯克里普斯码头采用垂直浮游生物网拖样法，累计完成266次采样，共获取21269枚鱼卵。研究人员借助DNA条形码（DNA barcoding）技术开展鱼卵鉴定：从单枚鱼卵中扩增COI基因或16S核糖体RNA基因并完成测序。所有成功完成测序的鱼卵，均可通过加州鱼类物种分子条形码数据库完成物种识别，最终实现13249枚鱼卵的物种级鉴定。此外，研究团队基于高频雷达流场图构建的沿岸环流表面输运模型，绘制了可估算采集鱼卵对应产卵位点的概率分布图。该分布图显示，海流通常源自北方，但水团往往会滞留于海洋保护区内；在斯克里普斯码头采集的鱼卵，其产卵位置大概率位于该海洋保护区内部。该表面输运模型还表明，尽管幼体大概率会滞留于海洋保护区内，但同时也存在显著的溢出效应，即幼体扩散至保护区周边区域。本研究为解析加利福尼亚沿海鱼类物种产卵模式可能受未来海洋环境变化影响的程度，提供了重要的监测基线。