A comparison of biomonitoring methodologies for surf zone fish communities

Surf zones are highly dynamic marine ecosystems that are subject to increasing anthropogenic and climatic pressures, posing multiple challenges for biomonitoring. Traditional methods such as seines and hook and line surveys are often labor intensive, taxonomically biased, and can be physically hazardous. Emerging techniques, such as baited remote underwater video (BRUV) and environmental DNA (eDNA) are promising nondestructive tools for assessing marine biodiversity in surf zones of sandy beaches. Here we compare the relative performance of beach seines, BRUV, and eDNA in characterizing community composition of bony (teleost) and cartilaginous (elasmobranch) fishes of surf zones at 18 open coast sandy beaches in southern California. Seine and BRUV surveys captured overlapping, but distinct fish communities with 50% (18/36) of detected species shared. BRUV surveys more frequently detected larger species (e.g. sharks and rays) while seines more frequently detected one of the most abundant..., Study Sites
To compare the effectiveness of seine, BRUV, and eDNA survey techniques for monitoring surf zone bony (teleost) and cartilaginous (elasmobranch) fish communities, we deployed the three survey techniques contemporaneously at 18 sandy beach sites across southern California, USA (Figure 1;Table S1); 14 on the California Channel Islands and 4 on the mainland. These represent novel fish community surveys for all but three of the mainland sites, providing important baseline data for fish assemblages. To maximize comparability, we surveyed surf zones using all three methods at each location on the same day using the methods described below. All surveys were conducted between August 15, 2018 and November 2, 2018. At one site, Soledad beach, on Santa Rosa Island, we were unable to conduct the BRUV surveys due to hazardous surf conditions.
Beach seine surveys
Beach seine surveys were employed using methods modified from the California Department of Fish and Wildlife (Monterey, CA, USA..., Github code: https://doi.org/10.5281/zenodo.7888385
Anacapa Toolkit: https://github.com/limey-bean/Anacapa
Reference Databases: https://github.com/zjgold/FishCARD

激浪带（surf zone）是高度动态的海洋生态系统，正面临日益加剧的人为活动与气候压力，为生物监测带来多重挑战。传统监测方法如海滩拉网（beach seine）与钩钓调查通常耗时费力、存在分类学偏差，且具有物理危险性。新兴技术如诱饵式远程水下视频（baited remote underwater video, BRUV）与环境DNA（environmental DNA, eDNA）是评估沙滩激浪带海洋生物多样性的极具前景的非破坏性工具。本研究针对美国加利福尼亚南部18处开放海岸沙滩的激浪带，对比了海滩拉网、BRUV与eDNA三种方法在表征硬骨鱼（teleost）和软骨鱼（elasmobranch）群落组成方面的相对性能。拉网与BRUV调查捕获的鱼类群落存在重叠但各具特征，共检测到36个物种，其中18个（占比50%）为两者共有。BRUV调查更易检测到体型较大的物种（如鲨类与鳐类），而拉网则更易检测到最为丰富的类群之一……

研究样地
为对比拉网、BRUV与eDNA三种调查技术在监测激浪带硬骨鱼与软骨鱼群落的有效性，我们于美国加利福尼亚南部的18处沙滩样地同步开展了三种调查（图1；附表S1）：其中14处位于加利福尼亚海峡群岛（California Channel Islands），4处位于本土海岸。除3处本土样地外，其余样地均为首次开展鱼类群落调查，可为当地鱼类群落提供重要的基线数据。为最大化可比性，我们于每个样地当日采用下述三种方法开展激浪带调查。所有调查均于2018年8月15日至2018年11月2日期间开展。在圣罗莎岛的索莱达海滩样地，因激浪条件恶劣，我们未能开展BRUV调查。

海滩拉网调查
海滩拉网调查采用了经加利福尼亚鱼类与野生动物部（美国加利福尼亚州蒙特雷）改良的方法。代码仓库：https://doi.org/10.5281/zenodo.7888385
阿纳卡帕工具包（Anacapa Toolkit）：https://github.com/limey-bean/Anacapa
参考数据库：https://github.com/zjgold/FishCARD