Data from: Effects of gear restriction on the abundance of juvenile fishes along sandy beaches in Hawai'i

In 2007, due to growing concerns of declines in nearshore fisheries in Hawai‘i, a ban on gillnets was implemented in designated areas around the island of O‘ahu in the main Hawaiian Islands. Utilizing a 17 year time-series of juvenile fish abundance beginning prior to the implementation of the gillnet ban, we examined the effects of the ban on the abundance of juveniles of soft-bottom associated fish species. Using a Before-After-Control-Impact (BACI) sampling design, we compared the abundance of targeted fishery species in a bay where gillnet fishing was banned (Kailua, O‘ahu), and an adjacent bay where fishing is still permitted (Waimānalo, O‘ahu). Our results show that when multiple juvenile fish species were combined, abundance declined over time in both locations, but the pattern varied for each of the four species groups examined. Bonefishes were the only species group with a significant BACI effect, with higher abundance in Kailua in the period after the gillnet ban. This study addressed a need for scientific assessment of a fisheries regulation that is rarely possible due to lack of quality data before enactment of such restrictions. Thus, we developed a baseline status of juveniles of an important fishery species, and found effects of a fishery management regulation in Hawai‘i.2007年，鉴于夏威夷近岸渔业资源衰退引发的日益严峻的关切，夏威夷主群岛的瓦胡岛周边指定海域实施了刺网（gillnets）捕捞禁令。本研究利用刺网禁令实施前便已启动的17年幼鱼丰度时间序列数据，分析了该禁令对软底生境关联鱼类幼体丰度的影响。研究采用对照影响前后采样设计（Before-After-Control-Impact, BACI），对比了实施刺网禁捕的海湾——夏威夷瓦胡岛凯卢阿湾，与仍允许捕捞的邻近海湾——夏威夷瓦胡岛怀马纳洛湾内目标渔业物种的丰度变化。结果显示，当将多种幼鱼物种合并统计时，两处海湾的幼鱼丰度均随时间出现下降，但四个被分析的物种类群各自呈现出差异化的变化模式。其中，北梭鱼（bonefishes）是唯一表现出显著BACI效应的物种类群，在刺网禁令实施后的时段内，凯卢阿湾的北梭鱼丰度显著更高。本研究填补了此前的空白：由于此类捕捞限制政策出台前缺乏高质量监测数据，相关渔业规制的科学评估往往难以开展。据此，我们建立了重要渔业物种幼体的基线现状，并探明了夏威夷一项渔业管理规制所产生的实际效应。