Hyperoplus lanceolatus in the Sylt Rømø bight in 2022@en

Due to changing temperature regimes in the North- and the Wadden Sea, a fish survey in the Sylt Rømø bight (SRB) was established in 2007 for at least ten years. The aim is to investigate the Wadden Sea fish fauna with special interest in changes of migration behavior, species composition and feeding habits. Since 2021 an assessment of the epibenthic species in the net hauls was included. Seven stations are sampled monthly inside the SRB. Two additional stations, one outside the bight, one close to the Danish border are sampled as references four times a year. For sampling a mini bottom trawl, total length 17 m, trawl opening 7 m, height 3 m with a mesh size of 36 mm in the wings, 16 mm in the mid part and 6 mm in the cod end is used. At every station one haul in the water column and another at the bottom are sampled, for 15 minutes at a speed of approximately 2 knots. The data will help to give a more detailed picture of food chains and energy flows inside the Wadden Sea.鉴于北海与瓦登海（Wadden Sea）的温度格局发生变化，2007年启动了叙尔特-勒姆湾（Sylt Rømø Bight，SRB）鱼类调查项目，原定持续时长至少10年。本项目旨在调查瓦登海鱼类区系，重点关注其洄游行为、物种组成与摄食习性的变化。自2021年起，新增了对网采样品中底上栖息物种的评估环节。SRB海域内共设7个监测站位，每月开展一次采样；另设2个参照站位，其中1个位于湾外、1个毗邻丹麦边境，每年开展4次采样。本次采样采用小型底拖网，该拖网总长度17米，网口宽7米、高3米，网翼部分网目尺寸为36毫米，网身中部为16毫米，拖网囊网（cod end）为6毫米。每个站位分别开展一次水层拖网与一次海底拖网采样，拖曳时长15分钟，拖曳速度约2节。本项目所获数据将有助于更细致地刻画瓦登海内部的食物链与能量流动格局。