Merlangius merlangus in the Sylt Rømø bight in 2022

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)的水温格局发生改变，研究团队于2007年启动了叙尔特-勒姆湾（Sylt Rømø Bight, SRB）鱼类调查项目，计划至少持续十年。本调查旨在研究瓦登海鱼类区系，重点关注洄游行为、物种组成及摄食习性的动态变化。自2021年起，调查新增了拖网样品中底上生物(epibenthic species)的评估环节。叙尔特-勒姆湾内设有7个固定采样站位，每月开展一次采样；另设2个对照站位：1个位于湾外，1个毗邻丹麦边境，每年采样4次。采样采用小型底拖网(mini bottom trawl)：总长度17米，网口宽7米、高3米，网翼网目尺寸为36毫米，中部网身网目为16毫米，拖网囊网(cod end)网目为6毫米。每个站位分别采集水体层与海底两层拖网样品，单次拖曳时长15分钟，拖曳速度约2节(knot)。本调查所获数据将助力更精准地刻画瓦登海内部的食物链结构与能量流动规律。