Larval fish at time series station Helgoland Roads, North Sea, in 2004

For the larval surveys, a CalCOFI ring trawl with a 500 µm mesh net (aperture 100 cm, length 400 cm, equipped with a flow meter) was towed for 15 min from a research vessel. The samples were transferred to the laboratory, fish larvae were sorted out immediately and classified to the species level according to Halbeisen (1988) and Russel (1976). Larval abundance was normalized to larvae/m**3. Members of the family Syngnathidae (pipefishes and seahorses) were excluded from the analyses as they are not a regular part of the ichthyoplankton and occurred only occasionally after storms.

本次仔鱼调查采用网目尺寸为500微米的CalCOFI环拖网（孔径100厘米，网长400厘米，配备流量计），由科研船舶拖曳作业15分钟。采集的样品即刻被转运至实验室，科研人员随即对其中的鱼类仔鱼进行分拣，并依据Halbeisen（1988）与Russel（1976）的分类标准将其鉴定至物种水平。仔鱼丰度经标准化处理为尾/立方米。海龙科（Syngnathidae，即海龙与海马）类群未纳入本次分析，因其并非鱼类浮游幼体（ichthyoplankton）的常规组成部分，仅在风暴过后偶有出现。