Survey : INA K 2/04 (part of Blackwater Herring Survey (FSS: INA K HER))

This survey was undertaken by Cefas as part of the Blackwater Herring Survey
(FSS: INA K HER);

A series of cruises carried out from 1989 to 2009 each November on the INA-K
in the Thames Estuary. The aims of which were to assess the state of herring
(*Clupea harengus*) stocks through measurements of length samples and by
ageing a stratified selection of fish. The latter was also to determine the
stock split between North Sea and Thames fish as there is a great deal of
mixing of stocks in the area. Stock identification was done by a combination
of first year growth observed in the otolith and the maturity stage of the
fish.

Survey took place between 11/11/2004 and 22/11/2004 on INA K

Equipment used during this survey :

- Larson Sprat Trawl

Survey operations were undertaken on 36 stations

28 different species were caught on this survey

本调查由Cefas承担，作为黑水鲱鱼调查（FSS: INA K HER）的一部分；自1989年至2009年，每年11月，INA-K号船在泰晤士河口进行了一系列巡航。其目的在于通过测量长度样本和分层选取鱼类的年龄来确定鲱鱼（Clupea harengus）种群的状态。此外，分层选取鱼类的年龄测定还旨在区分北海和泰晤士河鲱鱼种群，因为该区域种群混合程度较高。种群鉴定是通过观察第一年生长在耳石中的生长线以及鱼类的成熟阶段来实现的。调查于2004年11月11日至22日在INA K号船上进行。本次调查使用的设备包括：Larson鲱鱼拖网。调查在36个站点进行，共捕获了28种不同的物种。