Most herring populations are migratory and often congregate on feeding and wintering grounds where aggregations may consist of mixtures of individuals from several populations, thus the standard concept of ‘a herring stock’ within a geographical area such as a management unit is not straight-forward to assume. The analysis of the genetic composition is becoming a widely and cost-effective tool for stock identification for separating herring into populations or stocks.
Recent advances include Next Generation Sequencing (NGS) and Genotyping by Sequencing (GBS) based approaches have recently been developed and applied to e.g., herring (Clupea harengus), cod (Gadus morhua), boarfish (Capros aper) and horse mackerel (Trachurus trachurus) for marker development and screening of spawning samples.
Given these developments, it is now timely to revisit this herring stock identification method after the conclusions of WKSIDAC in 2017 (ICES, 2017).
The objectives of this workshop are:
- review recent status of genetic stock identification for herring and outstanding issues affecting identification accuracy/success
- analyze the optimal baseline requirements for stock assessment purposes, both for specific survey as well as commercial catches
- outline a general description of prerequisites for the implementation of stock identification of herring
- provide guidance on a retrospective correction of herring survey and catch time-series where necessary
Key stocks to focus on:
| Stock / component | Abbr. | Area |
| Icelandic Summer Spawning Herring | ISSH | 27.5.a |
| Norwegian Spring Spawning Herring | NSSH | 27.2.a |
| North Sea Autumn Spawning Herring | NSAS | 27.4, 27.3.a, 27.7.d |
| Downs Winter Spawning Herring |
| 27.4.c,27.7.d |
| Western Baltic Spring Spawning Herring | WBSS | 27.3.a, etc. |
| Central Baltic Herring | CBH | 27.3.d |
| Irish Sea Herring | NIRS | 27.7.aN |
| Celtic Sea Herring | CSH | 27.7.aS, 7.g-h, 7.j-k |
| 6a North Autumn spawning herring | | 27.6.aN |
| 6a South 7bc herring | | 27.6.aS, 7.bc |
In addition, the following stocks may be considered:
| Norwegian Autumn Spawning Herring | NASH | 27.2.a |
| Faroese Autumn Spawning herring | | |
| Baltic Autumn spawning herring | BASH | 27.3 |
| 6a North Spring spawning herring | | 27.6.aN |
| Thames/Blackwater herring | | |
| Clyde herring | | 27.6.aN |
| Herring in Divisions 7ef | | 27.7.e, 27.7.f |
