Changing conditions and pressures that act across both the freshwater and marine phases of the salmon life cycle have impacted stock status, with estimated pre-fishery marine abundance showing downward trends since the 1980s throughout their native range.
In 2019, along with the North Atlantic Salmon Conservation Organisation (NASCO), ICES established a workshop series, WKSalmon, to bring together salmon and marine ecosystem experts to understand the reasons for these declining trends and improve the scientific assessments and advice available for the conservation of wild Atlantic salmon in the North Atlantic.
The group wanted to explore the best way of accessing and integrating available data that describes changes in the marine ecosystems used by salmon and to develop better understanding to advance their conservation.
The first workshop in June 2019 (WKSalmon1) identified potential data sources that could inform estimates of salmon mortality at sea as well as ecosystem data (including oceanographic time-series, plankton surveys, pelagic or demersal fish surveys) that describe the marine ecosystems occupied by Atlantic salmon. The group reported that many of the potentially useful datasets were complex and not readily accessible, had variable spatial and temporal scales but were “seemingly extractable with some concerted effort".
Following considerable intersessional progress on data mobilization, WKSalmon2 will take place in 2022 and hopes to prioritise key mortality hypotheses to progress understanding of the mechanisms behind marine mortality variation (eg. climate change-induced, changes to food web, increased predation, smaller size of salmon entering from freshwaters, disease, etc.). The group will also agree on definitions of key time and space “domains" for Atlantic salmon during their marine phase (i.e. key points in time and space where a substantial amount of the mortality occurs), as a way of organizing data resources. Identified and refined data resources can then be matched up to enable testing of key mortality hypotheses and help identify potential proximate drivers, and partition the losses, amongst them.
WKSalmon2 will take place in two sessions. A one-day online preparatory meeting will take place on 15 June 2022 to build on the work of WKSalmon1. Marine ecosystem experts, ecosystem-based management, data specialists, salmon ecologists, and modellers are invited to participate. This one-day session will discuss proposed marine mortality hypotheses, potential new data sources and the salmon “marine domains" concept to frame the WKSalmon2 process.
A three-day hybrid workshop will then take place from 30 August until 01 September to agree to a final set of high priority mortality hypotheses and define salmon “marine domains". Opportunities and mechanisms to leverage existing data sources within ICES region and beyond will be explored to assist hypotheses-testing, and an ICES Data Call drafted in preparation for WKSalmon3.
Both meetings will be co-chaired by co-chaired by Colin Bull (UK) and Glenn Nolan (Ireland). The one-day preparatory workshop will be online only, whereas participants have the option of joining the three-day workshop online or at ICES Secretariat in Copenhagen. All interested participants should register their interest with ICES Secretariat.