In order to measure and track progress towards environmental targets such as those outlined in the UN's SDGs or the EU's MSFD, scientists and policy makers rely on ecosystem assessments. A key aspect of these assessments is whether or not human activities within an ecosystem are sustainable. Researchers try to determine this by studying indicators that demonstrate how food webs change in response to multiple pressures. Yet despite the critical nature of these assessments, a best approach to determine trophic guilds (groups of consumers with similar diets) has not been internationally agreed.
The Euromarine-funded foresight workshop EFIMBA will address this gap by seeking an agreeable definition of feeding guilds for species and size classes in order to assess change in food-web structure and function. The definition of guilds will be based on an analysis of the fundamental diet of marine organisms, using stomach contents sampling with data from across the Atlantic Ocean and the Mediterranean Sea. The use of these guilds, supplemented by additional information on species occurrence and behaviour, as indicators of functional groups will be discussed and recommendations provided. The international approach will provide a useful means to more easily compare change in ecosystems and communicate outcomes of analyses.
While many countries collect stomach contents data, these are often not collated even when surveying the same ecosystems and/or species, and there is no consensus on what exactly should be collected. This workshop will therefore follow up on recent initiatives focussed on the optimisation of trophic data collection in Europe, and consolidate and harmonise their findings. These initiatives, each of which has/had participants that will be involved in EFIMBA, include:
- The DGMARE project FishPi reviewed key species needing routine trophic data across a series of case studies and produced updated cost-effective collection protocols to feed the next DCMAP
- The 2018 RCG-Med & BSWKSTCON workshop recommended a common sampling protocol to study stomach content at Mediterranean level
- The ICES WKBECOSS workshop on Better Coordinated Stomach Sampling between ICES members
- EFIMBA will draw together collaborators and datasets from Europe, USA, S. Africa and Iceland to develop an internationally agreed approach to collect and integrate stomach contents data to assess change in marine food webs through trophic guilds.
- The participants will aim to understand the fundamental diets of fishes at the Atlantic Ocean-scale, which when combined with survey data can demonstrate why realised diets differ spatially. This will enable follow-up work to assess what impact consumption of prey may have, alongside direct impacts of human activities and identify areas where these impacts are synergistic or antagonistic. Ultimately, this can alter the food sources available to humans and top predators including those of conservation concern (sharks, marine mammals and seabirds).
EFIMBA will seek to have a direct impact through the development of an internationally-agreed approach for food web assessments. They will support this agreement through:
- A collated database.
- A thorough meeting report capturing the discussions and outcomes of the workshop.
- A peer-reviewed publication (ideally in the Journal of Applied Ecology).
The trophic guild approach and indicators developed in the workshop will allow the scientists to make complementary recommendations on how to optimise the collection of trophic data, which in turn will support more accurate food web and ecosystem assessments. This will help policy makers and their supporting scientific organisations more effectively measure, track and adjust their progress toward given environmental targets.