Session 1: Integrating approaches, dimensions and scales for the study of small pelagic fishes
The study of small pelagic fishes is closely linked to their specific characteristics. Their way of life in dense schools in the water column requires the use of acoustics in addition to trawling to assess their abundance. Their intermediate position in the marine trophic chain and their dynamics, which are strongly influenced by their abiotic and biotic environment, have justified the development of ecosystem campaigns to observe and analyze their environment, prey and predators. Their small size and high abundance have so far limited the use of tagging to follow their movements and migrations. Their fragility has severely limited our ability to raise them and study the impact of various factors or stresses on their vital functions under experimental conditions. It is for these species that the combination of in-situ, experimental and modeling approaches most clearly overcomes the limitations of each approach. There are still some peculiarities regarding professional catch data and the downstream end of the industry. Fish flows are very often carried out on an over-the-counter basis, without going through the auctions, while the industrial supply is increasingly internationalized, requiring the exploration of international databases. Sometimes the lack of socio-economic data can also be overcome through surveys or participatory workshops.
For this session, we invite contributions that illustrate:
- the specificities of observation and data collection on small pelagic fish and their industry,
- the integrated, ecosystem-based aspect of small pelagic assessment campaigns
- the contribution of approaches combining in situ observations, experiments and modeling, and/or different scales from gene to ecosystem, to an integrated understanding of the functioning of the small pelagic fish compartment
- the translation of quantitative data from surveys or participatory workshops into quantitative data that can be used to develop diagnoses and scenarios,
- the benefits and means of pooling indicators for the different components of small pelagic fish socio-ecosystems.
Session 2: Spatio-temporal variability of habitat, small pelagic population dynamics, fishing fleets and associated markets
Populations of small pelagic fishes have always been subject to strong variations in biomass and/or abundance, linked on the one hand to recruitment, which is strongly influenced by the abiotic and biotic environment, and on the other hand to fishing mortality, which sometimes exceeds the limits that ensure the sustainability of the stocks. Fisheries and downstream industries have had to adapt and reorganize on a regular basis to cope with these risks. The seasonal dimension of the availability and quality of small pelagics has also historically been a structuring factor for the industry. In addition, over the past two decades or so, pronounced trends in size, weight, and condition at different ages, as well as an increase in mortality at older ages, have altered population dynamics, complicated stock assessment, and added a major constraint to the management of these species. Hypotheses to explain these trends seem to converge on bottom-up factors, particularly those related to changes within planktonic communities. However, the mechanisms involved remain poorly understood. This has a major impact on the downstream fishing and canning industries, in a sector that is increasingly globalized and competitive in terms of supply.
For this session, we invite contributions that illustrate:
- the spatio-temporal variability of life-history, physiological and behavioral traits or recruitment within or between populations, from seasonal to inter-annual scales, and the mechanisms at play under the influence of intrinsic factors (e.g. genetics, density dependence) or extrinsic factors (environment and fishing),
- the spatio-temporal dynamics of fleets, in particular in relation to the dynamics of small pelagic fishes
- downstream supply and market dynamics at national, European and international levels,
- stock assessment and management approaches taking into account this variability.
Session 3: Small pelagic fish: a central link in socio-ecosystems
Small pelagic fish, the forage species of marine ecosystems, provide energy transfer between low and high trophic levels. They are also rich in essential nutrients (proteins, fatty acids, etc.) that they transfer within food webs, ultimately for human consumption. These nutrients are also essential for the proper functioning of marine ecosystems and for predators (piscivorous fish, birds, marine mammals). Small pelagic fish generally exhibit opportunistic feeding behavior that varies with age, space and time. Understanding the spatial distribution and variability of the trophic transfer of these essential nutrients is critical to a better understanding of ecosystem function. This knowledge can improve our understanding of the spatial distribution of foraging areas, fluctuations in fish stock recruitment, and inform fisheries management. Under the influence of climate change, planktonic production of essential fatty acids (omega-3) is expected to decrease, a risk factor for the health of the marine food web and human populations. In this context, a key challenge is to ensure the best possible valorization of proteins and fatty acids from small pelagic fish, in line with informed use by downstream industries and consumers.
For this session, we invite contributions that illustrate:
- Bottom-up and top-down forcing mechanisms on small pelagic fish,
- The dynamics of trophic and spatial interactions within the pelagic ecosystem and with benthic species,
- The transfer of energy, nutrients and contaminants within the food web and downstream value chains under the influence of global change,
- The different ways in which raw materials are used in downstream industries and consumer perceptions of these products.
Session 4: How can industries adapt to global change?
Given the central role of small pelagics in marine ecosystems and for human consumption, it is essential to ensure the sustainability of their stocks and the appropriate distribution of associated nutrients among human populations. The sustainability of the industry also depends on fair valuation along the value chain. Faced with the challenges of climate change, which affects the quality and distribution of raw materials, and the economic challenges associated in particular with globalization, value chains will necessarily have to adapt in a transition that must be profitable for all.
For this session, we invite contributions on the following topics :
- The challenges of good ecological status for pelagic ecosystems, the sustainability of stocks and the viability of fisheries,
- The sustainability of all types of industries and the maintenance of fishing and industrial activities in local areas,
- Food security and the sharing of resources among a wide range of consumers,
- Product traceability and health issues,
- The environmental transition of fisheries and downstream industries,
- Scenarios for the evolution of pelagic populations, ecosystems and industries.
