Ecosystem-based fisheries management increases catch and carbon sequestration through recovery of exploited stocks: The western Baltic Sea case study

Abstract

Legal requirement in Europe asks for Ecosystem-Based Fisheries Management (EBFM) in European seas, including consideration of trophic interactions and minimization of negative impacts of fishing on food webs and ecosystem functioning. This study presents the first mass-balanced ecosystem model focused on the western Baltic Sea (WBS). Results show that heavy fishing pressure exerted on the WBS has forced top predators such as harbour porpoise and cod to cover their dietary needs by shifting from forage fish to other prey or find food outside of the model area. The model was then developed to explore the dynamics of four future fishery scenarios: (1) business as usual (BAU), (2) maximum sustainable fishing (F = FMSY), (3) half of FMSY, and (4) EBFM with F = 0.5 FMSY for forage fish and F = 0.8 FMSY for other fish. Simulations show that BAU would perpetuate low catches from depleted stocks with a high risk of extinction for harbour porpoise. In contrast, the EBFM scenario would allow the recovery of harbour porpoise, forage fish and cod with increases in catch of herring and cod. EBFM promotes ecosystem resilience to eutrophication and ocean warming, and through the rebuilding of commercial stocks increases by more than three times carbon sequestration compared to BAU. The model provides an interrelated assessment of trophic guilds in the WBS, as required by European law to assess whether European seas are in good environmental status.

Jellyfish blooms challenge the provisioning of ecosystem services in the Korean coastal waters

“…Marine ecosystem dynamics is shaped by climate variance through its influence on the pelagic physical environmental, which molds trophic interactions among successive trophic levels. Warming scenarios are expected to disturb plankton communities and marine food webs, i.e., eroding ecosystem structure and resilience, which will likely magnify the impact of growing fishing stress on harvested fish (Möllmann et al, 2021;Scotti et al, 2022). Such scenarios of ecosystem health degradation also promote ecological spaces for opportunistic species, such as jellyfish, which impair harvested populations and rise uncertainties on the governance of coastal marine resources.…”

Ecotrophic perspective in fisheries management: a review of Ecopath with Ecosim models in European marine ecosystems

“…Several EwE models have been developed in this area, including Ecopath (Sandberg et al, 2000;Harvey et al, 2003;Tomczak et al, 2012;Tomczak et al, 2013), Ecosim (Österblom et al, 2007;Niiranen et al, 2013;Costalago et al, 2019) and Ecospace (Bauer et al, 2018;Bauer et al, 2019) applications, focusing mostly on primary production fluctuations and climate change impacts on the food webs. Recently, an EwE model of the western Baltic Sea was constructed to assess the impact that alternative fisheries management strategies have on the status of commercial stocks, diversity of top predators and fishing yield (Scotti et al, 2022a). At a smaller scale, an Ecopath model was developed for an open coastal area in the southwestern part of the Bothnian Sea to evaluate radioactive fluxes in the food web using the Ecotracer tool (Sandberg et al, 2007).…”

“…Software programs simulating ecosystem dynamics have facilitated the holistic study of marine ecosystems. Ecosystem modelling has provided a means for incorporating management perspectives (Fath et al, 2019); i.e., by implementing scenarios related to fisheries management, climatic and other environmental conditions (e.g., Scotti et al, 2022a), as well as the establishment of marine protected areas (MPAs; Dahood et al, 2020). Ecopath with Ecosim (EwE: Polovina, 1984;Christensen and Walters, 2004a) is the most widely used software tool for modelling marine food webs.…”

Trophic structure and fishing impacts on an oligotrophic ecosystem in the Western Mediterranean: the Balearic Islands

“…The Prebal diagnostics introduced by Link ( 2010) are used to ensure that the input data follow general ecological and fisheries principles. These diagnostics guide the balancing procedure, and are applied before the model is balanced and the dynamic application is run (Scotti et al, 2022). The aim is to increase the robustness and the reliability of the results generated.…”