Interacting regional-scale regime shifts for biodiversity and ecosystem services

Current trajectories of global change may lead to regime shifts at regional scales, driving coupled human–environment systems to highly degraded states in terms of biodiversity, ecosystem services, and human well-being. For business-as-usual socioeconomic development pathways, regime shifts are projected to occur within the next several decades, to be difficult to reverse, and to have regional- to global-scale impacts on human society. We provide an overview of ecosystem, socioeconomic, and biophysical mechanisms mediating regime shifts and illustrate how these interact at regional scales by aggregation, synergy, and spreading processes. We give detailed examples of interactions for terrestrial ecosystems of central South America and for marine and coastal ecosystems of Southeast Asia. This analysis suggests that degradation of biodiversity and ecosystem services over the twenty-first century could be far greater than was previously predicted. We identify key policy and management opportunities at regional to global scales to avoid these shifts

Assessing the contribution of marine protected areas to the trophic functioning of ecosystems: a model for the Banc d'Arguin and the Mauritanian shelf.

Most modelling studies addressed the effectiveness of marine protected areas (MPA) for fisheries sustainability through single species approach. Only a few models analysed the potential benefits of MPAs at the ecosystem level, estimating the potential export of fish biomass from the reserve or analysing the trophic relationships between organisms inside and outside the MPA. Here, we propose to use food web models to assess the contribution of a MPA to the trophic functioning of a larger ecosystem. This approach is applied to the Banc d'Arguin National Park, a large MPA located on the Mauritanian shelf. The ecosystem was modeled using Ecopath with Ecosim, a model that accounts for fisheries, food web structure, and some aspects of the spatial distribution of species, for the period 1991-2006. Gaps in knowledge and uncertainty were taken into account by building three different models. Results showed that the Banc d'Arguin contributes about 9 to 13% to the total consumption, is supporting about 23% of the total production and 18% of the total catch of the Mauritanian shelf ecosystem, and up to 50% for coastal fish. Of the 29 exploited groups, 15 depend on the Banc for more than 30% of their direct or indirect consumptions. Between 1991 and 2006, the fishing pressure increased leading to a decrease in biomass and the catch of high trophic levels, confirming their overall overexploitation. Ecosim simulations showed that adding a new fleet in the Banc d'Arguin would have large impacts on the species with a high reliance on the Banc for food, resulting in a 23% decrease in the current outside MPA catches. We conclude on the usefulness of food web models to assess MPAs contribution to larger ecosystem functioning

Using trophic models to assess the impact of fishing in the Bay of Biscay and the Celtic Sea

Using the Bay of Biscay and Celtic Sea area as a case study, we showed how stock-assessments and trophic models can be useful and complementary tools to quantify the fishing impacts on the whole food web and to draw related diagnoses at the scale of marine ecosystems. First, an integrated synthesis of the status and trends in fish stocks, derived from ICES assessments, was consolidated at the ecosystem level. Then, using the well-known Ecopath and Ecosim and the more recently developed EcoTroph approach, we built advice-oriented ecosystem models structured around the stocks assessed by ICES. We especially analysed trends over the last three decades and investigated the potential ecosystem effects of the recent decrease observed in the overall fishing pressure. The Celtic/Biscay ecosystem appeared heavily fished during the 1980–2015 period. Some stocks would have started to recover recently, but changes in species composition seem to lead to more rapid and less efficient transfers within the food web. This could explain why the biomass of intermediate and high trophic levels increased at lower rates than anticipated from the decrease in the fishing pressure. We conclude that, in the frame of the Ecosystem approach to fisheries management, trophic models are key tools to expand stock assessment results at the scale of the whole ecosystem, and to reveal changes occurring in the global parameters of the trophic functioning of ecosystems

Fisheries Centre research reports, Vol. 8, no. 1

This report presents a literature review of marine protected areas (MPAs) throughout the world, with an emphasis on 16 case studies that involve community participation and indigenous peoples. Details of three MPAs, namely the Great Barrier Reef Marine Park in Australia, San Salvador Marine Reserve in the Philippines, and the Fagatele Bay Marine Sanctuary in American Samoa, are included to illustrate the importance of community involvement in establishing MPAs. A table summarises each MPA reviewed in terms of its establishment, purpose, level of protection, planning and management process, enforcement, community involvement, problems and results. The successful establishment of marine reserves or marine protected areas depends largely on public support and community participation in as early stage as in the planning process. Yet, in practice, many M PAs are established using a traditional 'top-down' approach. Opposition from users groups, resource use conflicts and economic concerns are common and are the most important factors which often lead to MPAs not being fully implemented. Participation of indigenous people is further limited due to barriers in the planning process such as cultural differences, and the time and format constraints. As a result, indigenous peoples' interests and concerns are not well represented in MPA design and planning.Science, Faculty ofNon UBCOceans and Fisheries, Institute for theUnreviewedFacultyGraduateUnknow

Fisheries Centre research reports, Vol. 9, no. 4

Part 1. Analysis of biomass trends -- Part 2. Northwest Atlantic -- Part 3. Northeast AtlanticScience, Faculty ofOceans and Fisheries, Institute for theUnreviewedFacultyGraduat

Fisheries Centre research reports, Vol. 17, no. 4

Directed forward. Extended abstract. Resume etendu. Introduction. 1. Materiel et methodes. 2. Resultats. 3. Discussion - Conclusion. Remerciements. References. Appendices.Fisheries Centre (FC)UnreviewedFacultyResearcherGraduat

Contrôle hydrodynamique de l'avalaison des œufs et des larves de poulamon atlantique

Les poulamons de la rivière Sainte-Anne frayent dans un secteur de rapides, situé à environ 7 km de la confluence avec le fleuve Saint-Laurent, et probablement aussi dans un secteur d'accumulation de frasil généré par ces rapides. Les variations interannuelles dans la dérive des œufs et des larves de poulamon, à différentes stations dans la rivière, sont reliées aux conditions annuelles de température de l'air et de débit. Des températures et débits bas et stables ont causé la rétention des œufs et des larves dans la partie amont du secteur d'étude (1980–1981, 1981–1982); les températures et débits plus élevés et variables ont causé une dérive régulière au fleuve Saint-Laurent de janvier à avril (1982–1983). En 1980–1981, une hausse soudaine de la température et du débit a causé une avalaison massive des œufs au Saint-Laurent durant la seconde moitié de février. Des œufs de poulamon sont retenus et incubés dans le frasil, qui s'accumule en un barrage suspendu pouvant s'étendre, selon les années, sur plus de 3 km de rivière. Peu de temps après la fraye, la densité moyenne d'œufs par 2 l de ce substrat, sur l'ensemble du barrage suspendu, atteignait 228 en 1981 (19 janvier), 235 en 1982 (6 février), et 54 en 1983 (15 février). Les variations interannuelles dans la distribution spatiotemporelle des œufs dans le frasil concordent avec celles suggérées par les résultats de la dérive

Biomass ratios for simulations involving an additional fictive fleet in the Banc (A) and the loss of the Banc as a habitat (B) for the three models (P30, Base, M30) by group of species (31spp, and coastal, pelagics and shelf functional groups).

<p>Biomass ratios for simulations involving an additional fictive fleet in the Banc (A) and the loss of the Banc as a habitat (B) for the three models (P30, Base, M30) by group of species (31spp, and coastal, pelagics and shelf functional groups).</p