Ocean Futures Under Ocean Acidification, Marine Protection, and Changing Fishing Pressures Explored Using a Worldwide Suite of Ecosystem Models

Abstract

Ecosystem-based management (EBM) of the ocean considers all impacts on and uses of marine and coastal systems. In recent years, there has been a heightened interest in EBM tools that allow testing of alternative management options and help identify tradeoffs among human uses. End-to-end ecosystem modeling frameworks that consider a wide range of management options are a means to provide integrated solutions to the complex ocean management problems encountered in EBM. Here, we leverage the global advances in ecosystem modeling to explore common opportunities and challenges for ecosystem-based management, including changes in ocean acidification, spatial management, and fishing pressure across eight Atlantis (atlantis.cmar.csiro.au) end-toend ecosystem models. These models represent marine ecosystems from the tropics to the arctic, varying in size, ecology, and management regimes, using a three-dimensional, spatially-explicit structure parametrized for each system. Results suggest stronger impacts from ocean acidification and marine protected areas than from altering fishing pressure, both in terms of guild-level (i.e., aggregations of similar species or groups) biomass and in terms of indicators of ecological and fishery structure. Effects of ocean acidification were typically negative (reducing biomass), while marine protected areas led to both "winners" and "losers" at the level of particular species (or functional groups). Changing fishing pressure (doubling or halving) had smaller effects on the species guilds Olsen et al. Ocean Futures Explored Using Models or ecosystem indicators than either ocean acidification or marine protected areas. Compensatory effects within guilds led to weaker average effects at the guild level than the species or group level. The impacts and tradeoffs implied by these future scenarios are highly relevant as ocean governance shifts focus from single-sector objectives (e.g., sustainable levels of individual fished stocks) to taking into account competing industrial sectors' objectives (e.g., simultaneous spatial management of energy, shipping, and fishing) while at the same time grappling with compounded impacts of global climate change (e.g., ocean acidification and warming).

Improving the spatial allocation of marine mammal and sea turtle biomasses in spatially explicit ecosystem models

“…The sophistication of EwE with Ecospace and Atlantis allows these modeling approaches to tackle a wide number of EBFM issues, including MPA effectiveness (e.g. Salomon et al 2002, Martell et al 2005, Savina et al 2013, Olsen et al 2018, the consequences of bycatch reduction measures (e.g. Fulton et al 2007, Walters et al 2010, Morzaria-Luna et al 2012, 2013, and management strategy evaluations integrating ecosystem considerations (e.g.…”

Ecological guidelines for designing networks of marine reserves in the unique biophysical environment of the Gulf of California

“…9). A recent paper assessing the effect of MPAs across multiple Atlantis ecosystem models, including the Northern GOC model, also found that MPAs led to both 'winners' and 'losers' at the level of particular species or functional groups (Olsen et al 2018).…”

Better Together: The Uses of Ecological and Socio-Economic Indicators With End-to-End Models in Marine Ecosystem Based Management

“…of these un-vetted indicators (Houle et al, 2012;Ortega-Cisneros et al, 2018;Shin et al, 2018). Fulton et al (2005), Samhouri et al (2009), Kaplan et al (2013), Olsen et al (2018) and Ortega-Cisneros et al (2018) used endto-end model simulations to examine the impacts of fishing and climate on indicators. In these studies model simulations were projected at different levels of fishing or environmental variability and indicators were calculated from these outputs and examined against ecosystem attributes (to examine validity and sensitivity) or pressures (specificity).…”