Predicting the Impacts and Socio‐Economic Consequences of Climate Change on Global Marine Ecosystems and Fisheries

Abstract

Climate change is accelerating and is already affecting the marine environment. Estimating the effects of climate change on the production of fish resources, and their dependent societies, is complex because of:1. difficulties of downscaling Global Climate Models (GCM) to scales of biological relevance; 2. uncertainties over future net primary production and its transfer through the food chain; 3. difficulties in separating the multiple stressors affecting fish production; and 4. inadequate methodology to estimate human vulnerabilities to these changes.QUEST_Fish, a research project led from the UK, is addressing some of these challenges through an innovative, multi-disciplinary approach focused on estimating the added impacts that climate change is likely to cause, and the subsequent additional risks and vulnerabilities of these effects for human societies. The project uses coupled shelf seas biophysical ecosystem models forced by GCM forecasts to predict ecosystem functioning in past, 32 World Fisheries: A Social-Ecological Analysis present, and future time-slices. For each slice, and for 20 Large Marine Ecosystems, we estimate plankton production and use this to estimate size-based fish production through models based on macro-ecological theory. Ways of assessing vulnerability of fisheries to future climate change are developed, including the market consequences for fish-based global commodities. The results provide a new framework and new insights into the complex interactions between humans and nature.

Modelling the potential impacts of climate change and human activities on the sustainability of marine resources

“…The limited spatial resolution of global circulation models has been long considered a hindrance to this work, as most fish populations concentrate in narrow bands around the continental shelves. Recently, the UK QUEST_Fish project has used a sizebased model combined with projections of changes in temperature and ecosystem productivity from very high resolution (0.18 Â 0.18) shelf sea models to project changes in abundance and production of different fish size classes of a number of regional large marine ecosystems [24].…”

“…Most impact analyses, as noted above, take the changes in the biophysical world at face value and then estimate the consequences for human societies [36 ]. Despite recent developments [24] few modelling studies incorporate humans in a two-way coupled system. Unveiling the impacts of climate change on the natural component of marine ecosystems tells only part of the story.…”

“…On the ecological side the approaches include many simplifications, and suffer from limited data and model resolution. Predictions are particularly uncertain at the temporal and spatial scales that are relevant to the management of living marine resources [24], although new highly resolved regional oceanographic and ecosystem models may partially overcome this problem [40 ]. Ecological predictions are also constrained by the uncertainty of the global models which determine the boundary conditions and by the potentially non-linear responses to climate forcing at different organizational levels.…”

Global in scope and regionally rich: an IndiSeas workshop helps shape the future of marine ecosystem indicators

“…Owing to the expertise gathered in IndiSeas II, we will use state-of-the-art ecosystem models including EwE (Christensen and Walters 2004), OSMOSE (Shin and Cury 2004;Travers et al 2009), Atlantis (Fulton et al 2004 and simpler size-based and multispecies models (Blanchard et al 2009Hartvig et al 2011) as test laboratories. Some ecosystems of IndiSeas II will also benefit from ongoing development of ''end-to-end modelling'' (Travers et al 2007;Rose et al 2010;Shin et al 2010c;Barange et al 2011), involving coupling ecosystem models that focus on higher trophic levels with hydrodynamic, biogeochemical and economic models. This important step allows models to handle explicitly multiple drivers, their impacts, and expected feedbacks in marine ecosystems.…”

Effects of a tropical cyclone on a pelagic ecosystem from the physical environment to top predators

“…They initiate a bottom-up forcing of the ecosystem, creating persistent patches of higher primary and secondary production, and may be regarded as a disturbance regime. data sets (Baum & Worm 2009, Overland et al 2010 and can be predicted by increasingly sophisticated physical-biological ecosystem models (Barange et al 2011). Processes that regulate the structural and functional characteristics of ecosystems -including stability, diversity, and productivity-are often classified as bottom-up (resource-driven, forced by physical factors) or top-down (consumer-driven, forced by biotic factors) (Hunter & Price 1992, Cury et al 2003.…”