News / Science & Technology
Response of Fish to Ocean Warming
According to the IPCC, CO2-induced global warming will be net harmful to the world's marine species. This summary examines this hypothesis for various fish species, presenting evidence in opposition to the IPCC's point of view.
Noting "effects of climate-driven production change on marine ecosystems and fisheries can be explored using food web models that incorporate ecological interactions such as predation and competition," citing the work of Cury et al. (2008), Brown et al. (2010)1 used the output of an ocean general circulation model driven by a "plausible" greenhouse gas emissions scenario (IPCC 2007 scenario A2) to calculate changes in climate over a 50-year time horizon, the results of which were then fed into a suite of models for calculating primary production of lower trophic levels (phytoplankton, macroalgae, seagrass and benthic icroalgae), after which the results of the latter set of calculations were used as input to "twelve existing Ecopath with Ecosim (EwE) dynamic marine food web models to describe different Australian marine ecosystems," which protocol ultimately predicted "changes in fishery catch, fishery value, biomass of animals of conservation interest, and indicators of community composition."
In discussing their findings, the seventeen scientists state under the IPCC's "plausible climate change scenario, primary production will increase around Australia" with "overall positive linear responses of functional groups to primary production change," and "generally this benefits fisheries catch and value and leads to increased biomass of threatened marine animals such as turtles and sharks," adding that the calculated responses "are robust to the ecosystem type and the complexity of the model used." Given these findings, in the concluding sentence of their paper, Brown et al. state the primary production increases suggested by their work to result from future IPCC-envisioned greenhouse gas emissions and their calculated impacts on climate "will provide opportunities to recover overfished fisheries, increase profitability of fisheries and conserve threatened biodiversity," which most would characterize as an important set of temperature-induced benefits.
