Climate Change Impacts On The Economics Of World Fisheries

Most biophysical and climate scientists agree that anthropogenic climate change is already causing long-term changes in atmospheric and oceanographic conditions that affect marine ecosystems. Ecologists and fisheries biologists suggest, using theory and experimental evidence, that changes in temperature and ocean chemistry directly affect the physiology, growth and reproduction of fish species. For example, fishes in warmer waters are expected to have a smaller maximum body size and smaller size at first maturity. Fishes with smaller bodies that live in warmer environments are likely to suffer higher natural mortality rates. These are important factors that determine population dynamics and productivity. There is also evidence that ocean acidification and expansion of oxygen minimum zones may have negative impacts on marine organisms and fisheries, although their generality is uncertain. Studies suggest that species’ responses to more acidic waters may vary between species — invertebrates are likely to suffer the most, but the effect on finfish is more uncertain. A key question addressed in this presentation is: how will climate change, through its impacts on the biophysics of the ocean, affect the economics of fishing worldwide?