Warming Up To Shrinking Fish
by Eizabeth Brown and Carl Safina, Blue Ocean Inst.
A few years ago, some scientists at the University of British Columbia were thinking about how climate change would affect fish. Climate change results from the collection of carbon dioxide in the atmosphere from our burning of fossil fuels (oil, coal, gas), which causes the earth to warm. The scientists wondered out loud if warming could affect fish growth. Warmer waters hold less oxygen than cold water.
And, as the water warms, fish need more oxygen to perform daily activities, like feeding. They asked how these competing factors would affect fish size: Would a fish be able to grow large as warmer water causes oxygen concentration to drop even as the fish’s oxygen needs increase?
And so, they set up a model to look at how predicted rises in ocean temperatures will change fish body size and fish distributions between the years 2000 to 2050. They input information on distribution, growth rates, temperature preferences, etc. for over 600 marine fish species (including groupers, cods, flounders, salmon, and other commercial species).
The model confirmed the scientists’ predictions: warming will limit the size fish grow to. This means SHRINKING fishes! By 2050, warming will shrink the average maximum body weight of fishes by 14-24% globally…
(read more: National Geo) (images: NOAA)