Genetic diversity is the raw material for evolution, and it allows species to adapt to changing environmental conditions. But can fisheries cause species to lose genetic diversity? In our meta-analysis just out this week in Molecular Ecology (OnlineEarly), we find strong evidence that the answer is yes. Previously, studies on individual populations have had somewhat ambiguous results: some studies found an effect, others did not. Our finding provides more evidence that the evolutionary impacts of overharvest are important for fisheries management, and may explain why some heavily overfished populations (e.g., Newfoundland cod) have had such a hard time recovering.
As ocean temperatures change, fish that provide food for people around the world are moving into new territories. While it’s been common to talk about broad expectations like species shifting towards the poles as the climate warms, the problem has been that many species are not shifting towards the poles, and even of those species that are, some are shifting quickly and others slowly. In a paper out today in Science, we show that the trick to more precise forecasts is to follow local temperature changes, expressed as climate velocities.
Climate velocities are the rate and direction that temperatures move across the seascape. The findings suggest that climate velocity will be a powerful tool for forecasting future range shifts and have implications for marine conservation and fisheries management. Transient populations are especially vulnerable to overexploitation.
As one example, lobster in the northeastern United States (above) moved north at a pace of 43 miles per decade. (Video by Leah Lewis and D. Richardson, National Oceanic and Atmospheric Administration)
Malin will talk about his ongoing research on climate and marine range shifts at the Ecological Society of America: August 6, 1:30pm, COS 5-1.