Warmer Temperatures Are Impacting Fish in North American Waters

It hasn't been a good year for the world's oceans. The plastic pollution problem is getting worse. We're seeing the biggest coral bleaching event in recent history. And now, there's growing evidence that even the small warming we've experienced due to climate change is having significant impacts on how fish reproduce, grow and even where they live.

This comes from a series of studies released by the United States Geological Survey (USGS), which, in turn, synthesize data from 31 other studies conducted across North America. It is one of the most comprehensive looks at how climate change is impacting fisheries. There is a caveat, of course, that even this is just a tiny piece of the puzzle, as there are thousands of different marine species in our waters, and only a tiny percentage of them were analyzed closely by scientists.

Some of the findings are quite worrisome: Scientists found new fish hybrids, a result of species that migrate at different times and now come into contact; altered prey-predator dynamics that could impact the food chain; and well-documented shifts in abundance of numerous inland fishes, including sockeye salmon.

While some species will benefit, others will not. And due to the complexities of ocean ecosystems, figuring out the long-term impacts will be a major challenge.

All hope is not lost, of course. With increased knowledge, fisheries managers can build responses that help build resiliency and also protect highly vulnerable fish species and their precious habitats.

“Even though climate change can seem overwhelming, fisheries managers have the tools to develop adaptation strategies to conserve and maintain fish populations,” said Craig Paukert, a lead author and fisheries scientist at the USGS Missouri Cooperative Fish and Wildlife Research Unit at the University of Missouri, in a press statement.

Key to that will be more research -- and increased knowledge. The climate is, as we know, incredibly complex. And we need to invest far greater resources in understanding the scientific impacts in order to create strategies to solve the problem. What we do know is worrying enough.

“The current state of the science shows that climate change is impacting fish in lakes, rivers, and streams, but knowing that is just the first step in effectively addressing the changes to these important natural resources and the communities which depend upon them,” said Abigail Lynch, a lead author and fisheries biologist with the USGS National Climate Change and Wildlife Science Center, in a press statement.

There is a strong financial component, too. Recreational fishing is a $25 billion industry, and coastal fisheries contribute almost $700 million in revenue to state agencies. There is a strong role that companies who sell fishing equipment, boats and other gear can play in both helping fund research and ensuring that our fisheries stay strong in the face of what is inevitable increased warming.

Together, we can protect our fish from climate change – but only if we take strong, science-based action soon.

Photo Credit: NASA Goddard Institute for Space Studies via Wikimedia Commons.