Scientists say high heat was one reason why thousands of menhaden along with other fish and 126 horseshoe crabs died. At the Chesapeake Bay Foundation, Joe Wood says that conditions on land were so hot that when it finally rained, warm water rushed into rivers and streams.
"If you’ve ever been out in July, some of these hot days we’ve had lately, and after a rain event you see steam coming off of the parking lot, water that rolls of pavement into rivers and streams can assimilate a lot of heat."
The lack of rain promoted algae growth, and water held less of the oxygen fish need to survive. Then, when storms came, they washed pollutants into waterways.
"Water that’s on parking lots, our homes, buildings, agricultural land – they carry pollution with it, and that pollution has an effect on water quality as well."
And some species are more vulnerable than others.
“Brook trout are known to be a cold-water species. They need these cold-water habitats to thrive, and those are harder and harder to find. Striped bass as well.”
Wood says people could help to prevent fish kills by planting trees along waterways.
“Trees are our greatest coolers. You know they have the capacity to intercept water. They give it a chance to cool off, or maybe they prevent it from getting to the stream altogether. They prevent the runoff.”
Less pavement in our cities and suburbs could also be a plus, since hot surfaces warm the rain that falls. Last week, the Potomac River set a record at 96 degrees.
