Southern California beaches will be cleaner and healthier for swimmers and surfers this summer, thanks to the lingering drought. But that drop of good news for humans probably won’t mean much for aquatic life, says marine scientist Catherine Clark, Ph.D., professor and associate dean in the School of Earth and Environmental sciences.

Professor Catherine Clark.

Professor Catherine Clark.

“Something that’s good in one sense isn’t necessarily good in another sense. It’s complex,” says Clark, who studies how seawater and dissolved compounds interact with sunlight and their relationship with climate change.

Heal the Bay’s annual Beach Report Card issued for this summer reported dramatically reduced pollution rates at California beaches, a trend Clark says she and her team had also observed in their field work, noting significant drops in bacterial degradation processes because of less storm runoff this winter.

Which means there will be less of those troublesome bacteria that can lead to earaches and intestinal illnesses for ocean swimmers. That’s nice for the moment, but in the long run it won’t equate to a respite for marine life impacted by prolonged pollution.

“Those are longer-term processes that are more related to chronic exposure. That’s going to be something that is much, much more difficult to tell. Plus, because of the heat, you get other changes in food sources,” she says.

So everything in the marine food chain from zooplankton to large marine mammals is affected not just by the present drought, but by the big picture of climate change.

But less crud in the water and fewer ear infections are a good thing, right? Indeed, but Clark says she still won’t dip into just any waves this summer: “Generally, I’m a little careful about where I swim.”

Read more about Clark’s research at her faculty profile page.

(Top image/Heal the Bay)