Unusually warm days in Humboldt County have had an impact on the local environment, impacting places like Trinidad State Beach, north of Arcata.
Daniel O’Shea, a professor at HSU and College of the Redwoods, answered questions about Trinidad Beach and how the heat is affecting it. He specializes mainly in ocean science and marine geology.
“I observed some apparent discoloration, or bleaching, of some of the intertidal rockweeds (seaweed) in the late spring 2013 at Trinidad Beach,” he said. “This was most likely due to the very low tidal water levels combined [with] exceptionally warm, sunny days we experienced last spring. This bleached seaweed was visible into the foggy summer months, however, the seaweeds seemed to recover somewhat. I did not notice any increased bleaching of the intertidal seaweeds over the past several weeks.”
O’Shea explained that elevated temperatures over the past several weeks were in part a result of a warm, humid air mass moving up the west coast from Mexico, and wrapping around an atmospheric upper level low pressure system that was stalled off the California coast.
“The combination of cloud cover, along with higher average tidal levels, may have mitigated some of the effects of the warmer air temperatures on the rocky intertidal flora and fauna,” O’Shea said.
Currently much of the life on the beach seems to be healthy, despite the heat in late mid-August to mid-October. If there have been slow, long term changes around the beach that seem to be occurring from the unusual heat though, they don’t seem to be obvious.
“It is difficult to assess long term changes without a good baseline data set of conditions over the past several decades or longer,” O’Shea said. “I am always amazed at the resilience of the rocky intertidal fauna to rebound after extreme weather events such as the warm weather we had late last spring.”
What should people know about the environmental changes that he’s seen?
“Many environmental changes are long-term and may not be noticeable even across one’s entire lifetime,” O’Shea said. “What is easy to observe are extreme weather related events, such as fires in the West, flooding in Colorado or the perfect storm of mid latitude storms and hurricanes combing to hit New York City 14 foot storm surges. Locally I have noticed that there seem to be fewer foggy days per summer then there were 20 or 30 years ago. The rocky intertidal is a fragile ecosystem and depends on the fog for protection from the extreme intense radiation from the Sun during the long days of summer. What we do does make a difference. And we have an instrumental role to play on the beach by picking up our trash, and removing garbage left by others that we find on the beach and putting it in the proper bins.”