One-by-one Marin City students joyously stepped aboard Sausalito’s finest sailboat, the Freda B. For most of the children, this was their first time experiencing life out on the waters of the San Francisco Bay. There was a palpable sense of…
I’m just synthesizing the conversations, data, and information presented at a workshop co-sponsored by the California Gray Whale Coalition and Ocean Conservation Research at the Oakland offices of the Center for Biological Diversity on Monday, April 11. The purpose of…
Earlier this year a paper by Christne Erbe et.al was published in the open source Public Library of Science (PLoS-One) that frames ocean noise exposures in a sensible and informative manner. For various adaptive reasons animals are sensitive to sounds…
Although much of the concerns about ocean noise orbits around the impact of noise on marine mammals, I have been equally concerned about the impacts of noise on the fish. At first brush fish don’t seem as charismatic as whales and dolphins; but as a class, fish are rather amazing. They’re also a pretty important feature in marine ecosystems (and the feeding habits of other vertebrates – like us humans). So while public sentiment has driven a lot of research on the impacts of noise on marine mammals (and the resulting protective regulations) fish are also subject to the impacts of human-generated noise.
This shows up occasionally when fishing catches plummet after seismic surveys, or after research team finds that larval fish imprint and navigate to sounds, including sounds that are not natural to their habitat. Noise impacts on fish came up again last week in a published study finding that the recorded sound of ship noise disrupted feeding behavior and foraging success of two species of freshwater fish.
I have a few technical bones to pick with the study: The tanks were much smaller than the wavelengths of most of the disruptive sounds, and the source of ship noise (played back through speakers) would not typically be in such close proximity to the impacted subjects. But it isn’t really too surprising that unnatural noise disrupts fish behavior; these animals depend on acoustical energy to sense their surroundings – finding prey, avoiding predation, establishing their relations with others, etc. And the paper does provide some numbers to substantiate the case.
With our current state of knowledge about how and what fish do with the sounds they hear it would be difficult to predict how any particular sound might impact any fish in their particular ecosystems. But we know that fish are sound-sensitive so we can assume that they will interact with the sounds of their surroundings. If the sounds are introduced by non-biological sources, it would be a good idea to know how fish respond.
This coming Friday, November 9, I will be giving a presentation on marine bio-acoustics at the Bodega Bay Community Center. Come hear the beasts of the deep sing, burp, chatter, clatter, and squeal their unusual sounds. Then try to figure…
A recent paper in Behavioral Ecology indicates that noise pollution may confuse the recruitment of larval reef fish to safe habitats. Coral reefs set up and interesting quandary for larval-stage reef inhabitants. When they are tiny, their “mother reef” is…