La Jolla Alert: A possible profusion of wild anchovy wild sex

“Anchovy Sex Is a Force of Nature” is the headline on a Hakai magazine report by Christina Crouch, on February 7, 2024. The report says, in part:

…But Castro’s study—which was published in 2022 and won a 2023 Ig Nobel Prize for humorous, thought-provoking scientific achievement—shows that within ocean layers, anchovy spawning causes significant, if subtle, swings in temperature. This finding suggests that in shallower water, the ruckus produced by plentiful piscine participants procreating all at once might be more powerful and more important for ocean mixing than previously thought….

It’s even possible, Castro says, that his study actually underrepresents the effects of anchovy sex. Local fishermen told him the anchovy aggregation he studied was much smaller than similar swarms spotted farther offshore. In places like La Jolla, California, researchers have seen anchovy aggregations of between 10 million and one billion fish—schools so vast and dense they look like an oil spill cutting through clear water. Other schooling species, such as sardines and herring, swim in groups of similar sizes. But scientists have very little data on whether these species produce similarly titillating turbulence.