Scripps Oceanography says rapid heating was caused by fair, hot weather
The high temperatures might be left over from the warm-water "blob" off California in 2014.
California State Parks scientists are running tests this week to determine what caused about 1,500 fish to die in Malibu Lagoon last week, but officials suspect higher-than-normal water temperatures may have played a role.
Marine heatwaves are growing longer, stronger and more frequent thanks to climate change.
