At a Glance Unusual June heat in the California combined with low tides to cause a mass die-off of California mussels. It was the worst die off in at least 15 years in Bodega Head, California, according to researchers. The mussels, completely exposed to the heat, baked in their shells. Unusually warm temperatures combined with seasonal low tides to roast California mussels in their shells in an mass die-off that could have larger implications on the local marine ecosystem. The...