New peril for gray whale survival? Predatory orcas spotted in Baja calving lagoon
A pod of orcas (top left) appeared in the waters off Baja on April 13, 2017.
Gray whales (Mesoplodon densirostris) wintering in the Baja California are at increased risk of harassment and death as climate change prompts a rise in the number of orcas, the National Oceanic and Atmospheric Administration said in a recent analysis.
The research, by the agency’s gray whale population and protection program, found that gray whale deaths, or attempted killings, are on the rise in the Baja California area. The agency’s analysis looked at the number of known gray whale strandings in Mexico since the start of the year, the number of potential strandings, and how these relate to the number of known whales in the area at the same time. They compared the results to the number of killer whales in the area estimated through a survey between 2014 and 2017.
A few killer whales can kill adult gray whales, even when their number remains small, so the study’s findings suggest killer whales are becoming more of a factor.
But, while the agency’s findings are alarming and suggest that gray whales are facing a greater threat from killer whales, it’s unclear what impact the rising numbers of killer whales, especially females and calves, might have on the gray whales. There’s also the possibility that killer whales are killing more gray whales because they can, and are less likely to report stranding or attempted kills.
“We are still in the early days of this crisis,” said Steve Anderson, chief of NOAA’s marine mammal program, in a statement. “But what is clear is that the rise in the known number of killer whales in the Baja California area and the growing concerns of people living along the coast are contributing to the situation. This is not the first time Mexican beachgoers have had to confront the problem of an increasing number of