This summer, an orca known as J-35 made national headlines while for 17 days in the waters of the Salish Sea.
Her loss gripped the nation and was also a huge blow for the . That鈥檚 because over the past 30 years the population of these Pacific Northwest orcas has declined 25 percent.
There are now 74 orcas in the population, down from nearly 100 in the late 1990s according to Mike Ford, director of the Conservation Biology Division at the in Seattle.
鈥淲e鈥檙e particularly concerned right now because there have not been any successful births in the population since 2015,鈥� he told OPB鈥檚 All Things Considered. 鈥淪o, obviously if you don鈥檛 have new babies coming into the population you can鈥檛 recover that population and see it grow.鈥�
The Southern Resident killer whale population has been listed as endangered under the since 2005. But even with that protection, their population hasn鈥檛 recovered and, in fact, has continued to decline.
Scientists identify three major threats to these orcas: a lack of food availability, most notably a decline in the orca鈥檚 primary prey Chinook salmon; increasing contamination in the water from chemical pollutants like ; and disturbances from vessels in the waters where the orcas live.
Those threats can often act together. 鈥淔or example, one of the reasons why noise is a concern is that it interferes with the killer whale鈥檚 ability to successfully hunt fish,鈥� Ford said.
But now, scientists are looking into a possible fourth threat: whether genetic factors could be limiting the population鈥檚 ability to grow. That鈥檚 why they鈥檝e with a global genomics company called and the nonprofit Nature Conservancy, to sequence the genomes of more than 100 members of the Southern Resident population, from samples collected over the past two decades.
鈥淯nderstanding whether there are [genetic] factors that are also influencing the population, may put greater urgency on some of those other factors,鈥� Ford said. 鈥淎nd it might open up seriously new ways of treating the population.鈥�
To hear the entire conversation with Mike Ford, use the audio player at the top of this story.
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