Dams Are Damning Southern Resident Killer Whales

J28 with “peanut-head” and J54 malnourished Photo by Ken Balcomb, October 2, 2016
J28 with “peanut-head” and J54 malnourished Photo by Ken Balcomb, October 2, 2016

The native peoples of the Pacific Northwest understood something important about the relationship between the region’s iconic killer whales and the region’s iconic salmon. The first could not survive without the second. “No fish, no Blackfish” they observed.

That observation is in danger of proving prophetic. As the Center For Whale Research’s Ken Balcomb warns, lack of prey food is threatening the demise of the endangered Southern Resident Killer Whales. The SRKW population is under pressure for a number of reasons–shipping, noise, habitat loss and pollution, among them. But Balcomb is warning that the most clear and present danger is hunger resulting from declines in the Pacific Northwest’s great salmon runs, mainly due to the damming of rivers. Currently, Balcomb and others are calling for breaching four dams on the lower Snake River which have devastated the region’s once-prolific Chinook salmon runs. And for compelling evidence of what is happening he points to the recent deaths of a mother killer whale and her calf, both of whom were evidently malnourished.

For the data-inclined, here is a chart that looks at the correlation of SRKW mortality and Chinook abundance.

The tension between dams and killer whales is just one more reminder of how closely connected different ecosystems can be, and the endless consequences for the natural world of human development. Dams may provide “clean” hydropower, but they do so at the unacceptable cost of destroying and damaging entire river systems and the species that rely on them. Wind and solar have impacts, too, but they are more local and limited.

Removing dams is one of the most promising environmental trends. And when you take dams down and allow rivers to flow freely again, remarkable things happen. Whether the Snake River dams will be breached in time to save Washington state’s killer whales involves an excruciating race against time and hunger. Even the courts are pushing hard on this issue. But Ken Balcomb, who has been studying this population for 40 years and knows more about these killer whales and what they need than anyone on the planet, is pretty clear that if dam breaching is going to happen it better happen very, very soon.

Killer Whale Menopause: It’s All About The Kids

This is pretty fascinating. A paper in Science on killer whale menopause reveals some interesting parallels with menopause in humans, and adds to our understanding of the incredibly tight mother-offspring bonds in killer whale society.

Here’s a summary from the Center For Whale Research:

Dr. Emma Foster has provided a brief summery of her paper that recently came out in Science:
“Adaptive Prolonged Postreproductive Life Span in Killer Whales”

1.      The key finding: We have discovered that female killer whales have the longest menopause of any non-human species so they can care for their adult sons. Our research shows that, for a male over 30, the death of his mother means an almost 14-fold-increase in the likelihood of his death within the following year.

2.      The relevance/link to humans: Biologically-speaking, the menopause is a bizarre concept! Very few species have a prolonged period of their lifespan when they no longer reproduce. Like humans, female killer whales buck this trend and stop reproducing in their 30s-40s, but can survive into their 90s. The benefit of a menopause to both human and killer whale mothers is in spreading their genes. The different ways this has evolved reflects the different structure of human and killer whale societies. While it is believed that the menopause evolved in humans partly to allow women to focus on providing support for their grandchildren, our research shows that female killer whales act as lifelong carers for their own offspring, particularly their adult sons.
3.      Why this is important: The menopause remains one of nature’s great mysteries. This research, which involved studying 36 years-worth of data, is the first ever study of its kind and is an exciting breakthrough in our understanding of the evolution of the menopause.
I wonder if there is a species with a more important mother-son bond? It certainly exceeds the same human connection.
The more we learn about killer whales, the more complex and sophisticated their relationships and culture appears.