Seals and sea lions may be slowing salmon recovery, hurting orcas

A young resident killer whale chases a chinook salmon in the Salish Sea near San Juan Island, WA. Sept 2017. Image obtained under NMFS permit #19091. Photo by John Durban (NOAA Fisheries/Southwest Fisheries Science Center), Holly Fearnbach (SR3: SeaLife Response, Rehabilitation and Research) and Lance Barrett-Lennard (Vancouver Aquarium’s Coastal Ocean Research Institute). (CC BY-SA 2.0) https://flic.kr/p/21wV8rV

A young resident killer whale chases a chinook salmon in the Salish Sea near San Juan Island, WA. Sept 2017. Photo by John Durban (NOAA Fisheries/Southwest Fisheries Science Center), Holly Fearnbach (SR3: SeaLife Response, Rehabilitation and Research) and Lance Barrett-Lennard (Vancouver Aquarium’s Coastal Ocean Research Institute). (CC BY-SA 2.0) https://flic.kr/p/21wV8rV

Increased consumption of Chinook salmon by seals and sea lions in the Salish Sea “could be masking the success of coastwide salmon recovery efforts,” according to a new study published this week in the journal Scientific Reports. Endangered resident orcas are said to be declining in part due to a lack of available Chinook, the orcas’ preferred prey.

Read the article by PSI senior writer Christopher Dunagan in Salish Sea Currents.

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Update: Killer whale miscarriages linked to low food supply

In this high-resolution image taken from a remotely operated hexacopter, a Southern Resident killer whale named Slick (J16) is about to surface with her youngest calf, Scarlet (J50). Scarlet, born in December 2014, was the first calf in the so-called “baby boom” — nine orcas born between December 2014 and January 2016. These images are used to measure the length and width of orcas within an inch or two, allowing for ongoing observations of their physical changes. Photo: NOAA Fisheries, Vancouver Aquarium under NMFS research permit and FAA flight authorization.

In this high-resolution image taken from a remotely operated hexacopter, a Southern Resident killer whale named Slick (J16) is about to surface with her youngest calf, Scarlet (J50). Scarlet, born in December 2014, was the first calf in the so-called “baby boom” — nine orcas born between December 2014 and January 2016. These images are used to measure the length and width of orcas within an inch or two, allowing for ongoing observations of their physical changes. Photo: NOAA Fisheries, Vancouver Aquarium under NMFS research permit and FAA flight authorization.

Our 2016 article “Killer whale miscarriages linked to low food supply” provided an early look at a study published this week in the journal PLOS ONE.

PSI senior writer Christopher Dunagan wrote the article based on research that was presented at the 2016 Salish Sea Ecosystem Conference, and it remains a helpful summary of the newly published findings.

Scientists have found that Puget Sound’s endangered Southern Resident Killer Whales are experiencing a high rate of miscarriages in large part because they are not getting enough food. The whales depend primarily on diminished populations of Chinook salmon and this scarcity magnifies other existing threats ranging from toxic PCBs to noise pollution.

The PLOS ONE study was co-authored by Samuel K. Wasser , Jessica I. Lundin, Katherine Ayres, Elizabeth Seely, Deborah Giles, Kenneth Balcomb, Jennifer Hempelmann, Kim Parsons, and Rebecca Booth. Dunagan’s article summarizing their findings is available on the Encyclopedia of Puget Sound.

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Killer whale miscarriages linked to low food supply

A Southern Resident Killer Whale is about to surface with her young calf. Photo: NOAA Fisheries, Vancouver Aquarium under NMFS research permit and FAA flight authorization.

A Southern Resident Killer Whale is about to surface with her young calf. Photo: NOAA Fisheries, Vancouver Aquarium under NMFS research permit and FAA flight authorization.

New techniques for studying orcas have been credited with breakthroughs in reproductive and developmental research. Drones and dogs are helping scientists connect declines in food supply with low birth rates and poor health.

Read the story this week in Salish Sea Currents. 

 

 

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New theory rethinks spread of PCBs and other toxics in Puget Sound

Puget Sound's orcas are among the most contaminated marine mammals in the world. Photo: Minette Layne (CC-BY-2.0) https://en.wikipedia.org/wiki/Killer_whale#/media/File:Orca_porpoising.jpg

Puget Sound’s orcas are among the most contaminated marine mammals in the world. A new theory rethinks how PCBs and other toxics enter the food web.Photo: Minette Layne (CC-BY-2.0)

Last month, more than 1100 scientists and researchers converged on Vancouver, B.C. to attend the Salish Sea Ecosystem Conference. The biennial conference is the region’s largest gathering on the state of the ecosystem, and we sent a group of reporters to bring back some of the highlights. Over the next several months, we’ll be collecting those highlights into a new series on the Encyclopedia of Puget Sound. We kick things off today with a must-read story from Christopher Dunagan. He reports that scientists may be changing their view of how PCBs and other toxics enter the Puget Sound food web. Read the story in Salish Sea Currents.

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Going viral: Concerns rise over potential impacts of disease on the ecosystem

Mist from the breath of killer whales is collected at the end of a long pole then tested for dozens of different types of bacteria. Photo: Pete Schroeder

Mist from the breath of killer whales is collected at the end of a long pole then tested for dozens of different types of bacteria. Photo: Pete Schroeder

From orcas to starfish to humans, disease affects every living creature in the ecosystem. Scientists are increasingly alarmed by its potential to devastate already compromised populations of species in Puget Sound.

Read the story in our Salish Sea Currents series.

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