Southern resident killer whales in B.C. waters. Research shows the population’s females are more negatively influenced by vessel traffic than males. (Photo supplied by Ocean Wise Conservation Association)

Southern resident killer whales in B.C. waters. Research shows the population’s females are more negatively influenced by vessel traffic than males. (Photo supplied by Ocean Wise Conservation Association)

Female orcas less likely to feed in presence of vessel traffic: study

Research the southern resident population raises concerns over reproduction capacity

Female orcas are more likely than males to stop eating when noisy vessels get too close to the pod, surprising new research indicates.

The study out of the San Juan Islands in Washington State, published recently in the journal Frontiers in Marine Science, looked at the foraging habits of the endangered southern resident killer whale population that shares its habitat in B.C. waters. The findings highlight the importance sex-specific responses to marine disturbances, and raises concerns over female reproduction capacity.

“A female’s decision to forego foraging states due to the close proximity of vessels could have cascading effects on the ability to meet energetic requirements to support reproductive efforts,” the study reads. “This is particularly concerning in an endangered population that is in decline.”

There are currently just 74 killer whales in the southern-resident population. The researchers hope the study will influence future management actions in preserving foraging opportunities and recovery efforts.

READ MORE: Coast Guard ramps up protections for B.C. whales

Between 2010 and 2014, researchers led by wildlife biologist Marla Holt with the National Oceanic and Atmospheric Administration attached temporary sensor-tags to members of the population to monitor their subsurface behaviour with prey capture in a critical habitat. Over the course of three seasons measurements were taken during variable vessel activity on the surface, including vessel counts, distance and speed.

Among the results, the findings showed the whales made fewer and shorter dives for prey when the vessels had an average distance of less than 366 metres.

The findings are consistent with other cetacean studies, but here researchers showed females were especially influenced by vessel activity.

It implies females experience risk to vessels differently than males. This is likely because they’re more attentive to the well-being of young offspring. Deep dives also put greater energy demands on the smaller female body.

“A female’s decision to forego foraging in the presence of close vessels could hinder her ability to meet energetic requirements to support reproductive efforts, including fetal growth in pregnancy and lactation costs after calving,” the study reads. “This is particularly concerning in an endangered mammalian population because recovery cannot occur without successful reproductive outcomes among breeding individuals, particularly in long-lived females with birthing intervals of 3–7 years.”

READ MORE: Victoria researcher finds ‘holy grail’ of killer whales

ScienceSouthern Resident Killer Whales

Get local stories you won't find anywhere else right to your inbox.
Sign up here

Just Posted

A beautiful sunny afternoon showcasing Mount Cain in all its glory. (Kimberley Kufaas Photography)
Mount Cain to start construction on new lodge once season ends

The North Island ski hill has been awarded $874,000 to build a brand new lodge.

The U’mista Cultural Society is getting $294,000 in funding. (North Island Gazette file photo)
North Island gets infrastructure and jobs boost from Economic Recovery Plan

“I’m thrilled that so many North Island organizations are benefiting from this funding”

Gordie Wigman and Edward Cote won $55,425.85 from the draw on Dec. 28. (BCLC photo)
Port McNeill friends win over 55 grand

Wigman and Cote purchased the ticket from the Port McNeill Petro Canada on Mine Road.

OrcaFest parade 2019. (North Island Gazette file photo)
COVID-19: Port McNeill’s annual OrcaFest cancelled again

“We promise you that once we are safely able to do so, OrcaFest will be back!!”

FILE – A COVID-19 vaccine being prepared. (Olivia Sullivan/Sound Publishing)
B.C. seniors 80 years and older to get COVID vaccine details over next 2 weeks: Henry

Province is expanding vaccine workforce as officials ramp up age-based rollout

Abbotsford’s Kris Collins turned to TikTok out of boredom when the provincial COVID-19 lockdown began in March 2020. She now has over 23 million followers on the video app. Photo: Submitted
Internet famous: Abbotsford’s Kris Collins is a TikTok comedy queen

Collins has found surprise stardom alone with a phone

This month, a Vancouver restaurant owner was found guilty of violating B.C.’s Human Rights Code by discriminating against customers on the basis of their race. (Pixabay)
Vancouver restaurant owner ordered to pay $4,000 to customers after racist remark

Referring to patrons as ‘you Arabs’ constitutes discrimination under B.C.’s Human Rights Code, ruling deems

BC Ferries experienced heavy traffic on Feb. 27 following cancellations the day before due to strong winds and adverse weather. (Black Press Media file photo)
BC Ferries sailings fill up quickly after Friday cancellations due to high winds

Waits expected on Swartz Bay-Tsawwassen route, Horseshoe Bay-Departure Bay route

Nanaimo children’s author and illustrator Lindsay Ford’s latest book is ‘Science Girl.’ (Photo courtesy Lindsay Ford)
B.C. children’s writer encourages girls to pursue the sciences in new book

Lindsay Ford is holding a virtual launch for latest book, ‘Science Girl’

Pig races at the 145th annual Chilliwack Fair on Aug. 12, 2017. Monday, March 1, 2021 is Pig Day. (Jenna Hauck/ Chilliwack Progress file)
Unofficial holidays: Here’s what people are celebrating for the week of Feb. 28 to March 6

Pig Day, Canadian Bacon Day and Grammar Day are all coming up this week

Staff from the Marine Mammal Rescue Centre, passersby, RCMP and Nanaimo Fire Rescue carried a sick 300-kilogram steller sea lion up the steep bluff at Invermere Beach in north Nanaimo in an attempt to save the animal’s life Thursday. (Photo courtesy Marine Mammal Rescue Centre)
300-kilogram sea lion muscled up from B.C. beach in rescue attempt

Animal dies despite efforts of Nanaimo marine mammal rescue team, emergency personnel and bystanders

Doctors and counsellors warn of an increase in panic attacks, anxiety, depression and suicide ideas between ages 10 to 14, in Campbell River. ( Black Press file photo)
Extended pandemic feeding the anxieties of B.C.’s youth

Parents not sure what to do, urged to reach out for help

Kara Sorensen, diagnosed with lung cancer in July, says it’s important for people to view her as healthy and vibrant, rather than sick. (Photo courtesy of Karen Sorensen)
B.C. woman must seek treatment overseas for inoperable lung cancer

Fundraising page launched on Karen Sorensen’s behalf, with a goal of $250,000

Gina Adams as she works on her latest piece titled ‘Undying Love’. (Submitted photo)
‘Toothless’ the kitty inspires B.C. wood carver to break out the chainsaw

Inspired by plight of a toothless cat, Gina Adams offers proceeds from her artwork to help animals

Most Read