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

The Great Bear Snowshed on the Coquihalla Highway (Highway 5) in British Columbia. Truck driver Roy McCormack testified in BC Supreme Court in Chilliwack on Feb. 25, 2021 that his brakes started smoking in about this location, and soon after he lost all braking, which led to a multi-vehicle crash further down the road on Aug. 5, 2016. (GoogleMaps)
Truck driver charged with criminal negligence in Coquihalla crash is accused of ignoring smoking brakes

Just before crashing the smoking truck was seen entering Zopkios brake check and leaving shortly after

Kathleen Gros will be helping local creatives explore the intersection of words and pictures through comic books in an upcoming online workshop.
Vancouver graphic novelist to share skills in online workshop with Agassiz Library

Kathleen Gros will be leading the Magical World of Words and Pictures workshop on March 6

(File Photo)
Crash causes delays on Coquihalla southbound, travel advisory issued

A vehicle incident between Merrit and Hope has caused major delays heading south

The last three wild northern spotted owls live near the Spuzzum Watershed outside of Hope. The province recently ordered a halt to logging for at least a year to give the owls a chance to survive.  (Photo/Jared Hobbs)
Logging halted in northern spotted owl habitat near Hope

Halt will last at least a year, gives time to formulate survival plan for Northern Spotted Owl

The Rocket Science S.T.E.M. camp will run virtually during spring break. (Submitted photo)
Abbotsford Airshow, Gearbots Educational Resources launch Rocket Science camp

Virtual format of camp open to students aged nine and up, will run during spring break

Provincial health officer Dr. Bonnie Henry updates B.C.’s COVID-19 situation at the B.C. legislature. (B.C. government)
B.C. reports 10 additional deaths, 395 new COVID-19 cases

The majority of new coronavirus infections were in the Fraser Health region

A new survey has found that virtual visits are British Columbian’s preferred way to see the doctor amid the COVID-19 pandemic. (Unsplash)
Majority of British Columbians now prefer routine virtual doctor’s visits: study

More than 82% feel virtual health options reduce wait times, 64% think they lead to better health

Captain and Maria, a pair of big and affectionate akbash dogs, must be adopted together because they are so closely bonded. (SPCA image)
Shuswap SPCA seeks forever home for inseparable Akbash dogs

A fundraiser to help medical expenses for Captain and Maria earned over 10 times its goal

Cory Mills, Eric Blackmore and A.J. Jensen, all 20, drown in the Sooke River in February 2020. (Contributed photos)
Coroner confirms ‘puddle jumping’ in 2020 drowning deaths of 3 B.C. men

Cory Mills, Eric Blackmore and A.J. Jensen pulled into raging river driving through nearby flooding

Join Black Press Media and Do Some Good
Join Black Press Media and Do Some Good

Pay it Forward program supports local businesses in their community giving

Cannabis bought in British Columbia (Ashley Wadhwani/Black Press Media)
Is it time to start thinking about greener ways to package cannabis?

Packaging suppliers are still figuring eco-friendly and affordable packaging options that fit the mandates of Cannabis Regulations

Castlegar doctor Megan Taylor contracted COVID-19 in November. This photo was taken before the pandemic. Photo: Submitted
Kootenay doctor shares experience contracting COVID-19

Castlegar doctor shares her COVID experience

Shaelene Keeler Bell. (Facebook)
Candlelight vigil planned for Chilliwack mother missing for four weeks

Virtual event to ‘spread some light’ for 23-year-old Shaelene Bell of Chilliwack

Ashley Paxman, 29, is in the ICU after being struck by a vehicle along Highway 97 Feb. 18, 2021. She remains in critical condition. (GoFundMe)
Okanagan woman in ICU with broken bones in face after being struck by car

She remains in serious condition following Feb. 18 incident

Most Read