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

Interior Health reported 33 new COVID-19 cases on March 5. (Black Press Files)
Interior Health reports 33 new COVID-19 cases on March 5

Over 300,000 vaccine doses have been administered provincewide.

Kimberley’s Local Food Working Group is looking for input from backyard gardeners. Eco friendly gardening file
Kimberley and area resident survey seeks insights on backyard food growing trends

In the past year or so, a number of Kimberley organizations have… Continue reading

Some of the folks behind Angel Flight East Kootenay: Todd Weselake is a director, partner and pilot while Brent Bidston is the president and lead pilot of the not-for-profit. Pictured here with their older plane, they hope to get an upgrade for thanks to RDEK funding. (Image courtesy of Angel Flight East Kootenay)
Angel Flight secures RDEK funding for next five years

$100,000 will go to the not-for-profit each year, with the funds to be used to acquire a larger plane

survey
City of Kimberley wants to know about your housing needs

There is no doubt that housing availability in Kimberley is an issue.… Continue reading

The city will undertake a feasibility study on the Marysville Arena. Bulletin file.
Feasibility study on viability of Marysville Arena about to get underway

Study will determine the future viability of Marysville Arena, and provide other alternatives for a second ice surface

Provincial health officer Dr. Bonnie Henry updates B.C. on the COVID-19 situation. (B.C. government)
Dr. Bonnie Henry predicts a ‘post-pandemic world’ for B.C. this summer

‘Extending this second dose provides very high real-world protection to more people, sooner’

Malawian police guard AstraZeneca COVID-19 vaccines after the shipment arrived in Lilongwe, Malawi, Friday March 5, 2021. Canada is expecting its first shipments of AstraZeneca vaccine next week. (Associated Press/Thoko Chikondi)
B.C.’s daily COVID-19 cases climb to 634 Friday, four more deaths

Currently 255 people in hospital, 66 in intensive care

A crashed helicopter is seen near Mt. Gardner on Bowen Island on Friday March 5, 2021. Two people were taken to hospital in serious but stable condition after the crash. (Irene Paulus/contributed)
2 people in serious condition after helicopter goes down on Bowen Island

Unclear how many passengers aboard and unclear where the helicopter was going

Surrey Pretrial in Newton. (Photo: Tom Zytaruk)
B.C. transgender inmate to get human rights hearing after being held in mostly male jail

B.C. Human Rights Tribunal member Amber Prince on March 3 dismissed the pretrial’s application to have Makayla Sandve’s complaint dismissed

Supporters rally outside court as Pastor James Coates of GraceLife Church is in court to appeal bail conditions, after he was arrested for holding day services in violation of COVID-19 rules, in Edmonton, Alta., on Thursday March 4, 2021. THE CANADIAN PRESS/Jason Franson
‘Law remains valid:’ Pastor accused of violating health orders to remain in jail

The Justice Centre for Constitutional Freedoms is representing the pastor

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

The Netflix logo on an iPhone. B.C. delayed imposing sales tax on digital services and sweetened carbonated beverages as part of its response to COVID-19. Those taxes take effect April 1, 2021. THE CANADIAN PRESS/AP, Matt Rourke
B.C. applies 7% sales tax on streaming, vaping, sweet drinks April 1

Measures from 2020 budget were delayed due to COVID-19

Chief Don Tom of the Tsartlip First Nation was outraged after Green MLA Adam Olsen revealed on social media that the community had been experiencing a COVID-19 outbreak – a fact the First Nation had chosen to keep private to avoid racist backlash as experienced by the Cowichan Tribes when an outbreak was declared there in January. (Black Press Media file photo)
B.C. First Nation ‘outraged’ after Green MLA reveals COVID-19 outbreak

Tsartlip First Nation chief shares concerns about racist backlash, MLA apologizes

A lawyer wears a face mask and gloves to curb the spread of COVID-19 while waiting to enter B.C. Supreme Court, in Vancouver, B.C., Friday, Aug. 28, 2020. British Columbia’s highest court has sided with the land owner in a dispute over public access to public land. THE CANADIAN PRESS/Darryl Dyck
B.C. high court finds in favour of large landowner in fight over access to pair of lakes

The Nicola Valley Fish and Game Club launched legal action after the cattle company blocked road and trail access

Most Read