Orcas and Boating

Over the past century vessel traffic has been dramatically increased in the Salish Sea. The cargo traffic going to the Port of Vancouver increased by 66% since 2009, and currently 11,000 large vessels pass through the Salish Sea annually. Furthermore, large vessels make up a small portion of the boats on our oceans. Recent studies have found that there are up to four times more recreational boats in the Salish Sea than large vessels.  Increased boating traffic means more pressure on the marine life that call our oceans home. Please help the Galiano Conservancy and make a difference by mitigating threats to cetaceans next time you and your family spend a day on the water!

Underwater Noise

Orcas are highly social animals. They live in matrilines, consisting of a head female, her offspring, and her offspring’s offspring, which all stay together for life – travelling in their matriline, hunt in their matriline, and sleep in their matriline. But none of these activities would be possible without their ability to communicate with each other. They use lower frequency sound and high frequency sounds to stay together and to coordinate hunts, often needing to communicate across distances as far as several kilometres. They locate shorelines and the ocean floor while they are navigating along coasts, locate prey in dark, and turbid waters. They also use songs to locate appropriate mates, and sometimes will even use bursts of loud noise to confuse prey. Unfortunately, Killer Whales are unable to use sound for any of these crucial survival strategies if there is excessive underwater noise, which is increasing dramatically in our oceans today. In the North Pacific, underwater noise has been doubling in intensity every decade for the past 60 years. Sources of noise include dredging, drilling, construction, seismic testing, military sonars, and most importantly, boating traffic. In some areas, vessel noise has reduced the ability for cetaceans to communicate by around 90%. Excessive noise causes erratic behaviour, unusually long calls, avoidance of certain areas, and mass strandings. It can also prevent whales from hunting effectively, causing many whales to be emaciated.

Whale Watching

Along with increased general vessel traffic came an increase in the number of whale watchers, which expanded from 1000 passengers in the 1970’s to half a million in 1998. There are many accounts of short-term behavioural changes of whales when exposed to whale watching vessels, such as travelling in less predictable paths, altering dive lengths, and moving to open water. The long-term effects of whale watching are less known, but prolonged exposure is thought to induce chronic stress and cause certain whales to abandon entire areas. Abandoning areas affects whales both because of the energy expenditure on locating new foraging grounds, and also the new area may be less well suited to the population of whales. Although, no studies have researched the direct impact of these stressors on the survival of the Killer Whales, a study on Bottle-Nose Dolphins found that behaviour disruption through boating lowered their reproductive rates.

Whaling presents its own set of challenges to the whales!

Boat Strikes

Few studies have been done on the impact of vessel strikes on the Southern Resident Killer Whales, however we can look to other whales for clues. On the Atlantic Coast, it is thought that vessel strikes could make the difference between extinction and survival of Right Whales, and in BC, boat strikes are the biggest threat to Fin Whales. Thirty collisions were reported to the BC marine mammal response unit between 2004 and 2011, the majority from small recreational vessels. Many more go unreported or unnoticed, especially collisions by large vessels, which oftentimes will not recognize the shake/impact on the vessel. In recent years, there has been one confirmed death of a Southern Resident Killer Whale from a boat strike. It is important to note that vessel strikes are not just a concern for large boats, also recreational vessels and jet-skis can pose a threat to marine life. Many times, Cetacean are underwater and are not seen until it is too late. Researchers at SFU (Simon Fraser University) are currently working on a project that uses hydrophones to provide real-time data to vessels to predict the Southern Resident Killer Whales’ paths and decrease the chance of a vessel strike.

Entanglement

The increase of recreational boaters is indicative of the increase of recreational fishers in the Salish Sea. Recreational fishers make up large portions of many fisheries, and account for 89% of the rockfish fishery in the Salish Sea. Increased fishing decreases numbers on prey for cetaceans, especially SRKW, and it also increases the chance of irresponsible disposal of fishing gear. Several Southern Resident Killer Whales have been found with recreational fishing lines in their stomachs, and there has been one confirmed death due to fishing gear.

Whale Wise Boating

Numerous regulations have been implemented to mitigate boating around Whales, and there are many more actions you can take while boating in order to safely share our oceans with marine life!

  • Slow down anytime you see a marine mammal. Slowing your boat down can significantly decrease engine noise, allowing marine mammals to communicate effectively.
    • It is mandatory to slow down to 7 knots when you are 1000 m away from whales.
  • Keep your engine and hull maintained and clean, to further reduce noise.
  • You can additionally modify your engine to make it quieter by:
    • Insulate the ships engine and use resilient mountings for onboard machinery.
    • Incorporate vessel quieting consideration during re-fits and vessel construction.
  • Modify your route to avoid whales.
  • Steer clear of orcas while boating: 400 m recommended and 200m minimum. https://www.bewhalewise.org/federal-regulations/
  • Steer clear of all other cetaceans a minimum of 100 m while boating.
  • Before your next boating trip, learn about new regulations here.
  • Properly dispose your fishing equipment in the landfill. Do not throw it in the oceans!
  • Choose a responsible way for whale watching, e.g. whale trails established along BC’s Coast
References/ Further Reading

http://noaacontent.nroc.org/lesson13/l13la2.html

https://wildwhales.org/threats/noise-and-cetaceans/

https://www.fisheries.noaa.gov/insight/understanding-vessel-strikes

https://meopar.files.wordpress.com/2018/05/smallvesseltrafficstudy_report_uvic2018.pdf

https://www.hindawi.com/journals/jmb/2012/807294/

https://wildwhales.org/threats/collisions/

https://www.cbc.ca/news/canada/british-columbia/report-confirms-ship-strike-caused-death-of-killer-whale-j34-1.5220616

https://www.sfu.ca/sfunews/stories/2019/07/sfu-developing-warning-system-to-protect-orcas.html

https://www.sfu.ca/sfunews/stories/2019/07/sfu-developing-warning-system-to-protect-orcas.html