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Deep Dive: Right Whale Vessel Strikes

Take a deep dive into right whale vessel strikes!

What is a vessel strike?

A vessel strike occurs when any type of vessel (from a kayak to a ship) accidentally hits a whale.  It can happen because the person operating the vessel didn’t see the whale (they weren’t looking, it was dark, it was foggy, or the whale suddenly surfaced). Sometimes the vessel operator couldn’t change course in time even if they did see the whale. This can happen if the vessel is traveling at high speed or the captain is not able to change course in the time and distance needed to avoid the strike.

Right whales are at high risk both because of where they live and how they behave.  Nicknamed the “urban whale”, right whales tend to live in busy waterways and fishing areas. They are also hard to detect. These stealth whales often feed and travel just below the surface, out of sight but not out of danger from the submerged hull or propeller of a passing vessel.

Why don’t whales avoid vessels?

Sometimes whales do appear to change course or avoid vessels, but not always.  In other cases, whales may not have time to react to a fast moving vessel or may not hear a vessel approaching.  Sail boats and large ships can be very quiet.  In the case of large ships the bow of the ship can actually block the engine noise coming from the back of the ship, making it difficult for a whale to hear the approaching threat.

A noisy ocean can make it hard for a whale to differentiate between noises or the whales may have gotten use to  the sounds of passing vessels.  It’s also possible that whales who are feeding or socializing are more focused on finding their food or their friends than they are on transiting vessels.

What about using radar to detect whales?

Radar on boats are currently designed to reflect off solid objects on the surface. While sometimes clusters of birds or even a whale can be detected, it is typically only when they are in close proximity of the vessel, the whale is spending a significant time at the surface, and the sea conditions are ideal.

For forward facing sonar (placed underwater on the hull of a vessel), the detection range is also relatively limited. It can really only detect large solid, stable objects like a pair that is a few hundred feet away. You would need to be tens of feet away to detect smaller solid objects like a mooring chain. As whales are not stationary, they would likely be in the strike zone by the time they were detected. Depending on the speed of the vessel, it may not be in time to avoid the collision.

Are vessel strikes intentional?

No! Vessel strikes are accidental. Vessel strikes of large whales can also cause damage to the vessels and can injure the people on-board. Vessel strikes are unfortunate incidents that happen when whales and vessels overlap in time and space.

How big of a problem are vessel strikes for right whales?

Vessel strikes are one of the top two modern-day causes for right whale deaths and a main reason why right whales are still endangered. It is estimated that approximately 45 right whales, over 10% of the entire population, were killed by vessel strikes over the past 10 years.

How will reducing vessel strikes help right whales?

Vessel strikes are one of the two biggest threats preventing right whales from recovering. Sharp force trauma occurs when the vessel’s propellers cut into the whale while blunt force trauma results from the vessel’s hull striking the whale. Injuries from blunt force trauma are sometimes only detectable when the whale is necropsied (animal autopsy). Some vessel strikes are immediately lethal but in other cases, the whale may succumb years later to an infection resulting from the injury.

Some whales survive, bearing the scars of their interaction but healing can take years. These painful injuries may also affect their ability to swim, feed, and socialize, and can cause chronic stress. Chronic stress can lead sub-lethal impacts such as an impaired immune system or difficulty reproducing.

What needs to happen to reduce or stop vessel strikes for right whales?

There are currently no technological solutions to adequately prevent or reduce vessel strikes to whales.  Research on ship alarms increased risked to right whales as the whales exposed to the alarms rapidly surfaced, which put them in harm’s way. Infrared thermal imaging of blows can help detect whales but only when they are at the surface and when the sea and weather conditions are ideal.

The best solutions currently available are:

  • Separate vessel traffic from areas where and when whales are known to aggregate
  • Slow down vessels to a speed of 10 knots or less when you can’t separate vessels from right whales.

What can you do?

1. Speak up for North Atlantic right whales!

Ask your Senator to support the Right Whale Coexistence Act. This legislation would provide 10 years of funding for conservation efforts to find solutions to help fishers and shippers safely share the ocean with North Atlantic right whales. You can send an email to your senators and ask them to co-sponsor the Right Whale Coexistence Act using our easy email tool. You can also send your senator a postcard that lets them know why this issue is so important to you.

2. Share the story of the North Atlantic right whales

The more people who know and love this unique species, the bigger our collective voices will be when action is needed.

3. Raise your RIGHT Hand!

WDC is committed to doing the next right things to protect right whales and it all starts with you. To be the first to be alerted when action is needed, sign our Raise Your RIGHT Hand Pledge and you will receive email action alerts to help out!