When Humans and Animals Collide; Vessel Strikes and Cetaceans

Drifting along the surface of the sea, the whale has very little time to escape. Within moments the ship is upon her.

On the 5th of May this year, an endangered north Atlantic right whale calf was found dead and drifting just off the coast of Cape Cod, USA. According to NOAA (National Oceanic and Atmospheric Administration), the calf had not been dead for long and had wounds indicating that a possible cause of death was boat strike. As one of only fourteen reported right whale calves born this year, and one of two which have already passed away this year, it is a devastating and significant loss to an already threatened species. Whilst these results remain in the preliminary stages, there is no doubt that it raises a very important issue – ship collisions are a very, very serious threat to cetaceans around the world.

Boat strikes are a very real and dangerous risk to whales, dolphins and porpoises. They can cause traumatic and disastrous injuries to those involved, from sharp trauma and lacerations to blunt trauma and internal injuries, and can even lead to death. You only have to take a quick look online to see just how many animals suffer horrific injuries after such collisions all over the world. For example, in 2014, the struggling southern right whale population suffered a horrendous loss when a sub-adult was killed, another was injured, and a calf went missing after being struck by a boat in Moreton Island, Australia. A year later in 2015, shocking images surfaced revealing the horrific damage caused to a bottlenose dolphin in Florida when it was hit by a propeller, causing deep and traumatic lacerations down its back. More recently, in May this year, a cruise ship arrived in Alaska with a dead, endangered fin whale draped over its bow, a potential victim of a strike. And closer to home in June this year, the beloved Irish dolphin Fungie of Dingle Bay was spotted sporting a deep wound on his side probably caused by a boat propeller.

Boat strikes are not country specific, they are not vessel specific and they are certainly not species specific.

The question is why do they happen? On a basic level, strikes occur when neither the animal nor the vessel manage to detect each other with enough time to change direction. There are, however, a number of factors which are thought to potentially increase the likelihood of such an incident occurring, both from the perspective of the animal and of the ships, as well as potential geographical issues.

Cetacean Factors

HABITUATION – Ever had a loud clock ticking away constantly? It seems like the loudest thing in the world and yet after a while, the noise simply fades into the background and becomes far less noticeable. This is what may happen with whales and dolphins who reside in high-vessel traffic areas. Whilst the noise may be very distracting to begin with, eventually it can be tuned-out, which means that potentially, a whale may not notice vessels getting closer.

AGE – Just as with human children, calves are more vulnerable than adults and as a result many reported collisions often occur with young cetaceans. This may be because, like babies, they are curious and unaware of the potential danger a vessel poses, as well as the fact that they often need to spend more time on the surface having not yet developed the speed of the adults, and so are more likely to be hit.

Geographical Factors

CONCENTRATED AREAS – Unfortunately, it goes without saying that in areas where there is a high concentration of cetaceans and a high concentration of vessels, there is sadly an increased risk of boat strikes.

Vessel Factors

VISIBILITY- From the perspective of the ship, the larger the vessel the more difficult it is to change course. If a whale was to appear in front of the bow, the time it would take to alter the direction of the ship often means that there is no other choice but to hit the animal.

Think of it like a supermarket trolley; the more empty it is, the easier and quicker it is to move out of the way but the heavier and bulkier it is, the more difficult it is to move, and so it takes a lot longer. Unlike an out-of-control shopping -trolley however, the result of a ship strike is devastating.

These are just a few of the many potential factors affecting the chance of a vessel strike occurring (more can be found here) but it is clear that with so many risk factors, procedures need to work to reduce the effect such strikes have on both the animals and humans.

So what can be done to help?

With boat strikes occurring in oceans around the world, and with whales regularly migrating through different seas and oceans, it is very important that any attempts to reduce the impact that ships are having upon our marine wildlife, are conducted globally. Sadly, there is no clear and concise way of doing this but different steps are being taken to make a significant difference. In 2009, the IWC (International Whaling Commission) established a global ‘ship strikes’ database to keep track of boat/whale impacts. With so many collisions going unreported and even unnoticed, encouraging more people to report strikes is a vital part of learning more about possible strike hotspots, and subsequently contributing to possible solutions. In the same year, the International Maritime Organisation (IMO) created a document advising crews on how to minimise the chance of collisions.

In terms of physical adaptations, ideally, the best option would be to completely separate ships and cetaceans with alternative routes. Whilst this has been effective in certain areas, such as the Strait of Gibraltar – a well-known cetacean dense area, increasing boat traffic throughout the world means that the likelihood and practicality of this being an effective global method is slim. A more effective method has been the implementation of speed limits in cetacean hotspots. A few years ago, Sea Watch director, Dr Peter Evans identified key hotspots for fin and sperm whales in NW Europe on behalf of the United Nations Environmental Programme’s international conservation agreement, ASCOBANS. He also mapped the densities of ships so as to determine where conflict was likely to be greatest, and then worked with WWF International to encourage shipping companies to either slow down to ten knots of less or divert around these hotspots.

In certain places, individual practices have also been set up such as those in the United States. Working together, the US Coast Guard and NOAA established a system, the Mandatory Ship Reporting Systems, which requires vessels larger than 300 tonnes who are entering two very well-known north Atlantic right whale habitats, to report to a station. By doing so, they are informed of any potential whales in the area, in the hope that they will be able to avoid them.

Boat strikes are an ongoing and complex problem and one that requires constant research and records to form effective solutions. Education has and always will be an incredibly important aspect and it is vital that this grows in the future. If we continue to increase our ocean activities, then we need to increase what we can do to help. Nothing deserves to suffer.


Image: Craig Hayslip, Oregon State University Marine Mammal Institute (2014)


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