Why do whales strand on beaches?

Posted by Willie — 26 January 2016 at 1:19pm - Comments
Sperm whales washed up on skegness beach
All rights reserved. Credit: Lee Swift
Sperm whales washed up on a Skegness beach

Shocking and sad images have been all over the media in the past few days as some massive sperm whales have washed up dead on British beaches. Normally humans and these deep water leviathans live far apart, so it’s understandable that we are surprised and distraught to encounter them like this. But why does it happen? And what can you do?

Sperm whales are huge. They have the biggest animal brain on the planet, and make some of the deepest dives in the ocean, where their legendary battles with giant squid fuel our imagination. Immortalised by Moby Dick and Pinocchio, their fictitiously fearsome reputation sometimes overshadows the fact that these were the first whale to be decimated by industrial whaling to be turned into oil. They tend to live and travel in groups, and you don’t normally see them in shallow water like the North Sea.

In fact, when we do see them in shallow water, it’s usually followed by bad news. Every year hundreds of dead whales, dolphins and porpoises wash up dead on British beaches. Amongst them there are usually a few sperm whales. They’re obviously far more noticeable and remarkable than a dolphin, because of their massive size and rarity.

In the UK we have some amazing organisations looking after our sea life, and amazing scientists monitoring what’s going on.

That was really evident 10 years ago when the city of London had its own whale stranding, when they all came together to try and help.

This week it seems that a whole pod of sperm whales has somehow got stuck in the North Sea, and tragically died. Scientists will be checking the bodies to try and determine why, but there’s a good chance they won’t be able to definitively say. For deep sea whales like sperm whales there’s a pretty good chance that they have become ‘stuck’ in shallow waters and not been able to find food (they can also dehydrate this way, as the Thames’ whale did, because they get all of their water from the food they eat).

That then begs a question as to how they got lost? Were they chasing prey? Was it freak weather? Were they affected by something humans did – busy shipping lanes, seismic testing, military noise or something else? There are also the ‘invisible’ threats that whales in our seas carry, most notably a heavy burden of toxic chemicals which could have played a part somehow.

Across the world, as whale populations recover from decades of commercial whaling, they increasingly face a range of new human-generated threats, which are much less visible, but just as deadly. That’s been shown in the pilot whales killed by underwater noise, and the killer whale that got caught up in fishing gear.

Of course not all whales getting into shallow water die, and sometimes a helping hand can make a huge difference - as the great work of the British Divers Marine Life Rescue team shows, or the recent efforts by Scottish fishermen to free a humpback whale.

So what should you do if you see whales or dolphins stranded on a beach or in shallow water?

If they are alive – contact your local Wildlife Trust, or British Divers Marine Life Rescue.

If you find a dead whale, dolphin or porpoise on a beach, then get in touch with the UK strandings network. It’s also a good idea to keep a distance as there might be nasty infections around, and decomposing whales have a tendency to ‘explode’.

About Willie

Hi, I'm Willie, part of the Greenpeace UK biodiversity team. I work mostly on oceans and fishy issues.

Twitter: @williemackenzie

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