Salt is a remarkable whale. In fact she's probably the most famous humpback whale in the world. She was one of the first humpbacks to be identified back in 1975 when researchers began recognising and cataloguing individuals, and we know that she's at least 46 years old. She has 15 children and is a great grandma.
Studying Salt has taught us much of what we know about humpback whales, and few know her better than Regina Asmutis-Silvia who heads up our team in the US. Being based in Plymouth, Massachusetts they are fortunate to be able to head out to sea during the summer months to study Salt or the other members of her population first hand.
But Salt isn't just a great teacher - she also helps to keep you alive! Whales are like ocean gardeners, keeping the marine environment healthy, circulating nutrients, locking away carbon and fertilising tiny plant-like organisms called phytoplankton which capture around the same amount of carbon dioxide every year as 148 billion trees!
As world leaders at COP26 talk about how we're going to save the world, a good start would be keeping whales like Salt safe from harpoons and fishing gear because a healthy planet needs more whales, not fewer.
In this short video, my colleagues Regina and Sabrina explain this through an imagined conversation with Salt about her vital climate role.
I asked Regina a few questions about this very special whale:
Why are Salt and her family so important for the ocean and how do they contribute to climate protection?
Salt and her huge family play an integral role in the health of the ocean and our planet. As the ocean’s gardeners, they bring nutrients to a surface forest of floating phytoplankton which provides around half our oxygen, stores most of the ocean’s carbon, and is the base for all fish populations. Salt helps give you every other breath you take, fights climate change, and sustains fish populations. She has a very busy and important role in all of our lives!
What is so special about Salt?
Salt provides a window into the secret lives of whales. For more than 40 years she has helped us understand the lives, and cultures of humpback whales as well as the threats they face. Salt was one of the first whales to be identified in the Gulf of Maine where they come to feed and in the Caribbean where they breed, helping us understand their migration patterns. Her DNA helped researchers develop techniques to learn the age of individual whales.
As a mother, grandmother, and great grandmother, she is giving us insights into how often and how long females can reproduce and the important role they play as matriarchs. Salt also showed us that whales can form friendships. She likes to hang out with specific adult females, especially when she is pregnant.
Perhaps most interesting is what she is helping us learn about whale culture. Salt forms bubble nets and bubble clouds when she feeds. These bubbles trap and school the fish to give her more of a mouthful. However, her granddaughter is a kick feeder. Kick feeders kick the water surface first, then form bubble clouds to startle and then school their fish. Salt did not pass this feeding technique down to her daughter and granddaughter which means it is a behaviour that is learnt from friends – what scientists call ‘culturally transmitted’.
What is WDC doing to protect Salt?
Salt feeds, travels, and rests in busy places so she faces the risk of becoming entangled in fishing gear or getting struck by a passing vessel. Resting is not always easy in areas where noisy boats and ships pass by on a regular basis. Here at WDC North America, we’re working to reduce these threats for Salt and her friends and family. We are working with fishers, scientists and state and federal agencies to ensure that fishing techniques are safer for whales.
We also helped to implement a rule that requires ships to slow down in high risk areas along the east coast and we have recently petitioned the US government to ask them to increase protection from vessel strikes. Through our Whale SENSE outreach project, we are working with commercial whale watch companies ensuring that they are operating safely around whales like Salt, and we are working to ensure that offshore wind projects are not only good for the environment, but also safe for whales in the areas in which they are being built.
As a researcher, what is your relationship with Salt?
She was one of the first whales I could identify as an individual. Her huge white dorsal fin was easy to spot through binoculars. She didn’t just teach me how to identify individual whales, but why it was important to tell them apart. Knowing her helped me learn about calving intervals (how often a mum has a baby), behaviour (I noticed that if she was in a big feeding group she was always the leader as the first one to dive and the first to surface through the bubble net), and most importantly that there is always something to learn. I had been watching her for more than 10 years before I realised she had a lobe in the roof of her mouth that was unique to her. Now I can pick her out of a crowd with her mouth open! She is a good mum, a focused leader, and a loyal friend.
What's the most fascinating thing about humpback whales?
To me, the most fascinating thing about whales is what we still don’t know about them. The more I learn about them the more I realise how little we really know. For example, when I was an intern, I was told that humpback males only sing in the breeding area but we now know they sing throughout their range. I love that they still have so much to teach us.