Whales, and Dolphins, and Cetaceans Oh My!
Hi everyone! In my last blog post, I mentioned that I have participated in conducting research into the abundance and distribution of cetaceans (whales & dolphins). In 2015, I trained to become a Marine Mammal Surveyor with the charity ORCA. ORCA undertake vital conservation research and have spent over a decade working to conserve cetacean species in UK, European and International waters. The data collected by volunteers is used to advise and influence legislation in order to protect cetaceans from fishing, shipping and waste.
In July and September, I was part of a team that conducted surveys into the distribution of whales and dolphins. One route was from Southampton to the Isle of Wight and the other from Dover to Calais. Whilst we didn’t see any cetaceans around the Isle of Wight, we did see a number of harbour porpoises during our trip to Calais. Even if there are no sightings, the data collected is very important as this helps to ascertain reasons why cetacean species are not abundant in certain areas, from example, because of heavy boat traffic. A lot of data is recorded during these surveys such as Sea state beaufort (measuring the wind intensity based on observing the sea conditions), swell of the waves, glare, speed of the vessel and its longitude and latitude. This is all vital data in order to ascertain exactly where the sightings of cetaceans occur and whether the sea conditions are affecting visibility.
Many people do not realise the vast abundance of whales and dolphins that occupy UK and European waters, but did you know that over a third of cetaceans can be found in our waters? If you are out at sea and hoping to spot cetaceans, keep a look out for seabirds and any fish visible near the surface of the water – food is a sure sign that cetaceans are likely to be in the area!
Scientists have tried to map Whales and Dolphins migratory patterns for decades however, they are known for their unpredictability. For example, a humpback whale made its way to Dover in March 2015 which is very unusual, a Northern Bottlenose Whale was seen in the River Thames in 2010 and many other sightings reported in the Thames over the past decade!
There are two groups (or sub-orders) of cetaceans, these are the Mysticeti (Baleen Whales) and Odontoceti (Tooth Whales). So if you spot a whale, dolphin or porpoise how do you know which sub-order it belongs to? Let me tell you…
Baleen Whales have ‘plates’ of baleen hairs that hang from the roof of their mouths which is made up of keratin which is a structural protein. Baleen Whales vary greatly in size, from the 7-meter Pygmy Right Whale to the Blue Whale which measures over 30 metres in length and is probably the one you are most familiar with. The baleen plates are used to filter out the immense amount of water the whales take in whilst feeding. The baleen plates act as filter system, pushing the water out whilst food such as krill remain inside the whale’s mouth to be digested. Baleen whales also have two blowholes through which they breathe.
Toothed whales have just one blowhole, and although they range in size, the biggest toothed whale is the Sperm Whale which grows to around 18 metres in length. Which is a lot smaller than the Blue Whale in comparison! The Toothed-whale group also include dolphins and porpoises. For identification purposes, toothed whales have a distinct rounded head, creatively known as the ‘Melon’ located near their blowhole, whereas Baleen Whales generally have a much straighter rostrum with their two blowholes situated behind.
By studying migration patterns, we know that different cetacean species occur in different waters during the months and seasons. However, the summer months (July-September) are usually the best time for whale watching in Europe as the sea is generally at its calmest. So know you know how to identify Baleen and Toothed Whales, keep a look out next time you are on a ship, cruise or ferry!
Stay tuned for the next post to learn more!
Image by http://www.godsavethewind.it/febbraio-2013/