As you may have seen in the news, the UK sometimes gets visitors from far flung places - like belugas in the Thames and walruses in the Scilly Isles. Species that live in specific locations around Britain may travel around, like the Scottish orcas who took a holiday to Cornwall earlier this year.

UK waters are teeming with life, and the varied marine geography of the British Isles provides lots of different habitats for sea-faring animals. Deeper waters to the north and off the continental shelf are favoured by the baleen or ‘filter feeding’ whales (like minke and humpbacks), and many smaller species (like dolphins and porpoises) prefer more sheltered and shallow waters. Warm ocean currents from the Mediterranean and the Atlantic Gulf Stream make Britain’s climate fairly mild for its latitude, while cooler waters and air currents coming down from the Arctic Ocean create diverse habitats to the north of the Isles. The mixing of warm and cool waters makes the sea very productive, with plankton populations blooming in the sunny summer months. These tiny organisms are the basis of the marine food chain; fish and squid feed on plankton, and whales and dolphins eat them in turn.

In short, you don’t have to go far to see amazing wildlife in the UK – and we have some awesome species living right here in the Solent! The region is quite sheltered, both by the Channel and the Isle of Wight, so we don’t tend to see the big baleen species, which prefer deep waters. The inshore habitat instead attracts dolphins and porpoises. While it is always possible for a wayfaring whale to drop by for a visit, you’re far more likely to see these three species: the short-beaked common dolphin, bottlenose dolphin, and the harbour porpoise. Between them they have a broad diet: mainly consisting of fish, with the latter two also eating squid and octopus, and bottlenose dolphins also eating crabs – all of which are found in the Solent.

Before we look at common features and behaviours of our Solent dolphins, we’ll look at where and how to find them. They all favour inshore habitats, and as ‘toothed whales’ they use echolocation to navigate underwater. With their sensitive hearing, lots of noise from boats or heavy machinery can disorientate them, so they generally try to avoid loud and busy channels. Sea state is a scale used to categorise how choppy the sea is by the size of the waves, from 0 (completely calm) to 9 (high waves with lots of foam). Anything above sea state 3 isn’t a good bet for spotting dolphins, as the spray and wave crests effectively hide the distinctive blow out of dolphins coming to the surface to breathe.

Now, onto our Solent dolphins!

Short-beaked common dolphins have distinctive hourglass shaped markings on their sides, with the front half tawny yellow, the back half a paler shade of grey, and even paler undersides. They can grow up to 2.5m long, and frequently travel in large groups, usually of around 20 individuals. Common dolphins are very energetic and inquisitive creatures, and can often be seen riding the waves made by moving vessels. They also like to ‘porpoise’ – which means leaping out of the water and getting completely air born.

Bottlenose dolphins are perhaps the most iconic and widely recognised species of dolphin, due to the popular fictional character, Flipper. As the name suggests, they have relatively short and stubby beaks, with foreheads that are more curved compared to common dolphins. They are grey all over, with no specific markings, and are much darker on their backs, with the colour fading to a lighter hue underneath. Bottlenose dolphins are also very energetic, move in groups of up to 50, and can grow to be just under 4m long. They are acrobatic when leaping out of the water, and are well known for harassing other species as they compete for food.

Harbour porpoises are much smaller, growing to a little over 1.5m, and are usually found in groups of around 6. Their small size, coupled with their shyer behaviour, can make them harder to spot than other species. Like bottlenose dolphins, porpoises are uniformly grey with the darker colour up top fading to a paler underside. They lack distinct beaks, which gives their head a more rounded appearance. The triangular shape of the dorsal fin is much smaller than the common and bottlenose dolphins, and lacks the distinctive ‘hook’ shape. As porpoises are slower and less lively than other species, they are easy to miss when the sea isn’t calm, and you’re more likely to spot them by their dorsal fins when they come up to breathe.

Rowena Cowton is a Marine Champion for our Secrets of the Solent project, with a background in Wildlife Conservation and Ecology. If you'd like to become a Marine Champion, or support our marine wildlife in another way, our project page is a great place to start.