I have always thought it a shame that most people in the British Isles tend to know more about the marine wildlife living in tropical seas, clown fish and the like, than what lives in our own coastal waters. Research has shown that many British people believe our seas to be grey, muddy and barren, which couldn’t be further from the truth. Wild Isles is the first big budget natural history series to showcase our very own marine wildlife – and wow!

I am so pleased that cuttlefish were included in the series. These are one of my favourite marine animals but don’t get the attention of their close relatives squid and octopus. They are completely amazing, colour-changing, intelligent creatures and are superb ambush predators, and yet they live such short lives, breeding only once before dying. Most people only know them from the white ‘bone’ washed ashore after death. I had a very memorable encounter with one individual that spent a whole dive following me around, clearly trying to communicate by displaying a dazzling lightshow of colours and patterns across its back. If only I could speak cuttle!

In summer, cuttlefish eggs sometimes get washed ashore onto beaches. The little clusters of black eggs are called 'sea grapes' as that’s what they resemble. At Dorset Wildlife Trust’s Fine Foundation Wild Seas Centre, we have been lucky enough to hatch cuttlefish eggs in our aquarium when they have been rescued from the beach. The pea-sized babies are able to change colour and to camouflage immediately and it has been a privilege to watch these superb predators sneaking up and seizing prey even at that tiny size. Of course they need to grow quickly as their lives are short.

For these intelligent molluscs to be showcased on Wild Isles, and their tragic plight and dramatic decline highlighted is incredible and will hopefully result in some conservation gains to restore their populations to what they once were.

Many people are surprised to learn that we have seahorses living in the shallows around our coastline, and Dorset is a hotspot. We have both British species here, the short snouted seahorse and the long snouted or spiny seahorse. While short snouted seahorses can be found in a variety of marine habitats, they are most frequently recorded in open water on rocky, shelly or sandy seabeds and are often accidentally pulled up with fishing gear. Spiny seahorses prefer the shelter of seagrass beds where they hide in plain sight thanks to their superb camouflage. Their mane of fleshy ‘spines’ breaks up their outline and blends in with the seaweed and other organic debris snagged amongst the tall seagrass fronds. Famously, it’s the dad who undergoes pregnancy and gives birth to the babies. After the mum deposits her eggs into dad’s brood pouch where he fertilises them, they embed into the soft tissue to develop, receiving all the minerals and oxygen they need. Gradually the fluid inside the pouch changes to become more like seawater, ready for when they are born.

I was lucky enough to help with some of the filming for the seahorse sequences, all shot in Dorset, of course. So I know the absolute care that the film crews take to avoid any kind of disturbance to the wildlife they are filming. They need to record natural behaviour so any kind of disturbance is out of the question. The film-makers spend hours watching animals to record the often secretive behaviour they want – and underwater this requires specialist equipment and an extremely experienced crew. For one sequence the camera team were underwater continuously for over six hours, waiting for just the right angle, just the right lighting and just the right behaviour! Once edited the sequence lasted only a few seconds.   

Who can forget the fabulous royal flush sea slugs swarming underwater? Although I have never had the good fortune to witness this wildlife spectacle myself, I know that we find these animals right here in Dorset. They are also called bubble snails, and as well as the royal flush sea slug we have another species of bubble snail which gathers in huge numbers on the seabed in winter. Normally buried beneath the sand, they congregate en masse in seagrass beds, mostly at night in winter. Why they do this is unclear as their jelly-like egg masses decorate the seagrass fronds in summer when adult bubble snails are almost never seen. These underwater wildlife spectacles go largely unseen and unknown by the vast majority of people so for Wild Isles to bring these spectacles into our living rooms, for all to see, is a dream come true for a long-time marine conservationist like myself.

While for most people their favourite marine creatures are probably the dolphins and seals shown on the programme, for me it’s the ones that often go unseen and unknown by all but a few. In particular amongst my favourite scenes were the plankton and especially the sea gooseberries and comb jellies. To be able to film in such detail these miniscule creatures, which ultimately power the entire marine ecosystem, was fabulous to watch. Phytoplankton produces over half of the oxygen in our atmosphere so without it we would not be here. Showcasing this vital but invisible part of our natural world really brings home the importance of protecting our ocean wildlife.

I am lucky enough to know and have dived with Doug Anderson, the world-class film-maker who filmed almost all of the scenes in this Oceans episode and who delivered an emotional finale to the programme. He has dived all around the world but this series meant more to him than any other because it was about our own British wildlife, living right here on our doorstep, but in need of drastic efforts to support it. Doug said that this series had given him an “amazing opportunity and responsibility” to not only show off our marine wildlife at its best but also to highlight its decline. He showed how allowing areas of the sea, like Lamlash Bay where he first went underwater, to remain undisturbed by human activities, can have a remarkable effect on their recovery and health, returning them in a relatively short time to a near-natural state. Such areas are called ‘no take zones’ or ‘highly protected marine areas’ and the government has announced the first three such areas to be established in England this year. While these are nowhere near enough, hopefully they will be the first of a network of large areas set aside to help recover the stunning marine wildlife around our Wild Isles.

Catch up on the BBC Wild Isles series on BBC iPlayer.