What is a Nudibranch?

Nudibranchs or “sea slugs” represent the mollusc phylum, the largest marine phylum (class). Nudibranchs occur in seas worldwide and live at all depths of salt water. To me they represent the beauty of life under the sea. Nudibranchia (scientific name), means naked gills – it describes the feathery gills and horns that most wear on their backs.

Why Nudibranchs?

My first encounter with a nudibranch was at the Poor Knights Islands marine reserve in New Zealand while scuba diving off a live aboard boat along “magic wall”. The well known scuba diver, Jacques Cousteau, rated those islands as one of the top ten dives spots in the world. Nudibranchs are tiny creatures and can easily be missed, but they are so colourful and interesting when encountered. I was hooked and just wanted to see more of them. I tried to take a photo and realised the skill needed for such a small subject, while fighting with the sea current and the need for good lighting to capture their true colours even at around 10 meters under water. I told people about my experience and not many knew about the existence of nudibranchs. They are better known as a sea slug, but not many are aware of the diversity of colour and variety. The fact that I could locate a book on “1001 Nudibranchs and Sea Slugs” meant my search would be never ending to meet them all. Only half the total number of nudibranch species has been discovered so far, despite this numbering an impressive 3000 or so to date. This year two new nudibranchs were recorded in Norway.

I have dived in two other marine reserves in New Zealand. The F69 Frigate wreck in Wellington and the Kapiti Island Marine reserve with a hole-in-the-wall underwater archway filled with jewel anemones. I have seen nudibranchs at the Great Barrier Reef in Australia and also in Fiji. My aim is to make sure we get more marine reserves in New Zealand. I have seen the area before the Wellington region got its only marine reserve and I could spot a big difference myself in the marine life!

There are some types of nudibranchs in regions in the world that are endangered, but I look at the bigger picture of their food supply that is slowly disappearing with pollution, climate change and over fishing. I would like my children and their children to be able to meet the little beauties one day in the future too. Apparently they are not the easiest to keep alive in aquariums which means they would decline this way also when captured and are not easy to breed.

To make a difference I would like to create more awareness to protect their environment – New Zealand has a big coastline. I celebrate their beauty by making everyday products or art to show them off. I would like to bring awareness to the community that it is up to us to make a difference. Marine Protected Areas are established through consultation – have your say. The top things we can do as a society today is: clean up, stop over fishing and create marine reserves.