The sixth annual sea-slug census on Lord Howe Island

Sixth Sea-slug census a roaring success

The sixth annual sea-slug census was held recently on Lord Howe Island.

Lord Howe Island hosted its sixth annual Sea-Slug Census between February 24th and March 5th.  

Launched at Nelson Bay, NSW in December 2013, the Sea-Slug Census program has spread across Australia with more than 3000 participants photographically documenting the distribution of over 900 species to date. The project has demonstrated that ‘Citizen Scientists’ can provide extensive, and very valuable data on sea-slug (nudibranchs and allies) diversity and how patterns of distribution are changing under climate change. 

To participate takes no special knowledge, just curiosity, and a camera to photograph any sea-slugs found whilst snorkel, rock-pooling or scuba diving. The program has been a great success with censuses now conducted at 12 locations in Australia as well as Vanuatu and Ambon, Indonesia. Results from censuses have been presented at conferences and have been used in a number of scientific papers, including a photographic inventory for Lord Howe Island.

Sea Slug Census logo

At Lord Howe Island the program is coordinated each year by Prof. Stephen Smith and Dr Ian Hutton from the Lord Howe Island Museum. Many locals and visitors participate in the census each year, with a total species count of 174 for the program. New species are added to this total every year, including new records for the island and Australia. 

In 2022, the Sea-Slug Census program teamed up with the iNaturalist initiative making images available to a global audience, helping to highlight Lord Howe Island’s amazing and unique marine biodiversity. Over time, the annual records provide data for examining changes and movements in species that may occur with warming oceans.

The weather for the 2023 Sea-Slug Census was fantastic, with many opportunities for participants to snorkel, scuba and explore rock pools in search of these amazing marine creatures. Some of the regular favourites were found – Verconia romeri and Sagaminopteron psychedelicum.  A number of new and exciting species including the first Island record of the tiny green sap sucking Sacoglosson Volvatella ventricose, and the Side gilled slug Berthella.  A number of interesting sand dwelling species were also observed – Melibe, Cerberilla and Limenandra.

A full report of the 2023 event will be made shortly. An analysis of the data from all census years will allow scientists to see any trends in the numbers and movements of species.  


iNaturalist website

Wrap-up of the 5th LHI Sea Slug Census
iNaturalist website, April 3rd, 2022

Lord Howe Island Nudibranchs
iNaturalist Website

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