Plenty of urchins at Ningaloo
Ashley combs the WA shores near the Jurabi Sand Dune for urchin specimens washed ashore from the Ningaloo Reef. Image: Susan Graham
Diverse, colourful and exciting, the urchins of Ningaloo put a sparkle in the eye of sea urchin expert, independent researcher and author of Sea Urchins of Australia and the Indo-Pacific, Ashley Miskelly.
"My role has been to search for, document and sample sea urchin species from Ningaloo Reef," Ashley said.
I first met Ashley when I was invited to the beach just hours after I had arrived. As we walked onto the beach, he ran to an area of washed-up, dried-out seaweed that other people would typically avoid. I was not yet aware what his role was on the project. He told me he was looking for the skeletal remains of sea urchins that had washed up.
As a result of both scuba diving and combing the shoreline, he has collected evidence of more than 23 species, either their remains or live specimens.
He said that number was on par with what he was expecting to find, around 20 to 30 species.
Ashley said that he has collected about three species that he had not expected at this location.
"All three are heart urchin species, and they are burrowing forms. One of them is a relatively common Indo-Pacific species that has been discovered in the past 20 or so years, but this is the first record of this species along the Western Australian coast," he said.
"Two of the other species are quite rare and they have not been found alive here yet. They are just known from fragments. This is a 450km extension of that species' distribution south from Dampier. Some of the other species that I have found are also extensions of the known distributions.
Some of the sea urchin skeletons Ashley collected at Ningaloo. Image: Gary Cranitch
"Most species I am finding are tropical and some of them are very widespread, occurring from the Red Sea and the Indo-Pacific region."
Ashley found his urchins by searching coral outcrops while scuba diving, looking for the species that are known for hiding in crevices. They are called regular urchins because they are radially symmetrical. They hide away in the day under large rocks or camouflage themselves with seafloor debris, but you can usually make out their outline or see some spines.
He collected these by hand, noting that some of the urchins looked more formidable than they really are; "the spines aren't poisonous, but they look like they are".
When it came to the burrowing species, including the sand dollars, heart urchins and sand urchins (of which there is one species here), he found them by sifting around in the sand with his hands in the clean coral sand. The sand urchin found here, Echinolampas ovata, doesn't burrow very deep, so are easy to find, once you find their habitat.
He said he had found eight species of heart urchins, three species of sand dollars with the remainder being radially symmetrical sea urchin species.