Sunday, 14 February 2021
The fine, warm weather for our postponed snorkelling event was in stark contrast to the rain which lead to the cancellation on the original date. By chance, the move from the 7th to the 14th brought the event closer to Darwin’s birthday, the 12th February.
Eighteen adults and two Young Nats attended plus several people saw The WA Naturalists’ Club sign and made enquiries about the club and our events. Unfortunately the sun slipped behind the clouds just as the snorkelers slipped into the water. However this did not deter people from heading towards the dive flag which had been placed on the reef about 50m offshore. The visibility was very good over the reef and many people were amazed to see the enormous number of Roe’s abalone (Haliotis roei) that inhabit the reef. Few people were brave enough to follow Don through the swim through due to the increasing swell and stirred up viz. However by grasping a ledge and looking over the edge some did spot the numerous Senator Wrasse, Banded Sweep and Western Blue Devil that live in the tunnel. Elsewhere it was easy to spot the Red-lipped Morwong by the clouds of sands they were ejecting after filtering their catch, mainly benthic invertebrates, through their gills. In the open water we spotted schools of tiny Woodward’s Pomfret with their distinctive bright yellow fins and darting Buffalo Bream who change from black to silver as they change direction. Less common were the whiting (species not identified) and blowfish.
The more adventurous snorkelers spread out and were rewarded with an even greater variety of marine life, including, colourful sponges and Gorgonian corals, several species of feather stars, numerous types of ascidians and schools of Old Wives and Bulleyes. Although Port Jackson sharks are known to rest in the area the only sizeable creatures we saw were three Eagle rays – distinguishable by the grey markings on their backs.
Back onshore, Mike Gregson set up his tarpaulin with labels for those who had found specimens along the shoreline. By the end of the session we had a collection of brown, green and red seaweeds, fragments of crustaceans and various gastropods shells, including a large Elephant snail. Kirstin went searching along the shoreline and found a small rock pool with several tiny common reef anemones (Isanemonia australis) in it and an empty mollusc full of amphipods.
Don Poynton brought along an assortment of local marine specimens and talked about several of the more interesting ones including the life cycle of the Port Jackson shark and how the Masked burrowing sand crab uses its two antennae to form a breathing tube that allows oxygenated water down into the substrate.
This was the first time the annual snorkelling event had been held so far north but there was general agreement Burns Beach had been a good choice.