We discovered during our stay in Denham that there was a lot of interesting things and places to visit both in the town and outside it in the Shark Bay region. On the morning we left Denham, we had decided we would visit Eagle Bluff, 18-20 Kms south of Denham. We were told there was a board walk there that stretches along the cliff giving spectacular views of the ocean and if you are lucky, Sharks, Dugongs and Dolphins. However on arrival at the turnoff, the barrier proclaimed that this entry road was closed.
Our next stop was Shell Beach and to understand this beach and the quarry we would find near Hamelin Pool’s Telegraph Station further on, we needed to understand the science and geography that makes these environments very different from the rest of Shark Bay, and indeed, the rest of the Indian Ocean. Shell Beach is in L’Haridon Bight and its beach is made up entirely of the small shells of the Fragum Cockle (Fragum erugatum); there can be over 4000 cockles living in one square metre of the Bight’s hypersaline waters. The waters of L’Haridon Bight and the much larger Bay of Hamelin Pool are not standard salty sea water. The diagrams from the highly informative notice boards at Shell Bay do a good job of explaining the link between the area’s hot climate and the highly salted water of these two bays. The low rainfall and the sand/seagrass banks out in the bay stop these bays from being flushed out with ordinary sea water. As a result, the main creature that can live in this environment is the Fragum Cockle.
“Because few animals are super-salt tolerant, the fragum cockle has few predators or competitors controlling its numbers.” (from onsite Info Board) Since the shells on this beach are replenished every year, there is a company that has a contract enabling them to mine the shells and sell them as shell grit for aviaries, as calcium supplements on stock farms and for landscaping purposes.
Whilst the Fragum Cockles thrive on the hot temperatures and the over salty water of L’Haridon Bight, we weren’t able to cope for too long on Shell Beach, particularly as we had another site along Shark Bay Road to visit before we continued our journey south.