AND OTHER MARINE INVERTEBRATES OF THE TWEED - BYRON COAST, AUSTRALIA.
Unlike other parts of the New South Wales coastline, the far northern region has very few rock platforms that are sheltered enough to provide a habitat for other than the more hardy species. Woody Head at Iluka is the finest example of such a habitat and has been recognised as such for many years. It has also been included in a National Park and given protection.
Another site of great importance is Hastings Point on the Tweed coast. Although not as large an area as Woody Head, in this area of long sandy beaches and exposed headlands it is a treasure for anyone interested in marine life. The diversity of tropical species observed here at various times can be amazing, notably Molluscs, as the partial checklist I have included will show. Other phyla are also well represented. I have so far been able to photograph 22 species of hermit crabs and 40+ crabs. Tropical Shrimps and Mantis shrimps also occur here as do many species of Flatworms, Polychaete worms, Sea Urchins, Brittle Stars, Anemones, Sponges, Sea Cucumbers and Tunicates. Some tropical species occurring intertidally here have yet to be found elsewhere on the New South Wales coast. For example, the first sightings in Australia of the sea-slug Bosellia sp and the crab Goniosupradens acutifrons were recorded here.
Apart from the pressures of a rapidly increasing population, which inevitably includes occasional acts of vandalism and stupidity there are also natural physical stresses in force. Due to the inshore current moving north along the beach, sand from the beach on the south side occasionally moves around the point and proceeds to fill in many of the rock pools and channels, smothering everything that cannot escape.
After a period of time the sand moves on and the various forms of life begin to slowly recolonize the barren areas. This rebuilding can be hampered by other factors, most obvious of which is the action of the waves that break over the area. Early in 2004 this area experienced some huge seas, with massive swells breaking across the rock-shelf, tearing up not only large areas of marine life but also ripping out parts of the rock reef as well. But this type of destruction and rebuilding has been going on since this area was formed and is probably one reason for the diverse forms that appear here at different times.
As I have no formal qualifications in marine studies, anyone wishing to obtain a much more in depth report on this area and its ecosystem (and why it needs protection) should contact Kerrie Trees or Ted Brambleby at the Marine Environments Field Study and Resource Centre at Hastings Point.
Mexichromis lemniscata - A tropical species and rarely seen as an individual so 3 in the same pool is unique.