ABC News 24 just broadcast an interview with Tony Abbott from Cairns in which he backs away from Marine Protected Areas because the science isn’t right! How predictable was that!? And how ironic when we think about the amount of dirty water that must be smothering the GBR right now.
The cow fish is a type of boxfish and are quite rigid. They are generally found on rocky reefs. We have about 20 species in Australia.
Fish are sometimes stranded alive in pools on outgoing tides, but usually they are dead, and a rare feast for seabirds. You might occasionally also find freshwater species on metropolitan beaches following rains that have washed fish, such as European carp, out of the Torrens.
Porcupine fish (a.k.a. balloon fish, puffer fish) Diodon sp
Best not to step on a dead, dried porcupine fish! It has nasty, long sharp spines. In a live fish the spines provide defence against predators, as does its ability to inflate its body, making the spines stick out – like an echidna in defensive mode. These fish are not built for speed.
Toad Fish Tetractenos
These fish grow to about 15 cm (this one was about full size) and are common in shallow water in southern Australia. Like other members of this family, toadies are poisonous.
Short-headed Lamprey (a.k.a. Australian Lamprey) Mordacia mordax
Looking like an eel, these fish grow to about 50cm in length and move from marine to fresh water to breed. In the sea they parasitise other fish. Most fish have jaws, but Lampreys are blood sucking and have a round funnel-like mouth with many small sharp teeth.
All crabs belong to the group called the Decapoda – Latin for ‘ten legs’.
There are lots of crab species in the Gulf, and they range in size from tiny to quite large. Most have hard shell (carapace) unless they are moulting. This happens as the crab is growing. Calcium is reabsorbed from the old shell, which gradually becomes softer, and is used to grow its next shell. When the new shell is ready the old shell is cast off, and the new shell hardens quickly. Sometimes the soft, old shell is washed up. Hermit crabs don’t have a hard carapace, and they use empty marine snail shells to protect their soft bodies. As they grow they need to find larger snail shells. If you are collecting shells on the beach, be sure to check that there is not a hermit crab in residence!
The Blue Swimmer is probably the best known crab, and is sought after because it is abundant and tasty! If you see one in the water while you are swimming, or in a tidal pool, don’t get too close – a nip from their claws is painful.
Sand crabs are pale reddish with two darker spots on the carapace.
Spider crabs range greatly in size, but characteristically have really long legs.
Rock crabs are smaller and chunkier than the swimmers and spider crabs, but are really good at wedging themselves under rocks and in cracks.
There are a few types of eggs or egg masses that are easy to recognize on the beach. Considering how many marine animals actually lay eggs, it is a bit surprising how few we see regularly!
The egg mass produced by a couple of species of the moon snail (Polinices conicus and P sordidus) is often mistaken for a jellyfish. That’s because you can barely see the miniscule eggs, but they are held in a transparent, firm, sausage-shaped jelly matrix. They start to appear on the beach in spring.
Squid eggs are also easy to recognize because they are soft, whitish and clumped together in a bunch.
The most common shark egg cases we find locally are those of either the Port Jackson sharks or skates. They are dark brown, rubbery and shiny when fresh, but when hatched or dry become hard brittle. The Port Jackson shark egg case is spiral shaped, tapering from the base to the tip. Skate egg cases are shaped like small pillows, with tendrils on each corner.
During the winter storms this year a couple of unusual objects washed up on the beach at Henley. This is the downside of making your own artificial reef – apart from the fact that it is dumping rubbish at sea. A big enough storm can dislodge very heavy objects, let alone hot water heaters and mattress bases.