About South West marine life

Seagrass

Geographe Bay, Western Australia, supports one the Worlds last remaining pristine seagrass meadows. The clear waters south of Cape Naturalist allow strapweed and wireweed species to form large beds at depths of 30 metres. Such extensive development of deep seagrass beds exposed t direct oceanic swell is not found anywhere else in the World. So when you’re diving, or checking your anchors, do your part to preserve our seagrasses.

Coral

To date, 14 species of coral have been identified in the South West. Surprisingly, 10 are tropical, two temperate and two are confined to south-western Australia. Of the 10 tropical species, five have their southern limit near Cape Naturalist. The presence of tropical species in our mainly temperate waters is largely because of the Leeuwin Current transporting tropical species south along the coast. However, the area’s geographic location ad variety of habitats also plays a big part in our unique diversity of marine life. Remember to take care when diving near coral. Don’t let your gauges drag. Try not to touch or break coral growth.

Fish

To date, 247 fish species have been recorded in the Bunbury-Geographe Bay area. The coastline between Busselton and Dunsborough provided important spawning and nursery habitats for at least 13 recreationally and commercially important fish, including Western Australian salmon, herring and King George whiting. The fish species vary from warm temperate varieties through to subtropical and tropical, many attributable to the movement of the Leeuwin current.

Invertebrates

Limestone reefs attract a wide variety of invertebrates, Areas with caves and overhangs support highly coloured sea squirts, sponges, bryozoans (or lace animals), and soft corals. Sea stars, sea urchins, crustaceans and shellfish are also found in limestone reef habitats. Many large fish, such as jewfish, western blue groper, and harlequin fish are associated with limestone and granite reef habitats.

The largest shoreline reef platforms area found at Yalingup, Cowaramup, Gnarabup, and around Hamlin Island and the islands of Cosy Corner. They are home to a diverse range of invertebrates such as, turban shells, dogwhelks, abalone, sea urchins, anemones, sea stars, sponges, mollusks and crustaceans – especially crayfish.

Whales

Watching humpback whales and southern right whales is now very popular, particularly from Cape Leeuwin, Cape Naturalist, Gracetown, Cowaramup, and the Sugar Loaf Rock car park.

The southern migration of humpback whales off the Cape Naturalist-Bunbury region occurs during mid-October, and the peak northern migration occurs at the end of June. Humpbacks are frequently observed with exceptionally small and pale calves in Geographe Bay and occasionally in Flinders Bay. This suggests these areas might be calving and nursery areas.

In November, blue whales (the largest living mammals on earth) frequent Geographe Bay. Over recent years, sightings of blue whales in Geographe Bay have increased. Scientists believe Geographe Bay has become an important feeding area for the Blue Whales, but as yet, are unsure why.