MEETING OF THE WATERS A journey on the marine side of Australia s Coastal Wilderness Part 2 The Fish
The Fish (and Sea Squirts) Over 100 species of fish intermingle in the waters of the region, with a rich and varied mix of temperate and tropical species. Morwong, Luderick, Drummer, Bream, Flounder, Kingfish, Tailor and Ling are but a few. The coast also provides safe haven for the Eastern Blue Groper, the marine emblem of New South Wales. Eastern Blue Groper Morwong Luderick Drummer Black Bream Flounder Yellowtail Kingfish Tailor Rock Ling Large pelagic fish species that migrate into our waters include the charismatic Sailfish and Marlin, Tuna and Salmon. Flying Fish can also be spotted in deeper water, and signal the arrival of warmer currents. 2
Sailfish Marlin Bluefin Tuna Eastern Australian Salmon Yellow winged flying fish A star visitor is the Southern Blue Fin Tuna, weighing up to 200 kilograms. These iconic and endangered fish - fast disappearing from other marine zones - pass through our waters in late June and early July during their long southward bound migration. They travel from their breeding grounds in the Indian Ocean, near Indonesia, right down the east coast of Australia and into south Australian waters, often in the company of cousins such as the Yellow Fin and Big Eyed Tuna. They are mostly found some 50 km offshore, exciting both commercial and recreational fishers. A fish of particular curiosity is the Snapper. It s widespread throughout southern Australia, but it appears that we have a unique pygmy sub-species in our waters. Regular adult snapper grow to 17 kilograms, but this local pygmy stops at 7 kilos, and is short and stumpy. And although a schooling species, each fish has its own individual appearance. Snapper Emperor Angelfish White Ear Damselfish The region is also the most southern point for wayward tropical fish species such as the Damsel Fish and Angelfish, who journey here from the faraway Great Barrier Reef. 3
Sharks Shark populations have been decimated throughout the global oceans, with most species endangered or on the brink of extinction. Although shark encounters are rare in our waters a number of species have been reported, most commonly the Bull Shark. Smaller species such as the Draftboard Sharks are commonly seen. White Tip Reef Shark Bull Shark Draftboard Shark Swell Shark There have been confirmed sightings of the critically endangered and heavily protected Grey Nurse Shark as well as the king of all sharks, the Great White. The risk to swimmers and divers is minimal, as sharks generally prefer deep, offshore waters. Sightings are rare, and attacks in this region are unknown. Great White Shark Grey Nurse Shark 4
Sharks are an ancient form of fish, with cartilage instead of bones. The region is host to fossils of these distant ancestors, dating back to the late Devonian period about 355 million years ago. Fossils occur in rocks in the Eden area and north of Tathra in Mimosa Rocks National Park. This is described in the accompanying series A journey through the earth history of Australia s Coastal Wilderness in Part 8 Ancient volcanoes and Armoured fish. Sharks are part of the class of vertebrates called the Chondrichthyes (from the Greek meaning cartilage fish). Sharks are in a subclass that includes rays and skates. There is a wide variety of rays in the region such as the large Black Stingray, Bull and Eagle rays. Black Stingray Bull Ray Eagle Ray Many protected species, officially designated by the NSW Government, find sanctuary in our waters, including the Great White, and Wobbegong sharks. Eastern Blue Devilfish, Weedy Sea Dragon and Black Rock Cod. Eastern Blue Devilfish Weedy Sea Dragon Black Rock Cod 5
Whale sharks A leviathan of the deep that visits our coast is the Whale Shark. This gentle plankton-eater is a relative of the shark (the subclass Elasmobranchii the sharks, rays and skates) and is in the carpet shark group (with their distinctive ornate skin patterns) that includes the Wobbegong shark. The NSW portion of Australia s Coastal Wilderness is at the southern boundary of its migratory path, and they have been encountered as far south as Eden. The most recent sighting was in February 2012, when excited locals gathered on Tathra Wharf to watch a young adult swim by. Their random visits here seem to coincide with warmer spikes in the local sea temperature and a related surge in plankton, the whale shark s principal food. Ocean Sunfish Whale Shark The Ocean Sunfish is also an occasional visitor. This is the largest bony fish in the world with an adult average weight of one tonne. Ocean sunfish 6
Big Belly Seahorse Green Moray Eel Feeding frenzies Feeding frenzies are inspired by the formation of baitfish balls and involve many oceanic creatures. It s a chain reaction set in motion by the presence of krill, which are predated upon by large schools - or balls of pilchards and mackerel. The fish in turn are targeted by birds from above and predators from below. Birds such as gannets pierce the water like arrows. Seals, dolphins, whales, sharks and predatory fish pursue their quarry through the water column, often breaking the surface. It s a feeding frenzy unlike any other, and visually spectacular - the sea a churning cauldron. Sea Squirts Baitfish ball and feeding shark Cunjevoi (or cunjies or sea squirts as they are often known) are commonly found on the rocky shores and as debris on beaches. They were a food source for Indigenous people. Today they are used as bait. 7
Cunjevoi These are not fish, nor are they plants. They are in fact related to us (Chordata) as animals with a primitive backbone and are classified as a Tunicate. They are found around the edge of the low-tide mark forming mats over the rocks. These mats are sometimes covered in green or brown algae and have a tough brown exterior or 'tunic'. This is a seriously weird group of animals. They are living fossils dating back to the early- Cambrian Period, some 500 million years ago - older than the oldest rocks in the south coast region. They belong to the class Ascidiacea that is worldwide with over 2000 species. Their closest local relative is the Sea Tulip, also locally found. Sea Tulip 8