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They have traveled the oceans and have outlived the dinosaurs. They have become an integral part of the traditional culture of many coastal indigenous peoples throughout the world. Today, all but one of the species features on the IUCN RED List as endagered or critically endangered. Extinction looms!

There are only a few large nesting populations of the green, hawksbill and loggerhead turtles left in the world. Australia has some of the largest marine turtle nesting areas in the Indo-Pacific region and has the only nesting populations of the flatback turtle.

Until fairly recent times, their long presence in the tropical and sub-tropical seas and beaches of the planet seemed set to continue...

Acanthaster planci

Sea stars (group name Stelleroidea), are sometimes called starfish, though lacking both vertebrae and fins, they are not real fish. There are two sub-types of sea stars: Asteroideas are the true sea stars and sun stars, whereas Ophiuroideas are brittle stars and basket stars.

Ophiuroid means ‘snake-like’, referring to the form and motion of the arms. The arms of brittle stars are easily broken off, but will regenerate in a few days to weeks. Sea stars can also regenerate arms that are broken off, but for most species, the central region of the body must remain intact

Class Asteroidea, the true sea stars, contains about 1700 living species of these echinoderms...

Serranidae

When people talk about coral reefs, fishermen tend to shrug their shoulders and complain about snagged lines and torn nets. But when you talk about groupers, they suddenly sit up and pay attention. Groupers are among the economically most important fishes of the coral reef, because of their popularity as food. Yet without the coral reef there would probably be no groupers. For this reason, groupers are an extremely important indicator species and your record of their existence or non-existence during your dive tells us a lot.

The goliath grouper (Epinephelus itajara), sometimes called the jewfish is classified as critically endangered on the IUCN Red List. Found in shallow, inshore waters to depths of 45m, this indicator prefers areas of rock, coral, and mud bottoms...

Identifying sharks in the wild is a great challenge! While scientists can spend weeks examining every detail of a species, divers may encounter a shark for only a few seconds or minutes. Many species look alike and one individual may not be identical to the next. There are, however, relatively few species in any one specific dive site and with some preparation and a little practice it is possible for all of us to recognise the more common and distinctive species. The key to successful shark identification underwater is a process of elimination, based on a mental checklist of the main features to look for in every animal encountered. One feature alone is rarely enough for a positive identification, so gather as much information as you can before drawing firm conclusions.

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Alcyonium digitatum

Dead mans fingers (Alcyonium digitatum) are colony building soft corals that are classified asOctocorallia, a group which also includes sea pens and sea fans. This group of corals is characterized by the eight tentacles clustered around the mouth of each polyp in the colony.

The tentacles sit in a circle around the edge and have small branches. Corals in the family Alcyonaria have a horny or leather-like skeleton supported by calcareous pins.

Colonies consist of small coral polyps and are white or orange in colour, but may appear reddish or brownish during periods of inactivity when the individual polyps are withdrawn into the colony...

Pecten maximus and Chlamys islandica

Scallops are bivalve molluscs with scalloped, fan-shaped shells (valves) whose shape and colour have inspired artists architects and designers for centuries.

The shells are further characterized by radiating ribs or grooves and concentric growth rings. Near the hinge, where the two valves (shells) meet, the shell flares out on each side to form small “wings”. Just inside each valve along the edge of the mantle there a row of short sensory tentacles and a row of small blue eyes.

A single adductor muscle, sometimes called the ’eye’ in culinary circles, opens and closes the two valves. Because they are active swimmers, the adductor muscle is more developed in the scallop than in oysters and clams...

Cancer pagurus

The common edible crab (Cancer pagurus) leads a benthic (bottom dwelling) existence living on a wide range rocky substrates, bottoms of sand or gravel and at depths from 6 to100 metres, although between 6 and 30 metres is more typical. The species is distributed from northern Morocco to northern Norway at latitude 70 degrees. It has a heavy, broadly oval shaped body, which is rather convex with very faint grooves. The edible crab is readily distinguished from

other species by the round lobes at the front of the carapace giving a ‘piecrust’ effect and the presence of massive black tipped chelae (pincers). The pincers are smooth and slightly unequal in shape. The last four pairs of legs are roughened by numerous groups of very short stiff black hairs...

Paralithodes camtschatika

Originating from the Sea of Okhotsk in the Camchatca region of eastern Russia, the red king crab (Paralithodes camtschatica) was introduced to parts of the Russian waters of the Barents Sea in the 1960’s. In the mid 1970’s, individual specimens started to appear as bycatch on both sides of the shared Russian/Norwegian border. Since that time, bycatch numbers have increased significantly in the region.

The king crab is a valuable food source and is the most commercially important of all crabs. Whilst a number of studies have examined the optimum harvesting strategies for the species in the region, very little has been done to understand the potential ecological impact that the species will have in non-native waters.

The crab’s diet appears to include a wi...

Homarus gammarus

Lobsters, like shrimps and crabs, are decapods – literally meaning 10 legs – and can be found in all of the world’s tropical and sub-tropical seas as well as more temperate waters. They are predatory, nocturnal animals with a vividly decorated coat. They are often numerous locally; they linger in crevices (with their long antennae sticking out) during the day and hunt small benthic organisms at night, but they also feed on organic detritus whenever they happen across it. As with all crustaceans, the lobster moults or sheds its shell to grow.

Up until the end of the 19th century lobster was so plentiful that it was often used as fish bait. Sadly, with lobster’s ever-increasing popularity those days are now gone forever...

Pleuronectes platessa

The European Plaice (Pleuronectes platessa) is a member of the order of Pleuronectiformes (flatfish), which also includes soles and other flounders.

It is generally recognised as the most important flatfish for commercial fisheries in Europe. Widely distributed in the Northeast Atlantic, it can be found from Greenland and Norway in the North to Morocco in the south, in temperate waters ranging from 2 – 15°C, with the Wadden Sea being reported as an excellent nursery area.

This species lives on mixed bottoms, tending to go deeper as it ages, with smaller individuals being encountered on bathing beaches. It is active at night, in shallow water, feeding on thin-shelled mollusks and polychaetes (marine worms), spending the day buried in the sand...