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Pagrus auratus

Strictly, or scientifically speaking, the New Zealand snapper (Pagus auratus) is not actually a “snapper” at all!

The snappers are a large and diverse group of robust-bodied, carnivorous fishes and belong to the family Lutjanidae. Like many other southern hemisphere species, the New Zealand snapper inherited its name from the northern species it most closely resembles, but is in fact a member of the family Sparidae, which are sea bream or porgies.

In New Zealand waters, this indicator can be found from the tip of the North Island down to the northern areas of the South Island. They are mostly encountered in deep water over offshore reefs and gravel beds, around islands and near undersea pinnacles.

The snapper is also known by the Maori name, ‘tamure’ and is a very ...

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 giant grouper (Epinephelus lanceolatus) is one of the largest reef-dwelling fish. It may grow to more than 270 cm and reach weights of 300 kg...

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.

Lobsters have recently suffered a dramatic demographic decline; intensive fishing has annihilated entire populations, especially where tourism abounds.

The lobster families that you may encounter are the spiny rock lobsters, Palinurida...

The marine habitats in which marine communities live are many and varied and are created, or caused, by a number of physical factors. These factors combine to determine which animal and plant communities can co-exist within a particular habitat, with the interplay of the communities themselves playing a large determining factor.

The physical factors include elements such as temperature, depth, tides and currents, relative salinity, wave action, light or shade, sea-bottom substrate, aspect and inclination. Extreme physical factors, such as a rise in sea temperature can have a significant and sudden impact on habitats, such as the El Nino effect on the coral reefs in the Maldives, where a small rise in sea temperature caused widespread coral bleaching.

In addition to the physical fact...

Approximately 500 miles north of the equator, the Republic of Palau lies just outside of the northern Pacific typhoon belt. Given its geographic location, only three typhoons have threatened the Palauan archipelago with serious damage over the last 60 years. In December 2012, however, NOAA weather reports called for “a one in a million typhoon” (later named, Super Typhoon Bopha) to hit Palau – a serious matter in this part of the world as the region’s natural and built environment is not able to easily recover from the direct impact of typhoon force winds and seas.

Typhoon Bopha was expected to hit Palau in the early morning of December 3^rd, but at the last minute Bopha veered ~50 miles south of Koror...

Sciaenidae

The sciaenids are a large family of primarily bottom associated, carnivorous fishes distributed throughout the Atlantic, Indian and Pacific oceans, in tropical and temperate inshore waters. The majority occur on open sand and mud bottoms and some are found only in brackish waters. The exact number of species is uncertain, but there are probably about 270, of which there is a limited number in the Mediterranean Sea.

Drums are also commonly called croakers, and for good reason. They have modified muscular swim bladders that they use to produce a drumming or croaking sound when they are excited. Drums are luminescent and appear pink when first removed from the water. A drum’s tail is slightly pointed, and it has faint stripes across its back and small chin barbels.

Dru...

Corallium rubrum

Red coral (Corallium rubrum) is another soft octocoral and is endemic to the Mediterranean. The beautiful deep red colour is retained even after the animal is removed from the water and dried. It is much valued in the manufacture of jewellery, and the resulting unsustainable levels of harvesting have depleted this species in many areas. The powdered endoskeleton is also used by some practitioners of alternative medicine.

It tends to be found at depths in excess of 20m, to perhaps as deep as 300m and grows on hard substrates, with a preference for dark environments with minimal sedimentation. At shallower depths it is often found in caves, overhangs and crevices. In common with the indicator sea fans in section 3...

Eunicella spp. and Paramuricea clavata

There are few more stunning marine fauna than the beautiful large seafans or gorgonia. They look like plants; in fact they are soft corals, colonial marine animals forming erect, flattened, branching colonies in mainly tropical and subtropical waters. The colonies may be up to 1m high and are often colourful, with purples, reds, and yellows predominating.

The individuals, or polyps have eight feathery tentacles (hence their description as octocorals) and are passive suspension feeders of plankton organisms. Colonies branch profusely and the branches are usually oriented in one plane and at right angles to the prevailing moderately strong currents. This helps maximise the plankton ‘harvest’...

Homarus gammarus and Palinurus elephas

The Crawfish or Crayfish (Palinurus elephas) or spiny red lobster is larger than the European lobster, growing to about 60cm in length. It has a stout, heavily armoured body. The colour is usually orange dorsally with darker spines and white underneath but brown, sandy and purple morphs are occasionally found. It has numerous sharp spines on the carapace, over much of the abdomen and on the larger appendages. It has long antennae but small hook-like claws.

Crawfish are found on open exposed rock faces and on the rocky seabed in the lower inter-tidal zone and to depths of 70m, and are distributed within the north and western Mediterranean shores, being largely absent from the eastern basin.

The only other large crustacean with a similar sh...

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 dusky grouper (Epinephelus marginatus) is solitary and territorial, with a preference for rocky bottoms. It feeds on reef fishes, crabs and octopi and can grow up to 150cm...