Reef Life (A Firefly Guide) - Softcover

Ferrari, Andrea; Ferrari, Antonella

Softcover

ISBN 10: 1552096254 ISBN 13: 9781552096253

Publisher: Firefly Books, 2002

Synopsis

Nowhere on earth is there a more beautiful and more abundant life than that which exists on the coral reefs just below the surface of the ocean. Reef Life is filled with information and images that brings order to the multitude of living things that exist here and allows the reader to appreciate the diversity and the richness of the world under the sea.

This handy guidebook will prove invaluable to the diver, tourist, student and naturalist. Each species of plant and animal is covered in detail: name, species, habitat, food, range, and a thorough description is provided for each entry. More than 400 species are covered and illustrated with 500 color photographs to provide a comprehensive look at this most magnificent world.

This is an ideal book for anyone interested in marine life. It provides up-to-date information, clear color photographs in a handy format for use in the field or at a desk. Readers who need essential facts quickly will be pleased with the orderly presentation of information, the completeness of the entries and the accuracy of the information. The color photographs help in identifying species as well as providing a visual reference for the information presented.

Reef Life is an ideal guide and reference for all levels of interest from school project to professional divers.

About this title

About the Author:

Based in Italy but working around the globe, Andrea and Antonella Ferrari have been professional nature photographers for more than fifteen years. During the past decade they have devoted themselves almost exclusively to underwater photography in tropical seas. They are the authors of four books of photographs and their work has appeared in many newspapers and magazines.

Excerpt. © Reprinted by permission. All rights reserved.:

The Coral Reef

The coral reef is an ecosystem without equal anywhere in the world. No other environment -- not even the densest tropical rain forest -- can convey so immediately such an impression of riches and vitality as is typical of an undisturbed and healthy reef. The transparency of tropical waters, their high luminosity at great depths, the inexhaustible bustle of innumerable creatures in every shape and color, the surprising and extremely delicate architecture of madreporic colonies never fail to astonish and fascinate even the most widely traveled observers.

The first traces of coral reefs date back more than 500 million years. Their distribution is remarkably varied over time, responsive in turn to phases of great geographic expansion and contraction following climatic changes that occurred during the different geologic eras. Today the distribution of reefs is limited to tropical seas, where reefs extend over a total area of nearly 600,000 square kilometers (232,000 square miles). Coral formations develop primarily between the surface and a depth of 30 m (100 ft) but only in waters whose average winter temperature stays above 20°C (68°F). Other factors that limit the development of coral reefs are water salinity, which must be constant, and the intensity of ambient light. Why are these three factors -- temperature, salinity and sunny exposure -- so important? If we think carefully about the reef environment, we quickly realize that the structural elements that underlie this ecosystem -- those that help determine its appearance -- are the so-called corals or, more correctly, madreporic colonies. These are admirably complex structures whose imperceptible growth and extraordinary fragility represent the very foundation of the reef habitat. At the simplest level, these coelenterate organisms can be described as countless tiny polyps (simple gelatinous "sacs" with an opening on top, ringed by tentacles) consolidated into a hard and fragile calcareous structure built by the organisms themselves: an exoskeleton (external skeleton) whose often bizarre but always functional shapes create the scenery of the reef. There are hermatypic corals that are able to build reefs slowly as the colonies expand and propagate themselves and ahermatypic corals, whose flexible framework does not tend itself to composite structures (like gorgonians, whose skeleton is composed primarily of a horny substance, and the so-called soft corals). Zooxanthellae are generally associated with the first kind; they are unicellular, symbiotic algae that live in the cells of coral polyps, averaging a million for every cubic centimeter of coral. Zooxanthellae furnish the polyps with caloric substances such as sugars and amino acids through photosynthesis (which explains the importance of ambient light). At the same time, they remove potentially harmful compounds like carbon dioxide, which could dissolve the colonies' limestone skeleton by converting to carbonic acid when it comes into contact with water. Coral polyps (easily pictured as tiny sea anemones) are not limited to using the zooxanthellae to procure nutrients. Indeed, they are endowed with extremely efficient weapons that allow them to paralyze and capture suspended microorganisms (plankton) that are carried on the current, especially at night.

The polyps' tentacles -- just like those of medusas (jellyfish) and anemones -- are thick with bulbous cells (called cnidoblasts) containing a thin hollow filament that is sharp and coiled like a spring (the nematocyst). The moment they contact prey, cnidoblasts open automatically and jab their nematocysts lightning fast into the victim's tissue, injecting a toxic compound. The tentacles of the polyp then carry the dead or paralyzed victim toward the oral cavity and ingest it. Up close at night, it is easy to observe the tiny distended polyps that stud the surface of a coral colony by the thousands, projecting their tentacles into the current and waiting for likely prey

Madreporic colonies assume profoundly different shapes depending upon the species that reside in them. In a typical coral reef it is fairly easy to find colonies that are laminate in structure (the classical tabular madrepores of the Acropora genus), fingerlike (with short and stubby branching characteristics, as in the Montipora genus), branching (Acropora again), massive (the giant rounded "loaves" of the Porites, Favites and Favia genera, among others), brain-shaped or labyrinthine (Diploria, Platyqira, Turbinaria) and even nonsessile (that is, detached from the substrate, as in the flat round colonies of the Fungia genus). In any case, every structure responds to precise conditions and often presents a serviceable refuge for a great number of different species such as fish, mollusks and crustaceans.

Not all coral reefs develop in the same fashion. Their shape and expanse vary according to wave action, the play of currents and their more or less rigid relationship with landforms. The basic structure is the so-called fringing reef, whose growth runs more or less parallel to the coast. In this form, the reef gives rise to an internal lagoon with a rubbly seabed separated from the open sea by a strip of coral whose summit lies at a very shallow depth and whose seaward wall (sometimes a soft drop-off interrupted by sandy terraces, sometimes a precipitous slope) hosts the highest number of species. Among the best known fringing reefs are the reefs characteristic of the Red Sea. So-called barrier reefs are an evolution of this structure and are typical of places where the continental shelf (or platform) moves away from land but continues to offer conditions that safeguard the development of madreporic colonies. The most famous examples of this type of reef -- looking like a more or less oblong platform, composed of parallel structures -- are found in Australia's Great Barrier Reef, in Papua New Guinea and in much of the Caribbean. Coral atolls embody the third model of reef development. Here, the progressive disappearance of a volcanic island leaves intact the fringing reef that surrounded it in remote times, generating an internal lagoon encircled by a more or less regular ring of coral. This structural type is generally found in open seas, and especially well-known examples are found in the Maldives Islands and Polynesian atolls. The extreme fragility of the reef's ecosystem is another important phenomenon that emerges from this short description.

Natural variations in water temperature, its transparency (the presence of sediments near estuaries), and its salinity (the huge intromission of fresh water near estuaries or following torrential rains) can limit or even interrupt its development. Irreparable damage is linked to human activities such as intensive fishing (shark, reef fish, seahorses and sea cucumbers for the food market and Chinese pharmacopeia, lobsters for the tourist industry), excessive coral removal (for industrial uses), the injection of polluting substances (related to mining operations, transport of toxic substances, cyanide fishing for the aquarium market, liquid sewage disposal from population centers), and fishing with explosives (practiced throughout southeast Asia). Unfortunately, all of this is happening in many of the places visited over the years by the authors of this book. Though many governments have officially assumed the protection and conservation of the reef environment, the damage is ever more evident and occasionally irreparable. Voices are being raised all over the world to protect this extraordinarily beautiful and important ecosystem before it's too late.

About this edition

• Publisher: Firefly Books
• Publication date: 2002
• ISBN 10: 1552096254
• ISBN 13: 9781552096253
• Binding: Paperback
• Number of pages: 288