Contribution to the Planning of the Research in Artificial Reefs Programs

Abstract

The final aim of man made structures is to simulate some parts of the natural environment where the populations of different species have evolved and where they are living. These structures may be set down on the bottom of the sea, set at mid depth in the water mass, and even floating at the surface.

In terms of ecological protection and species consumed by mankind, is it possible to obtain better results than natural environments to obtain increased profits from natural production carried out in the euphotic zone?

Systematic assays have to be done to understand more clearly the effects of the factors affecting the attraction, the presence, and the growth of different species living inside and around these artificial habitats.

The research subjects are numerous and are different from one site to another. Among them, specific studies have to be developed on the effects of reef sizes on the presence of certain species not only inside the reefs, but in also in its wake, in the close sediments, above the reefs, and on the surrouning ecosystems.

Surface studies have to be developed as well, in terms of micro- and macro-rugosity, chemical nature (adhesive biological cements), optimal sizes of micro-holes, and habitats, for instance. Effects on successive bacterial populations have to be known as well.

Ecological studies are necessary concerning the water quality of the currents flowing through the artificial structures; the number and nutritional quality of particles transported inside the reefs, then consumed by filter-feeder species, various larvae of vertebrates and invertebrates, and the vagile fauna. Microphyto­benthos, endogenous fauna, and bioturbation need to be understood with some precision.

The production of eggs and larval forms of different species and their exportation in the surrounding ecosystems have to be evaluated.

Physical aspects of the presence of these artificial structures, modifications of local currents, induced turbulences, and modification of granulometry are also other subjects of researches; local hydrology controls organic production and biological oceanography: these elements have to be known with precision in each site.

Chronobiological and seasonal behavior of different species of fishes, crustaceans, and molluscs (larval, and adult forms) associated after some time into and around these artificial structures need to be described not only concerning their presence, but also their behavior, their stomach content, their physiology.

Nutrition studies may give various subjects of comparative experimental approaches in species living in nature and maintained in large aquariums.

Even if artificial reefs concept is known since a rather long time, numerous subjects of researches have to be developed to make them producing more than nature, and, in the same time, to protect natural environment.