Sclerochronology service: age and composition revelation of calcified tissues
Sclerocronology is the study of physical and chemical variations in calcified structures of aquatic organisms to reconstruct their life history and the relationship with ecological, anthropic and environmental processes.
The development of a fish and the conditions in which this development has taken place leave its mark in a small structure located in the inner ear of the fish: the otolith. The otolith is constituted by different precipitations of calcium carbonate around an initial nucleus. Like the concentric rings of trees, it reveals information about age and also under what circumstances the organism developed, what were the environmental conditions, if there was any nutritional deficit or contaminating element. Other calcified structures are also studied, such as coral exoskeletons, mollusk shells, statoliths, scales, bones, operculars, vertebrae, calcareous skeletons and teeth, among others.
Currently, sclerochronology is projected as an interdisciplinary science with several applications: (i) paleoclimate reconstruction (study of climate throughout history), (ii) climate and environmental change, (iii) physical and biological studies, (iv) presence of contaminants and their effects, or (v) applications in studies of management and conservation of fishery resources, including studies of mortality, growth and fish reproduction rate.
A research group from the IMEDEA (CSIC-UIB) have analysed otoliths chemical composition of corvinas (Argyrosomus regius) captured by a fishing fleet in Alicant. In the area there are several corvinas hatcheries, and when they place the individuals in the sea cages, the fisheries capture more species because fishes escape. The otolith microchemical analysis goal is identify escape fishes by separating the chemical signals from when the individuals were in captivity and at natural environment. For this reason, transects of laser points have been made from the nucleus to the edge of the otolith to obtain data of the whole life of the fish.