Effects of environmental changes on early stages and reproduction of anchovy in the Adriatic Sea
Slobodan Regner

This paper is a review of the knowledge on the anchovy planktonic stages in Adriatic sea. The area of reproduction of this species is very wide in the Adriatic since the anchovy will spawn anywhere down to the depth of 200 m. However the main spawning area is in the eutrophic waters of the western part of the shallow northern Adriatic and along the Italian coast to the peninsula of Gargano. Anchovy spawn in the Adriatic generally from April to October, in the temperature and salinity ranges of 11.6 - 27.6°C and 9.1 - 39.6 ppt, respectively. Developmental times of Adriatic anchovy eggs and larvae, as well as the growth curves of larvae and postlarvae, were estimated under experimental conditions. The growth curves of postlarvae were also estimated from otolith readings. Biomass assessments of Adriatic anchovy by means of egg production method was made possible by the known temperature-development relationships, as well as the knowledge of the residence times of particular developmental stages. Spawning biomass was estimated in the northern and middle Adriatic during the period from 1976 to 1990. Detailed investigations of long-term fluctuations of anchovy egg production, quantity of larvae and postlarvae, as well as of instantaneous mortality rates of postlarvae, were performed in the middle Adriatic for the period from 1962 to 1976. Fluctuations of egg production and larval abundance were found positively correlated with fluctuations of temperature, salinity, primary production and zooplankton quantity, with a lag of one year. As eutrophication particularly affected the shallow northern Adriatic and the zone along the Italian coast as far as the peninsula of Gargano, it seems that this phenomenon negatively affected the reproduction of the anchovy in its main spawning areas.

Keywords: Anchovy, Engraulis encrasicolus, eggs and larvae, reproduction, Adriatic.
Contents of this volume Sci. Mar. 60(Suppl.2) : 167-177 Back PDF
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