TEMPORAL VARIABILITY AND SPATIAL DIVERSITY OF SMALL
PELAGIC FISH BIOMASS IN THE NORTHERN ADRIATIC SEA
M. Azzalia, A. De Felicea, I. Leonoria and M. Lunaa
a
Istituto di Scienze Marine (ISMAR-CNR), Largo Fiera della Pesca, 60125 Ancona,
Italy
ABSTRACT
Small pelagic fish aggregate, forming distributions of abundance on a wide variety of
space and time scale. This phenomenon is of great ecological and biological
importance and has relevant effects on fishery. The major difficulty for understanding
fish variability is the lack of sufficient data on biomass variability over both temporal
and spatial scales expecially over long periods. In the Adriatic Sea distributions of
abundance of small pelagic fish were acoustically estimated for more than two
decades on a time scale of one year and on spatial scale from aggregations (tenths of
metres) to the whole North Adriatic Sea (hundreds of kilometres).
The aim of this paper is to provide a conceptual framework and mathematical tools for
study this variety, using acoustic data.
Keywords: Temporal variability, Spatial diversity, Small pelagic fish, North
Adriatic Sea, Acoustics