Page 1 - DeidunSchembri2006

Biol. Mar. Medit. (2006), 13 ( 1): 355-363

A. D EIDUN, P.J. S CHEMBRI

Department of Biology, University of Malta - Msida MSD 06, Malta.
patrick.j.schembri@um.edu.mt

COMPOSITION OF THE NOCTURNAL MOTILE FAUNA
FROM THE UPPER INFRALITTORAL FRINGE

OF SANDY BEACHES IN THE MALTESE ISLANDS:
ARE THERE ANY IMPLICATIONS FOR CONSERVATION?

COMPOSIZIONE DELLA FAUNA VAGILE NOTTURNA
DELLA FRANGIA INFRALITORALE DELLE SPIAGGE

SABBIOSE DELLE ISOLE MALTESJ:
POSSIBILI IMPLICAZIONI PER LA CONSERVAZIONE

Abstraet
Sarnples of nocturnal, shallow-water ( <I m ), moti/e fauna were collected using a 1 mm-mesh handnet

during each season between autumn of 2001 and summer of 2003 from four sandy beaches in the Ma/tese
lslands. Beaches on Lampedusa, Favignana and Pozzallo l·vere a/so sampled during one season only for
qualitative comparison with the Ma/tese beaches. Mysids and amphipods were the most abundant taxa,
1vhifst omnivores/scavengers were the most abundant feeding types. Beaches on the Ma/tese Jslands were
faunistically distinct .from each other, an observation that has important implications for conservation.

Key-words: moti/e fauna, infralittoral ji-inge, Malta.

Introduction
The major exchanges of organic materials and nutrients between sandy beaches

and the sea take piace in the surf zone (Brown & McLachlan, 1990), defined as
that part of the beach extending from the waterline to the most seaward point at
which waves approaching the coastline commence breaking (Barros et al., 2002).
The surf zone is described as lying in the uppermost infralittoral in the coastal
biocoenoses classification scheme of Pérès (1967).

Surf zone biota form an important link in shallow water food chains, and con-
sumers feedin on these assemblages include larvae of commercially exploited fish
(see reviews by Viherluoto, 2001 and Munilla & San Vicente, 2005). Despite their
ecological importance, surf zones bave received little scientific attention, possibly
due to the difficulties associated with working in these high-energy environments
(Munilla & San Vicente, 2005).

Deidun et al. (2003) made night-time collections in the surf zone of five Mal-
tese beaches during one season (summer 2000) and recorded only 92 individuals
belonging to 12 different species, with abundances ranging from 0.6 to 21 indi-
viduals/m2, suggesting a very impoverished biota both in terms of species richness
and abundance. Other studies on Maltese beaches (Deidun & Schembri, 2004;
Borg et al., 2003; Gauci et al., 2005) bave hinted at 'compartmentalisation' of
beach fauna, where distinct upper shore fauna! assemblages were identified on
different beaches, despite geographical proximity.

The present study aimed to characterise the surf zone assemblages of a number
of Maltese beaches, to study seasonal and inter-annual variability in these assem-
blages, and to discover if the compartmentalisation demonstrated for upper shore