Preprint volume - SIBM

Pre-print Volume – Posters
Topic 3: INTEGRATED COASTAL ZONE MANAGEMENT
A. PETROCELLI, E. CECERE
Istituto per l’Ambiente Marino Costiero (IAMC) – CNR, Via Roma, 3 – 74100 Taranto, Italia.
ester.cecere@iamc.cnr.it
BIODIVERSITY AND MOLLUSC TRANSFER: NEED OF OBSERVANCE
OF THE LAWS TO AVOID ALIEN SEAWEEDS INTRODUCTION
MACROALGHE ALLOCTONE E IMPORTAZIONE DI MOLLUSCHI
Abstract – The seaweeds Undaria pinnatifida, Codium fragile, Grateloupia turuturu and Ascophyllum
nodosum were accidentally introduced into the Taranto seas probably by means of pacific oysters both as a
packing material and as microscopic life stages settled on mollusc valves. Therefore, the need is
highlighted of making mussel farmers and fishmongers aware of risks coming from alien species
introduction and of severe control measures.
Key-words: alien species, Crassostrea gigas, introduced species, Ionian Sea, Mediterranean Sea.
Introduction – Taranto seas are particularly subject to the introduction of alien species
(Gravili et al., 2010). Despite the numerous laws issued by the European Commission
to regulate the transfer of molluscs (e.g. 2003/804 and 2007/158) and, in particular, of
exotic species for aquaculture purposes (2008/535), in Taranto the number of
introduced species is more and more increasing due to the lack of both sense of
responsibility and controls. In the present paper we deal with four introduced seaweeds
and their more probable vector.
Materials and methods – The Mar Piccolo of Taranto is an enclosed where many
mussel farms are present. Monthly surveys, also by SCUBA diving, were carried out
since 1998 in this basin, along the dock of the old town which houses many fish-shops
and mollusc import-export firms, to early detect possible alien seaweeds. Specimens of
the suspicious species were brought to the lab for taxonomic identification. Inquiries
were performed among mussel farmers and fishmongers to know their possible vector.
Results – First finding of each species follows: in 1998 Undaria pinnatifida (Harvey)
Suringar (Ochrophyta, Laminariales) (Fig. 1a), in 2001 Codium fragile (Suringar)
Hariot (Chlorophyta, Bryopsidales) (Fig. 1b) and in 2007 Grateloupia turuturu
Yamada (Rhodophyta, Halimeniales) (Fig. 1c) specimens were found settled on the
dock (Cecere and Petrocelli, 2009). In 2009, floating thallus fragments of Ascophyllum
nodosum (Linnaeus) Le Jolis (Ochrophyta, Fucales) (Fig. 1d) were observed, by
chance, outside the Mar Piccolo basin, near a mussel culture farm (Cecere, personal
communication).
Conclusions – U. pinnatifida, C. fragile and G. turuturu are native from Japan and are
present along the Atlantic French coasts where they were probably introduced by
Crassostrea gigas Thunberg specimens to be reared. A. nodosum is native from
northern Atlantic. Great quantities of oysters are usually imported to Taranto from
northern France. Since it was already demonstrated that oyster transfer is one of the
main vector for unintentional macroalgal introductions (Hewitt et al., 2007), we
hypothesized that C. fragile was probably introduced as microscopic life stages settled
on oyster valves; A. nodosum as a packing material to keep oysters fresh and the other
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