Research Article Mediterranean Marine Science Indexed in WoS (Web of Science, ISI Thomson) and SCOPUS The journal is available on line at http://www.medit-mar-sc.net DOI: http://dx.doi.org/10.12681/mms.1426 Spatial and temporal distributions of the sponge fauna in southern Italian lagoon systems C. LONGO, F. CARDONE, M. MERCURIO, C. NONNIS MARZANO, C. PIERRI and G. CORRIERO Department of Biology, University of Bari “Aldo Moro”, Via Orabona, 4 - 70125 BARI, Italy Corresponding author: [email protected] Handling Editor: Argyro Zenetos Received: 16 June 2015; Accepted: 3 November 2015; Published on line: 23 February 2016 Abstract The present work focused on the taxonomic composition, spatial distributions, and temporal distributions of the sponge fauna from the main lagoon systems of southern Italy: Lesina, Varano, Taranto, Alimini, Faro, Ganzirri, Tindari and Marsala. Overall, 62 sponge species were recorded, belonging to the classes Demospongiae (52 species), Calcarea (8) and Homoscleromorpha (2). All the lagoon systems studied hosted sponges, even if with marked differences. Species richness varied from one (Lesina) to 45 (Marsala). A large number of the species recorded during this study (52%) was found only at a single site, whereas a species only (Halichondria (H.) panicea) was present in all the environments studied. Sponges colonised all available substrates. Salinity was the ecological factor that best explained the spatial distribution of sponges, even though the wide heterogeneity of sponge as- semblages, strongly suggests an important role of stochastic factors acting on pre- and post-settlement phases. Comparison of the present data with lists available from the literature shows that sponge assemblages from most of the studied lagoons were quite persistent. However, in some of the lagoons remarkable extinction processes, probably related to massive and prolonged anthro- pogenic pressures, have contributed to large changes in the sponge patterns. Keywords: Porifera, Mediterranean lagoons, taxonomy pattern, spatial distribution, temporal distribution. Introduction or through localised infections by pathogens or predator bites (Wulff, 1985). They may live loose on the sediment, Lagoons are high sedimentation environments, typi- partially or completely buried in it, thanks to some special cally poor in natural hard substrates, with a few excep- adaptations that mitigate the occlusion of aquiferous system tions (e.g. mangrove roots, phanerogam rhizomes, mol- caused by sediment grains. Some species incorporate for- lusc shells, calcified bryozoan skeletons). However, in eign bodies that allow them to stabilize themselves on the the last centuries, human activities have led to the intro- mobile substrate (Cerrano et al., 2004), while others adopt duction of stone debris, ropes and material lost by farm- adaptive shape modifications to live in unattached condi- ers and by the artisanal fisheries, sometimes causing ma- tions, displaced over sediment or rolling on it (Mercurio et jor structural changes in lagoon environments (Cardone al., 2006). et al., 2014; Gristina et al., 2015). In highly trophic en- According to literature, the lagoon systems in the west- vironments, both natural and introduced hard substrates ern Mediterranean richest in sponges are the Mar Piccolo of are usually colonised by peculiar macrozoobenthic com- Taranto (north-western Apulia), with 45 species (Scalera et munities mainly dominated by filter-feeders, which often al., 1976; Pulitzer-Finali, 1983; Longo et al., 2004) and the form rich and stratified assemblages (Nonnis Marzanoet Marsala Lagoon (north-western Sicily), inhabited by 47 spe- al., 2007; Cardone et al., 2014; Gristina et al., 2015). cies (Corriero, 1989; 1990). Twenty-five species of sponges Porifera may be very abundant within lagoon hard were recorded by Topsent (1925) for the Etang de Thau benthic communities. Rützler et al. (2000) surveyed 95 (Gulf of Lion), 20 species, with high coverage of hard bot- species of sponges in a 3-hectar lagoon of Belize, point- toms, were reported for the lagoon of Venice (north-eastern ing out how in such environments sponges provide sub- Italy) (Sarà, 1960; Corriero et al., 2007), 18 and 17 for the strate, shelter, and defence for many other organisms and basins of Fusaro (north-western Campania) (Siribelli, 1963) positively affect habitat structure. Similarly, rich sponge and Faro (north-eastern Sicily) (Labate & Arena, 1964), re- assemblages are also associated with natural and artificial spectively. By contrast, the more confined coastal lakes dis- hard substrates in some western Mediterranean lagoons placed along the Italian coast usually host a lower number (Corriero, 1989; Corriero et al., 2007; Longo et al., 2004). of sponge species. In particular: four and three species are In lagoon environments, however, there are several respectively reported for Alimini (south-eastern Apulia) and sponge species able to also colonize soft sea bottoms. These Varano (north-eastern Apulia) coastal lakes, six and four for sponges usually originate by asexual fragmentation, the de- the lagoon systems of Ganzirri and Tindari (north-eastern tachment of individuals from hard substrates during storms, Sicily), and only one sponge species is reported for both the 174 Medit. Mar. Sci., 17/1, 2016, 174-189 lakes of Lesina (north-eastern Apulia) and Ugento (south- circle having the same surface of the lagoon. Openness is western Apulia) (Labate & Arena, 1964; Nonnis Marzano et the ratio (expressed in percentage) between the measure- al., 2003b; Cardone et al., 2014). No other relevant data re- ment of the surface area of the outlet and the perimeter; ferring to the occurrence of the sponge fauna in the western in a completely isolated ecosystem, the openness will be Mediterranean lagoons are noted from the literature. equal to 0%. Environmental data were collected from The aim of the present paper is to improve the knowl- published articles (see Nonnis Marzano et al., 2007; Bar- edge of Mediterranean lagoon sponge fauna by compar- bone & Basset, 2010; Giangrande et al., 2012; Basset et ing the sponge assemblages from the main lagoon sys- al., 2013; Caruso et al., 2013; Cardone et al., 2014). Bi- tems of the southern Italian coast. The research analyzes otic and abiotic data were organised into two matrices: a the pattern of sponge assemblages in light of the main presence/absence matrix with sponge data, and an abiotic ecological traits and evaluates the resilience of sponge data matrix with environmental parameters. assemblages in the studied environments. Taxonomic records gathered from field research were coupled with literature data in order to evaluate the trends of the taxonomic patterns through time. Articles Materials and Methods retrieved were further screened according to sampling Data collection, spatial and temporal scales of the design and taxonomic resolution (taxa classified down to datasets species level) of the present paper. Literature data refer to sampling performed in the years 2000 and 2007 for Lesi- Data refer to the following Italian lagoon systems na Lagoon (Nonnis Marzano et al., 2003a, b; Cardone et (Fig. 1): Lesina (LES), Varano (VAR), Taranto (TAR), al., 2014), 2007 for Varano and Alimini (Cardone et al., Alimini (ALI), Faro (FAR), Ganzirri (GAN), Tindari 2014); 1976-1983 and 2001-2004 for Taranto (Scalera (TIN) and Marsala (MAR). They included closed and Liaci et al., 1976; Pulitzer Finali et al., 1983; Longo et semi-enclosed wetlands, from saline to brackish waters. al., 2004), 1964 for Faro and Ganzirri (Labate & Arena, Sampling was performed from 2004 to 2012, and in par- 1964); 1984 for Tindari (Corriero, unpublished data); and ticular: in 2004 at Tindari; in 2006 at Faro and Ganzir- 1990 and 2001 for Marsala (Corriero, 1990; Mercurio et ri; in 2010 at Taranto and Marsala; in 2012 at Lesina, al., 2004). Taxonomic revision was carried out according Varano, and Alimini. At each site a different number of to World Porifera Database (part of the World Register stations was considered, depending upon the dimensions of Marine Species, http://www.marinespecies.org/), up- and morphology of the lagoon, and on habitat patchiness. dated with the revised classification of Demospongiae by In particular, two stations were considered at Faro and Morrow & Cárdenas (2015). Ganzirri, three at Alimini and Tindari, and four stations at the remaining sites (Lesina, Varano, Taranto, and Mar- Study areas sala) (Fig. 1). In each station (100 x 100 m in size) the presence of sponges was carefully detected by SCUBA Lesina divers, considering all the substrates present. Sponge The lagoon of Lesina (Foggia, Apulia) (Fig. 1A) is samples were collected for taxonomic identifications, an elongated coastal basin separated from the sea by a that were performed in the laboratory following standard sand bar and stretching for approximately 22 km west to procedures (see Corriero, 1990; Longo et al., 2004; Mer- the east, with a maximum width of 2.2 km. It communi- curio et al., 2004). cates with the sea by means of two artificial channels, the The list of the analysed environmental parameters western one longer and narrower than the eastern chan- (those available for all studied environments) is pre- nel. Usually, the water flow in both channels is limited on sented in Table 1. The parameters are: 1) surface area of the lagoon side by sluices and partially obstructed grilles the basin; 2) number of freshwater inlets; 3) number of once used for fishing purposes. Freshwater inflows are marine channels; 4) maximum depth; 5) minimum salin- due to small tributaries mainly located in the eastern sec- ity; 6) mean salinity; 7) maximum salinity; 8) salinity tor of the basin. The combination of sea water and fresh- stability; 9) sinuosity of the water body; 10) presence water inflows produces a salinity gradient with values de- of Posidonia oceanica meadows; 11) presence of other creasing from west to east (Nonnis Marzano et al., 2007). phanerogams (number of species); 12) presence of rocky substrates; 13) presence of artificial substrates; 14) open- Varano ness; 15) minimum water temperature; 16) mean water The lagoon of Varano (Foggia, Apulia) (Fig.