3 research outputs found
Meiobenthic biodiversity in areas of the Gulf of Taranto (Italy) exposed to high environmental impact
No full textBiological and chemical parameters (meiofauna density and diversity, redox profiles) were investigated in relation
to the environmental conditions of sediments in the Gulf of Taranto. Sediment cores were collected from 42
stations from 5 to 20m depth, in 1995, 2000 and 2001. Meiofauna abundance and diversity were significantly
lower in the Mar Piccolo, the area most heavily polluted by organic loads; in Mar Grande and Chiatona areas
the same parameters showed slightly higher values. Eh profiles revealed anoxic conditions in coastal sediments
impacted by industrial and sewage discharges. Meiofauna density ranged from 186 to 1370 individuals 10 cm 2.
Generally, over 80% of total meiofauna was composed of nematodes; the contribution of other taxa is much less
important. The widespread presence of the lessepsian Chlorophyte Caulerpa racemosa since 1996, seemed to
enhance the abundance of meiofauna, and increased microhabitat complexity, but reduced diversity of some taxa,
such as the meiobenthic crustaceans. Comparing 2001–2002 data with 1995 (before C. racemosa invasion), the
recent decrease of some groups (ostracods, amphipods, isopods, tanaids and cumaceans) was markedly evident. In
conclusion, our findings confirm the chronically degraded environmental conditions in the Gulf of Taranto, and
draw attention to the further contribution of C. racemosa invasion
Meiofauna and nematode diversity in some Mediterranean subtidal areas of the Adriatic and Ionian Sea
No full textSediments of three different subtidal areas (15-705 m depth) of the Italian coasts (Manfredonia, Brindisi and Gallipoli) were investigated to study meiofauna and nematode composition. The nematodes were identified to the genus level and their abundances compared using multivariate analysis. Our data showed an evident depth gradient in meiofauna abundance: the shallowest sites had more diverse and abundant meiobenthic communities than the deeper ones. Nematodes were the dominant taxon (83-100%) at all sites, followed by Copepoda (0.5-8%). Sabatieria, Astomonema, Dorylaimopsis, Terschellingia and Daptonema were among the dominant nematode genera in the three areas. Nematode genus H’ diversities were not significantly dissimilar, though at community level some differences were detected among the study areas. The greatest differences were observed in the comparison of the communities from Manfredonia and Gallipoli. Furthermore, there was a difference between shallow (Astomonema, Dorylaimopsis, Sabatieria and Terschellingia)
