Meiofaunal communities of Nisida and the environmental status of the Flegrean area

Nisida is a volcanic islet of the Flegrean Islands archipelago connected to the mainland by a stone bridge. It lies very close to Cape Posillipo, just north of Napoli. The islet has a circular shape, with a flooded crater forming the bay of Porto Paone. In the 1800s Nisida was the site of a Bourbon prison, then an Italian state penitentiary, and, now, a reformatory for juvenile offenders. Since then the access to the island has been limited and this results in a very preserved area, but in the 1900 Nisida was encroached upon by the unsightly steel industry in Bagnoli affecting the state of health of marine communities. Recently Meiofauna has acquired an important role as a indicator of the marine ecosystem. We performed a meiofauna survey in Porto Paone, sampling were made from June 2014 to December 2015 in 4 areas resulting by the division of the bay in 4 quadrants (North-South; West-East), in each area 4 samples to cover all kind of substrate present were collected. To have a comparable parameter of the anthropic effect on meiofauna communities we performed sampling also in the closest area of Bagnoli during the period from November to December 2015. The fauna extraction was performed according to Heip et al. (1985). In Porto Paone, throughout the whole study period we found a diversity resulting in the presence of 24 taxa. A seasonal fluctuation has been observed with a major diversity during fall with the presence of 20 taxa versus 14 taxa in summer. Comparing the same period (November/December 2015) of sampling in Porto Paone and in Bagnoli we found a significant differences in taxa presence resulting in respectively 20 and 8. Beside to give an overview of the meiofaunal communities in Porto Paone to fill the gap in the recent literature, this work represent a starting point to monitor the environmental recovering of the Flegrean marine area.