Βenthic hydrozoan assemblages as potential indicators of environmental health in a Μediterranean Μarine protected area

Abstract

The comparative study of marine benthic hydrozoan assemblages can improve our understanding of environmental and ecological conditions in marine protected areas (MPAs) such as the large Mediterranean MPA of Datça-Bozburun, where important prospects for future intensive tourism development exist. The analysis of such assemblages may help managers detect changes in important parameters of ecosystem health within this MPA. In this study we compared the hydrozoan assemblages occurring on hard (rocky) and soft (Posidonia meadows) bottoms from stations belonging to three different conditions: i) small marinas (medium anthropogenic impact), ii) yacht stopovers (low impact), and iii) unspoiled sites (no impact) in the southern part of the Datça Peninsula during summer and winter 2015 and 2016. Significant differences in the structure, species composition and richness of benthic hydrozoans among the sampling sites were detected. In both seasons, hydroid assemblages in medium-impact sites significantly differed from little-impact and no-impact sites in terms of qualitative composition. Large structural species were widely represented in all hard-bottomed sampling sites, but small inconspicuous taxa with diverse life histories were much less abundant at the medium impacted sites. Species richness and diversity in Posidonia meadows was much higher in little- and no-impact sites, where highly specific hydroid epibionts were abundant.

The First Record of Geryonia proboscidalis (Forskål, 1775), (Cnidaria: Hydrozoa) on the Coasts of Gökçeada, the Aegean Sea, Turkey

“…Consequently, the aggregation of G. proboscidalis observed in the different coastal areas of Gökçeada was an apparent bloom and was concentrated at one coastal location due to strong winds/ currents, transporting them to the coast. The number of new records of Hydrozoa species in the Aegean Sea coast of Turkey has increased in recent years (Gülşahin et al, 2013;Isinibilir, Martell, Topçu, Yilmaz, & Piraino, 2015;Yilmaz, Martell, Topcu, & Isinibilir, 2020). The hydrozoa species diversity in Gökçeada was found to include 48 species (Isinibilir et al, 2015).…”

Odd family reunion: DNA barcoding reveals unexpected relationship between three hydrozoan species

“…Lafoeina tenuis is a widespread taxon with confirmed records from the northeastern and northwestern Atlantic Ocean ( Sars, 1874 ; Calder, 2003 ; Vervoort, 2006 ; Moura, 2015 ), as well as the Arctic Ocean ( Ronowicz, Kukliński & Mapstone, 2015 ); but the species has not been reliably observed in subantarctic waters, where H. ocellata occurs ( Kramp, 1961 ; Genzano, Mianzan & Bouillon, 2008 ), or in the northwestern Pacific Ocean, where M. polydiademata occurs ( Arai & Brinkmann-Voss, 1980 ; Larson, 1987 ; Mills, 1993 ). Conversely, L. tenuis is present in tropical and subtropical waters of the Gulf of Mexico and southern Atlantic ( Bouzon, Brandini & Rocha, 2012 ; Mendoza-Becerril, Simões & Genzano, 2018 ), as well as in the Mediterranean Sea—the latter in the form of the synonymized name Lafoeina vilaevelebiti Hadzi, 1917 —( Isinibilir et al, 2015 ; Topcu et al, 2018 ; Yilmaz et al, 2020 ), where no confirmed records of the two hydromedusan species exist. Disentangling the complicated taxonomic history of L. tenuis and testing the potential for cryptic diversity in H. ocellata and M. polydiademata requires a thorough taxonomic revision, an aim that is outside the scope of the present contribution.…”

Epiphytic hydroids on Posidonia oceanica seagrass meadows are winner organisms under future ocean acidification conditions: evidence from a CO2 vent system (Ischia Island, Italy)

“…This association is promoted by certain peculiarity of hydroids, as rapid growth and asexual reproduction by stolonization . In previous studies, the potential use of benthic hydrozoans as indicators of environmental conditions is investigated (Mergner 1977(Mergner , 1987Gili & Hughes 1995;Megina et al 2013Megina et al , 2016Gravili et al 2017;Yilmaz et al 2020). They often form characteristic assemblages in different marine habitats presenting a set of life-history traits (sessile colonies, key-actors role in marine food webs, rapid population responses to stress and disturbances) (Boero 1984;Gili & Hughes 1995) that make them suitable candidates for environmental monitoring.…”

“…They often form characteristic assemblages in different marine habitats presenting a set of life-history traits (sessile colonies, key-actors role in marine food webs, rapid population responses to stress and disturbances) (Boero 1984;Gili & Hughes 1995) that make them suitable candidates for environmental monitoring. Morphological changes suffered by colonies of some species may be indicative of several disturbance factors, such as increased concentrations of heavy metals (Karbe 1972;Theede et al 1979), particular hydrodynamic conditions (Riedl 1966;Mergner 1972Mergner , 1977Mergner , 1987Wedler 1975;Da Silveira & Migotto 1991), climate change effects (Puce et al 2009;Gonzalez-Duarte et al 2014;Gravili et al 2017;Rossi et al 2019), and anthropogenic impact (Megina et al 2013(Megina et al , 2016Topçu et al 2018;Yilmaz et al 2020).…”