Short Communication |
Corresponding author: Maurizio Pinna ( maurizio.pinna@unisalento.it ) Academic editor: Isabel Sousa-Pinto
© 2018 Vanessa Marrocco, Alessandro Sicuro, Francesco Zangaro, Maurizio Pinna.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Marrocco V, Sicuro A, Zangaro F, Pinna M (2018) First record of the protected species Pinna nobilis (Linnaeus, 1758) in the Aquatina Lagoon (NATURA 2000 site IT9150003, South-East Italian coastline). Nature Conservation 28: 51-59. https://doi.org/10.3897/natureconservation.28.26112
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Information on the presence of Pinna nobilis (Linnaeus, 1758) in the Mediterranean Sea is largely reported in literature because it is an endemic and, at the same time, endangered species. Besides, this record contributes to enlarge the spatial distribution of this species in the South-East Italian coastline (Adriatic Sea). P. nobilis is a protected species under the EU Habitats Directive (1992). In particular, P. nobilis has been recorded for the first time in the Aquatina Lagoon, a transitional water ecosystem included in the NATURA 2000 site “Aquatina di Frigole” (IT9150003). Therefore, this finding underlines the role of transitional water ecosystems as “nursery habitats” for P. nobilis as well as the relevance of conservation actions introduced by the EU with the NATURA 2000 network for preserving the biodiversity.
pen shell, Pinna nobilis , transitional water ecosystems, NATURA 2000 network
The key species Pinna nobilis Linnaeus, 1758, also called pen/fan shell, is an endemic species identified in the Mediterranean Sea since the Miocene Era (
Despite its ecological relevance, the conservation actions and the current interest as a target species in the MSFD, P. nobilis is highly vulnerable to illegal exploitation and it is threatened by abiotic and biotic sources of perturbations (e.g. climate change, parasites). For all the above reasons, a more detailed description of the occurrence of P. nobilis in the Mediterranean Ecoregion is required to preserve this species.
Here, we describe the first record of P. nobilis in a transitional water ecosystem located in Italy along the coastline of the South Adriatic Sea (Aquatina Lagoon) and included in a NATURA 2000 site. In this lagoon, the presence of P. nobilis has never been previously recorded. This finding suggests that Mediterranean coastal lagoons could be considered as “nursery ecosystems” for the recruitment of the species as well as for other marine species and underlines the effectiveness of the NATAURA 2000 network for preserving the biodiversity.
The high relevance of this first record is due to the fact that the species P. nobilis has been recognised in a transitional water ecosystem, Aquatina Lagoon (40.442463°N, 18.237675°E; Fig.
Location and map of Aquatina Lagoon (South-East Italian coastline). The lagoon is included in the NATURA 2000 site “Aquatina di Frigole” - IT9150003.
At the beginning of January 2018 and during an exceptional low tide, we observed some specimens of P. nobilis had partially emerged. After this finding, we conducted in the area close to the lagoon mouth an underwater visual census (Fig.
A specimen of Pinna nobilis in the Aquatina Lagoon (NATURA 2000 site “Aquatina di Frigole” IT9150003).
The study of population structure of P. nobilis shows an instantaneous image and provides a quantitative approximation of the stock of the population. The possibility and benefits of carrying out an explorative sampling should always be the first aspect to be considered when a field survey to study P. nobilis populations is going to be undertaken. This is the cheapest and fastest option, but also that in which the least information is compiled. Data gathered is qualitative or the counts of individuals are inaccurate and not referred to a surface area and few statistics -if any- are required to analyse the results. The specimens found were measured according to the protocol proposed by
Measurements of interest to estimate the orientation and body-size of Pinna nobilis. In situ can be measured: W and w, maximum and minimum width respectively; UL, unburied length and Or, orientation of the gape. Maximum shell length (Ht) and length of the buried part (h) can be measured by removing the specimens from the bottom. Besides, Ht can be estimated by applying specific mathematical models (Garcia-March and Vicente 2006).
Eleven specimens of P. nobilis were recorded; they were orientated in the North-East direction, ranging from 5° to 80° NNE. Maximum and minimum widths were 15.16 cm ± 0.726 and 13.81 cm ± 0.611, respectively and the unburied length was 16.66 cm ± 0.441. The abiotic parameters of water column were also recorded (temperature 12.69°C ± 0.207, dissolved oxygen 7.21 mg*l-1 ± 0.278, salinity 24.77 PSU ± 0.963, pH 7.73 ± 0.084).
Probably the presence of P. nobilis in the Aquatina Lagoon is relatively recent because the species was not recorded in the last update of NATURA 2000 Standard Data Forms (2015). This finding can be justified by the availability of food which seems to be a driving force in determining the patchy distribution of P. nobilis populations. In marine habitats, the fan mussel seems to favour meadows of the marine seagrass with P. oceanica and C. nodosa (
In the Aquatina Lagoon, the relative position of the specimens in relation to the meadows was not studied because only dead leaves of P. oceanica were present in the lagoon bottom. Besides, the presence of P. nobilis in the proximity of the lagoon mouth could be justified by a constant hydro-dynamism and water exchanges with the sea and the recruitment of juveniles from the sea. Since P. nobilis is actually exposed to many abiotic and biotic sources of perturbations that are dramatically depleting the populations in the Mediterranean Sea (
This research was supported by ex-60% fund (FUR, Italian MIUR), by FFABR (Italian MIUR) and by ImPrEco project (Interreg ADRION Programme 2014-2020) attributed to M. Pinna. The authors are grateful to Inter-Asia project (CUP F82I17000000008) for supporting N. Bizhanova and G. Utebayeva during sampling activity.