Appendix 12. Posidonia Survey Report. Page 173 of 173. Rev.:00 / at07

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1 Page 173 of 173 E.ON New Build & Technology GmbH ERM S.p.A. ESIA Italy Annex 7 Baseline Data and Maps Rev.:00 / at07 Appendix 12 Posidonia Survey Report

2 Page 2 of 14 1 Preliminary statement On Wednesday 24th and Thursday 25th July 2013, the Cooperative Pelagosphera, on behalf of ERM Italy, conducted a diver survey in the waters close to the town of San Foca (LE). The aim of the survey was to investigate the presence of the seagrass Posidonia oceanica and to describe the conditions of Posidonia meadows. As part of the survey, the inspected area corresponds to a rectangular polygon of about 7000 m 2 (50 x 140 m) in South-West/North-East direction. The two subareas at the ends of the center line of this polygon had to be described in as much detail as possible. 2 Fieldwork plan As the target area is located more than 800 m from the coastline, the monitoring survey needed the support of a dive boat. For this activity, the Cooperative Pelagosphera selected the 7.5 m rubber dinghy Alturas, property of the association South East Diving based in Otranto and transported to the San Foca harbour for the period necessary to perform the survey. The aforementioned boat fully satisfied the safety requirements for all diving activities including, but not limited to, safety tank equipped with regulator for possible stop at 5 m water depth, oxygen tank and first-aid kit, in addition to the standard safety on-board equipment (life jackets, parachute flare, hand flares). Before every trip, the Cooperative ed the Coast Guard (district of Otranto) to formalize starting time and anticipated return time. The planning of the activities and applied methodology were agreed on Wednesday 24th July, after briefing and checking out of maps and detailed data provided by ERM Italy.

3 Page 3 of 14 3 Methodology The methodology adopted for monitoring the San Foca seabed follows the "Manual of methods for sampling and study of Mediterranean marine benthos" (Gambi - Dappiano Editori), prepared under the supervision of S.I.B.M. (Italian Society of Marine Biology), of APAT (National Agency for the protection of the environment and for technical services) and of ICRAM (central institute for scientific research and technology applied to the sea). The monitoring was "non-destructive", since no living item was removed from the substrate or from the water column. In particular, the divers used two of the three underwater sampling methods applicable to benthic populations: visual census and video-camera recording. Visual census. This sampling technique applied to the biotic communities of seagrasses had the main aim of identifying composition, size and structure of marine meadows, as well as of providing information on the habitat features such as type and quality of the bottoms, seabed morphology, depth, turbidity and brightness of the water. A set of different descriptors were applied to characterize the conservational status of a marine meadow. They can be divided into three main groups (i.e. physical, physiographical, and structural): - physical descriptors define the characteristics of the environment where seagrasses occur, such as the seabed geomorphology, bathymetric range and sedimentology; - physiographical descriptors designate the meadow type and its boundaries, with particular reference to the lower limit; -the most important structural descriptors are the density and the covering. The density indicates the number of leaf shoots per surface area unit (1 m 2 by convention); the covering is given as a percentage of the bottom covered by plants. The following visual sampling techniques were used: - survey on a defined path (transect). The census was performed on a lead line stretched on the bottom and perpendicular to the coastline (depth transect). Data were recorded on a diving slate. - survey on a fixed area (squared plot). The standard area used for assessing the density of seagrasses in situ is a square of 40 x 40 cm. Within this area all leaf shoots present on two or more randomized points were counted; conventionally counting is performed by each diver and then averaged in order to overcome operator related error. Video-camera recording. Beyond the documentation purpose, the underwater photography has often been used to assess the spatial distribution of benthic populations. This technique is nowadays promoted and facilitated thanks to the availability of versatile and compact size equipment. The GoPro camera, for instance, allows to shoot long lasting HD video. All transects were video-recorded and observed once ashore to provide further details to the in situ observations.

4 Page 4 of 14 4 Results In order to provide a detailed maps, as accurate as possible, appropriate marker buoys were placed on the sea surface, according to GPS coordinates, immediately above of the study area to facilitate the work underwater just before the diver survey. Moreover in order to bring to the surface each biocenotic discontinuity found on the sea bottom during the underwater visual survey, the divers used some small marker buoys launched from the bottom, whose coordinates were recorded by the on boat support crew by mean of GPS. Following a GPS track, the boat led the biologists to points delimiting the survey area. The two ends of the centre line, the one nearest the coast (identified by the code 938) and the northern boundary of the study area, were marked by coloured buoys. Those two points were made visible through the use of a lead rope ending with a float, that was unrolled from the rubber dinghy (next Figures ). It has to be noted that no markers or others devices were left on the sea bottom or in the sea water after the survey, thus all the buoys and ropes were removed by divers crew once the offshore activities were closed. Figure 4-1 Positioning of a marker buoy. Coloured floats temporarily positioned on the surface of the sea

5 Page 5 of 14 Each point was then checked with a GPS to verify that neither the movement of the boat nor the strong superficial current of the area would have moved the buoy. To conclude the fieldwork preliminary phase another lead rope was lowered from the boat between the two coloured buoys. Then divers descended vertically under one of the surface marker buoy and, by stretching the rope on the seabed, they were able to get the opposite surface marker buoy staying exactly on the centre line. Around the two ends, a sub-circular area of 12.5 m radius has also been investigated (Figure 4-2). Biologists worked together to simplify the methodology: an operator was holding a tape measure (Fiberglass) staying at the base of the surface marker buoy, a second diver made a circular path after having stretched a 12.5 m rope (as the radius). The third operator, above the others, simultaneously collected data on the biocenosis, wrote down notes on the diving slate and took pictures and video of the whole process. Figure 4-2 The biologist stretches the measuring tape to measure the buffer

6 Page 6 of 14 The surface marker buoy at the Northeast point was placed at m water depth on a bottom ascribed to the DC biocenosis (coastal detritus sensu Pérès and Picard, 1964 Figure 4-3). It is a soft bottom (incoherent) un-colonised by seagrasses and made of mud, sand and high-particlesize grit, interspersed with carbonate remains of dead organisms (mollusc shells, skeletons of cnidarians and bryozoans, polychaete tubes, exoskeletons of crustaceans, and dermaskeletons of echinoderms). It is worth noticing that on this substrate, we recorded the presence of the invasive green algae Caulerpa racemosa (lessepsian alien species), which has not been reported yet in the checklist of the flora and fauna of the Mediterranean, issued by the Italian Society of Marine Biology, for that portion of the Adriatic Sea. Figure 4-3 The Coastal Dertitus biocenosis (DC). The remains of invertebrate animals are clearly visible on the bottom right of the picture The biocenosis DC develops, proceeding along the center line, up to more than half of the study area and is then replaced by the SFBC biocenosis (fine sands well calibrated) on which we observed the presence of the Atlantic boreotropical seagrass Cymodocea nodosa. Along the centre line, Cymodocea showed the limit, sometimes progressive (Figure 4-4), of its meadow with a very low density at the bathymetry of 23.7 m water depth, while the transition zone (Figure 4-5) between the lower band and a denser meadow was located at 21.3 m water depth.

7 Page 7 of 14 Figure 4-4 Lower progressive limit of Cymodocea nodosa meadow Figure 4-5 Transition zone between the lower band and a denser meadow

8 Page 8 of 14 Both of these limits were marked by small stakes connected with small floats launched on the surface, but set on purpose at a few metres deep (Figure 4-6). In such a way points were visible from the boat and thus easily traceable from the surface. Floats were removed as soon as the position was recorded from the boat. Figure 4-6 The small floats are positioned a few meters deep The meadow coverage increased approaching the coast line towards the opposite surface marker buoy on the centre line (938), located at 19.4 m water depth. The survey of a 12.5 m radius area was also performed around this point and showed a good seabed coverage by Cymodocea (Figure 4-8) alternating with Caulerpa racemosa algae (Figure 4-9, left) and with the congeneric Caulerpa prolifera, a Circumtropical but autochthon green algae species (Figure 4-9, right).

9 Page 9 of 14 Figure 4-7 Usage the tape measure to monitoring the buffer at the southern end of the center line. Cymodocea nodosa meadow near the surface marker buoy 938 Figure 4-8 Lessepsian green algae Caulerpa racemosa among Cymodocea meadow. Autochthon green algae Caulerpa prolifera among Cymodocea meadow. About 2 metres South and 2 metres North of the surface marker buoy, density counts were made on square plots (Figure 4-10). The average density recorded was ± 3.2 (South) and ± 4.5 (North) leaf shoots/m 2, respectively.

10 Page 10 of 14 Figure 4-9 The square technique to the counting of shoots density of C. nodosa The meadow was also investigated by ideally extending the centre line towards the coast until the water depth of 17.5 m; here coverage and density are significantly higher than in other surveyed areas (Figure 4-11).

11 Page 11 of 14 Figure 4-10 High density and covering in the portion of the meadow nearest to coast. On the second working day a monitoring of the whole 7000 m 2 buffer was carried out. Due to the scarce visibility on the bottom (high turbidity by fine suspended sediment), especially in the deeper portions of the area, it was decided to operate simultaneously on three parallel transects starting from the signal of the Cymodocea meadow lower limits towards Northwest at first and then to Southeast direction. The diver along the centre line had the task of controlling the two colleagues while performing the survey on the Southern and Northern parts of the buffer. In this way the entire substrate surface was verified by double-checked observations; first from the coast to the open sea (55 ) over the surface marker buoy delimiting the buffer (water depth max about -30 m) and then back to the starting point (235 ). The observations revealed similar results as data collected along the center line, on the previous day: an extensive biocenosis DC with the absence of seagrass. Noteworthy is the sporadic presence of Posidonia oceanica leaf shoots on the bottom (Figure 4-11 left), which supposedly arrived from the surroundings of the investigated areas, likely carried by anchors of boats. Small portions of low matte with remains of Posidonia were also identified (Figure 4-11 right); partially emerged roots and scarce, low rhizomes suggest a residual Posidonia meadow died in the last few years.

12 Page 12 of 14 Figure 4-11 Dead leaf shoot of Posidonia oceanica on the bottom. Small portions of low matte with remains (roots and rhizomes) of Posidonia By means of the above described methods also the area colonized by Cymodocea nodosa was investigated, from its lower limit up to the 938 surface marker buoy, along the route 235. In this phase of the work the meadow profile was designed by indicating the depth of both its limits, along the 50 m width of the area. The existence and extent of seabed portions the devoid of Cymodocea nodosa were also recorded. Figure 4-12 A portion of the sediment devoid of seagrass in the middle of meadow.

13 Page 13 of 14 Gathering all the information obtained by underwater mapping, GPS data relating to the two surface marker buoy and bathymetries, it was possible to get a biocenotic map of the whole buffer, which is comprehensive of all the data collected (Figure 4-13). Figure 4-13 Biocenotic map At the end of the work, superficial and divers surface marker buoys, stakes, weights and the whole rope marking the centre line were taken on board. No damage was caused to the biocenosis on the bottom and no tools were abandoned in situ.

14 Page 14 of 14 5 Concluding remarks Compared to the data provided by ERM and to the biocenotic maps developed on the basis of bibliographic data and of tracked ROV made in the vicinity of the buffer, the complete absence of Posidonia oceanica throughout all the surveyed area has been confirmed. Bundles with leaves were only sporadically found, which were probably removed from the surrounding Posidonia meadows. The existence of Posidonia along the coast of San Foca is undeniable, as evidenced by the presence of banquette on the coast line and debris matte in some portions of the bottom around -20, -22 m depth. The plant would likely be present on the substrate at shallower water depths than those investigated, while much of the seabed from 15 metres towards the open sea is now colonized by Cymodocea. Due to its extensive adaptability, this species tends to quickly colonise the areas abandoned by P. oceanica. It is therefore a portion of coast with evidences of ecosystem regression, in part indicated by the presence of Caulerpales, which are generally pioneer chlorophytes (also inhabiting substrates previously colonized by P. oceanica), and partly proved by the presence of C. nodosa, which, based on commonly recognized ecological succession models, temporally and spatially precedes the appearance of Posidonia. Unlike the latter, Cymodocea nodosa is not listed in the Annexes I or IV of the Habitats Directive and is not included among vulnerable species of the IUCN red list. Nevertheless, it should be noted the importance of any marine seagrass meadow as fundamental producer of oxygen, nursery for marine animal species, and substrate for algae and epifauna.