Sessile epibenthic communities at the oil pockets of Zenobia’s Car deck station, 25m depth.

<p>A) Oil and an epibenthic community dominated by the coral <i>Madracis pharensis</i>; arrows indicate direction of the spillage. B) A temporal oil “pond” large enough to surround <i>M</i>. <i>pharensis</i> colonies and other species creating temporal “islands” of live organisms. C) A more enduring pond with coral communities in the vicinities. D) Oil droplets reaching a community of corals (<i>Caryophyllia</i> spp.) and associated organisms. The droplets are produced by collision with the ponds of air bubbles from divers.</p

Main characteristics of the Zenobia and Alice-B shipwrecks.

<p>Main characteristics of the Zenobia and Alice-B shipwrecks.</p

Coral species found at the shipwrecks.

<p>A) Percent contribution (mean + SD) of coral species to total live coral cover at the Zenobia (by sampling station and pooled together) and Alice-B shipwrecks; N = number of photo-frames were corals were present. Th = Thermistor; Cd = Car deck; St = Stacker; see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0182486#pone.0182486.g002" target="_blank">Fig 2C</a> for sampling stations at the wreck. B) Heavily fouled <i>Spondylus</i> sp. shell by calcareous species (e.g. <i>Caryophyllia</i> spp. corals). (C) An unusually elongated form of the coral <i>Phyllangia mouchezii</i>. (D) <i>P</i>. <i>mouchezii</i> fouling loose ropes. All photos from the Zenobia wreck, 25-40m depth.</p

Representative examples of epibenthic communities on the shipwrecks.

<p>A) Aggregations of serpulid polychaetes <i>(e</i>.<i>g</i>. <i>Rhodopsis cf</i>. <i>pusilla)</i> on dead coral skeletons <i>(Madracis pharensis</i>, <i>Phyllangia mouchezii)</i>, sponges, calcareous and green algae and ascidians; Zenobia, 34m depth. B) Live azooxanthellate <i>M</i>. <i>madracis</i> corals, branching bryozoans (e.g. <i>Caberea</i> sp.), brachiopods and other species overgrown by sponges, mostly <i>Chondrosia reniformis</i>; Zenobia, 36m depth. C) Large clusters of bivalves (e.g. <i>Chama pacifica</i>, <i>Pinctada imbricata radiata)</i> fouled by filamentous algae, ascidians and sponges; Alice-B, 32m depth. D) Pigmented and dead <i>M</i>. <i>pharensis</i> colonies on a calcareous structure within turf-algae, sponges and ascidians; Alice-B 32m depth. </p

Percentage of cover (mean + SD) of seven benthic categories on the shipwrecks.

<p>A) Three sampling stations at the Zenobia shipwreck: Th = Thermistor; Cd = Car deck; St = Stacker; see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0182486#pone.0182486.g002" target="_blank">Fig 2</a> for position of the sampling station at the wreck. B) Alice-B. C) Comparison of the pooled data (three stations) from Zenobia with Alice-B. N = number of photo-frames.</p

Seasonal satellite-derived data.

<p>A) Mean sea surface temperature (SST, 2010–2015); B) Chlorophyll-<i>a</i> (Chl-<i>a</i>, 2002–2015). From <a href="http://giovanni.gsfc.nasa.gov/giovanni" target="_blank">http://giovanni.gsfc.nasa.gov/giovanni</a>. Circles indicate studied areas in Cyprus (Zenobia) and Lebanon (Alice-B).</p

Schematic representations of the shipwrecks orientation and position on the seafloor and sampling stations.

<p>A) Zenobia resting on its portside. B) Alice-B resting upright. Indicated are the prevailing sea currents (arrows), the exposition to sunlight (solar symbol), and the stern section (stars) of the vessels. C) Three sampling stations at the Zenobia: 1 = Thermistor, 2 = Car Deck, 3 = Stacker; illustration courtesy of Larnaka Sea Cruises. D) Sampling transect (stripped arrow) at the Alice-B; photo Nadja Wohlleben.</p

Unpublished Mediterranean records of marine alien and cryptogenic species

Good datasets of geo-referenced records of alien species are a prerequisite for assessing the spatio-temporal dynamics of biological invasions, their invasive potential, and the magnitude of their impacts. However, with the exception of first records on a country level or wider regions, observations of species presence tend to remain unpublished, buried in scattered repositories or in the personal databases of experts. Through an initiative to collect, harmonize and make such unpublished data for marine alien and cryptogenic species in the Mediterranean Sea available, a large dataset comprising 5376 records was created. It includes records of 239 alien or cryptogenic taxa (192 Animalia, 24 Plantae, 23 Chromista) from 19 countries surrounding the Mediterranean Sea. In terms of records, the most reported Phyla in descending order were Chordata, Mollusca, Chlorophyta, Arthropoda, and Rhodophyta. The most recorded species was Caulerpa cylindracea, followed by Siganus luridus, Magallana sp. (cf. gigas or angulata) and Pterois miles. The dataset includes records from 1972 to 2020, with the highest number of records observed in 2018. Among the records of the dataset, Dictyota acutiloba is a first record for the Mediterranean Sea. Nine first country records are also included: the alga Caulerpa taxifolia var. distichophylla, the cube boxfish Ostracion cubicus, and the cleaner shrimp Urocaridella pulchella from Israel; the sponge Paraleucilla magna from Libya and Slovenia; the lumpfish Cyclopterus lumpus from Cyprus; the bryozoan Celleporaria vermiformis and the polychaetes Prionospio depauperata and Notomastus aberans from Malta.</p