78 research outputs found

    Suivi biologique d'une réserve marine de la CÎte Bleue (Golfe de Marseille, Méditerranée, France)

    Get PDF
    The “CĂŽte Bleue” marine parc, located between Fos and Marseilles (French Mediterranean coast), includes two fisheries reserves at Carry-le-Rouet (85 ha, created in 1983) and Cape Couronne (210 ha, created in 1996), both provided with anti-trawling and production artificial reefs. The biological survey of Cap-Couronne reserve has been repeated with the same protocol every three years since 1995 and took into account the initial state of communities before protection. This programme aims at assessing (i) the ecosystem restoration, (ii) the benefits of this protection regime for sustaining the resources exploited by the low-tech small fisheries. It includes visual censuses of fish assemblages and standardized fishing operations made by professional (trammel net) and amateur (hook-and-line) fishermen within and outside the reserve. Both methods attest that the abundance and the individual size of the most valuable fish species are markedly increasing, and that the behaviour of these species tends to be more natural. After five years of protection, the reserve fish stocks are still in a replenishment stage, but the greater abundance of large-sized individuals of targeted species and changes in their behaviour suggest that the reproductive success of those species will increase significantly and will benefit the fishing activities outside the reserveLe Parc Marin de la CĂŽte Bleue, situĂ© entre Fos et Marseille, gĂšre deux rĂ©serves intĂ©grales, Ă  Carry-le-Rouet (85 ha, crĂ©Ă©e en 1983) et au cap Couronne (210 ha, crĂ©Ă©e en 1996). Ces deux rĂ©serves sont amĂ©nagĂ©es avec des rĂ©cifs artificiels de protection anti-chalut et de production et font l'objet de suivis biologiques depuis leur crĂ©ation. Le programme de suivi de la rĂ©serve de Cap-Couronne a Ă©tĂ© rĂ©pĂ©tĂ© trois fois selon le mĂȘme protocole depuis 1995 avec un point zĂ©ro de l'Ă©tat des peuplements avant l'application des mesures de protection et d'amĂ©nagement. Ce programme a pour objectifs : (i) la mise en Ă©vidence de la rĂ©gĂ©nĂ©ration de l'Ă©cosystĂšme littoral ; (ii) l'Ă©valuation des acquis de la protection d'une zone bien dĂ©finie pour une gestion concertĂ©e des ressources halieutiques au bĂ©nĂ©fice de la petite pĂȘche artisanale. Il comprend des recensements visuels des assemblages de poissons et des pĂȘches standardisĂ©es rĂ©alisĂ©es avec des pĂȘcheurs professionnels (filet trĂ©mail) et amateurs (lignes). Les deux mĂ©thodes d'Ă©valuation montrent que l'abondance et la taille individuelle des poissons les plus recherchĂ©s sont en nette augmentation, et qu'il y a une restauration de leur comportement naturel. AprĂšs cinq ans de protection, le peuplement ichtyologique de la rĂ©serve est encore en phase de restauration, mais l'augmentation observĂ©e du nombre de gros gĂ©niteurs d'espĂšces de forte valeur commerciale et l'amĂ©lioration de leur comportement permettent de prĂ©dire un accroissement du succĂšs reproductif de leurs populations dans la rĂ©serve, au bĂ©nĂ©fice de l'exploitation halieutique en pĂ©riphĂ©rie

    Re-shifting the ecological baseline for the overexploited Mediterranean red coral

    Get PDF
    Overexploitation leads to the ecological extinction of many oceanic species. The depletion of historical abundances of large animals, such as whales and sea turtles, is well known. However, the magnitude of the historical overfishing of exploited invertebrates is unclear. The lack of rigorous baseline data limits the implementation of efficient management and conservation plans in the marine realm. The precious Mediterranean red coral Corallium rubrum has been intensively exploited since antiquity for its use in jewellery. It shows dramatic signs of overexploitation, with no untouched populations known in shallow waters. Here, we report the discovery of an exceptional red coral population from a previously unexplored shallow underwater cave in Corsica (France) harbouring the largest biomass (by more than 100-fold) reported to date in the Mediterranean. Our findings challenge current assumptions on the pristine state of this emblematic species. Our results suggest that, before intense exploitation, red coral lived in relatively high-density populations with a large proportion of centuries-old colonies, even at very shallow depths. We call for the re-evaluation of the baseline for red coral and question the sustainability of the exploitation of a species that is still common but ecologically (functionally) extinct and in a trajectory of further decline

    Action plan for the conservation of habitats and species associated with seamounts, underwater caves and canyons, aphotic hard beds and chemo-synthetic phenomena in the Mediterranean Sea (Dark Habitats action plan)

    Get PDF
    Dark habitats are environments where the luminosity is extremely weak, or even absent (aphotic area) leading to an absence of macroscopic autochthonous photosynthesis. The bathymetric extension of this lightless area depends to a great extent on the turbidity of the water and corresponds to benthic and pelagic habitats starting from the deep circa-littoral. Caves which show environmental conditions that favour the installation on of organisms characteristic of dark habitats, are also taken into account. Dark habitats are dependent on very diverse geomorphological structures (e.g. underwater caves, canyons, slopes, isolated rocks, abyssal plains, cold seeps, brine anoxic lakes, hydrothermal springs and seamounts). Dark habitats represent outstanding and potential ecosystems with regard to their: Frailty and vulnerability to any land-based pressure Play an important part in the way the Mediterranean ecosystem functions, insofar as they constitute the main route for transferring matter between the coast and the deep sea Considered as biodiversity hotspots and recruiting areas forming a veritable reservoirs of knowledge and biodiversity Natural habitats that come under Habitat Directive on the conservation of natural habitats and of wild fauna and flora and appear as such as priority habitats requiring protection (Directive 92/43). A certain number of underwater caves enjoy protection status because they fall within the geographical boundaries of Marine Protected Areas (MPAs) Understanding of these functions is necessary for a better understanding and management of the biodiversity of Mediterranean coastal zones and continental shelf.peer-reviewe

    Ecosystem-based assessment of a widespread Mediterranean marine habitat: The Coastal Detrital Bottoms, with a special focus on epibenthic assemblages

    Get PDF
    IntroductionCoastal detrital bottoms (CDB) are one of the most extensive habitats of the continental shelf worldwide, in the upper levels of the circalittoral zone. Hosting a diverse community structured by sediment grain size, trophic interactions and calcified organisms, CDB exhibit important ecological functions. In the Mediterranean Sea, CDB are constituted by recent elements partly provided by adjacent infralittoral and circalittoral ecosystems. Since the 2010s, the offshore extension of many Marine Protected Areas (MPAs) has resulted in the incorporation of vast areas of CDB, raising the issue of their management. The Marine Strategy Framework Directive (MSFD) has embraced the concept of an ecosystem-based approach involving taking into account the functioning of marine habitats and their related ecosystem services. The purpose of this paper is to propose an ecosystem-based quality index (EBQI) tested on CDB from the north-western Mediterranean Sea, focusing mainly on epibenthic assemblages.MethodsThe first step has been to define a conceptual model of the CDB functioning, including the main trophic compartments and their relative weighting, then to identify appropriate assessment methods and potential descriptors. Twenty-nine sites were sampled along the coast of Provence and French Riviera (Southern France). Study sites were chosen with a view to encompassing a wide range of hydrological conditions and human pressures.ResultsVery well-preserved sites were found in Provence in areas without trawling and terrigenous inputs, while impacted and low-ES sites were located in the vicinity of urbanized areas. The cover of rhodoliths characterizes the seascape and might be an indicator of the good ES of CDB and reduced human pressure. However, the absence of rhodoliths may also be induced by natural phenomena.DiscussionThe EBQI designed for CDB proved representative and useful for a functional assessment based on epibenthic assemblages. However, some descriptors have shown their limitations and should be further explored. We highlight here the priority of establishing an index corresponding to a societal demand (e.g., European Directives, Barcelona convention) as a basis for a broad and large-scale assessment, for practical reasons. We stress the need to better apprehend the role of the macro-infauna and to extend this index over a wider geographical scale

    New Mediterranean biodiversity records (March 2016)

    Get PDF
    In this Collective Article on “New Mediterranean Biodiversity Records”, we present additional records of species found in the Mediterranean Sea. These records refer to eight different countries mainly throughout the northern part of the basin, and include 28 species, belonging to five Phyla. The findings per country include the following species: Spain: Callinectes sapidus and Chelidonura fulvipunctata; Monaco: Aplysia dactylomela; Italy: Charybdis (Charybdis) feriata, Carcharodon carcharias, Seriola fasciata, and Siganus rivulatus; Malta: Pomacanthus asfur; Croatia: Lagocephalus sceleratus and Pomadasys incisus; Montenegro: Lagocephalus sceleratus; Greece: Amathia (Zoobotryon) verticillata, Atys macandrewii, Cerithium scabridum, Chama pacifica, Dendostrea cf. folium, Ergalatax junionae, Septifer cumingii, Syphonota geographica, Syrnola fasciata, Oxyu- richthys petersi, Scarus ghobban, Scorpaena maderensis, Solea aegyptiaca and Upeneus pori; Turkey: Lobotes surinamensis, Ruvettus pretiosus and Ophiocten abyssicolum. In the current article, the presence of Taractes rubescens (Jordan & Evermann, 1887) is recorded for the first time in the Mediterranean from Italy. The great contribution of citizen scientists in monitoring biodiversity records is reflected herein, as 10% of the authors are citizen scientists, and contributed 37.5% of the new findings.peer-reviewe

    Draft Guidelines for Inventoring and Monitoring of Dark Habitats

    Get PDF
    UNEP(DEPI)/MED WG. 431/Inf.12Dark habitats1 are distributed throughout the Mediterranean basin from the sea surface (i.e. caves) to the deep-sea realm. Various habitats of unique scientific and conservation interest are included in this broad habitat category, such as dark caves, submarine canyons, seamounts and chemo-synthetic features supporting sensitive assemblages which require special protection. Therefore, dark habitats were considered under the Action Plan adopted in the Eighteenth Ordinary Meeting of the Contracting Parties to the Barcelona Convention (Turkey, December 2013). In the context of implementation schedule of the Dark Habitats Action Plan (UNEP-MAP-RAC/SPA, 2015a) a set of guidelines should be identified aiming to reduce the imminent pressures and threats affecting these vulnerable assemblages. This document aims to establish guidelines for inventorying and monitoring Mediterranean deep-sea habitats and marine caves in order to settle the basis for a regional-based assessment

    Callopora bathyalis n. sp., nouvelle espĂšce de Bryozoaire chilostome de l’OcĂ©an Atlantique nord-oriental

    No full text
    A new species of Callopora (Bryozoa, Cheilostomata Anasca), C. bathyalis n. sp., was discovered on Madreporaria from the bathyal zone of the Atlantic Ocean. Its main characteristic consists in an entire covering of the area by a calcified racketshaped plate joined to the proximal gymnocyst by a peduncle. This plate bears an avicularium and represents a highly modified avicularian chamber. This structure appears to be a striking adaptation to the deep habitat of this species. Its supposed function is to protect the frontal membrane from silt deposit

    Hornera Lamouroux 1821

    No full text
    Genus <i>Hornera</i> Lamouroux, 1821 <p> TYPE SPECIES. — <i>Hornera frondiculata</i> Lamouroux, 1821 (synonym of <i>Retepora frondiculata</i> Lamarck, 1816, see below), by original designation.</p>Published as part of <i>Harmelin, Jean-Georges, 2020, The Mediterranean species of Hornera Lamouroux, 1821 (Bryozoa, Cyclostomata): reassessment of H. frondiculata (Lamarck, 1816) and description of H. mediterranea n. sp., pp. 525-545 in Zoosystema 42 (27)</i> on page 528, DOI: 10.5252/zoosystema2020v42a27, <a href="http://zenodo.org/record/4134444">http://zenodo.org/record/4134444</a&gt

    Celleporaria sherryae Winston 2005

    No full text
    ? <i>Celleporaria sherryae</i> Winston, 2005 <p>(Fig. 8 A–C; Table 8)</p> <p> ? <i>Holoporella vagans</i> (Busk, 1881): Canu & Bassler 1928: 148, pl. 25, figs 7–13, text-fig. 33e–g.</p> <p> ? <i>Celleporaria subalba</i>: Winston 1986, p. 14, figs 31–34. Non <i>Holoporella subalba</i> Canu & Bassler, 1928: 146, pl. 25, figs 1–6, text-fig. 33b.</p> <p> ? <i>Celleporaria sherryae</i> Winston, 2005: 51, figs 141–142.</p> <p> <b>Material examined.</b> <i>Specimens from Lebanon</i>: 1) Stn 5A, 3 colonies on concretions and skeleton of <i>Polycyathus</i> (scleractinian); 2) Stn 11A, 1 colony on <i>Spondylus</i> shell from rocky wall. <i>Other material examined</i>: SEM photos of a specimen from Brazil, São Sebastião (São Paulo), attributed to <i>C. mordax</i> by L.M. Vieira.</p> <p> <b>Description.</b> Colony encrusting, multilamellar, generally small, moderately calcified. Frontal shield finely nodular or smooth, 6–8 small to medium-sized marginal pseudopores. Orifice broader than long, anter semicircular, poster with sides slightly concave and indented by small U-shaped sinus, condyles lacking; operculum light brown. Orificial spines 4, occasionally 5–6, or 2 when distal ones immersed in secondary calcification, often long (up to 425 µm) and persistent. Small adventitious suboral avicularium placed on raised, bulging cystid just below sinus, directed upwardly and facing laterally, rostrum rounded with distal edge serrated by 3–5 broad, triangular teeth. Vicarious avicularia arising by frontal budding in largest colonies, large, with sides parallel or slightly concave, tip rounded, often with low visor, distal palate medium-sized, crossbar complete, without columella. Ooecium forming open, relatively narrow, slightly nodular hood, leaving proximalmost spines free.</p> <p> <b>Remarks.</b> The Lebanese specimens belong to a group of <i>Celleporaria</i> species having in common a primary orifice with a semicircular anter, a slightly concave poster with a median notch, a small, suboral adventitious avicularium with serrated rostrum facing laterally at the tip of a bulging mucro, and generally four oral spines. This species group includes at least <i>Celleporaria mordax</i> (Marcus, 1937) from Brazil, a species from Jamaica ascribed to <i>C. mordax</i> by Winston (1986, p. 13, figs 27–30), <i>Celleporaria sherryae</i> Winston, 2005 from Florida, Caribbean and Gulf of Mexico, <i>Celleporaria aperta</i> (Hincks, 1882) from the Indo-Pacific realm, and <i>Celleporaria mauritiana</i> Hayward, 1988 from Mauritius. Each of these species differs from the others in several features that need to be better characterized, the most apparent criteria being <i>a priori</i> the presence or absence of condyles at the base of the anter and the shape of the vicarious avicularia. For instance, specimens from NW Florida assigned to <i>Holoporella mordax</i> by Shier (1964) differ in having vicarious avicularia with a rostral chamber apparently occulted by the palate except for a central keyhole-shaped lucida. SEM photos of specimens of <i>C. mordax</i> recently collected near the type-locality of this species (courtesy of L. Vieira and J. Winston) show vicarious avicularia having the rostrum with concave edges, a serrated tip and its greatest width at the level of the columella. The Lebanese specimens closely resemble the Jamaican specimens illustrated by Winston (1986) as <i>C. mordax</i>, which belong in fact to another species (J.E. Winston, pers. comm. 3 June 2014). They have in common similar-shaped orifices lacking condyles, with a small sinus, four oral spines, a small suboral avicularium with few broad distal teeth and large vicarious avicularia with a rounded tip but not distinctly spatulate. The only apparent difference may be the width of the sinus, which is broader in the Jamaican species. The Lebanese material also presents some features in common with <i>C. aperta</i> (Hincks, 1882), including a small U-shaped sinus, up to four oral spines and a small suboral avicularium whose irregular edge is scalloped (Winston & Heimberg 1986). This Indo-Pacific species has been recorded from the Red Sea (Waters 1909), the Suez Canal (Hastings 1927), and the Eastern and central Mediterranean, i.e. Israel (Powell 1969a; Eitan 1972; d’Hondt 1988) and Malta (Agius <i>et al</i>. 1977). According to Winston & Heimberg (1986), who examined the type of <i>C. aperta</i>, the rostrum of the vicarious avicularia of this species is subtriangular and serrated, thus clearly different from these structures in the Lebanese specimens. They also pointed out that several species were mixed together under this name, particularly by Harmer (1957). The specimens from Ghana, West Africa, ascribed to <i>C. aperta</i> by Cook (1968, 1985), who noticed relationships with <i>C. mordax</i>, may belong to another species. Finally, <i>C. sherryae</i>, well-illustrated in Winston (1986) as <i>C. subalba</i> (Canu & Bassler, 1928) (cf. Winston 2005), is the species that appears to present the greatest similarity with the Lebanese specimens, as confirmed by J. Winston (pers. comm. 3 June 2014). Similarities between them concern the orifice, the adventitious avicularium, the oral spines, the form of the frontal shield and the pale color of operculum. <i>Celleporaria sherryae</i> is frequent in fouling (Winston 2005), a trait which promotes human-mediated dispersal. However, unlike the Lebanese specimens, its colonies are massive (Winston, pers. comm.) and the shape of the vicarious avicularia is slightly different. Thus, the Lebanese specimens are only provisionally ascribed to <i>C. sherryae</i>, but, as noticed by Winston (2005), revision of the whole species group is needed.</p>Published as part of <i>Harmelin, Jean-Georges, 2014, Alien bryozoans in the eastern Mediterranean Sea — new records from the coast of Lebanon, pp. 301-338 in Zootaxa 3893 (3)</i> on pages 318-319, DOI: 10.11646/zootaxa.3893.3.1, <a href="http://zenodo.org/record/250297">http://zenodo.org/record/250297</a&gt
    • 

    corecore