First records of Mnemiopsis leidyi (Ctenophora) from the Ligurian, Thyrrhenian and Ionian Seas (Western Mediterranean) and first record of Phyllorhiza punctata (Cnidaria) from the Western Mediterranean.

* Corresponding author Abstract The gelatinous macroplankters Mnemiopsis leidyi and Phyllorhiza punctata are recorded for the first time from the Italian coasts of the Western Mediterranean. In the framework of the CIESM Jellywatch campaign in the summer of 2009, M. leidyi was recorded from the Ligurian, Tyrrhenian, and Ionian Seas, including swarming episodes that, together with those reported from Spain in the same period, suggest a great success of the species in the Western Mediterranean. A single specimen of P. punctata has been recorded from Sardinia. These species do not sting or harm humans and no impact on tourism is expected, but they might harm fisheries by predating on fish eggs and larvae and their prey, zooplankton. The large distribution area of M. leidyi suggests that the species invaded the Western Mediterranean during the summer of 2009, but its establishment is still uncertain, since the populations might not withstand winter conditions. The isolated record of P. punctata just indicates that it can reach this part of the Mediterranean

Non-native species spread in a complex network: the interaction of global transport and local population dynamics determines invasion success

The number of released individuals, which is a component of propagule pressure, is considered to be a major driver for the establishment success of non-native species. However, propagule pressure is often assumed to result from single or few release events, which does not necessarily apply to the frequent releases of invertebrates or other taxa through global transport. For instance, the high intensity of global shipping may result in frequent releases of large numbers of individuals, and the complexity of shipping dynamics impedes predictions of invasion dynamics. Here, we present a mathematical model for the spread of planktonic organisms by global shipping, using the history of movements by 33 566 ships among 1477 ports to simulate population dynamics for the comb jelly Mnemiopsis leidyi as a case study. The degree of propagule pressure at one site resulted from the coincident arrival of individuals from other sites with native or non-native populations. Key to sequential spread in European waters was a readily available source of propagules and a suitable recipient environment. These propagules were derived from previously introduced ‘bridgehead’ populations supplemented with those from native sources. Invasion success is therefore determined by the complex interaction of global shipping and local population dynamics. The general findings probably hold true for the spread of species in other complex systems, such as insects or plant seeds exchanged via commercial trade or transport

Invasion Pathway of the Ctenophore Mnemiopsis leidyi in the Mediterranean Sea

Gelatinous zooplankton outbreaks have increased globally owing to a number of human-mediated factors, including food web alterations and species introductions. The invasive ctenophore Mnemiopsis leidyi entered the Black Sea in the early 1980s. The invasion was followed by the Azov, Caspian, Baltic and North Seas, and, most recently, the Mediterranean Sea. Previous studies identified two distinct invasion pathways of M. leidyi from its native range in the western Atlantic Ocean to Eurasia. However, the source of newly established populations in the Mediterranean Sea remains unclear. Here we build upon our previous study and investigate sequence variation in both mitochondrial (Cytochrome c Oxidase subunit I) and nuclear (Internal Transcribed Spacer) markers in M. leidyi, encompassing five native and 11 introduced populations, including four from the Mediterranean Sea. Extant genetic diversity in Mediterranean populations (n = 8, Na = 10) preclude the occurrence of a severe genetic bottleneck or founder effects in the initial colonizing population. Our mitochondrial and nuclear marker surveys revealed two possible pathways of introduction into Mediterranean Sea. In total, 17 haplotypes and 18 alleles were recovered from all surveyed populations. Haplotype and allelic diversity of Mediterranean populations were comparable to populations from which they were likely drawn. The distribution of genetic diversity and pattern of genetic differentiation suggest initial colonization of the Mediterranean from the Black-Azov Seas (pairwise FST = 0.001–0.028). However, some haplotypes and alleles from the Mediterranean Sea were not detected from the well-sampled Black Sea, although they were found in Gulf of Mexico populations that were also genetically similar to those in the Mediterranean Sea (pairwise FST = 0.010–0.032), raising the possibility of multiple invasion sources. Multiple introductions from a combination of Black Sea and native region sources could be facilitated by intense local and transcontinental shipping activity, respectively

A basin-wide Black Sea Mnemiopsis leidyi database

A specific marine biological data management tool, the Black Sea Mnemiopsis leidyi database system was created within the European Commission 6th framework Black Sea SCENE project for the Black Sea region and is now being supported by the Permanent Secretariat of the Black Sea Commission. The core team of scientists studying M. leidyi in the Black Sea was brought together and all their available M. leidyi data and metadata were loaded into the common database. This works on the Internet and has a simple user interface. It gives Black Sea scientists the option to load all their corresponding data on the database and to use it as an effective tool to work both with M. leidyi and, in future, with other gelatinous organisms’ data, including another invasive ctenophore Beroe ovata. All loaded metadata and historical data are available to the entire scientific community. More recent data are available to the team members and with some restrictions to other scientists.JRC.H.5-Land Resources Managemen

A MSFD complementary approach for the assessment of pressures, knowledge and data gaps in Southern European Seas : the PERSEUS experience

PERSEUS project aims to identify the most relevant pressures exerted on the ecosystems of the Southern European Seas (SES), highlighting knowledge and data gaps that endanger the achievement of SES Good Environmental Status (GES) as mandated by the Marine Strategy Framework Directive (MSFD). A complementary approach has been adopted, by a meta-analysis of existing literature on pressure/impact/knowledge gaps summarized in tables related to the MSFD descriptors, discriminating open waters from coastal areas. A comparative assessment of the Initial Assessments (IAs) for five SES countries has been also independently performed. The comparison between meta-analysis results and IAs shows similarities for coastal areas only. Major knowledge gaps have been detected for the biodiversity, marine food web, marine litter and underwater noise descriptors. The meta-analysis also allowed the identification of additional research themes targeting research topics that are requested to the achievement of GES. 2015 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license.peer-reviewe

Native and non-native ctenophores in the Gulf of Trieste, Northern Adriatic Sea

Observations of stenophore species were made in the Gulf of Trieste between 2003 and 2006. We examined native ctenophore species with special attention to representatives of the orders Lobata and Beroida..

Native and nonnative ctenophores in the Gulf of Trieste, Northern Adriatic Sea

examined native ctenophore species with special attention to representatives of the orders Lobata and Beroida, and we recorded among them two non-native ctenophores: Mnemiopsis leidyi A. Agassi