First record of Mnemiopsis leidyi A. Agassiz, 1865 (Ctenophora; Lobata; Mnemiidae) off the Mediterranean coast of Israel

Expansion of Mnemiopsis leidyi in the French Mediterranean lagoons along the Gulf of Lion

Blooms of the invasive ctenophore, Mnemiopsis leidyi, occurred in 2009 along the Mediterranean Sea coasts of Spain and Israel. This voracious zooplanktivore spread throughout the Black Sea basin after its introduction in the early 1980s, throughout northern European coastal waters, and now occurs throughout the Mediterranean Sea. M. leidyi occurred throughout the summer along the entire Catalan Spanish and Israeli coasts in 2009. Those locations had high temperatures (18–26°C) and salinities (37–38) during the blooms. The patterns of abundance of large jellyfish along the Catalan coast were unusual in 2009, with low numbers during July, August, and September when ctenophores were abundant. Small populations of those potential predators and food competitors of M. leidyi could have contributed to the ctenophore bloom. The identity of the ctenophores from Spain and Israel was confirmed as M. leidyi by molecular analysis based on DNA sequencing of the nuclear internal transcribed spacer (ITS) regions. This is the first molecular confirmation of M. leidyi in the Mediterranean Sea. Most ctenophores had an ITS genotype previously found in M. leidyi from other invaded regions (the Black, Azov, and Mediterranean seas), as well as native regions in the United States, suggesting common ancestry. Based on the circulation patterns of Mediterranean surface waters and shipping activities, we conclude that the spread of M. leidyi in the Mediterranean probably resulted from re-introductions by ballast water transport and subsequent distribution by currents. We also conclude that the near-simultaneous blooms in opposite ends of both the Mediterranean basins indicate that M. leidyi is resident around the Mediterranean. We discuss environmental conditions, food, and predators of M. leidyi in both regions that would influence the future effects of this voracious consumer on the pelagic food web of the Mediterranean Sea.

Mnemiopsis leidyi in the northern Adriatic: here to stay?

Refugia area for the ctenophore Mnemiopsis leidyi A. Agassiz 1865 in the Berre Lagoon (southeast France): The key to its persistence

Preface.- Identification key for young ephyrae: a first step for early detection of jellyfish blooms.- Blooms of the invasive ctenophore, Mnemiopsis leidyi, span the Mediterranean Sea in 2009.- Effects of pH on asexual reproduction and statolith formation of the scyphozoan, Aurelia labiata.- Effects of low salinity on settlement and strobilation of scyphozoa (Cnidaria): Is the lion's mane Cyanea capillata (L.) able to reproduce in the brackish Baltic Sea?.- Effects of El Nino-driven environmental variability on black turtle migration to Peruvian foraging grounds.- Recurrence of bloom-forming scyphomedusae: wavelet analysis of a 200-year time series.- Behavior of Nemopsis bachei L. Agassiz, 1849 medusae in the presence of physical gradients and biological thin layers.- Avoidance of hydrodynamically mixed environments by Mnemiopsis leidyi (Ctenophora: Lobata) in open-sea populations from Patagonia, Argentina.- Response of Chrysaora quinquecirrha medusae to low temperature.- Use of respiration rates of scyphozoan jellyfish to estimate their effects on the food web.- Planktonic cnidarian distribution and feeding of Pelagia noctiluca in the NW Mediterranean Sea.- Bioenergetics and growth in the ctenophore Pleurobrachia pileus.- Degradation of the Adriatic medusa Aurelia sp. by ambient bacteria.- Identification of jellyfish from Continuous Plankton Recorder samples.- Separation and analysis of different types of nematocysts from Cyanea capillata (L.) medusae.- Characterisation of neurotoxic polypeptides from Cyanea capillata medusae (Scyphozoa).- Gill cell toxicity of northern boreal scyphomedusae Cyanea capillata and Aurelia aurita measured by an in vitro cell assay.

Mnemiopsis leidyi A. Agassiz, 1865 (Ctenophora: Lobata) in a Colombian Coastal Lagoon

Human interventions on the Earth’s natural systems are evident even in remote regions of the Antarctic and rain forests deep within the Amazon. In addition to human-induced climate change and habitat destruction, an emerging anthropogenic threat to biodiversity is the drastic species re-distribution (the movement of species from one place to another due to human intervention) at a global scale. This creates fertile conditions for biological invasions which in turn cause substantial economic and ecological losses. These human-mediated invasions, often referred to as “biological pollution”, are a worldwide problem that is increasing in frequency and magnitude, causing significant damage to the environment, economy and human health. Bioinvasions have strong impact on biodiversity and ecosystem functioning and stability. They are ranked as the second most important threat to biodiversity (after habitat destruction) by the World Conservation Union. The Ctenophore, Mnemiopsis leidyi, is one of the invasive species that naturally lives in the Atlantic coastal waters of North America and South America, but discovered in Azov, Black, Caspian, North, Baltic and Mediterranean (north-eastern part) seas in early 1980s. It seems that the main factor of its redistribution was the ballast waters of ships. As an alien species, Mnemiopsis leidyi caused many alterations in the Caspian Sea ecosystems. The fact that it feeds on the eggs of native fish Clopeonella spp., has resulted in a significant decline of its population; Clopeonella spp. were the main source of industrial fishing in the Caspian Sea and also the main source of food for precious fish species, the sturgeons, and therefore, their decline has caused a huge economical loss for the area's inhabitants and a significant decline of sturgeon populations. This species has caused massive ecosystem changes and substantial economic losses in the late 1980s-1990s, and it has been recognized as a problem of main ecological concern for the sustainable development of the region, together with the high level of anthropogenic pressures on the Caspian Sea ecosystems. Some special characteristics of this species, such as adaptation to a wide range of salinity and temperature, high capability of reproduction, hermaphroditism and dissogeny, have led to huge increases of its mass, especially in southern regions of the Caspian Sea, the coastal waters of Iran. In addition, it has become clear that this species does not have any natural predators in the Caspian Sea, and also that it can feed on any organisms smaller than itself in size. Owing to these facts, it is a huge ecological threat for the Caspian Sea ecosystems. The aim of the present paper is to review the biological and ecological impacts of this invasive species on the Caspian Sea ecosystems.

Ocean climate drivers and phytoplankton life strategies interact in a complex dynamic to produce harmful algal blooms (HABs). This study aims to integrate historical biological data collected during “red tide” events along the Ecuadorian coast between 1997 and 2017 in relation to five ocean variables derived from satellite remote sensing data to explain the seasonal drivers of coastal processes associated with HABs dynamics. Seasonality of the occurrence of HABs was assessed in relation to oceanographic variables by applying multiple correspondence analysis (MCA) to the Ecuadorian central coast (Zone 1) and at the outer and inner Gulf of Guayaquil (Zone 2). Sixty-seven HABs events were registered between 1997 and 2017. From a total of 40 species of phytoplankton identified, 28 were identified as non-toxic and the remaining 12 are well known to produce toxins. Dinoflagellates were the taxonomic group most highly associated with potential HABs events along the entire Ecuadorian coast. HABs appear to be constrained by the Humboldt coastal upwelling, high precipitation, and associated coastal runoff, with higher biomass abundance in the Gulf of Guayaquil than in the central coast. Results from the MCA reveal that in the central Ecuadorian coast (oligotrophic system), toxic HABs occurred with low abundance of dinoflagellates, while in the Gulf of Guayaquil (eutrophic system), toxic HABs corresponded to a high abundance of dinoflagellates. In both cases, high values were found for sea surface temperature, precipitation, and irradiance—characteristic of wet seasons or El Nino years. Non-toxic HABs occurred with a high abundance of dinoflagellates, ciliates, and centric diatoms, corresponding to colder waters and low levels of precipitation and irradiance. These findings confirm that dinoflagellates display several strategies that enhance their productive capacity when ocean conditions are warmer, allowing them to produce toxins at high or at low concentrations. Considering that the Gulf of Guayaquil is essential to tourism, the shrimp industry, fisheries, and international shipping, these findings strongly suggest the need to establish an ecosystem health research program to monitor HABs and the development of a preventive policy for tourism and public health in Ecuador.

High primary productivity along the central east coast of India is usually related to coastal upwelling activity that injects nutrients into the euphotic zone in response to prevailing longshore winds. The upwelling process has maximum intensity during March and August-September, with the coastal upwelling index varying from 10 to 150 m3/s per 100 m of coastline. Along the entire coast of the peninsula, the upwelling intensity changes in accordance with local wind conditions. I have identified the seasonal and synoptic variability of upwelling signatures on the central east coast of India, using averaged monthly and weekly sea surface temperature (SST) distributions obtained from remote sensing imagery from the Advanced Very High Resolution Radiometer in the period from 2000 to 2003. Analyse the seasonal mean variability of the upwelling-forced conditions, the average monthly PFEL coastal upwelling index (CUI) for 1990 through 2003 have been calculated for the entire central east coast with latitude resolution of 0.5°, attending to the local coastline orientation for each point. The index also shows a near-perfect confirmation of both the upwelling intensification during March, and the decrease of upwelling-favorable conditions towards the south. Spectra calculated using entire time series of from 2000 to 2003 wind data show that the frequency ranges from 0.1 to 0.2 cycles/day (corresponding to periods of 5 to 10 days) and has a number of significant energy peaks. The presence of energy frequency ranges from 0.1 to 0.2 cycles/day became evident, especially for the Visakhapatnam and Chennai stations.

Food-web traits of the North Aegean Sea ecosystem (Eastern Mediterranean) and comparison with other Mediterranean ecosystems

The invasive ctenophore, Mnemiopsis leidyi , was recently observed for the first time in Danish waters where it was widely distributed during the summer of 2007. In certain areas, including Limfjorden, it exhibited mass occurrence. In this study, we assess the abundance of M. leidyi in Limfjorden in the late summer of 2007 and give a preliminary evaluation of the predation effects of this ctenophore. On two cruises in August and September, M. leidyi was found in every net sample from 9 locations in Limfjorden. The population densities were high, up to more than 800 individuals m -3 in the innermost part, but body lengths were small (5 to 15 mm). The bio-volumes were very high (100 and 300 ml m -3 ) in the central parts of Limfjorden and are even greater than those from the Black Sea, where the greatest mean bio-volume was about 184 ml m -3 in the autumn of 1989 when the zooplankton and fish stocks collapsed. The possible ecological consequences of the mass occurrence of this ctenophore are discussed. Key words: Ctenophora, comb jelly, alien species, jellyfish, zooplankton,

Observations of ctenophore 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, and we recorded among them two non-native ctenophores: Mnemiopsis leidyi A. Agassiz 1865 and Beroe ovata sensu Mayer, 1912. The validity of the Mediterranean species Beroe ovata is discussed. We determined that among the native species, it is not Beroe ovata but rather Beroe cucumis sensu Mayer, 1912 that occurs in the Mediterranean Sea.

The comb jelly Mnemiopsis leidyi was first reported in July 2009 along the Spanish coast of the NW Mediterranean Sea and occurred throughout the summer (last report 26 September 2009). Large numbers of the ctenophore were reported by many participants of the Medusa Project. The high concentrations of M. leidyi along the Spanish coast, together with its blooms earlier this year in Israel, suggests establishment in the Mediterranean Sea. This is of great concern because of the well-known effects of M. leidyi on marine ecosystems and the consequences for commercial fisheries.

First record of Beroe ovata Bruguière, 1789 (Nuda, Beroida, Beroidae), another non-native ctenophore species off the Syrian coast (Eastern Mediterranean Sea)

: LONG-TERM GOALS. The long-term objective is to develop predictive models of bioluminescence potential in the coastal zone environment. OBJECTIVES. The ubiquitous nature of bioluminescent plankton in the world s ocean and its extreme sensitivity to mechanical excitation pose serious threats to clandestine operations. This is particularly true in the coastal zone where watershed run-off and discharge of submarine ground-water can profoundly impact growth conditions on very short space and time scales. Bioluminescent blooms include dinoflagellate red tides, which are occurring more frequently, lasting longer and extending further off shore due to excessive nutrient loading from land-based run-off and blooms of the carnivorous ctenophore Mnemiopsis leidyi that may be either seasonal or event driven, can develop on remarkably short time scales (Kremer, 1994) and also appear to be on the increase (Sullivan et al., 2001). Mnemiopsis leidyi, a native-American comb jelly (Figure 1), was first introduced into the Black Sea in 1982, where it caused the total collapse of the local fisheries. It has recently broken out into the Mediterranean Sea. Also, there is evidence that blooms within its native range along the east coast of the United States are increasing and producing profound impacts on coastal ecosystems. Given its ubiquity and its exceptional hardiness there is concern that it may continue to spread. The causes of jellyfish blooms are not well understood, but are generally assumed to be a combination of physical and biological factors, with temperature and salinity being the primary determinants of distribution and food availability, and predation being critical controlling factors of abundance (Graham et al., 2001, Kremer, 1994).