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Remarkable new records included in the dataset: (A) Caulerpa cylindracea, a first record for the Black Sea reported by Ergün Taşkın; (B) Grateloupia turuturu, also a first record for the Black Sea reported by Ergün Taşkın.
Source publication
To enrich spatio-temporal information on the distribution of alien, cryptogenic, and neonative species in the Mediterranean and the Black Sea, a collective effort by 173 marine scientists was made to provide unpublished records and make them open access to the scientific community. Through this effort, we collected and harmonized a dataset of 12,64...
Contexts in source publication
Context 1
... et al. (2021) have monitored the distribution of C. cylindracea along the Aegean coasts of Turkey since 1993 and noticed its considerable range expansion towards the northern Aegean Sea ( Güreşen et al. 2015). The species was detected on 28 February 2020 in the Dardanelles Strait, Turkey (40.0464°N; 26.3463°E) on rocky substratum ( Figure 6A). The rhodophyte Grateloupia turuturu was first detected in the Mediterranean Sea in southern France in 1982 ( Riouall et al. 1985) and has spread across the Mediterranean basin ( Verlaque et al. 2015). ...
Context 2
... red alga was often misidentified as Grateloupia doryphora (Montagne) M.Howe ( Verlaque et al. 2015). Grateloupia turuturu was detected on 26 June 2021 in the Sea of Marmara (40.4008°N; 27.9145°E) on rocky substrata where it was abundant at 0-1 m depth ( Figure 6B). ...
Context 3
... et al. (2021) have monitored the distribution of C. cylindracea along the Aegean coasts of Turkey since 1993 and noticed its considerable range expansion towards the northern Aegean Sea ( Güreşen et al. 2015). The species was detected on 28 February 2020 in the Dardanelles Strait, Turkey (40.0464°N; 26.3463°E) on rocky substratum ( Figure 6A). The rhodophyte Grateloupia turuturu was first detected in the Mediterranean Sea in southern France in 1982 ( Riouall et al. 1985) and has spread across the Mediterranean basin ( Verlaque et al. 2015). ...
Citations
... A similar pattern of functional compensation was observed within the herbivorous species group (FG6). Surprisingly, only two native species belonging to this functional group were recorded in this study, with no sightings of Siganus luridus, a well-established Invasive Alien Species (IAS) within the Maltese archipelago [64]. The two main herbivorous species observed, Sparisoma cretense and Sarpa salpa, exhibited contrasting trends along the thermal effluent gradient. ...
Ocean warming poses significant threats to coastal ecosystems. This study investigates the impact of thermal effluents from power plants, as proxies for climate-driven temperatures increase, on Posidonia oceanica meadows and associated fish communities. Using a gradient-based approach, we analyzed environmental variables, seagrass indicators, fish assemblages, and functional group (FG) dynamics across a thermal gradient extending from the effluent outfall itself. Results indicate that temperature is the dominant factor influencing P. oceanica, with reduced leaf length, shoot density, and rhizome weight characterizing samples closest to the effluent. Despite compensatory mechanisms, the overall photosynthetic biomass and resilience declined under thermal stress. Fish assemblages exhibited reduced species richness and biodiversity close to the thermal effluent, with opportunistic and thermophilic species dominating. An FG analysis revealed disrupted seasonal patterns, shifts in trophic dynamics, and functional compensation among species, highlighting potential ecological imbalances. Notably, transient predators thrived near the effluent, while more sedentary and temperate species were displaced. These findings underscore the cascading effects of rising temperatures on coastal habitats such as P. oceanica meadows and their associated communities, emphasizing the urgency for conservation measures. By identifying critical thresholds and adaptive responses, this study contributes valuable insights into the consequences of localized impacts of thermal stress on coastal biodiversity and ecosystem services.
... Biological invasions are one of the main threats for marine and transitional ecosystems. Invasive alien species (hereafter: IAS) are constantly increasing in the Mediterranean basin (e.g., Galil et al., 2008Galil et al., , 2017Galil et al., , 2018Ulman et al., 2017;Servello et al., 2019;Katsanevakis et al., 2020;Zenetos et al., 2022;Ragkousis et al., 2023), and often generate significant ecological and economic impacts. The invasiveness of some marine alien species can compromise the functions and the structure of ecosystems and, at the same time, favor the onset of alterated aquatic food webs and increase the biodiversity loss (Streftaris et al., 2005;Hulme, 2007;Vilà et al., 2011;Boudouresque & Verlaque, 2012;Seebens et al., 2017;Azzurro et al., 2019;Tsirintanis et al., 2022). ...
Invasive species are a growing threat to marine ecosystems, and the recent proliferation of the Atlantic blue crab (Callinectes sapidus) in the Po Delta (Italy) has had significant ecological and economic impacts, particularly on clam farming. This study explores the influence of C. sapidus on clam production in the Po Delta, combining biological and ecological data with socio-economic analysis. Field data collected between August and December 2023 from the Canarin and Scardovari Lagoons revealed seasonal fluctuations in crab abundance, with a peak in captures during the warmer months. The predatory behaviour of C. sapidus has led to a sharp decline in clam production, reaching near-zero levels in early 2024. Statistical analysis confirmed a strong correlation between the increase of the invasive crab population and the decrease in clam yields. This study also explores potential management strategies, including the economic valorisation of C. sapidus as a commercial resource, turning an ecological challenge into an opportunity. These findings highlight the urgent need for targeted management interventions to mitigate the impact of this invasive species on local fisheries and ecosystems.
... A similar pattern of functional compensation was observed within the herbivorous species group (FG6). Surprisingly, only two native species belonging to this functional group were recorded in this study, with no sightings of Siganus luridus, a well-established Invasive Alien Species (IAS) within the Maltese archipelago [64]. The two main herbivorous species observed, Sparisoma cretense and Sarpa salpa, exhibited contrasting trends along the thermal effluent gradient. ...
Rising sea temperatures, driven by climate change, pose significant threats to coastal ecosystems. This study investigates the impact of thermal effluents from power plants, as proxies for climate-driven temperature increases, on Posidonia oceanica meadows and associated fish communities. Using a gradient-based approach, we analyzed environmental variables, seagrass indicators, fish assemblages, and functional group (FG) dynamics across a thermal gradient extending from the effluent outfall itself. Results indicate that temperature is the dominant factor influencing P. oceanica, with reduced leaf length, shoot density, and rhizome weight characterising samples closest to the effluent. Despite compensatory mechanisms, the overall photosynthetic biomass and resilience declined under thermal stress. Fish assemblages exhibited reduced species richness and biodiversity close to the thermal effluent, with opportunistic and thermophilic species dominating. FG analysis revealed disrupted seasonal patterns, shifts in trophic dynamics, and functional compensation among species, highlighting potential ecological imbalances. Notably, transient predators thrived near the effluent, while more sedentary and temperate species were displaced. These findings underscore the cascading effects of rising temperatures on coastal habitats such as P. oceanica meadows and on their associated communities, emphasizing the urgency for conservation measures. By identifying critical thresholds and adaptive responses, this study contributes valuable insights into the consequences of localized impacts of thermal stress on coastal biodiversity and ecosystem services.
... Between 2007 and 2010 it was found in European waters probably introduced with oyster transfers. The first record in the Mediterranean was documented in the Lagoon of Venice, probably in 2000 (Marchini et al., 2014) and the species has subsequently spread to Mediterranean marinas (Marchini et al., 2015;Tempesti et al., 2016;Ragkousis et al., 2023). In the Iberian Peninsula, P. japonica has been present in Barcelona and Valencia marinas at least since 2011 (Martínez-Laiz et al., 2018). ...
... Macrophytes are a group of aquatic plants that play a significant role in various ecosystems. Prior to the construction of the Suez Canal in 1869, numerous species were documented and believed to be indigenous by certain researchers [74]. Notably, Asparagopsis taxiformis has been included in this study due to the rapid and recent alterations in its distribution across the Mediterranean region. ...
This chapter explores the intricate relationship between climate change and Lessepsian migration to the Mediterranean region, shedding light on the implications for biodiversity and ecosystem dynamics. The construction of the Suez Canal in 1869 initiated a significant transformation, facilitating the exchange of marine species between the Red Sea and the Mediterranean, a phenomenon known as Lessepsian migration. Climate change, characterized by escalating warming trends, further amplifies this migration process. Rising sea surface temperatures, attributed to climate change, create more hospitable conditions for thermophilic species originating from the Red Sea to migrate and establish themselves in the Mediterranean. Consequently, there is an increased likelihood of species introductions and range expansions, altering the composition and distribution of marine biodiversity in the region. Furthermore, climate-induced changes in ocean currents and circulation patterns play a crucial role in facilitating the dispersal of Lessepsian species, augmenting their colonization success in the Mediterranean. This dynamic interaction between climate change and Lessepsian migration poses significant challenges for ecosystem management, as invasive species introductions can disrupt native ecosystems and biodiversity. Understanding the complex interplay between climate change and Lessepsian migration is paramount for developing effective management strategies to mitigate the impacts of invasive species and safeguard the ecological integrity of the Mediterranean Sea. This chapter aims to provide insights into these interconnected processes, contributing to a comprehensive understanding of the implications of climate change for marine biodiversity and ecosystem dynamics in the Mediterranean.
... The ongoing introduction of Non-Indigenous Species (NIS) is a significant and increasing threat to global biodiversity, including in the Mediterranean (e.g., Tsirintanis et al., 2022;Zenetos et al., 2022a). This consideration extends to bryozoans, with a continuous increase in species records (e.g., Katsanevakis et al., 2020;Ragkousis et al., 2023) and new species becoming established (Zenetos et al., 2022b). While shipping and aquaculture are well-recognised pathways for NIS introduction in the Mediterranean (e.g., Zenetos et al., 2012), the role of drift plastic and other waste materials has not been thoroughly examined. ...
Despite being a major threat to biodiversity, often causing homogenization and banalization in ecosystems, the understanding of marine bioinvasions remains limited, especially regarding non-economically important taxonomic groups and newly emerging vectors or dispersion pathways. In this paper, we report the finding of viable colonies of five Microporella species on plastic debris stranded on sandy beaches, predominantly in the Ionian Sea, and subordinately in the Tyrrhenian Sea and Sicily Strait. Three species, M. appendiculata, M. modesta and M. ichnusae, are native to the Mediterranean, with the former two widespread in the investigated area, and the latter previously known only from its type locality in northwestern Sardinia, now widening its known distribution range to the west coast of Sicily. Conversely, findings of M. hastingsae and M. browni in Sicily represent localities far from their previously known distributions in the Suez Canal and the Levantine and Red Sea-Indian Ocean regions, respectively. We suggest that these pioneering colonies, found on drift plastics between April 2023 and May 2024, may have arrived through rafting by surface currents, at least in the western Ionian Sea. Human activities, especially commercial and recreational shipping, may have also facilitated their spread, especially in the Tyrrhenian Sea and the Sicily Strait. Fouling on buoyant plastics could originate directly from unknown populations in the eastern Mediterranean, or secondarily through shipping, which may have introduced larvae that subsequently attached to plastics along the coast of Sicily. These findings point to the need for further investigations to confirm whether established populations of M. hastingsae and M. browni exist in coastal artificial and/or natural habitats in these areas.
... In recent years, there has been a notable interest in these peracarid crustaceans as indicators of the Mediterranean biodiversity (Servello et al., 2019;Navarro-Barranco et al., 2020;Bakalem et al., 2024). It is therefore of great importance to update knowledge to maintain an accurate overview of the basin and regional patterns Martínez-Laiz et al., 2019;Ragkousis et al., 2023). ...
In recent decades, intense human activities and increased maritime transportation triggered heavy pressure on the Israeli coastal ecosystem and, meanwhile, the eastern Mediterranean experienced the highest temperature values. With the assumption that both kinds of anthropogenic drivers could alter the benthic taxocenosis, a monitoring survey covering a period ranging from 2010 to 2017 was addressed to assess changes in the macrozoobenthos on spatial and temporal scales. The present study focused on the crustacean amphipod fauna collected on the soft bottom littoral area. Twenty-five species and taxa (genus level) were detected under the temporal survey in the same stations, located along a north-south axis, from the northernmost Haifa Bay to the southern area. The dataset showed a temporally stable assemblage of the most common species. Seven species showed the greatest abundance and a constant presence: the Levantine endemic Cheiriphotis mediterranea; the Mediterranean endemic Megaluropus massiliensis; the NE-Atlantic-Mediterranean Bathyporeia guilliamsoniana and Perioculodes longimanus; and the widely distributed Photis longicaudata and Urothoe grimaldii. In addition, an alien species was recorded, the circumtropical aorid Grandidierella bonnieroides which resulted naturalized. Differently, the spatial dataset discriminated two geographical regions, the northernmost Haifa Bay and the remaining Southern Israeli Coast, based on the different substratum granulometry. On the whole, the Israeli assemblage showed a low diversity composed of dominant species strictly associated with the features of the sediment and characterised by local abundance fluctuations. It is a pattern that provides baseline knowledge for successive monitoring years and contributes to implementing the knowledge of the ecological traits of amphipod fauna.
... Additional NIS are reported in the recent literature (2020-2024), related mostly to findings of new species in Greek coastal waters and/or in Turkish coastal waters [23,27,[43][44][45][46][47][48][49][50][51]. In addition to the new records for the study area, recent publications address the geographic expansion from the South to the North Aegean Sea [11,39,52], as well as the successful establishment of certain invasive species. ...
... The distribution of NIS in the neighboring seas was extracted from the unpublished database of the Hellenic Centre for Marine Research (HCMR) for the Ionian and Levantine Seas, while for the Marmara Sea [14], it was updated with the recent literature, e.g., [39,51]. ...
In this work, combined efforts by Greek and Turkish scientists produced an updated validated NIS inventory of the Aegean ecoregion, covering 120 years of records up to August 2024. Of the 342 NIS currently present in the Aegean Sea, the majority (281 species) have invaded the South Aegean, followed by the North Aegean (128 species out of 206 NIS). A total of 73 species were added to the list, while 56 were removed. Overall, unaided spread of Lessepsian immigrants from the Levantine Sea and shipping are equally responsible for NIS reported at the regional level. An increase in publications addressing NIS matches the upward trend of NIS since the mid-1990s, which continues to the present day. While unaided introductions of Lessepsian species and/or direct introductions via the Suez Canal peaked in the South Aegean during 2000–2005, they peaked in 2012–2017 in the North Aegean—a decade later. The opposite pattern was observed in ship-transferred NIS. The spatial distribution of introduction hotspots largely reflects the following phenomena/processes: unaided introduction is witnessed initially in the southeastern Aegean Sea; monitoring efforts are concentrated in vulnerable and at-risk areas; and research efforts relate to the spatial allocation of institutions and marine experts working on marine NIS along the Aegean coasts.
... In addition, instances of species observed within their already established invasion ranges are seldom reported. As a result, valuable spatio-temporal data, of significant interest to both researchers and stakeholders, often remain unreported and also fragmented across various repositories or personal files (Ragkousis et al. 2023). This information gains even greater significance in the case of the Mediterranean Sea, which is experiencing exceptionally rapid warming compared to the global ocean and unmatched biological invasions (Schroeder et al. 2016;Cramer et al. 2018;Pörtner et al. 2019;Pisano et al. 2020). ...
On September 1st, 2023 three specimens of the blue button Porpita porpita (Lin-naeus, 1758) (Cnidaria, Hydrozoa) were found stranded along the store of the Genoa metropolitan area (northwest Mediterranean Sea, Ligurian Sea) as a result of a citizen science contribution. This record represents the second observation of the species in this area after the first one, occurred in 2019. The general increase in observations of P. porpita in the Mediterranean basin, from 2010 on, may suggest a higher abundance of specimens in the sea, likely due to climate change, an intensified effort in reporting sightings of citizens scientist (whose data accounts for more than 85% of total available records), or a combination of both factors. The analysis of environmental data related to this latest stranding event suggests that this occurred under specific meteorological conditions. Since monitoring the spread of non-indigenous species is fundamental to study global warming effects on marine biodiversity, the understanding of the precise environmental settings under which they may occur might reduce observational biases and contribute to the acquisition of sound data less linked to fortuitous observations.
... Upeneus pori, originally known from the northern Red Sea and Madagascar (Uiblein et al., 2020), was recorded for the first time in the Mediterranean in 1942 by Kosswig (1950), albeit misidentified as Upenoides tragula ( = Upeneus tragula Richardson, 1846), from the Iskenderun Bay, southeastern Turkey. Since its first appearance, and like many other lessepsian species (Golani, 2010), after its colonization of the eastern Mediterranean, U. pori spread westwards to the Aegean Sea as far north as the Thermaikos Gulf (Kampouris et al., 2020) and to the central-western Mediterranean in Tunisia (Azzouz et al., 2010;Ragkousis et al., 2023), the Strait of Sicily (Geraci et al., 2018), and eastern Sicily (Deidun et al., 2018;Katsanevakis et al., 2020). Along with the congeneric lessepsian U. moluccensis, this species shows the characteristics of an invader. ...
... The Gulf of Castellammare is the finding locality of several nonindigenous algae and invertebrates (Katsanevakis et al., 2020;Pipitone et al., 2020;Ragkousis et al., 2023) and one nonindigenous fish, Fistularia commersonii Rüppell, 1838 (Azzurro, 2023), found as one or two individuals although it was considered already established in the central Mediterranean (Zenetos et al., 2010). S. diaspros is among the most widely spread lessepsian fishes, and in the Mediterranean, it reaches a size even larger than in its native range (Metin and Akyol, 2021). ...
The reticulated leatherjacket Stephanolepis diaspros and the Por’s goatfish Upeneus pori occur as lessepsian migrants in the
eastern and central Mediterranean Sea. This article reports on the findings of one reticulated leatherjacket and two Por’s goatfishes in
the Gulf of Castellammare, southern Tyrrhenian Sea, which suggest a possible westbound expansion of the Mediterranean distribution
for the latter species. The specimens were three adults collected by professional fishermen on inshore sandy bottoms with a trammel net.
The main meristic characteristics of both species, the identification issues of S. diaspros, and the potential impact of U. pori on the native
biota and artisanal fisheries are briefly discussed.
