Introduction Of Non-indigenous Species Research Articles

Spatiotemporal distribution of the non-indigenous peach blossom jellyfish Craspedacusta sowerbii in British Columbia, Canada

The introduction of non-indigenous species (NIS) to exotic habitats can have tremendous impacts on native biodiversity, food webs, and ecosystem services. One globally distributed aquatic NIS is the hydrozoan Craspedacusta sowerbii Lankester, 1880. The species’ northern distribution boundary in North America is situated in British Columbia (BC), Canada. It is thus of paramount interest to understand its ecology in this warming invaded habitat, allowing for insights into other regions. Specimens of the genus Craspedacusta have been reported in 34 freshwater systems since August 1990. These reported locations are generally shallow (<10 m), most often of natural origin, and have a small surface area (<0.1 km2). We observed an exponential trend of medusa observations from 1990 till the end of the 2020s. The first seasonal records are in July and the latest in October, with peak sightings reported in August and September. After 2012, regional temperature anomalies during July and August were mostly positive, which overlaps with the period of the majority of reported C. sowerbii sightings. Until this day, all examined medusae are males.

New records of the Non-native Amazon sailfin catfish Pterygoplichthys pardalis (Castelnau, 1985) in Bangka Island Indonesia

Abstract The freshwater species known as Pterygoplichthys pardalis (Castelnau, 1985), commonly referred to as the Sailfin catfish, is native to temperate and tropical regions of South America, with a particular prevalence in the Amazon. Due to insufficient regulation of the pet fish industry, certain species from this family have been inadvertently or deliberately introduced to various places worldwide. In Indonesia, the occurrence of the sailfin catfish has been recorded in the natural freshwater habitats of Java and Sumatra. The introduction of non-indigenous fish species into natural aquatic environments has had adverse effects on biodiversity due to factors such as competition for resources, modification of habitats, and transfer of diseases so the presence of the P. pardalis is a danger alert. This study presents the first evidence of the presence of the sailfin catfish P. pardalis on Bangka Island, located in the western region of Indonesia. During the field trip conducted in August 2023, a total of twenty specimens were obtained from the Rangkui River, Pangkal Pinang.

Environmental DNA as Early Warning for Alien Species in Mediterranean Coastal Lagoons: Implications for Conservation and Management

Non-indigenous species (NIS) introduction notoriously threatens the Mediterranean Sea. In addition, Mediterranean coastal lagoons play a crucial role as nurseries for marine species, which new NIS arrivals can threaten. Therefore, monitoring and early warning of NIS presence is essential in preserving biodiversity. An innovative technique for rapid and accurate species identification and biodiversity screening is the application of environmental DNA (eDNA) metabarcoding. In this research, different Penaeidae (Arthropoda, Crustacea, Decapoda) NIS specimens were collected from a Mediterranean coastal lagoon after an early warning about a potentially invasive NIS arising from next-generation sequencing data. DNA barcoding of the DNA extracted from tissue samples and amplified with specifically designed primer pairs led to the recognition of Penaeus aztecus in this NATURA 2000 protected ecosystem for the first time. DNA barcoding from DNA isolated from the water where the living specimens were stored further validated the possibility of identifying P. aztecus starting from eDNA. This approach demonstrated the validity of environmental DNA analysis in the early screening of potentially invasive NIS presence in Mediterranean protected areas and ecosystems. This work describes an applicative example of the efficacy in improving the biomonitoring of lagoon ecosystems using molecular tools and it represents a guideline for the validation of eDNA metabarcoding data for the presence of potentially invasive species.

A morphogenetic characterisation of a potentially dominant African marine species in Europe

Studying the early stages of the introduction of non-indigenous species (NIS) is crucial as it allows immediate management actions aimed at preventing NIS spread at a time when these actions are more likely to be effective. Recent species introductions present unique opportunities to study key aspects of the invasion process. However, comprehensive information on how and when NIS are first introduced remains rare. We assessed the characteristics of the introduction of a member of the widespread Pyura stolonifera species group (Chordata, Tunicata) in Europe. These ascidians are important bioengineer species that can attain amongst the highest benthic biomass per surface area ever reported. We collected introduced individuals on the coast of the northwestern Iberian Peninsula, an area with high shipping traffic and one of the world’s most important mussel farming regions. The specimens were analysed using taxonomic and genetic tools. Both field surveys and taxonomic analysis showed that one of the African members of the species group, Pyura herdmani, has recently been introduced to Europe and, although it does not yet form the large aggregates found in the native range, it is already well-established. Genetic data revealed that only the northwest African lineage of P. herdmani has been introduced to Europe. Considering the low dispersal capabilities of the early life-history stages of P. herdmani, the introduction of this species into Europe can only be explained via human mediated transport of NIS. In order to prevent any detrimental effects on both native biota and/or economically-important anthropogenic activities, regular monitoring of recent NIS introductions is urgently required.

The influence of recreational boat traffic in the introduction of non-indigenous fouling species in three Ligurian marinas (Mediterranean Sea, Italy)

The role of navigation in transporting and introducing non-indigenous species (NIS) in ports is globally acknowledged, and maritime traffic is correlated with increasing NIS introductions. On the other hand, different types of vessels can occur in a port (e.g., for commercial or recreational purposes) and the success of a NIS in a new area also depends on several chemical-physical and biotic conditions of the arrival port.In this context, a study was conducted in 2020 in three marinas at Sanremo (Ligurian Sea, Italy) with the aim to assess if boat traffic influences the presence of NIS in marine fouling communities.Samples were collected from docks and pontoons with a hand-held rigid net in the marinas of Sanremo (Porto Sole, characterized by international recreational boat traffic; and Porto Vecchio, hosting only local fishing boats), as well as in Ospedaletti, a nearly finished, abandoned and unused marina. Overall, 47 species (including 9 NIS), 45 (8 NIS) and 86 (2 NIS) were collected in Porto Sole, Porto Vecchio and Ospedaletti, respectively. Number and proportion of NIS were significantly lower in the unused marina of Ospedaletti in comparison with the other two ones, which in turn exhibited similar sessile assemblages and comparable NIS richness. The peculiarity of Ospedaletti fouling community, despite the geographical proximity and similar habitat conditions of the other marinas, highlights the role of boating traffic in facilitating NIS settlement, while the sole presence of artificial substrates is not sufficient to promote NIS introduction. This site could provide opportunities for experimenting novel NIS management measures.

Using biophysical modelling and marine connectivity to assess the risk of natural dispersal of non-indigenous species to comply with the Ballast Water Management Convention

The introduction of Marine Non-Indigenous Species (NIS) poses a significant threat to global marine biodiversity and ecosystems. To mitigate this risk, the Ballast Water Management Convention (BWMC) was adopted by the UN International Maritime Organisation (IMO), setting strict criteria for discharges of ballast water. However, the BWMC permits exemptions for shipping routes operating within a geographical area, known as a Same-Risk-Area (SRA). An SRA can be established in areas where a risk assessment (RA) can conclude that the spread of NIS via ballast water is low relative to the predicted natural dispersal. Despite the BWMC's requirement for RAs to be based on modelling of the natural dispersal of NIS, no standard procedures have been established. This paper presents a methodology utilizing biophysical modelling and marine connectivity analyses to conduct SRA RA and delineation. Focusing on the Kattegat and Øresund connecting the North Sea and Baltic Sea, we examine two SRA candidates spanning Danish and Swedish waters. We provide an example on how to conduct an RA including an RA summary, and addressing findings, challenges, and prospects. Our study aims to advance the development and adoption of consistent, transparent, and scientifically robust SRA assessments for effective ballast water management.

Intra-decadal increase in globally-spread Magallana gigas in southern California estuaries.

Introduction and establishment of non-indigenous species (NIS) has been accelerated on a global scale by climate change. NIS Magallana gigas' (formerly Crassostrea gigas') global spread over the past several decades has been linked to warming waters, specifically during summer months, raising the specter of more spread due to predicted warming. We tracked changes in density and size distribution of M. gigas in two southern California, USA bays over the decade spanning 2010-2020 using randomly placed quadrats across multiple intertidal habitats (e.g., cobble, seawalls, riprap) and documented density increases by 2.2 to 32.8 times at 7 of the 8 sites surveyed across the two bays. These increases in density were coincident with 2-4° C increases in median monthly seawater temperature during summer months, consistent with global spread of M. gigas elsewhere. Size frequency distribution data, with all size classes represented across sites, suggest now-regular recruitment of M. gigas. Our data provide a baseline against which to compare future changes in density and abundance of a globally-spread NIS of significant concern.

Recreational vessel networks reveal potential hot spots for marine pest introduction and spread

Abstract Recreational vessels are an important pathway for spreading marine non‐indigenous species (NIS) around coastal environments globally. However, most vessels are not tracked, limiting our ability to map their movements and identify locations at greater risk of NIS introductions. Using New Zealand as a case study, we quantified spread and risk patterns of recreational vessel movements, using a web‐based survey allowing the more than 1,800 respondents to map significant trips with over 12,000 visits. These vessel routes were used to build a network model representing nationwide recreational vessel movements. Two proxies were used to quantify the risk of introduction of marine NIS: (i) incoming hull length and (ii) cumulative residency periods at sites. There was significant variation in the distances travelled, the destinations they visited and the duration of their stays. New Zealand's recreational boating network contained 317 destinations with over 4,000 unique connections, concentrated within two distinct areas of the country. Network‐based metrics and risk proxies quantified the relative importance of domestic locations as incursion or spreading hubs for NIS. This approach highlighted several areas that pose high relative biosecurity risk within the national network, but are underrepresented within current surveillance programmes. Synthesis and applications. Our study demonstrates how the movement dynamics of recreational vessels can be quantified at a regional scale to inform proactive management. The identification of spreading hubs and locations at particular risk of NIS introductions, enables managers to design risk‐based and effective surveillance and monitoring programmes. Our network‐based approach to determine the biosecurity implications posed by recreational vessels is transferable to other parts of the world. It enables managers to understand the distribution of risk within an area of interest (e.g. a jurisdiction) and develop optimised approaches for mitigating impact.

Microporella hastingsae Harmelin, Ostrovsky, Cáceres-Chamizo and Sanner, 2011 (Bryozoa, Cheilostomatida): a possible new Lessepsian species in the Mediterranean Sea?

The introduction of Non-Indigenous Species (NIS) in the Mediterranean Sea is one of the main threats to biodiversity and its increasing frequency could bring a significant ecological impact on native species. However, knowledge of marine bioinvasions, the spreading patterns of NIS and their possible pathways of dispersion is still limited, especially for particular taxonomic groups. In this paper, we report the first Mediterranean record of a colony of a non-indigenous bryozoan, Microporella hastingsae Harmelin, Ostrovsky, Cáceres-Chamizo and Sanner, 2011, found on plastic litter stranded south of Catania (Sicily, western Ionian Sea) during spring 2023. Based on this colony, a formal taxonomic description of M. hastingsae is provided for this species, which was recently erected for old, misidentified material collected in the early twentieth century in the Suez Canal and the north Red Sea. We suggest that the species could be considered a Lessepsian migrant assuming it entered the Mediterranean Sea at any time, through larval dispersal and/or the possible facilitation by human activities, presumably shipping. Further surveys in coastal localities of Sicily and the eastern Mediterranean are needed to confirm the establishment of M. hastingsae or if the present colony only represents an occasional record of the species in the basin.

Quantifying the probability of a successful marine bioinvasion due to source-destination risk factors.

The increasing spread of marine non-indigenous species (NIS) due to the growth in global shipping traffic is causing widespread concern for the ecological and economic impacts of marine bioinvasions. Risk management authorities need tools to identify pathways and source regions of priority concern to better target efforts for preventing NIS introduction. The probability of a successful NIS introduction is affected by the likelihood that a marine species entrained in a transport vector will survive the voyage between origin and destination locations and establish an independently reproducing population at the destination. Three important risk factors are voyage duration, range of environmental conditions encountered during transit and environmental similarity between origin and destination. In this study, we aimed for a globally comprehensive approach to assembling quantifications of source-destination risk factors from every potential origin to every potential destination. To derive estimates of voyage-related marine biosecurity risk, we used computer-simulated vessel paths between pairs of ecoprovinces in the Marine Ecoregions Of the World biogeographic classification system. We used the physical length of each path to calculate voyage duration risk and the cross-latitudinal extent of the path to calculate voyage path risk. Environmental similarity risk was based on comparing annual average sea surface temperature and salinity within each ecoprovince to those of other ecoprovinces. We derived three separate sets of risk quantifications, one each for voyage duration, voyage path and environmental similarity. Our quantifications can be applied to studies that require source-destination risk estimates. They can be used separately or combined, depending on the importance of the types of source-destination risks that might be relevant to particular scientific or risk management questions or applications.

National assessment on the status, trends and impacts of marine non-indigenous species for the European Union marine strategy framework directive

The Marine Strategy Framework Directive (MSFD) of the European Union aims to enhance the protection of marine ecosystems by assessing Good Environmental Status using several descriptors. Descriptor 2 of the MSFD states that the status of marine non-indigenous species (NIS) should be assessed using specified criteria regarding newly introduced NIS, abundance, and spatial distribution of established NIS, as well as proportions of native species groups adversely altered due to NIS. The current study presents a national NIS indicator assessment for the six sub-basins associated with the Finnish marine waters. The study additionally aimed to develop a methodology to assess changes in native species communities over time. A new biodiversity index was created for this purpose by combining the Gini-Simpson index, and species and phyla richness into a Community Biodiversity Index (CBI). CBI was calculated to measure changes in biodiversity within the soft-bottom benthic communities of the study area, and correlation analyses were conducted between the index scores and NIS proportion. Overall, 34 NIS have been recorded from the Finnish marine waters by 2022, and more than half of them have arrived since 1992. Spatial distribution of three established non-indigenous taxa (Marenzelleria spp., Cercopagis pengoi and Neogobius melanostomus) has expanded during the latest assessment periods and nowadays cover most of the national marine waters. Meanwhile, abundance of Marenzelleria spp. in benthic communities has increased heavily in most sub-basins. The study outcomes indicated that NIS proportion correlated significantly with the CBI within the soft-bottom benthic communities. This correlation was significantly negative for the samples with a higher NIS proportion than the median, suggesting that when NIS became more dominant, biodiversity of the communities decreased. The current study provides an applicable method to evaluate changes in biodiversity for various species groups, and how to link them to changes in the distribution and abundance of established NIS. It can be concluded that the national biological monitoring program has severe temporal and spatial gaps, as the national monitoring data enabled the assessment on native species groups, adversely altered due to NIS to be completed only for one species group, soft-bottom macrozoobenthos. Most importantly, the study emphasised the crucial need for management actions to prevent further NIS introductions.

Non-Indigenous Freshwater Fishes as Indicators of Ecological Quality in Running Waters

The European Union Water Framework Directive (WFD) is a comprehensive initiative guiding river basin water management, addressing pressures such as pollution from diffuse and point sources, and hydromorphological alterations. However, pressures that can deteriorate the ecological quality of water bodies through biotic changes (i.e., by the introduction of non-indigenous species) are not rigorously addressed by the WFD. This study explores associations between conventional ecological quality indices based on physicochemical and biotic quality elements (fish and macroinvertebrates) against the presence and densities of non-indigenous freshwater fish species (NIFS) in lotic ecosystems of Greece, aiming to unravel the potential usage of NIFS in future ecological assessments. The dataset comprises 277 samplings at 115 sites, covering physicochemical and biotic (fish and macroinvertebrate) quality indices, and anthropogenic pressure variables. Based on our findings, the occurrence and densities of four NIFS (Lepomis gibbosus, Pseudorasbora parva, Gambusia holbrooki, and Carassius gibelio) were highly associated with the ecological quality assessments of the applied indices. Higher occurrences and densities of these NIFS were related to samplings of lower ecological quality. In addition, NIFS exhibited a positive association with anthropogenic pressures, likely due to their adaptability to less optimal environmental conditions or higher tolerance to pollution and other stressors. Our findings underscore the need for a paradigm shift in ecological quality assessments, emphasizing the use of NIFS either as a potential indicator of ecosystem health or as a pressure that deteriorates ecological quality.

Non-indigenous seaweeds in the Northeast Atlantic Ocean, the Mediterranean Sea and Macaronesia: a critical synthesis of diversity, spatial and temporal patterns

ABSTRACT Effective monitoring of non-indigenous seaweeds and combatting their effects relies on a solid confirmation of the non-indigenous status of the respective species. We critically analysed the status of presumed non-indigenous seaweed species reported from the Mediterranean Sea, the Northeast Atlantic Ocean and Macaronesia, resulting in a list of 140 species whose non-indigenous nature is undisputed. For an additional 87 species it is unclear if they are native or non-indigenous (cryptogenic species) or their identity requires confirmation (data deficient species). We discuss the factors underlying both taxonomic and biogeographic uncertainties and outline recommendations to reduce uncertainty about the non-indigenous status of seaweeds. Our dataset consisted of over 19,000 distribution records, half of which can be attributed to only five species (Sargassum muticum, Bonnemaisonia hamifera, Asparagopsis armata, Caulerpa cylindracea and Colpomenia peregrina), while 56 species (40%) are recorded no more than once or twice. In addition, our analyses revealed considerable variation in the diversity of non-indigenous species between the geographic regions. The Eastern Mediterranean Sea is home to the largest fraction of non-indigenous seaweed species, the majority of which have a Red Sea or Indo-Pacific origin and have entered the Mediterranean Sea mostly via the Suez Canal. Non-indigenous seaweeds with native ranges situated in the Northwest Pacific make up a large fraction of the total in the Western Mediterranean Sea, Lusitania and Northern Europe, followed by non-indigenous species with a presumed Australasian origin. Uncertainty remains, however, regarding the native range of a substantial fraction of non-indigenous seaweeds in the study area. In so far as analyses of first detections can serve as a proxy for the introduction rate of non-indigenous seaweeds, these do not reveal a decrease in the introduction rate, indicating that the current measures and policies are insufficient to battle the introduction and spread of non-indigenous species in the study area.

Exploring visual methods for monitoring marine non-indigenous species colonizing artificial structures in the Madeira archipelago (NE Atlantic)

The introduction of non-indigenous species (NIS) poses a significant threat to biodiversity in coastal communities globally, with maritime traffic serving as a primary vector for introducing these species into new habitats. Managing potential new marine invasions begins in harbours and marinas, where artificial structures are the first step towards establishing new habitats. In this study, we aimed to examine and compare the performance of three methods: Plate, Photo quadrate, and a new Video approach, using image analysis for monitoring fouling communities in artificial structures, with a specific focus on NIS in marinas. Additionally, we evaluated attributes for each method, including cost, area, deployment/sampling time, and logistics, to determine the most reliable, efficient, and affordable method with respect to species richness (S) and cover (N). The video (VID) method performed similarly to the plate (PLA) method in species identification and outperformed the photo (PHO) method. The VID method represents a novel and faster approach for monitoring NIS in artificial structures, offering several advantages. It allows data gathering that can be performed by non-taxonomic experts, facilitating rapid detection and intervention in managing marine invasions in port environments. By assessing the effectiveness of these methods, we sought to contribute to developing improved strategies and faster approaches for monitoring and mitigating the impact of NIS in coastal communities.

Estuarine versus coastal marinas: Influence of the habitat on the settlement of non-indigenous peracarids on the polychaete Sabella spallanzanii (Gmelin, 1791)

Recreational marinas are key points for the introduction and secondary spread of non-indigenous species (NIS). However, little is known about the influence of the habitat surrounding the marina on NIS communities. To explore this issue, we compared peracarid assemblages associated to the widespread ecosystem engineer Sabella spallanzanii in lower estuarine marinas (with oceanic salinity) and coastal marinas of the south of the Iberian Peninsula. Sabella spallanzanii hosted a total of 23 species, 7 of them NIS. While NIS richness was similar between marinas located in estuaries and coastal habitats, NIS abundance was significantly higher in estuarine marinas. The NIS community structure was influenced by both the marina itself and the surrounding habitat. These results suggest that lower estuarine conditions promote NIS abundance in marinas, increasing potential invasion risks. This supports prioritization of estuarine marinas in NIS monitoring programs and the suitability of S. spallanzanii as a bioinvasion monitoring tool.

A multi-taxa assessment of aquatic non-indigenous species introduced into Iberian freshwater and transitional waters

Aquatic ecosystems are particularly vulnerable to the introduction of non-indigenous species (NIS), leading to multi-faceted ecological, economic and health impacts worldwide. The Iberian Peninsula comprises an exceptionally biodiverse Mediterranean region with a high number of threatened and endemic aquatic species, most of them strongly impacted by biological invasions. Following a structured approach that combines a systematic review of available information and expert opinion, we provide a comprehensive and updated multi-taxa inventory of aquatic NIS (fungi, macroalgae, vascular plants, invertebrates and vertebrates) in Iberian inland waters. Moreover, we assess overall patterns in the establishment status, introduction pathways, native range and temporal introduction trends of listed NIS. In addition, we discuss the legal coverage provided by both national (Spanish and Portuguese) and European NIS regulations. We inventoried 326 aquatic NIS in Iberian inland waters, including 215 established, 96 with uncertain establishment status and 15 cryptogenic taxa. Invertebrates (54.6%) and vertebrates (24.5%) were the groups with the highest number of NIS, with Arthropoda, Mollusca, and Chordata being the most represented phyla. Recorded NIS originated from diverse geographic regions, with North and South America being the most frequent. Vertebrates and vascular plants were mostly introduced through intentional pathways (i.e. release and escape), whereas invertebrates and macroalgae arrived mostly through unintentional ways (i.e. contaminant or stowaway). Most of the recorded NIS were introduced in Iberian inland waters over the second half of the 20th century, with a high number of NIS introductions being reported in the 2000s. While only 8% of the recorded NIS appear in the European Union list of Invasive Alien Species of Union concern, around 25% are listed in the Spanish and Portuguese NIS regulations. This study provides the most updated checklist of Iberian aquatic NIS, meeting the requirements set by the EU regulation and providing a baseline for the evaluation of its application. We point out the need for coordinated transnational strategies to properly tackle aquatic invasions across borders of the EU members.

EDNA Metabarcoding Analysis as Tool to Assess the Presence of Non-Indigenous Species (NIS): A Case Study in the Bilge Water

One of the most important causes of biodiversity loss are non-indigenous species (NIS), in particular invasive ones. The dispersion of NIS mainly depends on anthropogenic activities such as maritime traffic, which account for almost half of the total NIS introduction in the European seas, as reported by the European Environmental Agency. For this reason, NIS management measures are mainly focused on commercial ports (i.e., ballast water management and Marine Strategy Framework Directive monitoring), underestimating the role of marinas and tourist harbors; these host small vessels (<20 m), such as recreational, fishery, and sail ones without ballast waters, but are also responsible for NIS arrival and spread through the bilge water as well as from hull fouling. With the aim of paying attention to marinas and tourist harbors and validating an innovative molecular methodology for NIS surveillance and monitoring, in the present work, eDNA metabarcoding of cytochrome oxidase subunit I (COI) was applied to both bilge waters and adjacent ones to assess species composition and particularly NIS presence. A total of 140 OTUs/species with extra-Mediterranean distribution were found in the bilge samples; several of these are most likely ascribed to food contamination (e.g., Salmo salar). Excluding food contamination species, twelve of these found in the bilge waters were already known as NIS in the Mediterranean Sea, belonging to algae, mollusks, crustaceans, annelids, echinoderms, and fishes. Nine of these species are new to Italian waters. The results obtained in the present work support the importance of NIS monitoring in marinas and small harbors, particularly in the bilge waters, through eDNA metabarcoding, having detected several potential NIS that otherwise would not have been discovered.

Ecosystem function modified by an invasive species: Density and distance dependent changes in sediment characteristics, fluxes, and benthic communities

Coastal marine benthic ecosystems are considered hotspots for biodiversity and productivity. However, the introduction of bio-engineering non-indigenous species can alter the delivery of key functions and services provided by these systems. Here, we investigated the influence of Sabella spallanzanii, a large structure-forming invasive polychaete, on a marine soft-sediment system in New Zealand, examining effects on sediment characteristics (organic matter and chlorophyll a content), solute fluxes, and benthic communities near and far from low-, medium-, and high-density clumps of Sabella. Fluxes of dissolved oxygen and inorganic nitrogen near (<10 cm) Sabella clusters were significantly lower to those 1 m away, and fluxes differed between low-, medium-, and high-density clumps. Larger densities of Sabella and clumps with greater overall biomass were associated with increased sediment oxygen consumption, particularly in areas 1 m distant from the Sabella clumps. Similarly, ammonium production (efflux from the sediment) increased with increasing Sabella biomass at the 1 m ‘distal’ sites (from 0 μ to 40 μmol/m2/h), but NOx efflux decreased (from 5 to 0 μmol/m2/h) with distance. The flux results were consistent with findings of higher organic matter content and finer grain size sediment in ‘distal’ plots to Sabella clusters. We also showed how benthic diversity and abundance increased with increasing Sabella clump biomass. Our investigation suggests that the building of biogenic structures and the filter feeding activity by Sabella may alter near-bed flows and concentrations of organic rich biodeposits in surrounding sediments, with ramifications for organic matter distribution and nutrient recycling rates. The continuous expansion and colonisation of Sabella could reshape local benthic communities and increase oxygen consumption rates in affected marine sediments.

The African Striped Grunt, Parapristipoma octolineatum (Valenciennes, 1833), in the Mediterranean Sea: The Third Record with Biological and Ecological Notes, and Identification Key for Haemulidae Recorded in the Mediterranean

The Mediterranean Sea biodiversity is undergoing a rapid reshaping due to different factors, many of which are directly related to human activities (e.g., pollution, habitat destruction, overfishing and introduction of non-indigenous species). In this context, climate changes, and in particular water warming, are the main factors that favor the arrival and subsequent spread of thermophilic species, regardless of their area of origin (e.g., Red Sea, Atlantic Ocean). In this research, we report the third and eastern-most well-documented record of the thermophilic species Parapristipoma octolineatum (Valenciennes, 1833) in the Mediterranean Sea, providing new morphological, genetic, ecological and biological data on this rare species in the basin. The integrative taxonomical approach was robust and unambiguously identified the species as P. octolineatum. The specimen was a large-sized female in maturation. The first high-quality photographic illustrations of otoliths were provided. Recent direct observations of fishermen in the area suggested a species abundance increase. However, data from the Mediterranean Sea remain scarce and further efforts are needed to better understand the abundance and distribution of this species. Modified keys for a rapid color pattern-based determination of all Haemulidae species recorded in the Mediterranean Sea to date are also provided. Finally, the potential further expansion under the future prediction of climate changes of this Atlantic origin fish in the Mediterranean Sea is discussed.

Validated Inventories of Non-Indigenous Species (NIS) for the Mediterranean Sea as Tools for Regional Policy and Patterns of NIS Spread

This work presents refined, updated subregional and regional non-indigenous species (NIS) inventories for the Mediterranean Sea, validated by national and taxonomic experts, with species records observed until December 2020. These datasets will be used as the baselines for the implementation of the Integrated Monitoring and Assessment Programme for the Mediterranean (IMAP) and the Mediterranean Quality Status Report 2023. In total, 1006 non-indigenous species have been found in Mediterranean marine and brackish waters. The highest numbers of NIS were observed in Israel, Türkiye, Lebanon and Italy. Approximately 45 species were categorized as data deficient, either due to lack of consensus on their alien status or the validity of their identification. Polychaeta, Foraminifera and macroalgae were the groups with the highest numbers of controversial species. There was a general increase in the yearly rate of new NIS introductions after the late 1990s, which appears to be slowing down in the last decade, but this may be confounded by reporting lags and differential research efforts. Between 1970 and 2020 there has been a steep increase in the proportion of shared species present throughout all four Mediterranean subregions, which are predominantly transported via shipping and recreational boating. While Lessepsian species are gradually spreading westwards and northwards, there is still a considerable invasion debt accumulating in the eastern and central Mediterranean.