Introduction Of Non-indigenous Species Research Articles

Current limitations and future prospects of detection and biomonitoring of NIS in the Mediterranean Sea through environmental DNA

The biodiversity of the Mediterranean Sea is currently threatened by the introduction of Non-Indigenous Species (NIS). Therefore, monitoring the distribution of NIS is of utmost importance to preserve the ecosystems. A promising approach for the identification of species and the assessment of biodiversity is the use of DNA barcoding, as well as DNA and eDNA metabarcoding. Currently, the main limitation in the use of genomic data for species identification is the incompleteness of the DNA barcode databases. In this research, we assessed the availability of DNA barcodes in the main reference libraries for the most updated inventory of 665 confirmed NIS in the Mediterranean Sea, with a special focus on the cytochrome oxidase I (COI) barcode and primers. The results of this study show that there are no barcodes for 33.18% of the species in question, and that 45.30% of the 382 species with COI barcode, have no primers publicly available. This highlights the importance of directing scientific efforts to fill the barcode gap of specific taxonomic groups in order to help in the effective application of the eDNA technique for investigating the occurrence and the distribution of NIS in the Mediterranean Sea.

What evidence exists on how changes in marine ecosystem structure and functioning affect ecosystem services delivery? A systematic map protocol

BackgroundThe current biodiversity crisis calls for an urgent need to sustainably manage human uses of nature. The Ecosystem Services (ES) concept defined as « the benefits humans obtain from nature » support decisions aimed at promoting nature conservation. However, marine ecosystems, in particular, endure numerous direct pressures (e.g., habitat loss and degradation, overexploitation, pollution, climate change, and the introduction of non-indigenous species) all of which threaten ecosystem structure, functioning, and the very provision of ES. While marine ecosystems often receive less attention than terrestrial ecosystems in ES literature, it would also appear that there is a heterogeneity of knowledge within marine ecosystems and within the different ES provided. Hence, a systematic map on the existing literature will aim to highlight knowledge clusters and knowledge gaps on how changes in marine ecosystems influence the provision of marine ecosystem services. This will provide an evidence base for possible future reviews, and may help to inform eventual management and policy decision-making.MethodsWe will search for all evidence documenting how changes in structure and functioning of marine ecosystems affect the delivery of ES, across scientific and grey literature sources. Two bibliographic databases, Scopus and Web of Science Core Collection, will be used with a supplementary search undertaken in Google scholar. Multiple organisational websites related to intergovernmental agencies, supra-national or national structures, and NGOs will also be searched. Searches will be performed with English terms only without any geographic or temporal limitations. Literature screening, against predefined inclusion criteria, will be undertaken on title, abstract, and then full texts. All qualifying literature will be subjected to coding and meta-data extraction. No formal validity appraisal will be undertaken. Indeed, the map will highlight how marine ecosystem changes impact the ES provided. Knowledge gaps will be identified in terms of which ecosystem types, biodiversity components, or ES types are most or least studied and how these categories are correlated. Finally, a database will be provided, we will narratively describe this evidence base with summary figures and tables of pertinent study characteristics.

Invasive species increase biodiversity and, therefore, services: An argument of equivocations

AbstractSome critics of invasion biology have argued the invasion of ecosystems by nonindigenous species can create more valuable ecosystems. They consider invaded communities as more valuable because they potentially produce more ecosystem services. To establish that the introduction of nonindigenous species creates more valuable ecosystems, they defend that value is provisioned by ecosystem services. These services are derived from ecosystem productivity, the production and cycling of resources. Ecosystem productivity is a result of biodiversity, which is understood as local species richness. Invasive species increase local species richness and, therefore, increase the conservation value of local ecosystems. These views are disseminating to the public via a series of popular science books. Conservationists must respond to these views, and I outline a method of rejecting such arguments against controlling invasive species. Ecological systems are valuable for more than local productivity and biodiversity is not accurately described by a local species count.

Plankton diversity in Anthropocene: Shipping vs. aquaculture along the eastern Adriatic coast assessed through DNA metabarcoding

Coastal ecosystems globally are exposed to the most pervasive anthropogenic activities, caused by a suite of human infrastructure and enterprises such as shipping ports, aquaculture facilities, fishing, and tourism. These anthropogenic activities may lead to changes in ecosystem biodiversity, followed by loss of ecosystem functioning and services. Shipping industry and aquaculture have also been recognized as the main vectors for introduction of marine non-indigenous species (NIS) worldwide. In this study, we used DNA metabarcoding-based methods to investigate plankton biodiversity under varying anthropogenic pressures (shipping and bivalve aquaculture) along the eastern Adriatic coast (the northernmost part of the Mediterranean Sea). Our comparative assessment revealed similar community structures among investigated coastal locations (Northern, Central and Southern Adriatic). When the whole plankton communities were considered, they did not differ significantly between port and aquaculture sites. However, the proportion of the unique zOTUs in the port samples was remarkably higher than that in aquaculture sites (40.5% vs 8.2%), indicating that port areas may receive higher abundance and species richness of NIS than aquaculture sites. Further important difference between the two types of anthropogenically impacted habitats was a high abundance of three notorious invaders – M. leidyi, M. gigas, and H. elegans in late summer at the aquaculture site in Northern Adriatic. Therefore, the plankton community of the area is under pressure not only from aquaculture activities, but also establishment of NIS. Port areas are probably under greater introduction pressure from NIS, but aquaculture sites may experience greater community changes due to their establishment.

Distribution of the seagrass Halophila stipulacea: A big jump to the northwestern Mediterranean Sea

The Red Sea and Indian Ocean seagrass Halophila stipulacea entered the Mediterranean in the late 19th century via the Suez Canal. Here, we report on the discovery of a population of H. stipulacea covering 16.5 ha off the harbour of Cannes, French Riviera, France. This represents the northernmost locality of the species and a jump of 350 km to the north from its closest western Mediterranean locality (Razza di Juncu in Sardinia). At Cannes, it was found dwelling between 11 and 17 m depth on a dead matte of Posidonia oceanica. The species has most probably been introduced through mega-yacht or cruise ship anchoring since the Bay of Cannes is among the most highly-frequented places for luxury yachting and tourism. The lack of effective regulation to prevent the introduction of non-indigenous species in France and Europe is highlighted.

Does Sand Beach Nourishment Enhance the Dispersion of Non-Indigenous Species?—The Case of the Common Moon Crab, Matuta victor (Fabricius, 1781), in the Southeastern Mediterranean

Sand beach nourishment (BN) is one of the commonest “soft solutions” for shore protection and restoration. Yet it may have ecological consequences. Can this practice enhance the introduction and dispersal of non-indigenous species (NIS)? There has been little research on the impacts of nourishment on NIS, especially in the southeastern Mediterranean, a region considered most affected by invading biota. However, so far only one study referred to the possible interaction between BN and the success of invading species. It reports increasing numbers and densities of the aggressive, omnivorous Indo-Pacific moon crab, Matuta victor (Fabricius, 1781) in Haifa Bay (northern Israel) between 2011 and 2017. This research suggests a possible role of anthropogenic disturbance in the outbreak of M. victor and blames the Israel Ministry of Environmental Protection for authorizing a (rather small scale) BN in Haifa Bay in 2011 as an alleged cause for this outbreak. Circumstantial indirect evidence is not sufficient to establish the role of nourishment in promoting the establishment and dispersal of NIS. There are plenty of examples of successful settlement and rapid and large-scale distribution of NIS (including another member of the genus Matuta), especially in the eastern Mediterranean, without any BN in the region. Furthermore, the location where the M. victor specimens were sampled was exposed to more prevailing and frequent anthropogenic marine stressors than BN, such as eutrophication, pollution, fishing activities and particularly port construction. To firmly establish an assumed role of nourishment in the invasion of NIS, assessments must be based on solid and orderly planned scientific research to be designed well before the beginning of any BN. It is suggested that direct communication between environmental regulators and scientists is crucial for improving both scientific research and environmental management policies.

Monitoring Non-indigenous Species in Port Habitats: First Application of a Standardized North American Protocol in the Mediterranean Sea

Baseline port monitoring for fouling communities is an essential tool to assess non-indigenous species (NIS) introduction and spread, but a standardized and coordinated method among Mediterranean and European countries has not yet been adopted. In this context, it is important to test monitoring protocols that allow for the collection of standardized and directly comparable data, replicated across time and space. Here, for the first time in the Mediterranean Sea, we tested a standardized protocol developed by the Smithsonian Environmental Research Center (SERC) and used now in several countries. The 3-year monitoring survey (2018–2020) was conducted in the Gulf of La Spezia (Ligurian Sea, Italy), with the deployment of a total of 50 PVC panels per year in five different sites (a commercial harbor, three marinas and a site in the proximity of a shellfish farm). A total of 79 taxa were identified, including 11 NIS, ranging from zero to seven NIS for each panel. In comparison with previous surveys, new NIS arrivals were observed in the Gulf of La Spezia: Botrylloides cf. niger, Branchiomma sp., Branchiomma luctuosum, Paraleucilla magna, and Watersipora arcuata. At the end of the 3-year monitoring, mean richness? and percent cover of NIS were measured, and both measures differed across the monitoring sites, with higher values in two marinas and in the commercial harbor. Among years, richness of NIS was relatively stable at each monitoring site. The structure of the fouling was influenced more by native and cryptogenic species than by NIS. Moreover, among the monitoring sites, the density of artificial structures was not a reliable predictor or proxy for local NIS abundance. This first application of the SERC method in the Mediterranean Sea, demonstrates both pros and cons, including the detection of new NIS reported here. Further direct comparisons with other NIS monitoring tools are recommended, and additional tests to assess its effectiveness in this biogeographical area are encouraged. A broader application of this and other standard methods across temporal and spatial scales in the Mediterranean basin should be implemented, providing critical data needed to assess changes in the structure of fouling communities.

Applying Limnological Feature-Based Machine Learning Techniques to Chemical State Classification in Marine Transitional Systems

On a global scale, marine transitional waters have been severely impacted by anthropogenic activities. Historically, developing human civilizations have often settled in coastal areas with about 2/3 of the human population inhabiting areas within 20-km range from coastal areas. Environmental management worldwide strives for sustainable development while minimizing impacts to ecosystem integrity and has resulted in several framework directives, management programs, and legislation compelling governments to monitor their coastal systems and improve environmental quality. Among the most significant anthropogenic impacts to these ecosystems are land reclamation, dredging, pollution (sediment discharges, hazardous substances, litter, oil spills, and eutrophication), unsustainable exploitation of marine resources (sand extraction, oil and gas exploitation, and fishing), unmanaged tourism activities, the introduction of non-indigenous species, and climate change. The multitude of stressors is not independent, and as such, the chemical status of marine systems has serious implications on its ecological status and needs to be addressed efficiently. Public monitoring databases provide a large amount of physico-chemical (nutrient, dissolved oxygen, and chlorophyll a concentration) and contaminant (trace metals and polycyclic aromatic hydrocarbons) data for all Portuguese transitional systems (estuaries and coastal lagoons). These data are used to classify the chemical status (eutrophication and contamination level) of these ecosystems considering pre-defined classification thresholds, which facilitates communication to government authorities and management entities. Artificial intelligence and machine learning techniques provide an automated and efficient opportunity to improve simulation accuracy and further advance our understanding of environmental problems in estuarine and coastal waters when dealing with large environmental datasets. In the present work, we applied machine learning models, namely, linear discriminant analysis, classification tree, naive Bayesian, and support vector machine, to nutrient, dissolved oxygen, chlorophyll a, trace metals, and polycyclic aromatic hydrocarbon concentrations to produce a chemical status classification of the Portuguese marine transition systems. This approach allowed us to efficiently classify in an automated way the transitional water’s chemical status within the pre-defined classification thresholds, producing numerical index values that can easily be communicated to the general public and managers alike.

Proxy-based model to assess the relative contribution of ballast water and biofouling’s potential propagule pressure and prioritize vessel inspections

Commercial shipping is the primary pathway of introduction for aquatic nonindigenous species (NIS), mainly through the mechanisms of ballast water and biofouling. In response to this threat, regulatory programs have been established across the globe to regulate and monitor commercial merchant and passenger vessels to assess compliance with local requirements to reduce the likelihood of NIS introductions. Resource limitations often determine the inspection efforts applied by these regulatory agencies to reduce NIS introductions. We present a simple and adaptable model that prioritizes vessel arrivals for inspection using proxies for potential propagule pressure (PPP), namely a ships’ wetted surface area as a proxy for the likelihood of biofouling-mediated PPP and ballast water discharge volume as a proxy for ballast water-mediated PPP. We used a California-specific dataset of vessels that arrived at California ports between 2015 and 2018 to test the proposed model and demonstrate how a finite set of inspection resources can be applied to target vessels with the greatest PPP. The proposed tool is adaptable by jurisdiction, scalable to different segments of the vessel population, adjustable based on the vector of interest, and versatile because it allows combined or separate analyses of the PPP components. The approach can be adopted in any jurisdiction across the globe, especially jurisdictions without access to, or authority to collect, risk profiling data or direct measurements for all incoming vessel arrivals.

Developing a conceptual influence diagram for socio-eco-technical systems analysis of biofouling management in shipping – A Baltic Sea case study

Ship hulls create a vector for the transportation of harmful non-indigenous species (NIS) all over the world. To sustainably prevent NIS introductions, the joint consideration of environmental, economic and social aspects in the search of optimal biofouling management strategies is needed. This article presents a multi-perspective soft systems analysis of the biofouling management problem, based on an extensive literature review and expert knowledge collected in the Baltic Sea area during 2018–2020. The resulting conceptual influence diagram (CID) reveals the multidimensionality of the problem by visualizing the causal relations between the key elements and demonstrating the entanglement of social, ecological and technical aspects. Seen as a boundary object, we suggest the CID can support open dialogue and better risk communication among stakeholders by providing an illustrative and directly applicable starting point for the discussions. It also provides a basis for quantitative management optimization in the future.

Non-indigenous freshwater fish research in Greece: Current status and future prospects

Many studies around the globe have documented that the introduction of non-indigenous fish species (NIFS) may pose severe impacts on native biota, ecosystem functioning, and ecosystem services. In Greece, publications on NIFS have increased in recent decades, however, review studies of past and current scientific research on freshwater NIFS in the country are currently lacking. Τhe aim of the present study was to: (a) assess the current state of knowledge of freshwater NIFS in Greece based on the existing scientific literature, (b) evaluate well-studied areas of NIFS research, and (c) identify important gaps that may direct national authorities to implement appropriate research, management and conservation actions reversing the negative impacts of NIFS. A systematic literature review on NIFS research within Greek inland waters was performed by applying the PRISMA methodology (Preferred Reporting Items for Systematic Reviews and Meta-Analyses). Overall, our initial search resulted in 2,794 published articles, 87 of which met our selection criteria and were thus included for full analysis. Evidently, NIFS failed to attract the interest of ecologists in Greece until the turn of the century, at which point, publications increased at a rapid rate. However, the majority of the studies were mainly monothematic concerning NIFS distribution within freshwater ecosystems of Greece (37%), followed by studies on ecological and biological aspects of NIFS (28%). Studies based on fieldwork and laboratory experiments were by far the most common type of research, followed by studies based on bibliographic data. Despite the fact that almost half of the publications were field observational studies, most of them used only qualitative data (plain presence/absence data). Critical aspects of impact assessment were missing; 84% of the reviewed studies did not provide any concrete evidence of NIFS impacts to native biota. Overall, the focus of the studies was uneven, with important gaps in areas of theoretical and practical importance for policy-relevant detection, control, and management of NIFS. Findings may assist researchers in filling scientific gaps identified by our review and guide authorities to define national priorities to prevent and control the spread of NIFS within the country.

Macroalgae niche modelling: a two-step approach using remote sensing and in situ observations of a native and an invasive Asparagopsis

We are facing a global loss of biodiversity due to climate change. This will lead to unpredictable changes in ecosystems, affecting the goods and services they provide introduction of non-indigenous marine species. This represents one of the major threats to marine biodiversity and therefore, there is a strong need to assess, map and monitor these alien species. The appearance of non-indigenous species is especially dangerous in fragile ecosystems and it is of great importance to better understand the invasion mechanisms of these invasive species. This is the case for invasive alga Asparagopsis armata, present in the Azores Archipelago. In this study we propose a methodology to define the realized ecological niche of this invasive alga, alongside the native Asparagopsis taxiformis, to understand better its distribution and potential impact on native communities and ecosystem services. These objectives comply with the EU Biodiversity strategy for 2020 goals and the need to map and assess ecosystems and their services. The lack of reliable high-resolution data makes this a challenging task. Within this scope, we propose a combination of Remote Sensing, Unmanned Aerial Vehicle based imagery together with in-situ field data to build ecological niche modelling approaches as a cost-effective methodology to identify and characterize vulnerable marine ecosystems. Our results show that this combination can help achieve monitoring, leading to a better understanding of ecological niches and the consequences of non-indigenous species invasion in fragile ecosystems, like small islands, when faced with limited data.

Meta-analysis on the ecological impacts of widely spread non-indigenous species in the Baltic Sea

The introduction of non-indigenous species (NIS) is a major driver for global change in species biogeography, often associated with significant consequences for recipient ecosystems and services they provide for humans. Despite mandated by several high-level international legislative instruments, comprehensive quantitative evaluation on ecosystem impacts of marine NIS is scarce and lack a robust and data-driven assessment framework. The current study is aiming at fulfilling this gap, through quantitative assessment on the effects of the widespread NIS of the Baltic Sea on multiple ecosystem features and components including direct food-web effects. The outcomes of this study allowed identifying the most impacting widespread NIS, together with defining the processes underlying the most significant changes and outlined major sources of uncertainty. Lack and/or bias in the availability of evidence of impacts was recorded for several (both recent and early) introductions. Realizing a sophisticated, data and information-hungry framework for the evaluation of ecosystem impacts of NIS is not pragmatic for management purposes in the foreseeable future. Instead, simple approaches, such as application of common statistical parameters like absolute effect size, are more likely to result in tangible outcomes. As bearing no unit, effect sizes can be later easily aggregated across taxa, affected ecosystem features or spatial scales. The proposed approach enables performing systematic comparisons on the severity of impacts of different NIS along different study disciplines and ecosystems.

Anthropogenic Modifications to Estuaries Facilitate the Invasion of Non-Native Species

New observations of non-indigenous species (NIS) in coastal waters, such as the Gulf of Cadiz (Spain) have increased since 1980 and more or less exponentially in the last five years. Ballast water has become the most significant pathway for unintentional introductions of NIS into marine ecosystems. For example, the marine larvae of crustacean decapods that inhabit the water column could be transported in ballast water. Although elevated concentrations of metals are toxic to many marine organisms, some of them have evolved effective detoxification, or avoidance mechanisms making it possible to consider they have a superior ability to withstand exposures to these toxicants. In this text, we try to reinforce the hypothesis that anthropogenic modifications (such as chemical alterations and modified environments) benefit NIS with broad environmental tolerances. Taking these risks into account, a reinforcement of efficient Ballast Water Management Systems to respond to today’s challenging environmental conditions is discussed.

The non-indigenous Oithona davisae in a Mediterranean transitional environment: coexistence patterns with competing species

The Venice lagoon (VL) has been recognized as a hot spot of introduction of non-indigenous species (NIS), due to several anthropogenic factors and environmental stressors that combined may facilitate NIS invasions. In the last decades an increasing number of zooplankton NIS have been observed in the VL. This work aims to provide a picture of the annual cycle and distribution of the recently recorded non-indigenous copepod Oithona davisae, considering the coexistence patterns with the congeneric resident Oithona nana. Therefore, zooplankton samplings were carried out monthly from August 2016 to July 2017 at five Long-Term Ecological Research LTER stations in the VL. Oithona davisae showed a persistent occurrence throughout the year with the highest abundances in the warm season and in the inner areas, while the congeneric O. nana, showing a different distribution pattern, resulted more abundant near the inlets of the Lagoon, where O. davisae reached the minimum density. Oithona davisae seems to find local conditions that promote its settlement and distribution, especially in the inner and more trophic lagoon sites. In other European coastal embayments or transitional waters, O. davisae occupied the niche left by the indigenous O. nana or can replace this congeneric species through competitive exclusion mechanisms. Our data indicate that, for now, such species replacement has not occurred in the VL. One of the causes is the extreme variety of habitats and niches offered by this environment allowing a balanced coexistence with O. nana and in general with the resident copepod community.

Non-indigenous and Invasive Freshwater Species on the Atlantic Islands of the Azores Archipelago

Freshwater systems on remote oceanic islands are particularly vulnerable to biological invasions. The case of freshwater ecosystems in the Azores Archipelago is especially relevant considering the islands’ youth and remoteness, and low natural connectivity. This study presents a review of the introduction and presence of non-indigenous freshwater species in the Azores, retrieved from various historical records, paleoenvironmental reconstructions, published records, and field data from two decades of the Water Framework Directive (WFD) monitoring programs. At least 132 non-indigenous freshwater species have successfully established in the Azores, belonging to several taxonomic groups: cyanobacteria (10), synurophytes (1), desmids (1), diatoms (20), plants (41), invertebrates (45), amphibia (2), and fishes (12). Intentional and accidental introductions have been occurring since the establishment of the first human settlers on the archipelago, impacting freshwater ecosystems. The first reported introductions in the Azores were intentional fish stocking in some lakes. Non-deliberate introductions have recently increased through transport-contaminants (51%) associated with the aquarium trade or agricultural products. In the Azores, the highest number of non-indigenous species occur on the largest and most populated island, São Miguel Island (116), followed by Flores (68). Plants constitute the most representative group of introduced species on all islands, but invertebrates, diatoms, and fishes are also well established on most islands. Among invertebrates, non-indigenous arthropods are the most well-established group on all islands except on the smallest Corvo Island. Many non-indigenous species will likely benefit from climate change and magnified by globalization that increases the probability of the movement of tropical and subtropical species to the Azores. Present trends in international trade, importations, and enhanced connectivity of the archipelago by increasing flights and shipping will probably promote the arrival of new species. Augmented connectivity among islands is likely to improve non-indigenous species dispersal within the archipelago as accidental transportation seems to be an essential pathway for non-indigenous freshwater species already present in the Azores.

Non-indigenous species likely introduced by shipping into the Adriatic Sea

By the intensification of maritime traffic, shipping could become one of the most likely pathways of introduction of non-indigenous species (NIS) in the Adriatic Sea. In this paper we provided an updated list of NIS introduced into Adriatic Sea by shipping as pathway, the most likely vectors of introduction, country of first detection, year, origin, establishing success and invasive characteristics. In total, 127 NIS were identified as the most probably introduced by maritime shipping into the Adriatic Sea. Rhodophyta, Arthropoda and Annelida represents almost 50% of all the listed species. The highest number of NIS introduced likely by shipping has been identified for period from 2001 to 2010 year. More than 73% of NIS listed for the first time in the Adriatic Sea were recorded in Italy. Half of listed NIS (50%) were probably introduced by external ship’s vector i.e. boat hull fouling (BHF). Majority of these species were classified as established. Screening of the potential risk of NIS being invasive in the Mediterranean and Adriatic Sea has not been done systematically, and for the most of NIS has never been performed. Increased number of sailing, motor recreational boats and cruise ships, lack on solutions for biofouling suppression and lack on regulations for anchoring may intensify NIS introductions by shipping as the most probable pathway into Adriatic Sea. That could become serious threat for native biodiversity and natural heritage, and it needs to be taken seriously by all relevant organisations and stakeholders.

Tracking Marine Alien Macroalgae in the Mediterranean Sea: The Contribution of Citizen Science and Remote Sensing

The accelerating rate of the introduction of non-indigenous species (NIS) and the magnitude of shipping traffic make the Mediterranean Sea a hotspot of biological invasions. For the effective management of NIS, early detection and intensive monitoring over time and space are essential. Here, we present an overview of possible applications of citizen science and remote sensing in monitoring alien seaweeds in the Mediterranean Sea. Citizen science activities, involving the public (e.g., tourists, fishermen, divers) in the collection of data, have great potential for monitoring NIS. The innovative methodologies, based on remote sensing techniques coupled with in situ/laboratory advanced sampling/analysis methods for tracking such species, may be useful and effective tools for easily assessing NIS distribution patterns and monitoring the space/time changes in habitats in order to support the sustainable management of the ecosystems. The reported case studies highlight how these cost-effective systems can be useful complementary tools for monitoring NIS, especially in marine protected areas, which, despite their fundamental role in the conservation of marine biodiversity, are not immune to the introduction of NIS. To ensure effective and long-lasting management strategies, collaborations between researchers, policy makers and citizens are essential.

Record of the non-indigenous species Sternaspis aff. nana Zhadan, Tzetlin & Salazar-Vallejo, 2017 (Annelida: Sternaspidae) in the Southwest Atlantic Ocean

The introduction of non-indigenous marine species in new habitats is generally associated with ships arriving at ports, driven by species transported in ballast water and sediment and biofouling communities on ship hulls, drifting object and underwater surfaces in dock areas. The present paper reports the record of the specie Sternaspis aff. nana in the Atlantic Ocean, discussing its possible conservation status and method of arrival to Brazil. Sediments samples were collected in the external area (11 m depth) of the Suape Harbor (Brazil) in February 2018. Two individuals of Sternaspis aff. nana were recorded, representing the first record of this species in the Southwest Atlantic Ocean. The way S. aff. nana arrived in Brazilian waters cannot be easily determined, the short-lived lecithotrophic larvae of sternaspids suggest that the specimens found in Suape have arrived in ballast sediment. An increase in trade between Brazil and Asian countries since the 2000s has led to that more ships coming from China having arrived in Brazilian harbors. The arrival of S. aff. nana, originally described in the South China Sea, in the Suape harbor area may have resulted from this intense movement of ships between China and Brazil.

Is the trend in new introductions of marine non-indigenous species a reliable criterion for assessing good environmental status? Τhe case study of Greece

This study presents the updated status of marine non-indigenous species (NIS) distribution in Greece and investigates trends in new NIS introductions, at both national and subnational level, during 1970-2017. The overall picture shows an increase in new introductions from the 1970s to 2017. The number of unaided introduced species (mainly Lessepsian immigrants) followed an upward trend in the South Aegean Sea until 2017. Similarly, the number of NIS associated with transport-stowaway (NIS introduced mainly via ballast and boat hulls) followed an upward until 2017 in the South Aegean Sea, but also in the Hellenic Levantine coasts. However, these results are greatly affected by a monitoring bias, which appears to be the main factor influencing the number of new NIS introductions reported from Greece and its subnational areas. This monitoring bias, as well as the continuous influx of Lessepsian NIS into the Aegean Sea, constitutes a challenge for Greece as regards setting exact boundaries for areas with or without Good Environmental Status (GES), based on Descriptor 2, primary criterion C1 (D2C1), of the Marine Strategy Framework Directive (MSFD). Dedicated monitoring of marine NIS should be established and be constant in space, time and across taxonomic groups. Prioritization should be given to hot-spot areas of new NIS introductions, such as ports, aquaculture units and marine protected areas. This should be a prerequisite for applying the primary criterion D2C1 of the MSFD properly, at both national and subnational level. Finally, as regards the implementation of D2C1 of the MSDF and setting exact threshold values, we highlight the need for subregional and regional coordination in the Mediterranean.