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Ballast water-mediated bioinvasion is a major threat to the health of aquatic ecosystems. Port environments are hotspots for marine bioinvasion due to ballast water uptake and discharge activities. As the first of its kind pilot study in a tropical ecosystem, we investigated short-term changes in the bacterial community at a port during ballast water discharge (BWD). Total bacterial count and total viable bacteria varied significantly in the port, which can be attributed to BWD. While Vibrio alginolyticus numbers increased, V. parahaemolyticus decreased during BWD, whereas total coliforms were reduced over time. Before BWD, Actinobacteria, β- and γ-proteobacteria were dominant at the port. However, Bacteroidetes and γ-proteobacteria were abundant after BWD, which may have been inoculated in the port through ballast water. Such a shift in bacterial diversity can alter the functional characteristics of the port and is a cause for concern. Investigating the long-term changes due to repeated inoculations will help in developing appropriate environmental management practices. [ABSTRACT FROM AUTHOR]

Pterois miles (Bennett, 1828), one of the most destructive marine invaders, was reported from the Mediterranean in 1991. It has invaded most parts of the Mediterranean from 2013, when it was reported for the second time, until today. On 7th October 2020, a single specimen of P. miles was collected by the bottom trawl from the Edremit Bay (Northern Aegean Sea). COI barcode region was used for the molecular identification of the specimen. DNA barcode data suggest that the specimen used in the present study is P. miles with a 99.69% probability. The current study is presented by providing the northernmost occurrence of the P. miles from the Aegean Sea with molecular confirmation. [ABSTRACT FROM AUTHOR]

Concern for marine bioinvasion has drawn international attention. The action plans in place to address this issue and those that are being promulgated are in need of a reassessment. A review of invertebrate invasions across the world indicates inter-linkages between vectors. In this paper an effort is made to illustrate the geographical spread of invasive invertebrate organisms from different bioregions and the possible causes for their success. Shipping, which is the major vector identified for the success of marine bioinvasion, needs to be addressed in tandem with domestic, intra- and inter-regional precautionary measures, as prevention is the only cure.

Mid-ocean ballast water exchange has been used since the past few years to control bioinvasion through ballast water (BW), which requires the ship to exchange part of its BW in the open ocean. The change in salinity is expected to be detrimental to coastal species. This study evaluates the changes in bacterial diversity with respect to salinity stress when translocated into an environment with non-ambient salinity. Surface water samples from three coastal ports, namely hypersaline Kandla port in Gujarat, saline Paradip port in Odisha, and freshwater Kolkata port in West Bengal, India were collected and aged in dark for 30 days to mimic BW tank conditions. The aged water samples were translocated into water collected from the estuarine mouth (Dona Paula), midestuary (Cortalim) and upstream location (Sanvordem) of Zuari Estuary, Goa and incubated in the laboratory. Quantitative polymerase chain reaction technique was used to assess major bacterial phyla. Culturable marine bacteria and Vibrio spp., including γ-proteobacteria preferred higher salinity, whereas culturable freshwater bacteria, including coliforms in conjunction with α-, β-proteobacteria, Bacteroidetes and Firmicutes preferred lower salinity. The fresh-water port bacteria could withstand salinity stress better than those from the hypersaline or saline ports. The species comprising these phyla could be region- and niche-specific. The invasive potential of these bacterial clades would depend on the environmental suitability of the recipient port. Studying the changes in the ecosystem of the port environment after BW discharge in real-time would provide meaningful insights into the invasive potential of these bacterial phyla. [ABSTRACT FROM AUTHOR]

The solitary ascidian Ciona intestinalis is among the most damaging of invasive fouling species in the world. It is mostly known from cold-water or temperate environments, where it is able to form dense aggregations. We present the first record of C. intestinalis type-A, now recognized as C. robusta, from the Eilat marina, Israeli Red Sea coast. Several individuals found fouling the bottom of the floating docks in March 2015 were identified using both mitochondrial sequencing and morphological tools. Periodical surveys revealed some of them with full gonoducts, and small individuals appeared two months later, indicating a reproductive population. The extremely high salinity and temperature at the Eilat marina indicates the wide environmental tolerance of this species. Since the only other report from this region dates to 100 years ago, from a dredging vessel at the entrance to the Suez Canal, and it has not since been recorded from any natural substrates in the region, it should be considered a non-indigenous species in the Red Sea. [ABSTRACT FROM AUTHOR]

Invasive ascidians (Chordata, Tunicata) are dominant nuisance organisms. The current study investigated the role of marine vessels in their dispersal and introduction. An examination of 45 dry-docked marine vessels, comprising recreational, commercial, and military craft, in five Israeli shipyards along the Mediterranean coast, revealed non-indigenous ascidians (NIA) on every second vessel investigated. Military vessels featured the highest ascidian abundance and richness, potentially related to their maintenance routine. Niche areas on the vessels such as sea chests and the propeller exhibited the highest occurrence of ascidians. Overall, these findings provide strong evidence that marine vessels play an acute role in NIA introduction and dispersal, with military vessels and niche areas on all the vessels being more susceptible to serving as vectors. A discovery of a new introduced species during the surveys suggests that the monitoring of marine vessels can serve as an effective tool for the early detection of NIA. [ABSTRACT FROM AUTHOR]

Few reports exist that describe marine non-native species in the Southern Ocean and near-shore waters around the Antarctic continent. Nevertheless, Antarctica's isolated marine communities, which show high levels of endemism, may be vulnerable to invasion by anthropogenically introduced species from outside Antarctica via vessel hull biofouling., Hull surveys of the British Antarctic Survey's RRS James Clark Ross were undertaken between 2007 and 2014 at Rothera Research Station on the Antarctic Peninsula (Lat. 67°34'S; Long. 68°07'W) to investigate levels of biofouling. In each case, following transit through scouring sea-ice, over 99% of the vessel hull was free of macroscopic fouling communities. However, in some surveys microbial/algal biofilms, balanomorph barnacles and live individuals of the cosmopolitan pelagic barnacle, Conchoderma auritum were found in the vicinity of intake ports, demonstrating the potential for non-native species to be transported to Antarctica on vessel hulls., Increasing ship traffic volumes and declining duration of sea ice in waters to the north and west of the Antarctic Peninsula mean the region may be at increased risk of non-native species introductions. Locations at particular risk may include the waters around popular visitor sites, such as Goudier Island, Neko Harbour, Whalers Bay, Cuverville Island and Half Moon Island, and around northern peninsula research stations., Simple and cost-effective mitigation measures, such as intentionally moving transiting ships briefly through available offshore sea ice to scour off accessible biofouling communities, may substantially reduce hull-borne propagule pressure to the region. Better quantification of the risk of marine non-native species introductions posed by vessel hulls to both Arctic and Antarctic environments, as sea ice patterns and shipping traffic volumes change, will inform the development of appropriate regional and international management responses., Copyright © 2016 The Authors. Published by Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Invasion by marine species, often considered a grave threat to marine ecosystems, occurs throughout the world as a consequence of many anthropogenic activities. In coastal Paraná, many factors including shipping, aquaculture and the use of artificial substrates provide suitable environments for the establishment and rapid spread of introduced marine species. To better understand this process, the encrusting community was studied on polyethylene plates (n = 120, 10 x 10 cm) that were placed seasonally at fixed locations on the inner continental shelf to detect non-native species. Of the 62 taxa found, 40 were identified to species, 14 of which were native, 9 introduced and 17 cryptogenic. We found a new introduction while most introduced species were previously reported at a nearby estuary with an international port. Possible complementary explanations for these detections are 1) estuaries influence ecological processes on the inner continental shelf, 2) the study area is near the route of cargo and other ships entering the port, 3) other local vectors, such as hulls of fishing and recreational boats, and artificial reefs link the estuary to the offshore areas. Thus, not only are estuaries invaded by exotic species, but also non-indigenous marine species may be present in the open sea where they are likely to colonize artificial substrates.

The number of biological invasions has grown dramatically in recent decades, as well as the world's human population and coastal development. Anthropogenic habitats, such as pier pilings and break waters, have been constantly added to marine environment, usually concentrated in estuarine areas. These habitats are focal points for marine invasions, but relatively little is known about the spread of non-indigenous species (NIS) to nearby natural habitats. This study aimed to determine the extent to which NIS have spread to natural substrates both inside estuarine areas and in the adjacent open sea. We conducted a field survey and a literature review, which have been critically discussed and validated. The updated NIS list of benthic invertebrates comprises 19 species: Ascidiacea (5), Cirripedia (5), Cnidaria (3), Mollusca (3), Polychaeta (1), Decapoda (1), and Echinodermata (1). Our results suggested substantial spread of non-indigenous species into natural substrates. Altogether, 18 and 16 NIS were recorded in artificial and natural substrata, both representing 13% of the total species in each habitat. The percentage of NIS was more pronounced in the estuarine areas, 17.6% in artificial habitats and 18.6% in natural ones. Programs developed for the monitoring of marine invasion have to broaden their focus including natural areas adjacent to ports and marinas, to follow the spread and impact of NIS on these areas. [ABSTRACT FROM AUTHOR]

The solitary ascidian Herdmania momus (Savigny, 1816) was first recorded in the Eastern basin of the Mediterranean, off the coast of Israel, in 1958. Since then, H. momus established along the shores of Israel, albeit restricted to artificial substrates (e.g., pier pillars, artificial reefs, and shipwrecks) and deeper waters (20-30 m) in comparison to its native range. It has recently spread to natural substrates (i.e. the rocky reef) and shallow water environments (< 1 m). Field surveys, augmented by observations by recreational divers, were conducted along the Israeli Mediterranean coast on natural substrates to assess the present distribution. H. momus was detected on natural substrates at eleven sites, some of them at very shallow depths. This change in the distribution of H. momus that now includes natural substrates in shallow waters along with deep water environments may have negative impacts on the native fauna in the Eastern Mediterranean. [ABSTRACT FROM AUTHOR]

Bacteria associated with plankton are of importance in marine bioinvasions and the implementation of ship’s ballast water treatment technologies. In this study, epibiotic and endobiotic bacteria associated with zooplankton, including barnacle nauplii, veliger larvae, and adults of the copepod Oithona sp., were characterized and quantified. Barnacle nauplius and veliger larva harbored ~4.4 × 10 5 cells ind −1 whereas Oithona sp. had 8.8 × 10 5 cells ind −1. Computation of bacterial contribution based on biovolume indicated that despite being the smallest zooplankton tested, veliger larvae harbored the highest number of bacteria, while barnacle nauplii, the largest of the zooplankton, tested in terms of volume contributed the least. Pulverization of zooplankton led to an increase in bacterial numbers; for example, Vibrio cholerae, which was initially 3.5 × 10 3, increased to 5.4 × 10 5 CFU g −1; Escherichia coli increased from 5.0 × 10 2 to 1.3 × 10 4 CFU g −1; and Streptococcus faecalis increased from 2.1 × 10 2 to 2.5 × 10 5 CFU g −1, respectively. Pulverized zooplankton was aged in the dark to assess the contribution of bacteria from decaying debris. Aging of pulverized zooplankton led to emergence of Chromobacterium violaceum, which is an opportunistic pathogen in animals and humans. [ABSTRACT FROM AUTHOR]

Hopkins, G. A., and Forrest, B. M. 2008. Management options for vessel hull fouling: an overview of risks posed by in-water cleaning. – ICES Journal of Marine Science, 65: 811–815.Hull fouling has been identified as an important pathway for the spread of non-indigenous marine species. However, the management of associated biosecurity risks has proven challenging. Left unmanaged, a fouled vessel can pose a biosecurity risk through the detachment and dispersal of viable material, and through spawning by adult taxa upon arrival in a recipient port or region. These risks can be managed effectively through the removal of the vessel to land for defouling (e.g. dry-docking). However, alternative methods are needed for small (e.g. recreational) vessels, as well as for large vessels fouled outside their dry-docking schedule. Among the various treatment options, in-water cleaning is relatively common, although some countries have placed restrictions on this method because of perceived biosecurity risks. Here, we present a conceptual framework that identifies risks posed by in-water cleaning compared with alternatives, including no management. Decisions on the appropriate management option will be influenced by many factors, including the species present, the level of fouling, and the time a vessel spends in a recipient region. It is important that any regulatory changes regarding in-water defouling be supported by relevant research that quantifies the risks associated with the various management options. [ABSTRACT FROM PUBLISHER]

Abstract: In October 2001, an unidentified didemnid ascidian, was recorded for the first time in New Zealand, smothering wharf piles and moorings in a northern harbour. A heavily-fouled barge then translocated the ascidian to an international shipping port some 500 km south, near the heart of the New Zealand mussel industry. The species was subsequently identified as Didemnum vexillum, but its status as indigenous or non-indigenous was disputed. Nonetheless, its presence was regarded as a significant threat to the mussel industry because of its demonstrated invasiveness on artificial structures, and its ability to over-grow and smother mussels. From the barge''s mooring area, D. vexillum subsequently spread to the seabed beneath, and to nearby vessels and artificial structures (i.e., barges, recreational vessels, moorings, salmon cages and wharf piles). Given the likelihood that infected vectors would spread the ascidian to mussel farms in the region, and in consideration of a benefit-cost analysis, an eradication program for D. vexillum was instigated. This paper provides a chronology of events surrounding the initial detection and spread of the ascidian, and describes the development of incursion response tools for the different substrata that were infected. The treatments included smothering soft-sediment habitats with uncontaminated dredge spoil, wrapping wharf piles with plastic, smothering rip–rap habitats using a geotextile fabric, and various other approaches based on water blasting, air drying or chlorine dosing. While many of the response methods were completely effective at eliminating D. vexillum from different substrata, the program overall failed to eradicate the organism from the region. The reasons for this failure are documented, and the important lessons learned are highlighted, as a contribution to the successful management of invasive species in the future. [Copyright &y& Elsevier]

Abstract: The expansion of artificial habitats and aquaculture activities in coastal environments has been accompanied by an increased demand for tools to mitigate the effects of biofouling pests. One approach is to manage anthropogenic pathways to prevent the spread of established pest organisms to uninfected localities that are beyond their natural dispersal capacity. This paper describes the efficacy of acetic acid treatments against a variety of cosmopolitan fouling taxa, and evaluates a potential application in the treatment of foulers transported with movements of shellfish seedstock between mussel farming areas in New Zealand. Laboratory and field experiments demonstrated that immersion in 4% acetic acid (in seawater) for as little as 1 min can eliminate many soft-bodied fouling organisms, with lower concentrations requiring longer immersion times. The effects of immersion treatment were enhanced when combined with a 24-h air exposure phase to simulate the inter-regional transport of mussel seedstock. We demonstrate that it is possible to cost-effectively treat mussels to eliminate the majority of problematical foulers without resulting in significant adverse effects to the stock either by: (i) a 4% treatment followed by a rinse to remove the acetic acid residue before transport, or (ii) application of the 4% treatment at the end of the transport phase. A concentration of 4% is equivalent to the acetic acid content of domestic vinegar, hence does not represent a significant environmental or occupational risk provided appropriate measures are put in place for handling and waste disposal. Acetic acid concentrations remain stable over time in the presence of organic matter, but may change during repeated use of treatment solutions. To ensure treatment criteria are being achieved, field determination of acetic acid levels can be made using simple titration-based approaches. Because of an apparent buffering effect in the case of sequential shellfish seedstock immersion, pH could not be used to estimate acetic acid concentrations in this instance, but may provide a simple and reliable field-based indicator for other fouling treatments. Further work to refine the treatment method should seek to maximise the ‘window’ between pest mortality and mussel survival, to provide assurance that high-risk species can be eliminated with minimal risk of adverse effects on seedstock. Where treatments that are completely effective against all pest organisms result in unavoidable mussel mortality, decisions about whether or not to apply them must balance treatment costs and benefits against the unmanaged risks and consequences of pest incursion. [Copyright &y& Elsevier]

Abstract: The role of aquaculture and other human activities in spreading non-indigenous marine organisms is well recognised. This paper assesses the feasibility of various ‘environmentally friendly’ treatments for key inter-regional transport vectors (equipment and seed-stock) within the New Zealand mussel farming industry, focusing on control of an internationally recognised seaweed pest, Undaria pinnatifida. The effects on Undaria of high pressure water blasting, natural air drying, and freshwater immersion at ambient (10 and 20 °C ) and hot (35–55 °C) temperatures are described, and the tolerance of mussel seed-stock to the freshwater and hot water treatments is investigated. Water blasting was completely effective in removing Undaria gametophytes from shells at pressures ≥2000 psi for 2 s. Undaria survived natural air drying for up to 2 days at ambient humidity (55–85% relative humidity; RH) and >8 weeks at high humidity (>95% RH). In freshwater, gametophytes survived immersion for 1–2 days, but plantlet mortality occurred within <10 min. Undaria survival in hot water across the 35–55 °C range was tens of minutes to a few seconds. Using these findings as guidelines, these treatments would be relatively easily applied to sterilise equipment such as farm floats and rope, with the preferred method selected based on cost, practicality and other constraints. Removing Undaria from mussel seed-stock is more problematical because of the importance of identifying treatment conditions that do not compromise mussel health. Mussels were not adversely affected when immersed in freshwater for a 2 day duration sufficient to ensure complete Undaria mortality. Hence, mussels could potentially be treated in freshwater at reasonable cost while being transported between aquaculture regions. However, to ensure an effective treatment the water would need to be exchanged during the transport phase in order to maintain salinities at ≤1 psu. Our findings also suggested that exposure to hot water at 55 °C for approximately 5 s would achieve complete Undaria mortality while maintaining a level of mussel survival comparable to untreated seed-stock. This method is likely to involve greater costs than freshwater immersion, and requires field validation to confirm both the efficacy against Undaria and to identify a method of implementation that ensures mussel survival is not compromised by the combined stresses of treatment and inter-regional transport. [Copyright &y& Elsevier]

We use a three-year study of sheltered low shore assemblages colonised by the non-indigenous Asian kelp Undaria pinnatifida to explore survey design issues for assessing the ecological impacts of invasive species. The weight of evidence overall suggested little impact from Undaria on low shore assemblages, with control–impact contrasts that could plausibly be interpreted as impacts probably reflecting natural causes. We demonstrate that the potential for reaching incorrect conclusions regarding the impacts of invasive species using control–impact designs is greater than when such designs are used to assess traditional forms of anthropogenic impact. We suggest that a before–after control–impact framework is essential, but recognise that such an approach has a number of limitations. In particular, there is no assurance that the before–after impact site will be invaded at all, or to the extent that provides worst-case impact information for coastal managers. We discuss possible ways of assessing invasive species impacts, but suggest that the uncertainty inherent in extrapolating impact information to other places and times means that the precautionary principle should be applied, and ‘worst-case’ impacts assumed, until the level of scientific uncertainty is reduced. Such an approach should only be applied, however, after an evaluation of the feasibility, costs and benefits of managing a particular pest in relation to other priorities for invasive species. [ABSTRACT FROM AUTHOR]

Ballast water (BW) mediated bioinvasion is one of the greatest threats to the health of aquatic ecosystems. Bacteria, unlike higher organisms, are transferred in large numbers through BW. Owing to their abundance and potential pathogenicity, they pose a direct threat to the prevailing microbiome in the recipient waters and also to human health. This study investigated the changes in the BW tank bacterial community during a trans-sea voyage from Visakhapatnam port, located along the east coast of India (Bay of Bengal) to Mumbai port, located along the west coast of India (Arabian Sea). Next generation sequencing was used to explore the unculturable segment of bacteria. The BW tank conditions led to a decrease in photoautotrophs and non-spore forming bacteria. On the other hand, biofilm forming and antibiotic producing bacteria, nutrient limiting condition sustaining bacteria, and those capable of synthesizing enzymes prerequisite for active metabolism under stress, increased over time. The shifts in the bacterial community were dependent on mechanisms adopted by the clades to cope with the BW tank conditions. Functional prediction of the bacterial community revealed a significant increase in the core metabolic functions, which enabled the survival of such bacteria. As the voyage progressed, an increase in the total viable bacteria in BW tanks could be attributed to the decrease in the abundance of phytoplankton and zooplankton. At the end of the voyage, the bacterial community in the BW tanks was significantly different, and the species diversity and richness were higher than that of the natural seawater (source water). Pathogenic species were more abundant during mid-voyage than at the end of the voyage, suggesting that voyage duration influences the pathogenic bacterial community. Investigating the fate of the discharged bacterial population at the deballasting point is a way forward in the assessment of marine bioinvasion. Image 1 • Bacterial metagenome in ballast tanks during tropical trans-sea voyage changed. • Autotrophs and non-spore formers decreased during the voyage. • Viable bacteria increased due to utilization of plankton derived organic matter. • Voyage duration influenced pathogenic bacterial diversity. • Discharge water bacterial community characteristically different from source water. [ABSTRACT FROM AUTHOR]

ABSTRACT The number of biological invasions has grown dramatically in recent decades, as well as the world's human population and coastal development. Anthropogenic habitats, such as pier pilings and break waters, have been constantly added to marine environment, usually concentrated in estuarine areas. These habitats are focal points for marine invasions, but relatively little is known about the spread of non-indigenous species (NIS) to nearby natural habitats. This study aimed to determine the extent to which NIS have spread to natural substrates both inside estuarine areas and in the adjacent open sea. We conducted a field survey and a literature review, which have been critically discussed and validated. The updated NIS list of benthic invertebrates comprises 19 species: Ascidiacea (5), Cirripedia (5), Cnidaria (3), Mollusca (3), Polychaeta (1), Decapoda (1), and Echinodermata (1). Our results suggested substantial spread of non-indigenous species into natural substrates. Altogether, 18 and 16 NIS were recorded in artificial and natural substrata, both representing 13% of the total species in each habitat. The percentage of NIS was more pronounced in the estuarine areas, 17.6% in artificial habitats and 18.6% in natural ones. Programs developed for the monitoring of marine invasion have to broaden their focus including natural areas adjacent to ports and marinas, to follow the spread and impact of NIS on these areas.