Rapid assessment of target species: Byssate bivalves in a large tropical port

Marine ecosystem health and biological pollution: Reconsidering the paradigm

Our study re-evaluates a fundamental paradigm in marine invasion ecology - whether introduced species are considered as contaminants, i.e. just present in the system, or whether they are pollutants per se, i.e. they cause biological harm. This re-evaluation includes the concepts of marine ecosystem health and biological pollution using the European Marine Strategy Framework Directive (MSFD) as an example. Hence, we clarify the distinction between "biological contamination" (pertaining to Non-Indigenous Species (NIS) introductions) and "biological pollution" (associated with Invasive Alien Species - IAS). We emphasize the need for comprehensive indicators that consider their ecological, economic, and societal impacts. The MSFD Descriptor D2 NIS is analysed using the "biocontamination-biopollution" gradient to better reflect the complexities of ecosystem health. We discuss limitations in current monitoring and evaluation criteria, such as the absence of unified NIS/IAS monitoring, challenges in interpreting ecological impacts, and context-dependent assessment results. We emphasize the importance of context-specific management measures, considering the origin of pressures, whether endogenic (caused within a management area such a regional sea) or exogenic (with causes from outside a management area). Ultimately, we underscore the importance of a holistic and adaptable approach to address the diverse challenges posed by biocontamination and biopollution, protecting both marine ecosystems and human well-being in an ever-changing environment.

Community assembly patterns and processes of microbiome responses to habitats and Mytilopsis sallei invasion in the tidal zones of the Pearl River Estuary

The sustainability of estuarine ecosystem functions depends on the stabilization of microbial ecological processes. However, due to the unique and variable habitat characteristics of estuarine areas, in-depth studies on ecological processes such as the spatial distribution and assembly patterns of microbial community structure are lacking. As methods to elucidate this structure, we used 16S rDNA, 18S rDNA and ITS sequencing technologies to study the composition, diversity, spatial pattern and aggregation mechanism of the bacterial, protist and fungal communities in the tidal zones of the Pearl River Estuary (PRETZ). The abundance of bacterial communities was much higher than that of protists and fungi, and the spatial pattern was obvious in PRETZ. The application of neutral and null models revealed the assembly process of three microbial communities dominated by stochastic processes. Among the stochastic processes, undominated processes (64.03 %, 62.45 %, and 59.29 %) were the most critical processes in the assembly of bacterial, fungal and protist communities. Meanwhile, environmental variables, geographic locations, and biological factors were associated with the composition and assembly of bacterial, protist, and fungal communities. Among the environmental variables, dissolved oxygen and salinity were the main predictors that jointly affected the differences in the community structure of the three microorganisms, and geographic location was the second predictor affecting the community structure of the three microorganisms and had a more pronounced effect on the diversity and network structure of the bacterial and fungal communities. However, biological factors exerted a weaker effect on the microbial community structure than spatial factors and only affected bacteria and protists; the invasive species Mytilopsis sallei only affected the process of protist community assembly. In addition, environmental variables affected the relative importance of stochastic processes. In summary, the formation of microbial communities in the PRETZ was affected by random processes, environmental variables, geographic location, and invasive species.

Exploring Ballast Water Management in Taiwan Using the PSR Conceptual Model Based on Stakeholders’ Perspectives

Accidental introduction of nonindigenous aquatic species (NIAS) is usually mediated by shipping through ballast water. Ballast water management plans are being developed and implemented around the world to prevent the spread of NIAS. However, for marine environmental management, incorporating stakeholders’ perceptions into designing and formulating management plans is key to achieving successful implementation. This study used qualitative interviews and grounded theory to induce the influencing factors and conceptual model of stakeholders’ perceptions on ballast water management (BWM) issues. The interplay of the pressure–state–response conceptual model based on grounded theory was established to elaborate on stakeholders’ perceptions. The study results indicated that local ballast water management required comprehensive port state control (PSC) and technical competency development. Second, an international commercial port can be used as a demonstration area to demonstrate the effectiveness and the potential benefits of BWM implementation due to its potential to link with international networks. Moreover, legislation, surveying/monitoring, institutional capacity and outreach/education are the four fundamentals to marine bio-invasion management. Initiating ballast water management measures as part of port environmental management aims to enhance marine pollution management capacity, especially in the field of marine bio-invasion management.

Detecting the occurrence of indigenous and non-indigenous megafauna through fishermen knowledge: A complementary tool to coastal and port surveys

Marine bioinvasions and other rapid biodiversity changes require today integrating existing monitoring tools with other complementary detection strategies to provide a more efficient management. Here we explored the efficacy of fishermen observations and traditional port surveys to effectively track the occurrence of both indigenous and non-indigenous megafauna in the Adriatic Sea. This consisted mainly of mobile taxa such as fishes, crustaceans and molluscs. Port surveys using traps and nets within 10 major Adriatic harbours, were compared with the information obtained from 153 interviews with local fishermen. Information gathered by traps and nets varied significantly and generally resulted of limited efficacy in exotic species detection. Interviews allowed tracking the occurrence of new species through time and space, providing complementary knowledge at the low cost. This combined approach improves our capability of being informed on the arrival of species of different origin, providing a more rational, improved basis for environmental management and decision making.

Sampling methods and approaches to inform standardized detection of marine alien fouling species on recreational vessels

Recreational vessels are important contributors to the spread of marine alien species, particularly in relation to secondary spread within novel regions. As such, these vessels should be considered a monitoring priority. The aim of this study was to identify a preferred method for monitoring recreational vessels for alien species, while simultaneously developing a framework that enables managers to objectively choose the most effective sampling approach given their financial constraints. Divers and a remotely operated vehicle (ROV) were considered in relation to four sampling approaches i.e. meanders, transects, inspection of niche areas and the collection of quadrats. Each was applied to the same 53 vessels which represented a spectrum of hull fouling cover. The most effective methods were diver scrape quadrats (Range of alien species numbers per quadrat: 0-9, Total alien species: 20) and inspections of niche areas (Range of alien species numbers: 0-5, Total alien species: 9). All methods employed using an ROV had low efficacy and incurred high costs. While scrape samples were one of the most expensive methods, this was offset by the lowest cost per species detected. Thus, it is recommended that monitoring programmes utilize scrape samples and niche area inspections, but when faced with financial constraints, diver meanders and niche inspections offer sound alternatives for detecting alien species.

DNA in a bottle-Rapid metabarcoding survey for early alerts of invasive species in ports

Biota monitoring in ports is increasingly needed for biosecurity reasons and safeguarding marine biodiversity from biological invasion. Present and future international biosecurity directives can be accomplished only if the biota acquired by maritime traffic in ports is controlled. Methodologies for biota inventory are diverse and now rely principally on extensive and labor-intensive sampling along with taxonomic identification by experts. In this study, we employed an extremely simplified environmental DNA (eDNA) sampling methodology from only three 1-L bottles of water per port, followed by metabarcoding (high-throughput sequencing and DNA-based species identification) using 18S rDNA and Cytochrome oxidase I as genetic barcodes. Eight Bay of Biscay ports with available inventory of fouling invertebrates were employed as a case study. Despite minimal sampling efforts, three invasive invertebrates were detected: the barnacle Austrominius modestus, the tubeworm Ficopomatus enigmaticus and the polychaete Polydora triglanda. The same species have been previously found from visual and DNA barcoding (genetic identification of individuals) surveys in the same ports. The current costs of visual surveys, conventional DNA barcoding and this simplified metabarcoding protocol were compared. The results encourage the use of metabarcoding for early biosecurity alerts.