New tools and recommendations for a better management of harmful algal blooms under the European Marine Strategy Framework Directive

Marine harmful algal blooms (HABs), caused by various aquatic microalgae, pose significant risks to ecosystems, some socio-economic activities and human health. Traditionally managed as a public health issue through reactive control measures such as beach closures, seafood trade bans or closure of mollusc production areas, the multifaceted linkages of HABs with environmental and socio-economic factors require more comprehensive ecosystem-based management approach tools to support policies. This study promotes a coordinated understanding and implementation of HAB assessment and management under the Marine Strategy Framework Directive (MSFD), targeting the achievement of Good Environmental Status (GES) in European marine waters. We introduce two novel tools: GES4HABs (GES for HABs) decision tree, and MAMBO (environMental mAtrix for the Management of BlOoms), a decision support matrix. These tools aim to streamline HABs reporting and prioritize resource allocation and management interventions. The GES4HABs decision tree defines a sequence of decision steps to identify HAB management strategies according to their state (evaluated against predefined baselines) and causes (anthropic or natural). MAMBO is proposed to address different HABs and their interaction with human and environmental pressures. The matrix utilizes two axes: natural trophic status and level of human influence, capturing major aspects such as nutrient supply. While acknowledging the limitations of this simplified framework, MAMBO categorizes marine regions into quadrants of varying management viability. Regions with high human influence and eutrophic conditions are identified as most suitable for effective management intervention, whereas regions with minimal or mixed human influence are deemed less amenable to active management. In addition, we explore and describe various indicators, monitoring methods and initiatives that may be relevant to support assessments of HAB status and associated pressures and impacts in the MSFD reporting. Finally, we provide some recommendations to promote the consideration of HABs in ecosystem-based management strategies, intensify efforts for harmonizing and defining best practices of analysis, monitoring and assessment methodologies, and foster international and cross-sectoral coordination to optimize resources, efforts and roles

Le risque écotoxicologique dans le bassin de la Seine

National audienceLe PIREN-Seine s’intéresse à la présence dans le bassin versant de la Seine de contaminants d’origines agricole, industrielle et domestique depuis une vingtaine d’années. Ces polluants, qui se retrouvent parfois à des concentrations très faibles dans l’eau, peuvent avoir des impacts sur l’homme et l’environnement qui restent peu connus. La présence de ces substances toxiques suscite un intérêt majeur auprès des gestionnaires de la ressource comme des consommateurs. Les perturbations endocriniennes, les effets cancérigènes, la présence de résidus de médicaments sont autant de sujets d’inquiétude largement médiatisés et débattus. Pour garantir la protection de la santé humaine et du milieu aquatique, la réglementation a défini des normes de qualité environnementale, les NQE. En application de la directive cadre sur l’eau, des seuils de concentrations moyennes et maximales ont été édictées par la directive fille 2008/105/EC du 16 décembre 2008 pour les 33 substances prioritaires initialement listées. Des NQE provisoires sont aussi disponibles pour plus de 100 autres substances. Les NQE reposent sur l’évaluation approfondie des effets toxiques en laboratoire de ces molécules. L’écotoxicologie traite des effets toxiques des substances chimiques sur les organismes vivants et l’environnement. Ce thème de recherche est étudié aujourd’hui par les équipes d’écotoxicologie, d’écologie et de chimie du PIREN-Seine, notamment via des études sur trois sites pilotes : le bassin de l’Orge, le bassin de la Vesle et l’axe Seine. Comment mesurer l’impact de ces substances ? Les analyses chimiques étant insuffisantes pour évaluer le risque des substances toxiques dans le milieu, les scientifiques étudient d’autres méthodes. Les bio-essais réalisés en laboratoire en font partie. Regroupant un ensemble très vaste d’essais réalisés sur des échantillons de l’environnement, ils permettent de caractériser le «potentiel toxique», comme la présence des perturbateurs endocriniens et la génotoxicité des masses d’eau. In situ, la bioaccumulation, mesurée sur des organismes «sentinelles» contribue à l’évaluation de l’exposition aux micropolluants. Enfin, les biomarqueurs constituent une solution prometteuse pour diagnostiquer l’impact sur l’environnement des contaminants chimiques

Potential transfer of aquatic organisms via ballast water with a particular focus on harmful and non-indigenous species: A survey from Adriatic ports

Ballast water discharges may cause negative impacts to aquatic ecosystems, human health and economic activities by the introduction of potentially harmful species. Fifty untreated ballast water tanks, ten in each port, were sampled in four Adriatic Italian ports and one Slovenian port. Salinity, temperature and fluorescence were measured on board. Faecal indicator bacteria (FIB), phyto- and zooplankton were qualitatively and quantitatively determined to identify the species assemblage arriving in ballast water. FIB exceeded the convention standard limits in 12% of the sampled tanks. Vibrio cholerae was not detected. The number of viable organisms in the size groups (minimum dimension) <50 and ≥10 μm and ≥50 μm resulted above the abundances required from the Ballast Water Management Convention in 55 and 86% of the samples, respectively. This is not surprising as unmanaged ballast waters were sampled. Some potentially toxic and non-indigenous species were observed in both phyto- and zooplankton assemblages

Towards a renewed research agenda in ecotoxicology

New concerns about biodiversity, ecosystem services and human health triggered several new regulations increasing the need for sound ecotoxicological risk assessment. The PEER network aims to share its view on the research issues that this challenges. PEER scientists call for an improved biologically relevant exposure assessment. They promote comprehensive effect assessment at several biological levels. Biological traits should be used for Environmental risk assessment (ERA) as promising tools to better understand relationships between structure and functioning of ecosystems. The use of modern high throughput methods could also enhance the amount of data for a better risk assessment. Improved models coping with multiple stressors or biological levels are necessary to answer for a more scientifically based risk assessment. Those methods must be embedded within life cycle analysis or economical models for efficient regulations. Joint research programmes involving humanities with ecological sciences should be developed for a sound risk management