The phenomenon of marine plastic pollution is now well-established, with documented impacts on marine biodiversity and biogeochemical cycles. In order to mitigate this environmental impact, a significant amount of research has been conducted in recent years with the objective of developing biodegradable alternatives to conventional polymers and their composites in marine environments. The findings of this research significantly enhanced our under [...]
L’essor grandissant, ces dernières années, des techniques liées à l’ADN environnemental (eDNA) et à leur accessibilité ouvre de nouvelles perspectives, non seulement pour le suivi de la biodiversité et ses variations au sein des écosystèmes soumis aux changements environnementaux et aux pressions anthropiques, mais aussi pour une aide à une meilleure gestion des ressources marines. L’eDNA est un mélange complexe d’ADN génomique provenant des org [...]
The development of an ecosystem accounting system to complete current wealth indicators is a core issue. Biophysical ecosystem accounts of the SEEA EA have been adopted as a statistical standard to bridge this gap. However, challenges remain as the specificities of marine ecosystems are poorly considered in the current standard, and link with policies is weak. This article aims at developing pilot biophysical ecosystem accounts in the European te [...]
Biogenic sedimentary structures offer a unique perspective for understanding the role of the biosphere in the interaction with other Earth subsystems and the building up of our planet. The record of their ancient equivalents provides a wealth of information for reconstructing the role of bioturbators as ecosystem engineers using multiple ichnological proxies and methods. In this study, we present an overview of how bioturbation has worked across [...]
Yessotoxin is one of the shellfish toxins leading to mussel farm closures in the Adriatic Sea of Italy. Two putative Gonyaulax spinifera strains GSA0501 and GSA0602 are known as yessotoxins producers, but their identities have remained elusive since 2005. To address this gap, we established five Gonyaulax strains by incubating sediments from the Adriatic Sea and subsequently isolating single cells. Both cyst and theca morphology were examined usi [...]
The possibility of predicting the occurrence of wave breaking and the intensity of the breaking events using linear wave models is investigated. For this purpose, a new linear breaking onset criterion is proposed, based on the definition of a linear-equivalent wave, which has the same energy and impulse as the associated nonlinear wave. The strength of breaking is characterized by the parameter introduced by Derakhtiet al. (2018) and we derive an [...]
Euphausiids (krill) are globally significant zooplankton prey for many commercially important or endangered predator species. In the productive upwelling system of the Northern California Current (NCC), two krill species, Euphausia pacifica and Thysanoessa spinifera, dominate the preyscape and constitute an important food resource for many seabirds, cetaceans, and fish. In this study, we use five years of hydroacoustic and net tow data collected [...]
Dust deposition, river runoff and glacial melt are the main sources of trace metals to the surface ocean. In the Canary Islands, deposition is dominated by dry dust deposition from the Saharan desert. However, during 85 days, from 19 September to 13 December 2021, the main source of trace metals on the island of La Palma changed drastically. The eruption of the Tajogaite volcano released tonnes of volcanic ash. Concurrently, several lava flows re [...]
This paper presents an approach to apply aquatic passive sampling (PS) in regulatory chemical water quality monitoring in Europe. Absorption-based passive sampling is well developed and suitable for the sampling of hydrophobic chemicals, some of which are European Water Framework Directive priority substances with Environmental Quality Standards (EQS) derived for biota. Considering a chemical activity approach to chemical risk assessment, we prop [...]
The seasonality of Arctic sea ice cover significantly influences heat, salt, buoyancy fluxes, ocean-ice stresses, and the potential and kinetic energy stored in the ocean mixed layer. This study examines the seasonal variability of oceanic scales and cross-scale flux of kinetic energy in the seasonally ice-covered Arctic, using a high-resolution, idealized coupled ocean-sea ice model. Our simulations demonstrate pronounced seasonality in the scal [...]
Harmful algal blooms (HABs) formed by toxic microalgae have seriously threatened marine ecosystems and food safety and security in recent years. Among them, Karenia selliformis has attracted the attention of scientists and society due to its acute and rapid neurotoxicity in mice. Herein, the growth and gymnodimine A (GYM-A) production of K. selliformis were investigated in diverse culture systems with different surface-to-volume (S/V) ratios and [...]
Fisheries that target tunas and tuna-like species are managed by tuna regional fisheries management organizations (t-RFMO) and are known to interact with various bycatch species, including sea turtles, with potentially negative effects. Actions and management measures implemented by t-RFMO to monitor sea turtle fisheries interactions, reduce their bycatch in fisheries, and carry out best practices for the handling and safe release of sea turtles, [...]
Background DPANN archaea, including Woesearchaeota, encompass a large fraction of the archaeal diversity, yet their genomic diversity, lifestyle, and role in natural microbiomes remain elusive. With an archaeal assemblage naturally enriched in Woesearchaeota and steep vertical geochemical gradients, Lake Dziani Dzaha (Mayotte) provides an ideal model to decipher their in-situ activity and ecology. Results Using genome-resolved metagenomics and [...]
Le présent rapport fournit un état des lieux de la connaissance en sédimentologie sur la zone d’étude au large de l’Île d’Oléron, définie par la DGEC dans le cadre de l’AO7 Sud-Atlantique. Un recensement des données a été mené par le Shom auprès des différents organismes publics (Ifremer, BRGM1, Parcs marins, EMODNET2), privés (RTE3), auprès des universitaires ayant effectué des travaux sur la zone (Université de la Rochelle et Université de Bord [...]
The definition of Best Practices for biological sensors stands as an acute need for the JERICO community, due to the multiplicity of procedures for calibration, operation, sampling and flagging. In the case of novel Biological Sensors, they help to understand plankton dynamics and distribution in coastal waters. Our task within WP5 ST7 is to work on the improvement of the readiness of ship-based and autonomous platform observing networks, guarant [...]
Ce rapport présente les principales réalisations de l'Ifremer en 2023 dans ses activités de surveillance, d'expertise et de référence en appui aux politiques publiques. Ces activités mobilisent l'ensemble des raisons d'être et des thématiques scientifiques de l'Ifremer. Le rapport présente également un aperçu des résultats de recherche ayant vocation à alimenter les politiques publiques auxquelles l'Ifremer concourt.
There is increasing interest in developing indicators to assess the state of benthic communities in shelf seas primarily affected by bottom trawling. Yet, many indicators have been developed in specific geographic regions making it difficult to determine their broader applicability. In the study, we systematically evaluated the complementarity, sensitivity, and specificity of 18 indicators in response to the pressure of bottom trawling using a sh [...]