Marine habitat mapping.

Fraschetti Simonetta, Strong James, Buhl-Mortensen Lene, Foglini Federica, Gonçalves Jorge M. s.

Accurate and extensive marine habitat maps are fundamental to support a wide variety of marine policies and ambitions. These include the European Union’s Marine Strategy Framework Directive and policies to deliver the ambitious plans of the European Green Deal. The simultaneous scaling-up of sustainable Blue Economy activities, while protecting and restoring marine ecosystems as part of the EU 2030 Biodiversity Strategy and the proposed Nature Re [...]

Van Wambeke France, Taillandier Vincent, Durrieu de Madron Xavier, Conan Pascal, Pujo-Pay Mireille

We investigated spatiotemporal variations of nutrients, dissolved organic pools (C, N, P), phosphomonoesterase (PME) and phosphodiesterase (PDE) activities, heterotrophic prokaryotic production and planktonic microorganisms within the mixed layer (ML) in the Eastern Mediterranean Sea. We characterized two contrasted situations: autumn 2018 (highly stratified period, deep chlorophyll maximum within 100 m depth) and winter 2019 (including a bloom p [...]

Baby Guillaume, Delaunay Antoine, Aslanian Daniel, Afifi Abdulkader m.

Nous caractérisons le domaine crustale d’étranglement de la marge orientale de la Mer Rouge par une analyse tectonostratigraphique de sa couverture sédimentaire. La marge est segmentée pendant la période de rift (∼28-14 Ma) entre : (i) un segment nord (28°N-21,5°N) structuré par des blocs basculés vers le continent et remplis par des sédiments siliciclastiques ; (ii) un segment sud (21,5°N−13°N) associé à des prismes sédimentaires à vergences opp [...]

Following a brief description of a typical GEOTRACES oceanographic cruise, this article illustrates the benefits of the multidisciplinary and multi-tracer approach that has characterized GEOTRACES. The value and organization of this type of research cruise—which requires many people and large vessels—are discussed in relation to the resulting carbon footprint and the potential alternatives.

Overcapacity and dynamics of a tuna fleet facing catch limits and high efficiency: The case of the Indian Ocean tuna fishery

The Indian Ocean Tuna Commission (IOTC) expresses concern over the overfished state and susceptibility to the overfishing of yellowfin tuna (Thunnus albacares). Acknowledging the challenges of increased fishing effort in a profitable fishery, our study aims to understand factors influencing French purse seine fishing vessel dynamics. Our primary goal is to assess purse seine vessel utilisation with recent catch limits and compliance with the Euro [...]

Wang Shasha, Jiang Lijing, Zhao Zhuoming, Chen Zhen, Wang Jun

Diazotrophic microorganisms regulate marine productivity by alleviating nitrogen limitation. So far chemolithoautotrophic bacteria are widely recognized as the principal diazotrophs in oligotrophic marine and terrestrial ecosystems. However, the contribution of chemolithoautotrophs to nitrogen fixation in organic-rich habitats remains unclear. Here, we utilized metagenomic and metatranscriptomic approaches integrated with cultivation assays to in [...]

Galgani Francois, Lusher Amy l., Strand Jakob, Larsen Haarr Marthe, Vinci Matteo

Marine litter and non-degradable plastic pollution is of global concern. Regular monitoring programs are being established to assess and understand the scale of this pollution. In Europe, the goal of the European Marine Strategy Framework Directive (MSFD) is to assess trends in Good Environmental Status and support large-scale actions at the regional level. Marine litter monitoring requires tailored sampling strategies, protocols and indicators, [...]

David J. McKenzie and Peter V. Skov discuss the impact of J.R. Brett's chapter “Environmental Factors and Growth” in Fish Physiology, Volume 8, published in 1979. This chapter reviews how abiotic and biotic environmental factors shape the growth of fishes, based upon how they influence “scope for growth”, the difference in growth rate between maintenance ration and maximum ration. Brett develops a framework to classify environmental factors base [...]

Sibuet Jean-Claude, Liu Siqing, Zhao Minghui, Wu Wen-Nan, Wu Yih-Min

We present an updated evaluation of SE Asian geodynamics that includes the interactions of the South China Sea (SCS) marginal basin with surrounding plates since the end of SCS spreading 20.5–18 Ma. Newly available Ar39/Ar40 ages of SCS oceanic crust drilled at IODP U1431 near the SCS East basin extinct spreading center are older than 18 Ma. Conversely, the oldest ages of the Luzon arc and forearc at Taiwan's Lanyu island, Coastal range and Lichi [...]

Loutrage Liz, Brind’amour Anik, Chouvelon Tiphaine, Spitz Jérôme

The deep-pelagic ecosystem is characterized by significant environmental gradients, particularly in food resources. The absence of primary production below the epipelagic zone leads to a decrease in food resources with depth. Two opposite feeding strategies have been described for this community in response to this decline in food resources: stochasticity, with species adopting opportunistic feeding strategies with a generalist diet, and determin [...]

Tovar-Bohórquez Oswaldo, McKenzie David, Crestel Damien, Vandeputte Marc, Geffroy Benjamin

Water temperature governs physiological functions such as growth, energy allocation, and sex determination in ectothermic species. The European sea bass (Dicentrarchus labrax) is a major species in European aquaculture, exhibiting early dimorphic growth favoring females. The species has a polygenic sex determination system that interacts with water temperature to determine an individual’s sex, with two periods during development that are sensitiv [...]

Georectifying drone image data over water surfaces without fixed ground control: methodology, uncertainty assessment and application over an estuarine environment

Watts Jennifer, Holding Thomas, Anderson Karen, Bell Thomas g., Chapron Bertrand

Light-weight consumer-grade drones have the potential to provide geospatial image data to study a broad range of oceanic processes. However, rigorously tested methodologies to effectively and accurately geolocate and rectify these image data over mobile and dynamic water surfaces, where temporally fixed points of reference are unlikely to exist, are limited. We present a simple to use automated workflow for georectifying individual aerial images [...]

Rozanski Romane, Velez Laure, Hocdé Régis, Duhamet Agnès, Waldock Conor

Marine fish communities suffer from anthropogenic pressures and climate change, which influence their spatio-temporal dynamics. Marine Protected Areas (MPAs) have been established worldwide to preserve these communities, while mesophotic ecosystems could provide natural refugia. Assessing the extent to which MPAs and deeper ecosystems can mitigate human and climate change impacts requires regular monitoring of temporal community dynamics. Environ [...]

Le Croizier Gael, Hoyos-Padilla Mauricio, Amezcua-Martinez Felipe, Aquino-Baleyto Marc, Besnard Lucien

Refining the role of apex predators in marine food webs is a necessary step in predicting the consequences of their global decline under the footprint of fishing activities. White sharks (Carcharodon carcharias) are vulnerable predators, performing large migrations and able to forage on a variety of prey in different habitats. In the Northeast Pacific, juvenile and adult white sharks are found seasonally at the same aggregation sites, such as Gua [...]

Ben Abbes Ali, Machicao Jeaneth, Corrêa Pedro L.p., Specht Alison, Devillers Rodolphe

Measuring socioeconomic indices at the scale of regions or countries is required in various contexts, in particular to inform public policies. The use of Deep Learning (DL) and Earth Observation (EO) data is becoming increasingly common to estimate specific variables like societal wealth. This paper presents an end-to-end framework ‘DeepWealth’ that calculates such a wealth index using open-source EO data and DL. We use a multidisciplinary approa [...]

Compound- and element-specific accumulation characteristics of persistent toxic substances and metals in sediments of the Yellow Sea

Kim Youngnam, Lee Yeonjung, Lee Chang-Eon, Jeong Hyeryeong, Ra Kongtae

This study investigated the large-scale distributions of persistent toxic substances (PTSs) and heavy metals in sediments of the Yellow Sea, collected from six transects between latitudes 32 and 37 degrees north (n = 35). Elevated concentrations of polychlorinated biphenyls (PCBs) were detected near the mainland, with a predominance of low-chlorinated congeners (di to tetra, ∼60%), indicative of atmospheric deposition. Analysis of traditional and [...]

Baker Megan l., Hage Sophie, Talling Peter j., Acikalin Sanem, Hilton Robert g.

Burial of organic carbon in marine sediments is a long-term sink of atmospheric CO2, and submarine turbidity currents are volumetrically the most important sediment transport process on Earth. Yet the processes, amounts, and efficiency of organic carbon transfer by turbidity currents through submarine canyons to the deep sea are poorly documented and understood. We present an organic carbon budget for the submarine Congo Canyon, offshore West Afr [...]

Priest Jamie, Ferreira Camilo m., Munday Philip l., Roberts Amelia, Rodolfo‐metalpa Riccardo

Climate change stressors are progressively simplifying biogenic habitats in the terrestrial and marine realms, and consequently altering the structure of associated species communities. Here, we used a volcanic CO2 seep in Papua New Guinea to test in situ if altered reef architecture due to ocean acidification reshuffles associated fish assemblages. We observed replacement of branching corals by massive corals at the seep, with simplified coral a [...]

Pannard Alexandrine, Souchu Philippe, Chauvin Christian, Delabuis Monique, Gascuel‐odoux Chantal

Because of the first observations in the 1900s of the oligotrophic and eutrophic states of lakes, researchers have been interested in the process that makes lakes become turbid because of high phytoplankton biomass. Definitions of eutrophication have multiplied and diversified since the mid‐20th century, more than for any other ecological process. Reasons for the high number of definitions might be that the former ones did not sufficiently descri [...]