Hydrothermal circulation along mid-ocean ridges is primarily controlled by the interplay between magmatic and tectonic processes. The Mohns Ridge, shaped by the Jan Mayen/Iceland plume and a shift from orthogonal to oblique accretion, provides a natural laboratory to test whether melt-flux, tectonic strain, and axial volcanic ridge (AVR) maturity predict hydrothermal venting, using a multiproxy approach combining bathymetry, magnetic, gravity, and seismicity data. Variations in mantle Bouguer anomaly and bathymetry along the axis show how plume distance and ridge obliquity jointly control melt distribution, dividing the ridge into three regions: high-melt-flux south of the 71.3°N, diffuse high-melt-flux between 71.3°N and 72.2°N, and a focused but melt-limited region northward. While AVR volume appears as an unreliable proxy for melt-flux and AVR maturity, along-axis correlation between magnetic, mantle Bouguer anomalies and sediment thickness distinguishes between well-developed active, well-developed inactive, and infrequent but recently active AVRs. Melt distribution style (focused vs. diffuse) and AVR magmatic state primarily dictate hydrothermal vent distribution: well-developed active AVR in focused regions promotes high-temperature venting, while a diffuse-melt distribution appears to hinder their development. The apparent tectonic strain in the axial valley shows no significant relationship with melt-flux or magnetic anomaly, reflecting the differing timescales between crustal accretion, alteration and surface activity. Similarly, seismic activity shows no relationship with AVR maturity, melt emplacement style, or hydrothermal venting, indicating that short-term events are decoupled from the long-term evolution of AVRs. Hydrothermal activity instead correlates more closely with the long-term magmatic evolution of AVRs than with these short-term events.
The 2025 Third United Nations Oceans Conference (UNOC3) called for “a strong science-policy interface to provide timely, credible and salient scientific and socioeconomic information to inform policies and action”. Renowned naturalist David Attenborough's narration of the recent film Ocean illustrates an important challenge to achieving that goal. It was released with much publicity in the lead-up up to UNOC3. The film presented a clear agenda and was intended to influence world leaders ahead of the Conference. In our view, while the film had merits, it presented over-simplistic and misleading messages about the nature of the challenges to the oceans and their solutions. Focused on the goal of a strong science-policy interface, this contribution examines the use of celebrities to influence public policy, the reasons for their influence, and the impacts they can have on the public and policy-makers. These impacts can lead to misguided and biased policies that will not achieve important societal objectives, such as the Sustainable Development Goals. The likelihood of flawed policies increases when the influence of celebrities on policy is based on other than the best available scientific information. To avoid or reduce the risk of this, we make recommendations on strengthening scientific advice and improving communication between scientists, policy-makers and the public. The media and celebrities could be important intermediaries in achieving this. Recommendations include scientists making greater efforts to improve communication and public trust in science, as well as other building blocks needed to ensure a sound scientific basis for policy and its implementation.
Microbial communities fundamentally shape ecosystem function and biodiversity across all biological systems through complex dynamics. In coral reef ecosystems, understanding the dynamics of these microbial communities has become critical for predicting reef responses to environmental stressors. Fish skin microbiota are highly susceptible to environmental changes and may vary significantly across species and geographic locations, yet the extent to which these variations occur remain poorly understood. Here, we compared the skin microbiota of four closely related and sympatric cryptobenthic gobiid species, that exhibit different behavioral ecologies (cleaning vs.non-cleaning), ecological niches (water column, coral-, or sand-dwelling) and phylogenetic affinities (Elacatinus vs. Coryphopterus), yet reside in the same reef patches in St. Croix and Puerto Rico, eastern Caribbean. Coral-dwelling gobies, including cleaning sharknose and non-cleaning peppermint gobies, exhibited significantly lower microbial diversity compared to reef-hovering and sand-dwelling species (both non-cleaning). These coral dwellers showed unique microbial signatures despite having similar alpha diversity levels. Core microbiota analysis also revealed striking differences between coral-dwelling and reef-hovering/sand-dwelling species, with the core microbiome of the former dominated by Vibrio, Pseudoalteromonas, and Alteromonas in the case of cleaning gobies and by Endozoicomonas in the case of peppermint gobies, while reef-hovering and sand-dwelling gobies exhibited diverse core microbiota with greater overlap between species. Ecological niche occupancy and reef habitat selection appear to be primary drivers of skin microbiota composition in gobiid fishes, rather than cleaning behavior and/or host phylogenetic affinities alone, though species-specific skin mucus properties likely also contribute to selective bacterial colonization patterns.
The atmospheric response to the solar eclipse of 8 April 2024 in North America is investigated with a specific focus on the marine atmospheric boundary layer (MABL). We leverage measurements collected during the Third Wind Forecast Improvement Project (WFIP3), including Doppler lidars, sonic anemometers, and thermodynamic profiler data to investigate the atmospheric response across sites that experienced partial eclipse conditions with nearly 90 1.2^∘C to 1.4^∘C in coastal regions and from 0.3^∘C to 0.5^∘C over the ocean. This analysis suggests that the MABL’s higher thermal inertia compared to coastal regions moderates the temperature decrease during the eclipse. Wind speed exhibits a more complex behavior, as it is influenced by both the MABL and preexisting synoptic conditions. Although a reduction in wind speed is observable up to approximately 140 m above ground level (AGL) at more inland sites, at other locations closer to the coast, this reduction is constrained to the lowest 100 m AGL. Turbulence parameters retrieved from sonic anemometers, such as turbulence kinetic energy, turbulent heat flux, and friction velocity, decrease during the eclipse at coastal sites, accompanied by a brief transition of atmospheric stability from unstable to neutral or weakly stable conditions. For the open-ocean sites, the variability in turbulence statistics and atmospheric stability is minimal during the occurrence of the eclipse.
Coral reefs are under threat worldwide. Yet, in these often-challenging marine habitats, biologists lack the tools to quantify the spatial heterogeneity of mobile reef fauna at high resolution (<1 meter), hampering monitoring and restoration efforts. Because of the diverse species present, multiple sensor modalities are needed to characterize the biodiversity. The urgent need to expand this study across unexplored reefs worldwide compounds these challenges. To address these problems, we propose a generative model of reef observations and develop a multimodal framework for seeking and mapping hotspots of biodiversity. In a case study on a healthy Caribbean reef, our autonomous underwater vehicle used passive acoustics and visual sensing to locate a biological hotspot around a large Dendrogyra pillar coral. We used the colocated multimodal data to self-validate the hotspot's prominence, representing a technological step forward to help understand the ecological dynamics of coral reefs.
