The overlapping missions of the NASA Surface Water and Ocean Topography (SWOT) satellite and NASA Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) satellite provide the opportunity to observe oceanic biophysical interactions from space at unprecedented spatiotemporal scales. We use provisional datasets from these two cutting-edge missions to investigate subseasonal to seasonal variability in the microbial community compositions of subtropical mesoscale eddies. The results highlight the capacity of mesoscale eddies to act as transient ecological niches that restructure the surface marine microbial community. For the first time, the combination of SWOT and PACE enables space-based observations of plankton community composition alongside the physical processes that structure it.

Widespread marine heatwaves (MHWs) affected Australia over the 2024/25 summer and autumn. They impacted marine species, ecosystems, and coastal communities, with emerging economic consequences. Across northern Australia, severe coral bleaching occurred for the first time along both the western and eastern coasts, and a mass fish kill occurred in Western Australia. In South Australia, prolonged MHW conditions and impacts from an extensive harmful algal bloom of the dinoflagellate Karenia included extensive fish kills, human health effects, losses for ocean-dependent industries, and currently unquantified effects on the broader marine ecosystem. In Tasmania, a range of impacts were linked to warm water, including blooms of salps, Noctiluca, and jellyfish. In New South Wales, a fish mortality event linked to thermal shock generated considerable community concern and media coverage. Trial seasonal forecasts available several months ahead of MHW emergence, combined with national marine climate briefings, helped prepare industry, researchers, and governments for possible impacts. This resulted in increased awareness and development of regional and industry MHW response plans with proactive strategies at both short and long timescales.

In this article we provide pipelines for acquiring and processing Sea-Bird Scientific Spectral Absorption and Attenuation Sensor (ac-s) data through a high-level Python package. The raw streamed and converted instrument output is complex and requires several post-processing steps rooted in optical theory and empirical methods to create base products for algorithms that approximate biogeochemical properties and appeal to a broader oceanographic community. Because datasets from the ac-s are becoming more available in public archives and in real time from large oceanographic infrastructure programs, it is important to establish uncomplicated software packages and interfaces that support the implementation of best practices and the distribution of findable, accessible, interoperable, and reusable (FAIR) data. acspype provides means to perform both instrument-intrinsic and human-in-the-loop corrections with flexibility and clear provenance following well-established manufacturer and research community guidelines. Core functions are provided that allow for the acquisition of real-time data and for post-processing archived datasets. As best practices continue to evolve, acspype would benefit from the addition of time-lag correction functions, methods for assessing instrument drift, and improved uncertainty estimation procedures.

Single beam sonars can provide valuable acoustic information on the structure of benthic habitats and the contents of the water column. Nominally, acoustic sensors that provide water column data in scientific applications can cost tens or hundreds of thousands of dollars. In contrast, consumer grade fish finders that are mass produced are very inexpensive, costing only tens or hundreds of dollars. Unlocking a fish finder for scientific use could increase access to low-cost sensing methods for coastal communities that are historically underserved. The principal challenge with using a fish finder for benthic habitat classification is that the sonars are generally not interoperable and are often limited to visualization on a display or chart plotter made by the sonar manufacturer. This vendor lock prevents the sonar data, and in particular water column data, from being stored and processed to create mapping products. In this project, “SonarPhony” was developed to provide interoperability software to enable the real-time visualization and logging of water column data from a low-cost fish finder. A machine learning approach was used to demonstrate that the logged data could be used to estimate bottom type and identify the presence of seagrasses. This solution thus provides a low-cost means for both benthic habitat classification and bathymetric mapping.

The dynamics governing nutrient concentrations in the ocean are primarily influenced by geophysical and biogeochemical processes that regulate the introduction of these elements into seawater and their transport, dispersion, and removal. In one of the world’s most productive marine regions, the East China Sea (ECS), numerous reports have documented the relationship between biological productivity on the shelf and the nutrients primarily supplied from the subsurface waters of the Kuroshio, a powerful western boundary current. However, the mechanism behind this nutricline variation is not well understood. In this study, we trace macronutrients from the Kuroshio’s source to the ECS shelf. As the Kuroshio flows northward along the eastern coast of the Philippines to the southern Luzon Strait (LS), part of it intrudes into the South China Sea (SCS) through the strait. Due to vigorous vertical mixing and upwelling, the thermocline and nutricline are elevated in the SCS compared with those near the origin of the Kuroshio. Subsequently, at the northern LS, the SCS outflow merges with the Kuroshio’s western side. This process preconditions the upwelling of nutrient-​rich subsurface Kuroshio waters onto the ECS shelf.

One of the biggest barriers to conducting ocean science around the globe is limited access to computational tools and resources, including software, computing infrastructure, and data. Open tools, such as open-source software, open data, and online computing resources, offer promising solutions toward more equitable access to scientific resources. Here, we discuss the enabling power of these tools in under-resourced and non-English speaking regions, based on experience gained in the organization of three independent programs in West African, Latin American, and Indian Ocean nations. These programs have embraced the “hackweek” learning model that bridges the gap between data science and domain applications. Hackweeks function as knowledge exchange forums and foster meaningful international and regional connections among scientists. Lessons learned across the three case studies include the importance of using open computational and data resources, tailoring programs to regional and cultural differences, and the benefits and challenges of using cloud-based infrastructure. Sharing capacity in marine open data science through the regional hackweek approach can expand the participation of more diverse scientific communities and help incorporate different perspectives and broader solutions to threats to marine ecosystems and communities.

In this issue of Oceanography, Laura Guertin describes her inspiration for launching the audio narrative project Tales from the Deep: Stories of Scientific Ocean Drilling, and she provides links to many of the conversations she has recorded with shipboard and shore-based participants. Projects like this are not new in the ocean sciences, but the recorded oral histories are often done with senior scientists and compiled as historical documentation by individual institutions—Woods Hole Oceanographic Institution, Scripps Institution of Oceanography, and Lamont-Doherty Earth Observatory, among others, have such oral history archives. Transcripts are often the only thing available for many of these oral histories, and several have restricted access. One of the great things about Tales from the Deep is that the stories provide varied perspectives, from early career scientists to senior scientists, and from folks who sailed on the various scientific drilling vessels and platforms over the years to onshore support staff and program managers. Some of the narratives contain funny stories while others are more serious. The recordings are all openly accessible to anyone with an internet connection.