Environmental impact of Methane seepage and sub-seabed characterization at LoVe - Node 7

The world continues to face a critical challenge due to climate change, largely driven by greenhouse gases like carbon dioxide (CO2). However, there is growing awareness of the powerful role methane (CH4) plays as a more potent greenhouse gas. While much focus has been placed on curbing CO2 emissions, methane release from marine sources remains poorly understood. Our project focuses on the Hola Trough in the Lofoten-Vesterålen area—a site of active methane release from the ocean floor. Here, a large cold-water coral reef thrives despite potential threats posed by methane emissions. Our work seeks to unravel the mysteries surrounding methane seepage in this area: What triggers these releases? How do they impact local ecosystems, such as coral reefs and fish stocks? And, critically, how might these emissions contribute to global methane levels if they reach the atmosphere? The research team has made great strides in addressing these questions. We have conducted a successful research cruise, collecting vital data from methane seep sites, which have provided crucial insight into the dynamics of methane seeps and their impact on the surrounding environment. One key finding from our recent publication, "Contrasting Methane Seepage Dynamics in the Hola Trough Offshore Norway: Insights From Two Different Summers," From Ferré et al., 2024, reveals a significant increase in methane seep activity between 2018 and 2022, with 3.5 times more seeps detected. Surprisingly, this increase does not appear linked to rising bottom water temperatures, as the area remains within the methane hydrate stability zone. Instead, our research suggests a combination of low tide conditions reducing sediment pore pressure and rising temperatures reducing methane solubility as key drivers. Despite this increase in seepage, the methane concentrations and gas flow rates near the seafloor remain low, likely due to strong ocean currents dispersing the gas before it can build up. Sub-seafloor investigations have also uncovered pathways for gas migration, shaped by the area's complex topography. Our upcoming publications will explore how methane influences cold-water corals, the evolution of seepage using foraminifera as biological indicators, and long-term sediment pressure dynamics. These findings will offer further insights into the interactions between methane seeps and marine ecosystems and help us better understand how these emissions might affect both local and global environments. With every step forward, our project contributes to the growing body of knowledge on methane seepage dynamics, providing essential data to help combat climate change.

At a time when climate change in no longer a debate, much focus has been placed on reducing anthropogenic inputs of greenhouse gases such as carbon dioxide (CO2). However, methane (CH4, a more potent greenhouse gas compared to CO2) associated with underwater reservoirs of hydrocarbons, can erupt as climate driven changes to the physical environment reduce its stability. In addition, increased anthropogenic activities in hydrocarbon rich areas (i.e., oil and gas exploration) may cause additional release of greenhouse gases (CH4 and CO2) altering several biogeochemical processes and threatening health of the local ecosystem. The EMAN7 project will use the state of the art observatory facility located in the resource rich area of Lofoten-Vesterålen (LoVe) for monitoring a wide range of physical, biological and chemical parameters associated with cold-water coral reefs and CH4 seepage. These parameters will provide cross-disciplinary research with a complete picture of the ecosystem response to CH4 seepage, as well as temporal and spatial variation of the seepage system itself. Furthermore, as this region serves as a conduit of warm Atlantic water transport to the Arctic, data collected at the LoVe nodes will provide needed insight to predict potential impacts of climate change in Arctic regions. Annual research surveys in the Hola Trough will complement the long-term data with spatial variability in CH4 seepage and greenhouse gases exchange across air-sea interface. We also anticipate that the results of our proposed research will improve the understanding of sub-seafloor fluid flow over a wide range of systems that are involved in the transfer of carbon from the sub-seafloor to the ocean. These results will thus provide constraints to estimate fluxes both at the studied sites and globally, while gaining particular insight into the properties, dynamics and fluxes of sediment-hosted systems.