Researchers find global ocean methane emissions dominated by shallow coastal waters
To predict the impacts of human emissions, researchers need a complete picture of the atmosphere's methane cycle. They need to know the size of the inputs—both natural and human—as well as the outputs. They also need to know how long methane resides in the atmosphere. [...]"
Global ocean methane emissions dominated by shallow coastal waters
"Oceanic emissions represent a highly uncertain term in the natural atmospheric methane (CH4) budget, due to the sparse sampling of dissolved CH4 in the marine environment. Here we overcome this limitation by training machine-learning models to map the surface distribution of methane disequilibrium (∆CH4). Our approach yields a global diffusive CH4 flux of 2–6TgCH4yr−1 from the ocean to the atmosphere, after propagating uncertainties in ∆CH4 and gas transfer velocity. [...]"
Source: Nature Communications
Authors: Thomas Weber, Nicola A. Wiseman & Annette Kock
The Dynamics and Impact of Ocean Acidification and Hypoxia:
Insights from Sustained Investigations in the Northern California Current Large Marine Ecosystem
"Coastal upwelling ecosystems around the world are defined by wind-generated currents that bring deep, nutrient-rich waters to the surface ocean where they fuel exceptionally productive food webs. These ecosystems are also now understood to share a common vulnerability to ocean acidification and hypoxia (OAH). In the California Current Large Marine Ecosystem (CCLME), reports of marine life die-offs by fishers and resource managers triggered research that led to an understanding of the risks posed by hypoxia. Similarly, unprecedented losses from shellfish hatcheries led to novel insights into the coastal expression of ocean acidification. [...]"
Authors: Francis Chan et al.
Oxygen supersaturation protects coastal marine fauna from ocean warming
"Ocean warming affects the life history and fitness of marine organisms by, among others, increasing animal metabolism and reducing oxygen availability. In coastal habitats, animals live in close association with photosynthetic organisms whose oxygen supply supports metabolic demands and may compensate for acute warming. [...]"
Source: Science Advances
Authors: Folco Giomi et al.
Identifying areas prone to coastal hypoxia – the role of topography
"Hypoxia is an increasing problem in marine ecosystems around the world. While major advances have been made in our understanding of the drivers of hypoxia, challenges remain in describing oxygen dynamics in coastal regions. The complexity of many coastal areas and lack of detailed in situ data have hindered the development of models describing oxygen dynamics at a sufficient spatial resolution for efficient management actions to take place. [...]"
Authors: Elina A. Virtanen et al.
Exploring the Susceptibility of Turbid Estuaries to Hypoxia as a Prerequisite to Designing a Pertinent Monitoring Strategy of Dissolved Oxygen
"Globally, there has been a decrease in dissolved oxygen in the oceans, that is more pronounced in coastal waters, resulting in more frequent hypoxia exposure for many marine animals. Managing hypoxia requires an understanding of the dynamics of dissolved oxygen (DO) where it occurs. The French coast facing the Bay of Biscay (N-E Atlantic Ocean) hosts at least a dozen tidal and turbid estuaries, but only the large estuaries of the Gironde and the Loire, are subject to a continuous monitoring. [...]"
Source: Frontiers in Marine Science
Authors: Sabine Schmidt et al.
Coastal Mooring Observing Networks and Their Data Products: Recommendations for the Next Decade
"Instrumented moorings (hereafter referred to as moorings), which are anchored buoys or an anchored configuration of instruments suspended in the water column, are highly valued for their ability to host a variety of interchangeable oceanographic and meteorological sensors. This flexibility makes them a useful technology for meeting end user and science-driven requirements. [...]"
Source: Frontiers in Marine Science
Authors: Kathleen Bailey et al.
Carbon cycling in the North American coastal ocean: a synthesis
"A quantification of carbon fluxes in the coastal ocean and across its boundaries with the atmosphere, land, and the open ocean is important for assessing the current state and projecting future trends in ocean carbon uptake and coastal ocean acidification, but this is currently a missing component of global carbon budgeting. This synthesis reviews recent progress in characterizing these carbon fluxes for the North American coastal ocean. [...]"
Authors: Katja Fennel et al.
Measuring carbon and nitrogen bioassimilation, burial, and denitrification contributions of oyster reefs in Gulf coast estuaries
"The eastern oyster (Crassostrea virginica) and the reefs they create provide significant ecosystem services. This study measured their possible role in nutrient mitigation through bioassimilation, burial, and oyster-mediated sediment denitrification in near-shore shallow water (< 1 m water depth) and deep-water (> 1 m water depth) oyster reefs in Louisiana. Nitrogen (N) and carbon (C) in shell and tissue differed by oyster reproductive status, size, and habitat type. [...]"
Source: Marine Biology
Authors: Phillip Westbrook, Leanna Heffner, Megan K. La Peyre
Tool to Capture Marine Biological Activity Gets Coastal Upgrade
"Upwelling hinders an efficient method to estimate a key measure of biological productivity in coastal waters, but accounting for surface temperatures could boost accuracy.
Although coastal waters make up only about 10% of the surface area of the ocean, they harbor most of its life. Measuring biological activity in these regions can reveal their impact on fisheries, low-oxygen dead zones, and the global carbon cycle, but coastal zones remain understudied. Now new research by Teeter et al. suggests how to improve the accuracy of a method that uses oxygen and argon measurements to quickly estimate marine biological activity. [...]"