A crisis in the water is decimating this once-booming fishing town
"TOMBWA, Angola — His ancestors were Portuguese colonialists who settled on this otherworldly stretch of coast, wedged between a vast desert and the southern Atlantic. They came looking for the one thing this barren region had in abundance: fish.
By the time Mario Carceija Santos was getting into the fishing business half a century later, in the 1990s, Angola had won independence and the town of Tombwa was thriving. There were 20 fish factories strung along the bay, a constellation of churches and schools, a cinema hall built in art deco, and, in the central plaza, massive drying racks for the tons upon tons of fish hauled out of the sea. [...]"
Source: The Washington Post
Article Open Access Published: 29 November 2019 Role of synoptic activity on projected changes in upwelling-favourable winds at the ocean’s eastern bo
"The climate of the ocean’s eastern boundaries is strongly influenced by subtropical anticyclones, which drive a surface wind stress that promotes coastal upwelling of nutrient-rich subsurface water that supports high primary productivity and an abundance of food resources. Understanding the projected response of upwelling-favourable winds to climate change has broad implications for coastal biogeochemistry, ecology, and fisheries. [...]"
Source: npj Climate and Atmospheric Science
Authors: Catalina Aguirre et al.
Global sea-surface iodide observations, 1967–2018
"The marine iodine cycle has significant impacts on air quality and atmospheric chemistry. Specifically, the reaction of iodide with ozone in the top few micrometres of the surface ocean is an important sink for tropospheric ozone (a pollutant gas) and the dominant source of reactive iodine to the atmosphere. Sea surface iodide parameterisations are now being implemented in air quality models, but these are currently a major source of uncertainty. [...]"
Source: Scientific Data
Authors: Rosie J. Chance et al.
Changes in oxygen concentrations in our ocean can disrupt fundamental biological cycles
"New research led by scientists at the University of Bristol has shown that the feedback mechanisms that were thought to keep the marine nitrogen cycle relatively stable over geological time can break down when oxygen levels in the ocean decline significantly.
The nitrogen cycle is essential to all forms of life on Earth - nitrogen is a basic building block of DNA.The marine nitrogen cycle is strongly controlled by biology and small changes in the marine nitrogen cycle have major implications on life. [...]"
Source: University of Bristol
Fundamentally different global marine nitrogen cycling in response to severe ocean deoxygenation
"The present-day marine nitrogen (N) cycle is strongly regulated by biology. Deficiencies in the availability of fixed and readily bioavailable nitrogen relative to phosphate (P) in the surface ocean are largely corrected by the activity of diazotrophs. This feedback system, termed the “nitrostat,” is thought to have provided close regulation of fixed-N speciation and inventory relative to P since the Proterozoic. [...]"
Authors: B. David A. Naafs et al.
Large projected decline in dissolved oxygen in a eutrophic estuary due to climate change
"Climate change is known to cause deoxygenation in the open ocean, but its effects on eutrophic and seasonally hypoxic estuaries and coastal oceans are less clear. Using Chesapeake Bay as a study site, we conducted climate downscaling projections for dissolved oxygen and found that the hypoxic and anoxic volumes would increase by 10‐30% between the late 20th and mid‐21st century. [...]"
Source: JGR Oceans
Authors: Wenfei Ni et al.
Dead-zone report card reflects improving water quality in Chesapeake Bay
Dr. Marjy Friedrichs, a Virginia Institute of Marine Science professor and report card co-author, says "Even with environmental conditions that favor severe hypoxia, including record-high river input and light winds, our analysis shows that the total amount of hypoxia this year was within the normal range seen over the past 35 years."
Distribution of iron in the Western Indian Ocean and the Eastern tropical South pacific: An inter-basin comparison
"The Western Indian Ocean (WIO) and Eastern Tropical South Pacific (ETSP) are distinctly different regimes, yet they share several important features. These include a strong upwelling system, a large oxygen minimum zone (OMZ) with active denitrification, a spreading center with extensive hydrothermal activity, and a vast oligotrophic upper water column. Here, we show that the distribution and geochemistry of iron shows remarkable similarities as well. [...]"
Source: Chemical Geology
Authors: James W. Moffett and Christopher R. German
Ocean studies look at microscopic diversity and activity across entire planet
"In an effort to reverse the decline in the health of the world's oceans, the United Nations (UN) has declared 2021 to 2030 to be the Decade of Ocean Science for Sustainable Development. One key requirement for the scientific initiative is data on existing global ocean conditions. An important trove of data is already available thanks to the Tara Oceans expedition, an international, interdisciplinary enterprise that collected 35,000 samples from all the world's oceans between 2009 and 2013. The samples were collected by researchers aboard one schooner, the Tara, at depths ranging from the surface to 1,000 meters deep. [...]"
Source: Science Daily
Unravelling the sources of carbon emissions at the onset of Oceanic Anoxic Event (OAE) 1a
"The early Aptian Oceanic Anoxic Event (OAE) 1a represents a major perturbation of the Earth's climate system and in particular the carbon cycle, as evidenced by widespread preservation of organic matter in marine settings and a characteristic negative carbon isotopic excursion (CIE) at its onset, followed by a broad positive CIE. The contemporaneous emplacement of a large igneous province (LIP) is invoked as a trigger for OAE 1a (and OAEs in general), but this link and the ultimate source of the carbon perturbation at the onset of OAEs is still debated. [...]"
Authors: Markus Adloff et al.