Interpreting Mosaics of Ocean Biogeochemistry
"Sea level rise, heat transport, ocean acidification, these ocean processes, well known in the public sphere, play out on a regional to global scale. But less well known are more localized processes that bring some ecological niches together, keep others separated, and help sustain ocean life by circulating nutrients.
Physical processes in the ocean that take place over intermediate and small scales of space and time play a key role in vertical seawater exchange. They also have significant effects on chemical, biological, and ecological processes in the upper ocean. [...]"
Reconstructing Aragonite Saturation State Based on an Empirical Relationship for Northern California
"Ocean acidification is a global phenomenon with highly regional spatial and temporal patterns. In order to address the challenges of future ocean acidification at a regional scale, it is necessary to increase the resolution of spatial and temporal monitoring of the inorganic carbon system beyond what is currently available. One approach is to develop empirical regional models that enable aragonite saturation state to be estimated from existing hydrographic measurements, for which greater spatial coverage and longer time series exist in addition to higher spatial and temporal resolution. [...]"
Source: Estuaries and Coasts
Authors: Catherine V. Davis et al.
Oysters as sentinels of climate variability and climate change in coastal ecosystems
"Beyond key ecological services, marine resources are crucial for human food security and socio-economical sustainability. Among them, shellfish aquaculture and fishing are of primary importance but become more vulnerable under anthropogenic pressure, as evidenced by reported mass mortality events linked to global changes such as ocean warming and acidification, chemical contamination, and diseases. Understanding climate-related risks is a vital objective for conservation strategies, ecosystems management and human health. [...]"
Source: Environmental Research Letters
Authors: Yoann Thomas et al.
The impact of ocean acidification on the byssal threads of the blue mussel (Mytilus edulis)
"Blue mussel (Mytilus edulis) produce byssal threads to anchor themselves to the substrate. These threads are always exposed to the surrounding environmental conditions. Understanding how environmental pH affects these threads is crucial in understanding how climate change can affect mussels. This work examines three factors (load at failure, thread extensibility, and total thread counts) that indicate the performance of byssal threads as well as condition index to assess impacts on the physiological condition of mussels held in artificial seawater acidified by the addition of CO2. [...]"
Source: PLOS ONE
Authors: Grant Dickey et al.
Oregon Now Has A Hypoxia Season, Just Like A Wildfire Season
"Scientists say warming ocean temperatures mean Oregon’s coastal waters now have a low-oxygen season, or hypoxia season, just as the state’s forests have a fire season.
Hypoxia is a condition in which the ocean water close to the sea floor has such low levels of dissolved oxygen that the organisms living down there die.
Some of the first signs came in 2002 when dead crabs were hauled up in crab pots. Since then, scientists and crabbers say things have worsened."
Author: Kristian Foden-Vencil
Acid coastal seas off US putting common fish species at risk
Scientists have recently discovered that marine creatures can be adversely affected by hypercapnia, a condition of too much dissolved CO2 in seawater (CO2 partial pressure, or pCO2). When this level rises above 1000 micro atmospheres (1000 μatm), some fish species suffer cognitive problems and disorientation, such as losing their way or even swimming towards predators. Surface ocean CO2 partial pressures tend to be around 400 μatm, so until now scientists have thought that hypercapnia was a problem which would only become apparent over time in subsurface waters. [...]"
Ocean acidification drives community shifts towards simplified non-calcified habitats in a subtropical−temperate transition zone
"Rising atmospheric concentrations of carbon dioxide are causing surface seawater pH and carbonate ion concentrations to fall in a process known as ocean acidification. To assess the likely ecological effects of ocean acidification we compared intertidal and subtidal marine communities at increasing levels of pCO2 at recently discovered volcanic seeps off the Pacific coast of Japan (34° N). This study region is of particular interest for ocean acidification research as it has naturally low levels of surface seawater pCO2 (280–320 µatm) and is located at a transition zone between temperate and sub-tropical communities. [...]"
Source: Scientific Reports
Authors: Sylvain Agostini et al.
Generality in multispecies responses to ocean acidification revealed through multiple hypothesis testing
"Decades of research have demonstrated that many calcifying species are negatively affected by ocean acidification, a major anthropogenic threat in marine ecosystems. However, even closely related species may exhibit different responses to ocean acidification and less is known about the drivers that shape such variation in different species. Here, we examine the drivers of physiological performance under ocean acidification in a group of five species of turf‐forming coralline algae. [...]"
Source: Global Change Biology
Authors: Allison K. Barner et al.
Local oceanographic variability influences the performance of juvenile abalone under climate change
"Climate change is causing warming, deoxygenation, and acidification of the global ocean. However, manifestation of climate change may vary at local scales due to oceanographic conditions. Variation in stressors, such as high temperature and low oxygen, at local scales may lead to variable biological responses and spatial refuges from climate impacts. We conducted outplant experiments at two locations separated by ~2.5 km and two sites at each location separated by ~200 m in the nearshore of Isla Natividad, Mexico to assess how local ocean conditions (warming and hypoxia) may affect juvenile abalone performance. [...]"
Source: Scientific Reports
Authors: C.A. Boch
Climate Change Projected to Exacerbate Impacts of Coastal Eutrophication in the Northern Gulf of Mexico
"The continental shelf in the northern Gulf of Mexico experiences expansive seasonal hypoxic conditions and eutrophication‐driven acidification in bottom waters. Rising surface ocean temperatures, freshwater and nutrient inputs, and atmospheric CO2 will further exacerbate these conditions. Using a high‐resolution, regional circulation‐biogeochemical model, we simulated the spatio‐temporal dynamics of oxygen and inorganic carbon in the northern Gulf of Mexico under present and a projected future (2100) climate state. [...]"
Source: Oceans (AGU Journal)
Authors: Arnaud Laurent et al.