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Outsmarting ocean acidification

CHATHAM – Although it was years ago, Dan Martino well remembers how hatcheries in the Pacific Northwest watched their shellfish seed die, ravaged by ocean acidification.

“The shellfish basically dissolved in front of their eyes,” Martino says. “The ocean water had grown too acidic.”

When Dan and his brother Greg got their oyster grant on Martha’s Vineyard in 2014, and became the first oyster farm in Oak Bluffs history, that memory became even more sinister.
The hatcheries in Washington State, which were using seawater to grow, changed their model and began buffering the water, adding something similar to lime, to bring up the pH.

The Martinos, who own Cottage City Oysters, figure it is only a matter of time before the same phenomenon hits the East Coast. They are trying to get in front of a problem that could crush an increasingly important industry to the economy of the Cape and Islands.

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OA-ICC bibliographic database updated

An updated version of the OA-ICC bibliographic database is available online.

The database currently contains more than 5,200 references and includes citations, abstracts and assigned keywords. Updates are made every month.

The database is available as a group on Mendeley. Subscribe online or, for a better user experience, download the Mendeley Desktop application and sync with the group Ocean Acidification (OA-ICC). Please see the “User instructions” for further details.

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Virtual reality helps students understand the reality of ocean acidification (text and video)

Virtual reality can be so much more than another device that lets young males carve each other up in interesting new ways in combat-themed video games. Researchers at Stanford and the University of Oregon have created a VR presentation they call the Stanford Ocean Acidification Experience and presented it to nearly 300 high school and college students. Participants see themselves as part of a living coral reef and watch as it deteriorates to become a lifeless ecosystem infested with weeds.

Continue reading ‘Virtual reality helps students understand the reality of ocean acidification (text and video)’

Ecological and functional consequences of coastal ocean acidification: perspectives from the Baltic-Skagerrak System

Ocean temperatures are rising; species are shifting poleward, and pH is falling (ocean acidification, OA). We summarise current understanding of OA in the brackish Baltic-Skagerrak System, focussing on the direct, indirect and interactive effects of OA with other anthropogenic drivers on marine biogeochemistry, organisms and ecosystems. Substantial recent advances reveal a pattern of stronger responses (positive or negative) of species than ecosystems, more positive responses at lower trophic levels and strong indirect interactions in food-webs. Common emergent themes were as follows: OA drives planktonic systems toward the microbial loop, reducing energy transfer to zooplankton and fish; and nutrient/food availability ameliorates negative impacts of OA. We identify several key areas for further research, notably the need for OA-relevant biogeochemical and ecosystem models, and understanding the ecological and evolutionary capacity of Baltic-Skagerrak ecosystems to respond to OA and other anthropogenic drivers.

Continue reading ‘Ecological and functional consequences of coastal ocean acidification: perspectives from the Baltic-Skagerrak System’

Decadal‐scale increases of anthropogenic CO2 in Antarctic Bottom Water in the Indian and western Pacific sectors of the Southern Ocean

We determined decadal‐scale increases of anthropogenic CO2 in the water column using data sets collected 17 years apart (1994‐1996 and 2012‐2013) along a transect at nominal 62°S in the Indian and western Pacific sectors of the Southern Ocean. Large increases of anthropogenic CO2 (up to 9.1 ± 1.5 μmol kg–1), closely following atmospheric CO2 increases, were found in Antarctic Bottom Water (AABW), previously considered a small sink of anthropogenic CO2. Vertical distributions of anthropogenic CO2 increases showed significant positive correlations with those of changes in CFC‐12 and SF6, implying that the distributions were mainly controlled by physical processes such as ventilation and circulation. Calculated uptake rates of anthropogenic CO2 by AABW were between 0.29 and 0.39 mol m–2 yr–1 in five longitudinal segments of the transect. In accounting for the large increase of anthropogenic CO2 in AABW, sea surface conditions in the formation region of AABW are important.

Continue reading ‘Decadal‐scale increases of anthropogenic CO2 in Antarctic Bottom Water in the Indian and western Pacific sectors of the Southern Ocean’

Northern cod species face spawning habitat losses if global warming exceeds 1.5°C

Rapid climate change in the Northeast Atlantic and Arctic poses a threat to some of the world’s largest fish populations. Impacts of warming and acidification may become accessible through mechanism-based risk assessments and projections of future habitat suitability. We show that ocean acidification causes a narrowing of embryonic thermal ranges, which identifies the suitability of spawning habitats as a critical life-history bottleneck for two abundant cod species. Embryonic tolerance ranges linked to climate simulations reveal that ever-increasing CO2 emissions [Representative Concentration Pathway (RCP) 8.5] will deteriorate suitability of present spawning habitat for both Atlantic cod (Gadus morhua) and Polar cod (Boreogadus saida) by 2100. Moderate warming (RCP4.5) may avert dangerous climate impacts on Atlantic cod but still leaves few spawning areas for the more vulnerable Polar cod, which also loses the benefits of an ice-covered ocean. Emissions following RCP2.6, however, support largely unchanged habitat suitability for both species, suggesting that risks are minimized if warming is held “below 2°C, if not 1.5°C,” as pledged by the Paris Agreement.

Continue reading ‘Northern cod species face spawning habitat losses if global warming exceeds 1.5°C’

Examining the impact of tropical cyclones on air‐sea CO2 exchanges in the Bay of Bengal based on satellite data and in‐situ observations

The impact of tropical cyclones (TCs) on the CO2 partial pressure at the sea surface (pCO2sea) and air‐sea CO2 flux (FCO2) in the Bay of Bengal (BoB) was quantified based on satellite data and in‐situ observations between November 2013 and January 2017. The in‐situ observations were made at the BoB Ocean Acidification (BOBOA) mooring buoy. A weak time‐mean net source of 55.78±11.16 mmol CO2 m–2 yr–1 at the BOBOA site was estimated during this period. A wide range in increases of pCO2sea (1.0–14.8 μatm) induced by TCs occurred in post‐monsoon (October–December), and large decreases of pCO2sea (–14.0 μatm) occurred in pre‐monsoon (March–May). Large vertical differences in the ratio of dissolved inorganic carbon (DIC) to total alkalinity (TA) in the upper layer (∆DIC/TA) were responsible for increasing pCO2sea in post‐monsoon. Relatively small values of ∆DIC/TA were responsible for decreasing pCO2sea in pre‐monsoon. Five TCs (Hudhud, Five, Kyant, Vardah and Roanu) were considered. Hudhud significantly enhanced CO2 efflux (18.49±3.70 mmol CO2 m–2) in oversaturated areas due to the wind effect during the storm and ‘wind‐pump’ effects after the storm. Vardah insignificantly changed FCO2 (1.22±0.24 mmol CO2 m–2) in undersaturated areas because of the counteraction of these two effects. Roanu significantly enhanced CO2 efflux (19.08±3.82 mmol CO2 m–2) in highly oversaturated conditions (∆pCO2 > 20 μatm) since the wind effect greatly exceeded the ‘wind‐pump’ effects. These five TCs were estimated to account for 55±23% of the annual‐mean CO2 annual efflux, suggesting that TCs have significant impacts on the carbon cycle in the BoB.

Continue reading ‘Examining the impact of tropical cyclones on air‐sea CO2 exchanges in the Bay of Bengal based on satellite data and in‐situ observations’


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OA-ICC HIGHLIGHTS

Ocean acidification in the IPCC AR5 WG II

OUP book