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Trends of pH decrease in the Mediterranean Sea through high frequency observational data: indication of ocean acidification in the basin.

Flecha S, Pérez FF, García-Lafuente J, Sammartino S, Ríos AF, Huertas IE - Sci Rep (2015)

Bottom Line: Assessing the impact of OA on marine ecosystems requires the accurate detection of the rate of seawater pH change.This work reports the results of nearly 3 years of continuous pH measurements in the Mediterranean Sea at the Strait of Gibraltar GIFT time series station.Both water masses also exhibited a decline in pH with time, particularly the WMDW, which can be related to their different biogeochemical nature and processes occurring during transit time from formation sites to the Strait of Gibraltar.

View Article: PubMed Central - PubMed

Affiliation: Instituto de Ciencias Marinas de Andalucía, (CSIC), Polígono Río San Pedro, s/n, 11519, Puerto Real, Cádiz, Spain.

ABSTRACT
A significant fraction of anthropogenic carbon dioxide (CO2) released to the atmosphere is absorbed by the oceans, leading to a range of chemical changes and causing ocean acidification (OA). Assessing the impact of OA on marine ecosystems requires the accurate detection of the rate of seawater pH change. This work reports the results of nearly 3 years of continuous pH measurements in the Mediterranean Sea at the Strait of Gibraltar GIFT time series station. We document a remarkable decreasing annual trend of -0.0044 ± 0.00006 in the Mediterranean pH, which can be interpreted as an indicator of acidification in the basin based on high frequency records. Modeling pH data of the Mediterranean outflow allowed to discriminate between the pH values of its two main constituent water masses, the Levantine Intermediate Water (LIW) and the Western Mediterranean Deep Water (WMDW). Both water masses also exhibited a decline in pH with time, particularly the WMDW, which can be related to their different biogeochemical nature and processes occurring during transit time from formation sites to the Strait of Gibraltar.

No MeSH data available.


Related in: MedlinePlus

(a) Potential temperature (), (b) Salinity obtained with the CT and (c) SAMI-pH data from August 2012 to June 2015.
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f1: (a) Potential temperature (), (b) Salinity obtained with the CT and (c) SAMI-pH data from August 2012 to June 2015.

Mentions: From August 2012 to June 2015, the data collected at the mooring site fluctuated within small ranges of values. Potential temperature () oscillated from 13.01 to 13.63 °C, salinity from 38.01 to 38.48 and pH in total scale at a reference temperature of 25 °C (pHT25) from 7.8618 to 7.9370 (Fig. 1). The pHT25 mean value was 7.8934 ± 0.0076 (n = 15937), which is in good agreement with the average pH in the MOW obtained from sustained spectrophotometric pHT25 measurements taken periodically within this layer at the GIFT stations from 2005 to 2014 (n = 102) and equivalent to 7.8875 ± 0.0124.


Trends of pH decrease in the Mediterranean Sea through high frequency observational data: indication of ocean acidification in the basin.

Flecha S, Pérez FF, García-Lafuente J, Sammartino S, Ríos AF, Huertas IE - Sci Rep (2015)

(a) Potential temperature (), (b) Salinity obtained with the CT and (c) SAMI-pH data from August 2012 to June 2015.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4660394&req=5

f1: (a) Potential temperature (), (b) Salinity obtained with the CT and (c) SAMI-pH data from August 2012 to June 2015.
Mentions: From August 2012 to June 2015, the data collected at the mooring site fluctuated within small ranges of values. Potential temperature () oscillated from 13.01 to 13.63 °C, salinity from 38.01 to 38.48 and pH in total scale at a reference temperature of 25 °C (pHT25) from 7.8618 to 7.9370 (Fig. 1). The pHT25 mean value was 7.8934 ± 0.0076 (n = 15937), which is in good agreement with the average pH in the MOW obtained from sustained spectrophotometric pHT25 measurements taken periodically within this layer at the GIFT stations from 2005 to 2014 (n = 102) and equivalent to 7.8875 ± 0.0124.

Bottom Line: Assessing the impact of OA on marine ecosystems requires the accurate detection of the rate of seawater pH change.This work reports the results of nearly 3 years of continuous pH measurements in the Mediterranean Sea at the Strait of Gibraltar GIFT time series station.Both water masses also exhibited a decline in pH with time, particularly the WMDW, which can be related to their different biogeochemical nature and processes occurring during transit time from formation sites to the Strait of Gibraltar.

View Article: PubMed Central - PubMed

Affiliation: Instituto de Ciencias Marinas de Andalucía, (CSIC), Polígono Río San Pedro, s/n, 11519, Puerto Real, Cádiz, Spain.

ABSTRACT
A significant fraction of anthropogenic carbon dioxide (CO2) released to the atmosphere is absorbed by the oceans, leading to a range of chemical changes and causing ocean acidification (OA). Assessing the impact of OA on marine ecosystems requires the accurate detection of the rate of seawater pH change. This work reports the results of nearly 3 years of continuous pH measurements in the Mediterranean Sea at the Strait of Gibraltar GIFT time series station. We document a remarkable decreasing annual trend of -0.0044 ± 0.00006 in the Mediterranean pH, which can be interpreted as an indicator of acidification in the basin based on high frequency records. Modeling pH data of the Mediterranean outflow allowed to discriminate between the pH values of its two main constituent water masses, the Levantine Intermediate Water (LIW) and the Western Mediterranean Deep Water (WMDW). Both water masses also exhibited a decline in pH with time, particularly the WMDW, which can be related to their different biogeochemical nature and processes occurring during transit time from formation sites to the Strait of Gibraltar.

No MeSH data available.


Related in: MedlinePlus