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Description:
Title:
Seasonal Variations of Carbonate Chemistry at Two Western Atlantic Coral Reefs
Author(s):
Meléndez, Melissa
Salisbury, Joseph
Gledhill, Dwight
Langdon, Chris
Morell, Julio M.
Manzello, Derek
Rodriguez‐Abudo, Sylvia
Musielewicz, Sylvia
Sutton, Adrienne
Dates of Publication:
2020
Abstract:
Time series from open ocean fixed stations have robustly documented secular changes in carbonate chemistry and long-term ocean acidification (OA) trends as a direct response to increases in atmospheric carbon dioxide (CO2). However, few high-frequency coastal carbon time series are available in reef systems, where most affected tropical marine organisms reside. Seasonal variations in carbonate chemistry at Cheeca Rocks (CR), Florida, and La Parguera (LP), Puerto Rico, are presented based on 8 and 10 years of continuous, high-quality measurements, respectively. We synthesized and modeled carbonate chemistry to understand how physical and biological processes affect seasonal carbonate chemistry at both locations. The results showed that differences in biology and thermodynamic cycles between the two systems caused higher amplitudes at CR despite the shorter residence times relative to LP. Analyses based on oxygen and temperature-normalized pCO2sw showed that temperature effects on pCO2sw at CR were largely counteracted by primary productivity, while thermodynamics alone explained a majority of the pCO2sw dynamics at LP. Heterotrophy dominated from late spring to fall, and autotrophy dominated from winter to early spring. Observations suggested that organic respiration decreased the carbonate mineral saturation state (Ω) during late summer/fall. The interactive effects between the inorganic and organic carbon cycles and the assumed effects of benthic metabolism on the water chemistry at both sites appeared to cause seasonal hysteresis with the carbonate chemistry. Improved integration of observational data to modeling approaches will help better forecast how physical and biogeochemical processes will affect Ω and carbonate chemistry in coastal areas.
Keywords:
Coral reefs and islands
Place Keywords:
Puerto Rico
Florida
Local Corporate Name:
OAR (Oceanic and Atmospheric Research)
AOML (Atlantic Oceanographic and Meteorological Laboratory)
PMEL (Pacific Marine Environmental Laboratory)
OAP (Ocean Acidification Program)
JISAO (Joint Institute for the Study of the Atmosphere and Ocean)
CoRIS (Coral Reef Information System
Type of Resource:
Journal Article
Note:
Time series from open ocean fixed stations have robustly documented secular changes in carbonate chemistry and long-term ocean acidification (OA) trends as a direct response to increases in atmospheric carbon dioxide (CO2). However, few high-frequency coastal carbon time series are available in reef systems, where most affected tropical marine organisms reside. Seasonal variations in carbonate chemistry at Cheeca Rocks (CR), Florida, and La Parguera (LP), Puerto Rico, are presented based on 8 and 10 years of continuous, high-quality measurements, respectively. We synthesized and modeled carbonate chemistry to understand how physical and biological processes affect seasonal carbonate chemistry at both locations. The results showed that differences in biology and thermodynamic cycles between the two systems caused higher amplitudes at CR despite the shorter residence times relative to LP. Analyses based on oxygen and temperature-normalized pCO2sw showed that temperature effects on pCO2sw at CR were largely counteracted by primary productivity, while thermodynamics alone explained a majority of the pCO2sw dynamics at LP. Heterotrophy dominated from late spring to fall, and autotrophy dominated from winter to early spring. Observations suggested that organic respiration decreased the carbonate mineral saturation state (Ω) during late summer/fall. The interactive effects between the inorganic and organic carbon cycles and the assumed effects of benthic metabolism on the water chemistry at both sites appeared to cause seasonal hysteresis with the carbonate chemistry. Improved integration of observational data to modeling approaches will help better forecast how physical and biogeochemical processes will affect Ω and carbonate chemistry in coastal areas.
URL:
DOI:
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