Metabolic CO₂ production in the Mediterranean Sea: A case study for estimating carbon budget in the sea

Abstract

SUMMARY: A synthesis of published metabolic CO 2 production rates determined in the water column of the Eastern Mediterranean Sea from 1993 to 1999 is reported with the aim of furnishing an overall picture of the remineralization processes occurring in the basin. The trends of the remineralization are also interpreted with respect to the so-called Eastern Mediterranean Transient (EMT) event. This study augments the sparse data set of respiration measurements, from oceanographic surveys, and highlights the tight coupling between biological processes and circulation patterns. In the photic zone, the rates decreased from West to East as well as from North to South. In the aphotic zone, the C remineralization trend followed the traditional routes of intermediate and deep waters in the Eastern Mediterranean Basin, and underwent the important modifications into the depths as a consequence of the EMT impact.

New insights on the mineralization of dissolved organic matter in central, intermediate, and deep water masses of the northeast North Atlantic

“…As indicated above, this SWT is composed of the diluted Levantine intermediate water (LIW) that crosses the sill of the Strait of Gibraltar and subducted North Atlantic thermocline waters (Á lvarez et al 2005). Considering the relatively high respiration rates measured by La Ferla and Azzaro (2004) in the LIW, from 4 mmol C kg 21 yr 21 in the Levantine basin to 1 mmol C kg 21 yr 21 in the Strait of Gibraltar, it is likely that most of the mineralization of the DOM carried by the MW, which results in its high ,DOC i . : ,DON i .…”

The carbon budget in the northern Adriatic Sea, a winter case study

“…Dense waters form in the northern Adriatic Sea under the dominant influence of strong and cold winds like the Bora [ Boldrin et al ., ] thus allowing annual bottom water ventilation and renewal [ Russo et al ., ]. This mechanism is responsible for the CO 2 sequestration and acidification of deep waters [ Luchetta et al ., ] and, together with the deep convection occurring in the southern Adriatic [ Civitarese and Gacic , ], makes this an important contributor to the Eastern Mediterranean Deep Water and to the whole Mediterranean circulation, and it is expected to have an impact on climate variability [ Marty et al ., ] and biogeochemical characteristics [ La Ferla and Azzaro , ].…”

Understanding tetrazolium reduction and the importance of substrates in measuring respiratory electron transport activity

“…This is associated with, but not stoichiometrically tied to the respiratory CO 2 production rate (CPR) (La Ferla and Azzaro, 2004). The CPR is the sum of the enzymatic reactions that catalyze the production of CO 2 (Packard et al, 1996b).…”