| Abstrakt: |
Gurung, D.P.; Chen, N.; Waguespack, Y.; Ishaque, A.B., and Chigbu, P., 2024. Assessment of alkaline phosphatase activity in the water column of Maryland Coastal Bays. Journal of Coastal Research, 40(2), 319–337. Charlotte (North Carolina), ISSN 0749-0208. Understanding maximum alkaline phosphatase activity (Vmax) is essential to understand the phosphorus (P) cycle in Maryland Coastal Bays (MCBs). The objectives of this study were to measure Vmax in the samples collected from different locations in MCBs and to examine the relationship between Vmax and dissolved reactive phosphorus (DRP) concentrations. Water samples were collected at 13 sites from 2014 to 2016, and Vmax was measured in whole water by using 4-methylumbelliferyl phosphate as the fluorogenic substrate. Although the measured Vmax was affected by multiple factors, P limitation events were recognized from spatial/temporal distributions in Vmax values, which might not be reflected by DRP condition. Regression analysis did not yield a significant relationship between DRP and Vmax, and monthly averages of DRP and Vmax provide better evidence of the connection between DRP and Vmax, including P limitation (high Vmax) and alkaline phosphatase inhibition (low Vmax). Results from this study support the view that Vmax is a good indicator of availability of DRP in aquatic environments. More work is needed to further understand the relationship between Vmax and DRP, in particular, when strong P limitation occurs in the Bays. Moderate to strong positive relationships were observed between Vmax and chlorophyll a. Moderately negative relationships were observed between Vmax and salinity and between Vmax and pH, which may be attributed to freshwater inputs. Likewise, a moderate positive relationship was observed between Vmax and temperature for only some months. [ABSTRACT FROM AUTHOR] |
