MEPS 468:43-56 (2012)  -  DOI: https://doi.org/10.3354/meps09954

ABSTRACT: Long-term interannual variations in the mean microphytobenthos chlorophyll a (chl a) of the Ems estuary were investigated. Concentrations in the 1990s were on average 1.5 times higher than during the period from 1976 to 1978, but a trend in chl a over the entire period (1976 to 1999) was not found. In agreement with findings from the late 1970s, the mean chl a concentrations over the post 1990 period correlated significantly with the station elevation related exposure time. Over the entire 1976 to 1999 study period, the estuary mean annual chl a concentrations correlated strongly and significantly with the mean annual air temperature. Although the range of the variation in the mean annual air temperature of the studied years was only 7.5 to 10.2°C, it surprisingly corresponded with a ca. 2.5-fold variation in the mean annual microphytobenthos chl a. In addition to chl a, mean monthly C:chl a ratios from 1976 to 1977 also correlated positively with changes in temperature. Microphytobenthos carbon biomass [chl a × (C:chl a)] may, therefore, respond even stronger to air temperature than chl a does. The correlations are most likely a combination of direct temperature effects on microphytobenthos and stronger, probably complex, indirect temperature effects on the seasonal development and standing stock of young and adult grazers (bivalves) and their carnivores like the brown shrimp Crangon crangon.

KEY WORDS: Benthic diatoms · Long-term temperature effect · Carbon: chlorophyll a ratio

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Cite this article as: de Jonge VN, de Boer WF, de Jong DJ, Brauer VS (2012) Long-term mean annual microphytobenthos chlorophyll a variation correlates with air temperature. Mar Ecol Prog Ser 468:43-56. https://doi.org/10.3354/meps09954 Export citation Share:    Facebook - - linkedIn