Ecology of amorphous aggregations (marine snow) in the northern Adriatic Sea. IV. Dissolved nutrients and the autotrophic community associated with marine snow

E. Kaltenbock, G. J. Herndl

Development over time of the inorganic nutrient regime as well as the autotrophic community was investigated in marine snow (up to 20 cm in diameter) and in clouds (up to 5m in length) in summer 1991. In marine snow mean enrichment factors (EFs) for inorganic nitrogen species ranged from 2.0 (NH3) to 3.5 (NO2

-) while for PO4

3- a mean EF of 27 was obtained. Clouds exhibited generally similar EFs. In ambient water, the mean atomic ratio of Ninorg:P-PO4

3- was c70, deviating significantly from the Redfield ratio of 16. This severe deficiency in phosphate availability might be one of the triggering factors for excessive production of mucoid material by phytoplankton. Cyanobacteria contributed c75% of the total chl a concentration in ambient water and 68% in marine snow. Particulate primary production in marine snow was c10 times higher (12.45μg C1-1h-1) than in ambient water and similar to the production in clouds while specific primary production in marine snow was significantly lower than in ambient water. In clouds specific productivity was an order of magnitude lower than in ambient water. The inorganic N pool is turned over five times faster in marine snow than in ambient water while inorganic phosphorus is turned over twice as fast in ambient water. The estimated contribution of primary production associated with marine snow and clouds to overall water column primary production amounts to 40%. (See also 93L/11254). -from Authors

Functional and Evolutionary Ecology
External organisation(s)
Universität Wien
Marine Ecology Progress Series
No. of pages
Publication date
Peer reviewed
Austrian Fields of Science 2012
106021 Marine biology
ASJC Scopus subject areas
Ecology, Evolution, Behavior and Systematics, Aquatic Science, Ecology
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