ARCA è l'archivio istituzionale ad accesso aperto della ricerca dell'Università Ca' Foscari Venezia e nasce nel 2014 con lo scopo di raccogliere, diffondere e conservare la produzione scientifica dell'Università. Costituisce di fatto il catalogo della ricerca di Ateneo.
ARCA è un sistema Open Access: è non solo consultabile da tutti e visibile nei motori di ricerca, ma anche interoperabile con il portale cerCa. In questo modo vengono valorizzate la produzione scientifica dell'Ateneo e la visibilità dei ricercatori.

Macroalgae biomass and concentrations of nitrogen, phosphorus and chlorophyll a were determined weekly or biweekly in water and sediments, during the spring-summer of 1985 in a hypertrophic area of the lagoon of Venice. Remarkable biomass production (up to 286 g m-2 day-1, wet weight), was interrupted during three periods of anoxia, when macroalgal decomposition (rate: up to 1000 g m-2 day-1) released extraordinary amounts of nutrients. Depending on the macroalgae distribution in the water column, the nutrients released in water varied from 3·3 to 19·1 μg-at litre-1 for total inorganic nitrogen and from 1·8 to 2·7 μg-at litre-1 for reactive phosphorus. Most nutrients, however, accumulated in the surficial sediment (up to 0·640 and to 3·06 mg g-1 for P and N respectively) redoubling the amounts already stored under aerobic conditions, Phytoplankton, systematically below 5 mg m-3 as Chl. a, sharply increased up to 100 mg m-3 only after the release of nutrients in water by anaerobic macroalgal decomposition. During the algal growth periods, the N:P atomic ratio in water decreased to 0·7, suggesting that nitrogen is a growth-limiting factor. This ratio for surficial sediment was between 6·6 and 13·1, similar to that of macroalgae (8·6-12·0).

Macroalgae biomass and concentrations of nitrogen, phosphorus and chlorophyll a were determined weekly or biweekly in water and sediments, during the spring-summer of 1985 in a hypertrophic area of the lagoon of Venice. Remarkable biomass production (up to 286 g m-2 day-1, wet weight), was interrupted during three periods of anoxia, when macroalgal decomposition (rate: up to 1000 g m-2 day-1) released extraordinary amounts of nutrients. Depending on the macroalgae distribution in the water column, the nutrients released in water varied from 3·3 to 19·1 μg-at litre-1 for total inorganic nitrogen and from 1·8 to 2·7 μg-at litre-1 for reactive phosphorus. Most nutrients, however, accumulated in the surficial sediment (up to 0·640 and to 3·06 mg g-1 for P and N respectively) redoubling the amounts already stored under aerobic conditions, Phytoplankton, systematically below 5 mg m-3 as Chl. a, sharply increased up to 100 mg m-3 only after the release of nutrients in water by anaerobic macroalgal decomposition. During the algal growth periods, the N:P atomic ratio in water decreased to 0·7, suggesting that nitrogen is a growth-limiting factor. This ratio for surficial sediment was between 6·6 and 13·1, similar to that of macroalgae (8·6-12·0). © 1987.

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