| Title | Nutrients, standing crop and primary production in western coastal waters of the adriatic sea |
| Abstract | Nutrients and standing crop over a 2-year period and primary production rates
over a 1-year period were measured at three stations located 1-5, 6 and 15
nautical miles (NM) from the coast, 150 km south of the Po river mouth. Both
nutrients and standing crop (the latter measured as chlorophyll a concentration
and phytoplankton cell density) showed a concentration gradient from west to
east with marked changes of average values from 6 to 15 NM off the coast.
Nutrients and standing crop appeared to be positively correlated and both
showed an inverse dependence on salinity which was mainly influenced by
freshwater inputs from the major Italian river, the Po. Primary production rates
showed values of about 260 and 210 g C m- e year- l at the 1-5 and 6 NM
stations respectively, indicating the presence of a narrow coastal belt with
productivity levels significantly higher than those previously reported for other
Adriatic areas affected by the Po. The offshore station at 15 NM gave an
average annual production of about 120 g C m- 2 year- l which lies in the
range reported for lagoons and coastal waters in the Po delta area. The
photosynthetic efficiency was similar at the 1 '5 and 6 NM stations (respectively
4-04-2-3 and 3.54-2.7) but significantly lower at the 15NM station
(1-9 4- 1 '7). This difference reflects either different nutrient levels in inshore
and offshore stations or different structures in phytoplankton community:
diatoms and phytoflagellates prevailed at 1 "5 and 15 NM, respectively. Photosynthetic
efficiency increased with increasing concentration of nutrients. The
behaviour was found to be linear as a function of total dissolved phosphorus,
and hyperbolic as a function of total dissolved nitrogen. This different dependence
suggests a surplus of nitrogen with respect to phosphorus for photosynthetic
processes in the study area, which is consistent with the assumption of
phosphorus as limiting element often made for the northern Adriatic. |
| Source | Estuarine, coastal and shelf science (Print) 41 (5), pp. 493–513 |
| Keywords | Adriaticnutrientsphytoplanktonprimary production |
| Journal | Estuarine, coastal and shelf science (Print) |
| Editor | Academic Press in association with the Estuarine and Brackish-water Sciences Association,, New York, Stati Uniti d'America |
| Year | 1995 |
| Type | Articolo in rivista |
| DOI | 10.1016/0272-7714(95)90024-1 |
| Authors | Zoppini, A.; Pettine, M.; Totti, C.; Puddu, A.; Artegiani, A.; Pagnotta, R. |
| Text | 338610 1995 10.1016/0272 7714 95 90024 1 Scopus 2 s2.0 0029479484 Adriatic nutrients phytoplankton primary production Nutrients, standing crop and primary production in western coastal waters of the adriatic sea Zoppini, A.; Pettine, M.; Totti, C.; Puddu, A.; Artegiani, A.; Pagnotta, R. Consiglio Nazionale delle Ricerche; Consiglio Nazionale delle Ricerche Nutrients and standing crop over a 2 year period and primary production rates over a 1 year period were measured at three stations located 1 5, 6 and 15 nautical miles NM from the coast, 150 km south of the Po river mouth. Both nutrients and standing crop the latter measured as chlorophyll a concentration and phytoplankton cell density showed a concentration gradient from west to east with marked changes of average values from 6 to 15 NM off the coast. Nutrients and standing crop appeared to be positively correlated and both showed an inverse dependence on salinity which was mainly influenced by freshwater inputs from the major Italian river, the Po. Primary production rates showed values of about 260 and 210 g C m e year l at the 1 5 and 6 NM stations respectively, indicating the presence of a narrow coastal belt with productivity levels significantly higher than those previously reported for other Adriatic areas affected by the Po. The offshore station at 15 NM gave an average annual production of about 120 g C m 2 year l which lies in the range reported for lagoons and coastal waters in the Po delta area. The photosynthetic efficiency was similar at the 1 5 and 6 NM stations respectively 4 04 2 3 and 3.54 2.7 but significantly lower at the 15NM station 1 9 4 1 7 . This difference reflects either different nutrient levels in inshore and offshore stations or different structures in phytoplankton community diatoms and phytoflagellates prevailed at 1 5 and 15 NM, respectively. Photosynthetic efficiency increased with increasing concentration of nutrients. The behaviour was found to be linear as a function of total dissolved phosphorus, and hyperbolic as a function of total dissolved nitrogen. This different dependence suggests a surplus of nitrogen with respect to phosphorus for photosynthetic processes in the study area, which is consistent with the assumption of phosphorus as limiting element often made for the northern Adriatic. 41 Published version http //www.scopus.com/record/display.url eid=2 s2.0 0029479484 origin=inward Articolo in rivista Academic Press in association with the Estuarine and Brackish water Sciences Association, 0272 7714 Estuarine, coastal and shelf science Print Estuarine, coastal and shelf science Print Estuar., coast. shelf sci. Print Estuarine, coastal and shelf science. Print romano.pagnotta PAGNOTTA ROMANO maurizio.pettine PETTINE MAURIZIO alberto.puddu PUDDU ALBERTO annamaria.zoppini ZOPPINI ANNAMARIA |
