Alkaline phosphatase activity and its relationship to inorganic phosphorus in the transition zone of the North-western African upwelling system
20 pages, 10 figures, 2 tables The enzymatic activity of alkaline phosphatase (APA) was studied in the transition zone between the African upwelling system and the open ocean waters of the Canary Islands region. This region is recurrently dominated by the presence of upwelling filaments that may tra...
Published in: | Progress in Oceanography |
---|---|
Main Authors: | , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Elsevier
2004
|
Subjects: | |
Online Access: | http://hdl.handle.net/10261/342796 https://doi.org/10.1016/j.pocean.2004.07.007 |
id |
ftcsic:oai:digital.csic.es:10261/342796 |
---|---|
record_format |
openpolar |
spelling |
ftcsic:oai:digital.csic.es:10261/342796 2024-02-11T10:06:40+01:00 Alkaline phosphatase activity and its relationship to inorganic phosphorus in the transition zone of the North-western African upwelling system Sebastián, Marta Arístegui, Javier Montero, María F. Escánez, José Niell, F. Xavier 2004-09 http://hdl.handle.net/10261/342796 https://doi.org/10.1016/j.pocean.2004.07.007 en eng Elsevier https://doi.org/10.1016/j.pocean.2004.07.007 Sí Progress in Oceanography 62(2-4): 131-150 (2004) 0079-6611 http://hdl.handle.net/10261/342796 doi:10.1016/j.pocean.2004.07.007 1873-4472 none Alkaline phosphatase Mesoscale activity Upwelling filaments North Atlantic Canary region artículo 2004 ftcsic https://doi.org/10.1016/j.pocean.2004.07.007 2024-01-24T00:42:59Z 20 pages, 10 figures, 2 tables The enzymatic activity of alkaline phosphatase (APA) was studied in the transition zone between the African upwelling system and the open ocean waters of the Canary Islands region. This region is recurrently dominated by the presence of upwelling filaments that may transport nutrient-enriched waters out into the open ocean before nutrients become exhausted by plankton. Turnover rates by APA were generally low in the whole region, but detectable in all the measurements carried out. On average, turnover rates were higher in the upwelling stations, and APA in those waters seemed to be mainly generated by heterotrophic bacteria to supply easily assimilable organic C. APA outside the upwelling area showed an inverse hyperbolic relationship with increasing phosphate, suggesting the presence of both constitutive and Pi-inducible APA. In these offshore waters, a threshold of 0.1 μM of phosphate could be defined for the regulatory function of Pi on APA. Thus, APA in nutrient-poor waters seemed to be induced to compensate for Pi-deficiency. Turnover rates in the filaments showed basal (probably constitutive) levels, whereas they increased in the surrounding waters, where phosphate concentration presumably did not satisfy plankton P-demands. The fertilising effect of the filaments and associated cyclonic eddies extended to at least 175 km offshore, where basal alkaline phosphatase activities were still found. The magnitude of this effect depends probably on the intensity of upwelling events and the degree of recirculation of filament water back to the coastal jet Peer reviewed Article in Journal/Newspaper North Atlantic Digital.CSIC (Spanish National Research Council) Progress in Oceanography 62 2-4 131 150 |
institution |
Open Polar |
collection |
Digital.CSIC (Spanish National Research Council) |
op_collection_id |
ftcsic |
language |
English |
topic |
Alkaline phosphatase Mesoscale activity Upwelling filaments North Atlantic Canary region |
spellingShingle |
Alkaline phosphatase Mesoscale activity Upwelling filaments North Atlantic Canary region Sebastián, Marta Arístegui, Javier Montero, María F. Escánez, José Niell, F. Xavier Alkaline phosphatase activity and its relationship to inorganic phosphorus in the transition zone of the North-western African upwelling system |
topic_facet |
Alkaline phosphatase Mesoscale activity Upwelling filaments North Atlantic Canary region |
description |
20 pages, 10 figures, 2 tables The enzymatic activity of alkaline phosphatase (APA) was studied in the transition zone between the African upwelling system and the open ocean waters of the Canary Islands region. This region is recurrently dominated by the presence of upwelling filaments that may transport nutrient-enriched waters out into the open ocean before nutrients become exhausted by plankton. Turnover rates by APA were generally low in the whole region, but detectable in all the measurements carried out. On average, turnover rates were higher in the upwelling stations, and APA in those waters seemed to be mainly generated by heterotrophic bacteria to supply easily assimilable organic C. APA outside the upwelling area showed an inverse hyperbolic relationship with increasing phosphate, suggesting the presence of both constitutive and Pi-inducible APA. In these offshore waters, a threshold of 0.1 μM of phosphate could be defined for the regulatory function of Pi on APA. Thus, APA in nutrient-poor waters seemed to be induced to compensate for Pi-deficiency. Turnover rates in the filaments showed basal (probably constitutive) levels, whereas they increased in the surrounding waters, where phosphate concentration presumably did not satisfy plankton P-demands. The fertilising effect of the filaments and associated cyclonic eddies extended to at least 175 km offshore, where basal alkaline phosphatase activities were still found. The magnitude of this effect depends probably on the intensity of upwelling events and the degree of recirculation of filament water back to the coastal jet Peer reviewed |
format |
Article in Journal/Newspaper |
author |
Sebastián, Marta Arístegui, Javier Montero, María F. Escánez, José Niell, F. Xavier |
author_facet |
Sebastián, Marta Arístegui, Javier Montero, María F. Escánez, José Niell, F. Xavier |
author_sort |
Sebastián, Marta |
title |
Alkaline phosphatase activity and its relationship to inorganic phosphorus in the transition zone of the North-western African upwelling system |
title_short |
Alkaline phosphatase activity and its relationship to inorganic phosphorus in the transition zone of the North-western African upwelling system |
title_full |
Alkaline phosphatase activity and its relationship to inorganic phosphorus in the transition zone of the North-western African upwelling system |
title_fullStr |
Alkaline phosphatase activity and its relationship to inorganic phosphorus in the transition zone of the North-western African upwelling system |
title_full_unstemmed |
Alkaline phosphatase activity and its relationship to inorganic phosphorus in the transition zone of the North-western African upwelling system |
title_sort |
alkaline phosphatase activity and its relationship to inorganic phosphorus in the transition zone of the north-western african upwelling system |
publisher |
Elsevier |
publishDate |
2004 |
url |
http://hdl.handle.net/10261/342796 https://doi.org/10.1016/j.pocean.2004.07.007 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
https://doi.org/10.1016/j.pocean.2004.07.007 Sí Progress in Oceanography 62(2-4): 131-150 (2004) 0079-6611 http://hdl.handle.net/10261/342796 doi:10.1016/j.pocean.2004.07.007 1873-4472 |
op_rights |
none |
op_doi |
https://doi.org/10.1016/j.pocean.2004.07.007 |
container_title |
Progress in Oceanography |
container_volume |
62 |
container_issue |
2-4 |
container_start_page |
131 |
op_container_end_page |
150 |
_version_ |
1790604509541564416 |