Oceanographical Context of the First Bloom of the Silicoflagellate Octactis speculum (Ehrenberg) Recorded to Cause Salmon Mortality in a Galician Ria: Was This Bloom a Rare Event in the Iberian Coast?
Harmful algal blooms are one of the leading causes of mortality in salmon aquaculture, with significant economic consequences. From 15 to 31 October 1996, a bloom of the skeletonized form of Octactis speculum (Ehrenberg) F.H. Chang, J.M. Grieve & J.E. Sutherland was detected in the small Merexo...
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2023
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Online Access: | http://hdl.handle.net/10261/330414 https://doi.org/10.3390/toxins15070435 |
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ftcsic:oai:digital.csic.es:10261/330414 2024-02-11T10:08:19+01:00 Oceanographical Context of the First Bloom of the Silicoflagellate Octactis speculum (Ehrenberg) Recorded to Cause Salmon Mortality in a Galician Ria: Was This Bloom a Rare Event in the Iberian Coast? Prego, Ricardo Carballeira, Rafael Pazos, Yolanda Bao, Roberto 2023-07-02 http://hdl.handle.net/10261/330414 https://doi.org/10.3390/toxins15070435 unknown Multidisciplinary Digital Publishing Institute doi:10.3390/toxins15070435 Toxins 15 (7): 435 (2023) http://hdl.handle.net/10261/330414 open artículo 2023 ftcsic https://doi.org/10.3390/toxins15070435 2024-01-16T11:50:32Z Harmful algal blooms are one of the leading causes of mortality in salmon aquaculture, with significant economic consequences. From 15 to 31 October 1996, a bloom of the skeletonized form of Octactis speculum (Ehrenberg) F.H. Chang, J.M. Grieve & J.E. Sutherland was detected in the small Merexo inlet (1.7 km 2 area), located on the southern shore of the Ria of Muxía (Galicia, NW Spain). The O. speculum population inside the inlet (data period: 1992–1996) seldom exceeded 4·10 3 cell·L −1 . However, its concentration reached 2·10 5 cell·L −1 during the bloom, coinciding with a decrease in light penetration from 5 to 2 m deep, as measured using a Secchi disk. Although similar concentrations were reported during late October 1992, this was the first time that a bloom was associated with caged salmon ( Salmo salar , Linnaeus 1758) mortality in the Galician coastal waters. This mortality was not associated with anoxia in the water column, but with fish gill irritations and mucus segregation due to gill clogging. Excess nitrate and silicate, the latter being essential for skeleton formation, were measured in the inlet during the bloom, with phosphate acting as the limiting nutrient (high negative correlation). Blooms of O. speculum occurred in autumn–winter, when water was retained within the inlet under meteorological conditions of southwest winds (which prompted downwelling conditions) and clear skies. A review of the oceanographic database of the Galician rias showed that massive O. speculum proliferations are also commonplace in other rias with similar environmental conditions, such as the Ria of Ares-Betanzos, and can therefore constitute a threat for the development of salmon aquaculture on this coast. Article in Journal/Newspaper Salmo salar Digital.CSIC (Spanish National Research Council) Sutherland ENVELOPE(168.467,168.467,-77.500,-77.500) Toxins 15 7 435 |
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Open Polar |
collection |
Digital.CSIC (Spanish National Research Council) |
op_collection_id |
ftcsic |
language |
unknown |
description |
Harmful algal blooms are one of the leading causes of mortality in salmon aquaculture, with significant economic consequences. From 15 to 31 October 1996, a bloom of the skeletonized form of Octactis speculum (Ehrenberg) F.H. Chang, J.M. Grieve & J.E. Sutherland was detected in the small Merexo inlet (1.7 km 2 area), located on the southern shore of the Ria of Muxía (Galicia, NW Spain). The O. speculum population inside the inlet (data period: 1992–1996) seldom exceeded 4·10 3 cell·L −1 . However, its concentration reached 2·10 5 cell·L −1 during the bloom, coinciding with a decrease in light penetration from 5 to 2 m deep, as measured using a Secchi disk. Although similar concentrations were reported during late October 1992, this was the first time that a bloom was associated with caged salmon ( Salmo salar , Linnaeus 1758) mortality in the Galician coastal waters. This mortality was not associated with anoxia in the water column, but with fish gill irritations and mucus segregation due to gill clogging. Excess nitrate and silicate, the latter being essential for skeleton formation, were measured in the inlet during the bloom, with phosphate acting as the limiting nutrient (high negative correlation). Blooms of O. speculum occurred in autumn–winter, when water was retained within the inlet under meteorological conditions of southwest winds (which prompted downwelling conditions) and clear skies. A review of the oceanographic database of the Galician rias showed that massive O. speculum proliferations are also commonplace in other rias with similar environmental conditions, such as the Ria of Ares-Betanzos, and can therefore constitute a threat for the development of salmon aquaculture on this coast. |
format |
Article in Journal/Newspaper |
author |
Prego, Ricardo Carballeira, Rafael Pazos, Yolanda Bao, Roberto |
spellingShingle |
Prego, Ricardo Carballeira, Rafael Pazos, Yolanda Bao, Roberto Oceanographical Context of the First Bloom of the Silicoflagellate Octactis speculum (Ehrenberg) Recorded to Cause Salmon Mortality in a Galician Ria: Was This Bloom a Rare Event in the Iberian Coast? |
author_facet |
Prego, Ricardo Carballeira, Rafael Pazos, Yolanda Bao, Roberto |
author_sort |
Prego, Ricardo |
title |
Oceanographical Context of the First Bloom of the Silicoflagellate Octactis speculum (Ehrenberg) Recorded to Cause Salmon Mortality in a Galician Ria: Was This Bloom a Rare Event in the Iberian Coast? |
title_short |
Oceanographical Context of the First Bloom of the Silicoflagellate Octactis speculum (Ehrenberg) Recorded to Cause Salmon Mortality in a Galician Ria: Was This Bloom a Rare Event in the Iberian Coast? |
title_full |
Oceanographical Context of the First Bloom of the Silicoflagellate Octactis speculum (Ehrenberg) Recorded to Cause Salmon Mortality in a Galician Ria: Was This Bloom a Rare Event in the Iberian Coast? |
title_fullStr |
Oceanographical Context of the First Bloom of the Silicoflagellate Octactis speculum (Ehrenberg) Recorded to Cause Salmon Mortality in a Galician Ria: Was This Bloom a Rare Event in the Iberian Coast? |
title_full_unstemmed |
Oceanographical Context of the First Bloom of the Silicoflagellate Octactis speculum (Ehrenberg) Recorded to Cause Salmon Mortality in a Galician Ria: Was This Bloom a Rare Event in the Iberian Coast? |
title_sort |
oceanographical context of the first bloom of the silicoflagellate octactis speculum (ehrenberg) recorded to cause salmon mortality in a galician ria: was this bloom a rare event in the iberian coast? |
publisher |
Multidisciplinary Digital Publishing Institute |
publishDate |
2023 |
url |
http://hdl.handle.net/10261/330414 https://doi.org/10.3390/toxins15070435 |
long_lat |
ENVELOPE(168.467,168.467,-77.500,-77.500) |
geographic |
Sutherland |
geographic_facet |
Sutherland |
genre |
Salmo salar |
genre_facet |
Salmo salar |
op_relation |
doi:10.3390/toxins15070435 Toxins 15 (7): 435 (2023) http://hdl.handle.net/10261/330414 |
op_rights |
open |
op_doi |
https://doi.org/10.3390/toxins15070435 |
container_title |
Toxins |
container_volume |
15 |
container_issue |
7 |
container_start_page |
435 |
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1790607417607716864 |