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Relationship between Algal Blooms, Fish Kill Incidents, and Oxygen Depletions Relationship between Algal Blooms, Fish Kill Incidents, and Oxygen Depletions

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Date added: 02/16/2013
Date modified: 02/19/2013
Filesize: 1.21 MB
Downloads: 7435
The Relationship between Algal Blooms, Fish Kill Incidents, and Oxygen Depletions along the Omani Coast
S.A. Piontkovski1), H.M.H. Al-Gheilani2), B. Jupp3), Y.V.B. Sarma1), and A.R. Al-Azri1)
1) Sultan Qaboos University, CAMS,PO Box 34, Al-Khod 123, Sultanate of Oman
2) Marine Science and Fisheries Center, Ministry of Agriculture and Fisheries,
P.O. Box 467, Muscat 113, Sultanate of Oman
3) GEO-Resources Consultancy, P.O. Box 175, Mina Al Fahal, Muscat 116
Sultanate of Oman

A persistence of hypoxia is a common feature for the Sea of Oman, and the western Arabian Sea. By using historical data complemented by ongoing measurements, the relationship between the frequency of harmful algal blooms, fish kill incidents, and oxygen depletions, was investigated. In the Sea of Oman, the seasonal pattern exhibited a tendency of fish kill incidents to increase, from January to November. In the western Arabian Sea, the pattern was different- maximal occurrence of fish kill incidences was observed in December and January.
In 1988-2011, the number of harmful algal blooms accompanied by fish kills was 4 times higher for the Sea of Oman (N= 91) compared to the Arabian Sea coast (N= 22), whereas the total number of fish kill incidents was about the same (22 versus 25). This means that the Arabian Sea coast faced more frequent harmful blooms than the Sea of Oman. The Sea of Oman coastal time series of the dissolved oxygen concentration implied a steady decline throughout the year, from January to December.
The fish kill incidents in this region were mainly driven by oxygen depletions, whereas in
the Arabian Sea these incidents were mediated by the harmful algal blooms along with the oxygen depletions. In analyzing the Omani coast as a whole, the Ridge Multiple Regression Analysis implied the dissolved oxygen concentration and monthly occurrence of algal blooms as the two variables explaining 75% of the seasonal variations in fish kill incidents.

A global diatom database A global diatom database

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Date added: 12/01/2012
Date modified: 12/01/2012
Filesize: 1.59 MB
Downloads: 1838
A global diatom database – abundance, biovolume and biomass in the world ocean

Phytoplankton identification and abundance data are now commonly feeding plankton distribution databases worldwide. This study is a first attempt to compile the largest possible body of data available from different databases as well as from individual published or unpublished datasets regarding diatom distribution in the world ocean. The data obtained originate from time series studies as well as spatial studies.

Mesoscale Eddies of Arabian Sea: Physical-biological Interactions Mesoscale Eddies of Arabian Sea: Physical-biological Interactions

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Date added: 11/07/2012
Date modified: 11/07/2012
Filesize: 771.96 kB
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Mesoscale Eddies of Arabian Sea: Physical-biological Interactions
S.A. Piontkovski1 , N.P. Nezlin2
1. Sultan Qaboos University, CAMS, P.O. 34, Al-Khod 123, Sultanate of Oman
2. Southern California Coastal Water Research Project, 3535 Harbor Blvd., Costa Mesa, CA 92626, USA

Satellite derived (SeaWIFS, TOPEX/Poseidon) products for chlorophyll-a concentration, sea surface heights, and calculated kinetic energy of eddies were employed, to analyze physical-biological coupling from 1997 to 2008. It was shown that, when cyclonic eddies dominated throughout the year, the chlorophyll-a concentration was positively related to the kinetic energy of eddies.
For the other years, when the total annual balance of negative to positive sea surface heights was dominated by anticyclonic eddies, the correlation was negative. The evaluated switch contributes a useful detail to the understanding of the mechanism mediating variability of the chlorophyll-a in regions with vigorous eddy fields.

Penilia avirostris: Regional and Global Patterns of Seasonal Cycles Penilia avirostris: Regional and Global Patterns of Seasonal Cycles

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Date added: 04/19/2012
Date modified: 04/19/2012
Filesize: 216.91 kB
Downloads: 2475

Penilia avirostris: Regional and Global Patterns of Seasonal Cycles
S.A. Piontkovski1, S. Fonda-Umani2, A. De Olazabal3 and A.D. Gubanova4
1Sultan Qaboos University, CAMS, PO 34, Al-Khod 123, Sultanate of Oman
2Department of Life Sciences, University of Trieste, v. Valerio 28/1 34123 Trieste, Italy
3Department of Biological Oceanography, OGS, v. Piccard, 42, Italy
4Institute of Biology of the Southern Seas, 2 Nakhimov Pr., Sevastopol 99011, Ukraine

Seasonal cycles of the Penilia abundance were compared, over five coastal regions-the north-western part of the Black Sea (Sevastopol Bay), the northern part of the Adriatic Sea (Gulf of Trieste), the north-eastern Atlantic (Vigo coast), the north-western Mediterranean basin (Barcelona coast), and the north-western part of the Arabian Sea (the Gulf of Oman). Satellite derived monthly data were used, to analyze coupling between the Penilia abundance, sea surface temperature, and chlorophyll a concentration over these regions.
Two types of seasonal dynamics were noticed: (1) a unimodal type of population dynamics with one peak lasting 3-4 months in summer to fall (in Vigo, Sevastopol, and Trieste regions) and (2) all year round persisting population in subtropical highly productive waters of the Arabian Sea (Gulf of Oman). A regional link between abundance and temperature was also reflected by the global geography of the Penilia habitats. As far as the global aspect is concerned, a general relationship representing the abundance as the linear function of two environmental variables-sea surface temperature and chlorophyll a concentration was proposed.

 http://repository.ibss.org.ua/dspace/handle/99011/2437

 

Mesoscale eddies and variability of chlorophyll-a in the Sea of Oman Mesoscale eddies and variability of chlorophyll-a in the Sea of Oman

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Date added: 03/01/2012
Date modified: 03/01/2012
Filesize: 447.57 kB
Downloads: 3980
Mesoscale eddies and variability of chlorophyll-a in the Sea of Oman
SERGEY A. PIONTKOVSKI*, NIKOLAY P. NEZLIN, ADNAN AL-AZRIand KHALID AL-HASHMI
Department of Marine Science and Fisheries, Sultan Qaboos University, Al-Khod 123, Sultanate of Oman
Southern California Coastal Water Research Project, Costa Mesa, CA 92626, USA

Satellite-derived (TOPEX/Poseidon, Jason-1, Jason-2, SeaWIFS (Sea-Viewing Wide Field-of-View Sensor) and MODIS (Moderate Resolution Imaging Spectroradiometer) Aqua) weekly and monthly products for sea surface height, sea surface temperature (SST) and chlorophyll-a (CHL) concentration were used to analyse the trends of physical–biological coupling. In the variability of chlorophyll, no interannual trends were found for the Sea of Oman (1997–2008). However, the variation of chlorophyll within the annual cycle has increased. A similar tendency was evaluated for the variability of the energy of mesoscale eddies. Themedian level of kinetic energy and the coefficient of variation of this energy within the annual cycle both increased from 1997 through 2008.
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