A global diatom database – abundance, biovolume and biomass in the world ocean
K. Leblanc1, J. Ar´ıstegui2, L. Armand3, P. Assmy4, B. Beker5, A. Bode6, E. Breton7,8,9, V. Cornet1, J. Gibson10, M.-P. Gosselin11, E. Kopczynska12, H. Marshall13, J. Peloquin14, S. Piontkovski15, A. J. Poulton16, B. Qu´eguiner1, R. Schiebel17, R. Shipe18, J. Stefels19, M. A. van Leeuwe19, M. Varela6, C. Widdicombe20, and M. Yallop21
1Aix-Marseille Universit´e, Universit´e du Sud Toulon-Var, CNRS/INSU, IRD, MIO, UM 110, 13288, Marseille, Cedex 09, France
2Instituto de Oceanograf´ıa y Cambio Global, Universidad de Las Palmas de Gran Canaria, 35017 Las Palmas Spain
3Department of Biological Sciences, Macquarie University, North Ryde, NSW, 2109, Australia
4Norwegian Polar Institute, Fram Centre, Hjalmar Johansens gt. 14, 9296 Tromsø, Norway
5Laboratoire des Sciences de l’Environnement Marin, UMR6539, CNRS, Institut Universitaire Europ´een de la Mer (IUEM), Place Nicolas Copernic, Technopˆole Brest Iroise, 29280 Plouzan´e, France
6Instituto Espa˜nol de Oceanograf´ıa, Centro Oceanogr´afico de A Coru˜na Apdo. 130, 15080, A Coru˜na, Spain
7Univ Lille Nord de France, 59000 Lille, France
8ULCO, LOG, 62930 Wimereux, France
9CNRS, UMR8187 LOG, 62930 Wimereux, France
10Institute for Marine and Antarctic Studies, University of Tasmania, Private Bag 129, Hobart, Tasmania 7001,
11The Freshwater Biological Association, The Ferry Landing, Far Sawrey, Ambleside, LA22 0LP, UK
12Institute of Biochemistry and Biophysics, Department of Antarctic Biology, Polish Academy of Sciences,
02-141 Warszawa, Poland
13Department of Biological Sciences, Old Dominion University, Norfolk, VA, USA
14Inst. f. Biogeochemie u. Schadstoffdynamik, Universit¨atstrasse 16, 8092 Z¨urich, Switzerland
15Department of Marine Sciences, Sultan Qaboos University, Sultanate of Oman
16National Oceanography Centre, Waterfront Campus, Southampton, SO14 3ZH, UK
17Laboratoire des Bio-Indicateurs Actuels et Fossiles (BIAF), UPRES EA 2644, Universit´e d’Angers, 49045
Angers CEDEX 01, France
18UCLA, Los Angeles, California 90095, USA
19University of Groningen, Centre for Life Sciences Ecophysiology of Plants, P.O. Box 11103, 9700 CC
Groningen, The Netherlands
20Plymouth Marine Laboratory, Prospect Place, West Hoe, Plymouth, PL1 3DH, UK
21School of Biological Sciences, University of Bristol, Woodland Road, Bristol BS8 1UG, UK
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. This effort is supported by the Marine Ecosystem Model Inter-Comparison Project (MAREMIP), which aims at building consistent datasets for the main plankton functional types (PFTs) in order to help validate biogeochemical ocean models by using carbon (C) biomass derived from abundance data. In this study we collected over 293 000 individual geo-referenced data points with diatom abundances from bottle and net sampling. Sampling site distribution was not homogeneous, with 58% of data in the Atlantic, 20% in the Arctic, 12% in the Pacific, 8% in the Indian and 1% in the Southern Ocean. A total of 136 different genera and 607 different species were identified after spell checking and name correction. Only a small fraction of these data were also documented for biovolumes and an even smaller fraction was converted to C biomass. As it is virtually impossible to reconstruct everyone’s method for biovolume calculation, which is usually not indicated in the datasets, we decided to undertake the effort to document, for every distinct species, the minimum and maximum cell dimensions, and to convert all the available abundance data into biovolumes and C biomass using a single standardized method. Statistical correction of the database was also adopted to exclude potential outliers and suspicious data points. The final database contains 90 648 data points with converted C biomass. Diatom C biomass calculated from cell sizes spans over eight orders of magnitude. The mean diatom biomass for individual locations, dates and depths is 141.19 μg Cl−1, while the median value is 11.16 μg Cl−1. Regarding biomass distribution, 19% of data are in the range 0–1 μg Cl−1, 29% in the range 1–10 μg Cl−1, 31% in the range 10–100 μg Cl−1, 18% in the range 100–1000 μg Cl−1, and only 3% > 1000 μg Cl−1. Interestingly, less than 50 species contributed to >90% of global biomass, among which centric species were dominant. Thus, placing significant efforts on cell size measurements, process studies and C quota calculations of these species should considerably improve biomass estimates in the upcoming years. A first-order estimate of the diatom biomass for the global ocean ranges from 444 to 582 Tg C, which converts to 3 to 4 Tmol Si and to an average Si biomass turnover rate of 0.15 to 0.19 d−1.
Link to the dataset:
Mesozooplankton of the Omani shelf: taxonomy, seasonality, and spatial distribution
Sergey A. Piontkovski, Asyla Al-Mawali,Ahlam Al-Kharusi, WardalMuna Al-Manthri, Sharon Smith & Elena Popova
The total zooplankton biomass was determined for 216 samples collected during seasonal surveys onboard a research vessel. Some of these samples were processed to the level of species. In 2007–2008, the Omani shelf was populated by a highly productive epipelagic plankton community. The chlorophyll-a concentration was high throughout the seasonal cycle and likewise the zooplankton biomass, where seasonal values varied from 543 to 723 mg m-3. Spatial distribution of zooplankton biomass over shelf waters was highly heterogeneous, with maximal heterogeneity observed during the South-west Monsoon. The mean biomass and size structure of the zooplankton community did not exhibit statistically significant seasonal changes. On the species level, seasonal changes dealt with a massive appearance of the copepod Calanoides carinatus s.f. in shelf waters, to which organisms migrated from the deep, during the South-west Monsoon. The population represented mainly by c4 and c5 copepodite stages ascending to upper layers during its ontogenetic migration has occupied the entire Omani shelf area. However, this migration did not contribute markedly to seasonal variation of the total zooplankton biomass.
Keywords Zooplankton , Arabian Sea , Coastal upwelling , Ontogenetic migration
Dynamics of potentially harmful phytoplankton in a semi-enclosed bay in the Sea of Oman
Khalid A Al-Hashmi 1 *, Sharon L Smith 2, Michel Claereboudt 1, Sergey A Piontkovski 1, Adnan Al-Azri 1
1 College of Agricultural and Marine Sciences, Sultan Qaboos University, P.O. Box: 34, Al-Khod
123, Sultanate of Oman.
2 Rosenstiel School of Marine & Atmospheric Science, University of Miami, 4600 Rickenbacker
Causeway, Miami, Florida 33149.
The dynamics of potentially harmful phytoplankton in relation to environmental parameters was investigated in the semi-enclosed Bay of Bandar Khayran (Sea of Oman) from April 2006 through April 2011. In total, 24 potentially harmful algal species were identified, including 11 species of dinoflagellates and eight species of diatoms. The dinoflagellates Prorocentrum minimum (Pavillard) Schiller, 1933, Scrippsiella trochoidea Balech ex Loeblich III, 1965, and Noctiluca scintillans (Macartney) Kofoid and Swezy, 1921 were most abundant during the Southwest Monsoon (SWM, July–September) and Northeast Monsoon (NEM, January–March) seasons, while other species occurred in low abundance and with no clear seasonal patterns. A dense bloom of Cochlodinium polykrikoides Margalef, 1961 that affected the distribution and abundance of other harmful algal species (HAB) was observed for the first time in the Sea of Oman during 2008–2009. Prorocentrum minimum increased in abundance during and after the decay of the Cochlodinium bloom while S. trochoidea was suppressed during this bloom, increasing thereafter once again. Noctiluca scintillans disappeared in the late SWM and NEM of 2008 and SWM of 2009, when blooms typically occur annually. Prorocentrum minimum and S. trochoidea persisted throughout the annual cycle of all years, enhancing their capability to bloom in the region under favorable conditions of high light intensities and relatively warm waters of low turbulence.