Nutrient regimes in a semi-enclosed marginal sea: The Persian Gulf

ABSTRACT

In this study, the results of hydrochemical measurement aboard the RV Kavoshgar Khalij Fars in the Persian Gulf (PG) in September 2018, May, and November 2019 are discussed. Nitrate, nitrite, ammonium, phosphate, and silicate concentrations, salinity, temperature, dissolved oxygen, and pH in the water column of a 1000-km transect in the PG were studied to determine the present status of nutrient regimes of this region. Nitrate, phosphate, and silicate were more concentrated at the bottom layer and showed a maximum just below the thermocline in summer and autumn. Seasonal distribution of nutrient ratios (N:P, N:Si, Si:P) indicates P limitation in autumn, N limitation in spring, P limitation and poor Si in summer throughout the upper layer. The results of this study do not infer eutrophication in the upper layer of the PG waters in autumn and summer.

Acknowledgements

The authors would like to thank the Iranian National Institute for Oceanography and Atmospheric Science (INIOAS) for funding this project (Grant 399-011-01-016-05) in terms of sampling, field measurements and laboratory analysis. This work was done as a part of Project No. 397-06-026-02.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by Iranian National Institute for Oceanography and Atmospheric Science.

Notes on contributors

Maryam Ghaemi

Dr. Maryam Ghaemi has a Ph.D. in analytical chemistry and faculty member of the Iranian National Institute for Oceanography and Atmospheric Science (INIOAS). She is head of the Persian Gulf Oceanography Center at INIOAS. Her research focuses on the study of the nutrients and chlorophyll across the Persian Gulf and the Gulf of Oman and carbonate chemistry in the Mangrove Ecosystem, as well as nanoparticles synthesis and application of synthesised nanoparticles. Since 2017, she has been one of the PIs of 9 research cruises to the Persian Gulf. She's currently the Vice-chair of the IOC Sub-Commission for the Central Indian Ocean (IOCINDIO).

Samad Hamzei

Dr. Samad Hamzei has a Ph.D. in physical chemistry and faculty member of INIOAS. His research focuses on physical oceanography, ocean currents and circulation, and coastal oceanography.

Abolfazl Saleh

Dr. Abolfazl Saleh has a Ph.D. in analytical chemistry and faculty member of INIOAS. His research focuses on the study of the hydrochemistry and carbonate system in seawater, including the measurements of the CO₂ variables, as well as the study of hypoxia and deoxygenation in the Persian Gulf, Oman Sea and Caspian Sea. Since 2017, he has been the chief scientist of 9 research cruises to the Persian Gulf and Oman Sea.

Sara Gholamipour

Ms. Sara Gholamipour is a marine chemist and a senior researcher at INIOAS.