210Po concentration in selected calanoid copepods in the northern Arabian Gulf

Copepods are the most abundant metazoans, forming a vital food chain link between the primary producers the phytoplankton and fish. This study presents baseline information on the concentration of ²¹⁰Po among calanoid copepods isolated from the Kuwait marine area. The concentration of ²¹⁰Po in six species of copepod, including Subeucalanus flemingeri, Parvocalanus crassirostis, Acartia pacifica, Calanopia elliptica, Acrocalanus gibber, and Euterpina acutifrons were 151.3-158.8 Bq kg^-1 wwt, 121.1-129.5 Bq kg^-1 wwt, 51.23-54.91 Bq kg^-1 wwt, 38.88-40.09 Bq kg^-1 wwt, 38.07-38.29 Bq kg^-1 wwt, and 33.46-36.50 Bq kg^-1 wwt, respectively. The ²¹⁰Po concentration in seawater shows a seasonal variation, with a higher concentration range of 0.58-0.70 mBq L^-1 during summer and autumn, while a lower concentration is found (0.30-0.38 mBq L^-1) during winter and spring. The concentration factor among the copepods varies between 8 ∗ 10⁴ and 5 ∗ 10⁵ that is an order of magnitude higher than the diatoms and dinoflagellates.

210Po concentration in selected diatoms and dinoflagellates in the northern Arabian Gulf

Marine phytoplankton is a primary producer in the ocean that forms the base of the marine food web and supports the pelagic food chain. The two dominant groups of phytoplankton observed in northern Gulf waters are diatoms and dinoflagellates. The diatoms outnumber dinoflagellates in the Gulf waters. This study presents baseline information on the concentration of ²¹⁰Po among selected phytoplankton in the northern Gulf. The concentration among diatoms varies between 6.99 and 11.4 Bq kg^-1 wwt, whereas a higher concentration range of 8.51-15.41 Bq kg^-1 wwt was observed among dinoflagellates. The diatoms analyzed includes Thalassiosira spp. - 10.2-11.4 Bq kg^-1 wwt; Chaetoceros spp. - 6.99-7.14 Bq kg^-1 wwt; Rhizosolenia spp. - 9.12-9.95 Bq kg^-1 wwt. The analyzed dinoflagellate genera include Gymnodinium spp. - 8.51-8.78 Bq kg^-1 wwt; Noctiluca spp. - 15.2-15.4 Bq kg^-1 wwt; and Karenia spp. - 14.1-14.9 Bq kg^-1 wwt. The ²¹⁰Po concentration in seawater shows a seasonal variation, with a higher concentration range of 0.70 and 0.58 mBq L^-1 during summer and autumn, whereas a lower range in concentration of 0.38 and 0.30 mBq L^-1 occurring during winter and spring. The resultant computed concentration factors vary between 2 ∗ 10⁴-5 ∗ 10⁴ demonstrating a significant ²¹⁰Po enrichment in the base of the pelagic food chain.

Plutonium and cesium baseline concentrations in seawater from northern Arabian Gulf

The Arabian Gulf is a semi-enclosed water body that has witnessed accelerated anthropogenic activity, in terms of commissioning of nuclear power plants, desalination facilities, oil refineries and extensive coastal development. Furthermore, three wars during the past three decades is a potential worry. This study presents the first plutonium baseline in seawater from the Northern Arabian Gulf. The ^239+240Pu concentrations in seawater vary, between 2.9 and 4.9mBqm^-3, a range that is comparable to other water masses at this latitude. The ²³⁸Pu ranged between 0.04 and 0.05mBqm^-3 and the ¹³⁷Cs concentration between 1.04 and 1.18Bqm^-3. The ratio of ²³⁸Pu/^239+240Pu at all eight sampling stations was 0.01, while the ratio of ^239+240Pu/¹³⁷Cs varied between 0.01 and 0.02. The presence of ¹³⁷Cs and ^239+240Pu in seawater from this region can mainly be attributed to the global atmospheric deposition and fluvial transport. The seawater concentration of ^239+240Pu is five order of magnitude lower than bottom sediments in the area.