Red tide of the Lingulodinium polyedrum (Dinophyceae) in Odessa Bay (Black Sea)

One of the most massive red tides at the Odessa Bay was observed in September October 2020. It was caused by a toxic dinoflagellate Lingulodinium polyedrum (Stein) Dodge. The maximum abundance (56.1 x 106 cells L-1) of L. polyedrum was registered at the Odessa port area on October 6 when a water temperature and a salinity were 19.7°C and 14.3 ‰ respectively. The red tide was so huge and dense that the water glowed at night due to the bioluminescence characteristic of this species. The article briefly describes the history of the study of L. polyedrum in this area and provides a detailed morphological description with original photographs of this species sampled from bloom. We associate the appearance of the red tide with an increased temperature of sea water and air, a high content of nutrients, the presence of viable L. polyedrum cysts, and a slight decrease in salinity in the bay during the period of a mass development of the species in autumn of 2020. The red tide was accompanied by Protoperidinium steini, P. divergens, Prorocentrum cordatum, P. minimum, P. micans, Gonyaulas scrippsae, Diplopsalis lenticula, Azadinium spinosum, Dinophysis rotundata, D. acuminata, Oblea rotunda, Scrippsiella trochoidea, Ceratium furca.

PHYTOPLANKTON COMPOSITION OF MARICULTURE AREA IN SUNGAI UDANG, PENANG, MALAYSIA, THE NORTHERN STRAIT OF MALACCA

A study was conducted in the marine finfish cage culture area in Sungai Udang, Penang, at the northern part of the Malacca Straits to examine the phytoplankton composition and abundance especially for potentially harmful phytoplankton. Monthly sampling were taken from March 2016 to January 2017 at nine sampling stations. Physio-chemical parameters of surface seawater such as pH, dissolved oxygen, temperature, salinity, total suspended solids, and nutrients (nitrate, nitrite, ammonium, phosphate and silicate) were also measured. A total of 54 phytoplankton taxa were recorded, with 37 genera belonged to diatoms, 15 of dinoflagellates, and 2 of cyanobacteria. The composition of phytoplankton was dominated by diatoms (>85%) at all sampling stations throughout the sampling period. The phytoplankton abundance ranged between 2.6×103 cells L-1 and 5.8×106 cells L-1. The potentially harmful toxic phytoplankton observed throughout the sampling period are dinoflagellates Alexandrium spp., Prorocentrum micans and Dinophysis caudata and diatoms, Pseudo-nitzchia spp but in low cell density. A total of six bloom-forming phytoplankton that can potentially trigger mass mortality of cultured fish such as Akashiwo sanguinea, Chaetoceros spp., Ceratium furca, Ceratium fusus, Margalefidinium spp. and Karlodinium spp. recorded at this area were relatively low in cell densities. Furthermore, no fish kill incident was reported in the area from blooms of phytoplankton during the period of study. Even though potentially harmful phytoplankton present were in low densities, they may pose significant risks to aquaculture activity if there is a sudden bloom. Hence, a monitoring program should be implemented to provide early warning of harmful algae blooms and safeguard the aquaculture industry in Sungai Udang, Penang.

Spatial and Seasonal Variations of Dinoflagellate Assemblages in Different Salinity Regimes along the Coast of Rakhine

Regarding the spatial and seasonal variations of dinoflagellates in different salinities regimes, Prorocentrum rostratum showed strongly correlated with high salinity (≥ 29ppt.) but P. micans indicated a negative correlation with salinity. In Dinophysoids, Dinophysis caudata showed wide salinity tolerance than other species in the group. D. miles, Ornithocercus magnificus, O. steinii and O. thumii showed a strong correlation with salinity. In Gonyaulacoids, Ceratium furca, C. fusus, C. horridum, C. trichoceros, C. tripos, Gonyaulax polygramma, G. spinifera, and Pyrophacus magnificus showed a strong correlation with salinity. In Peridinoids, Protoperidinium depressum, P. oblongum, P. oceanicum, P. pyreforme, and Podolampus palmipes showed a strong correlation with salinity. In Gymnodinoid and Noctilucoid, Gyrodinium estuariale and N. scintillans showed a strong correlation with salinity.

Species composition and distribution of some phytoplankton in Myeik Archipelago, Southern Myanmar

The species composition and distribution of some phytoplankton, the primary producer in the food chain of fish and shrimp, was studied from water samples that collected at surface layer of 20 stations in the Myeik Archipelago, Southern Myanmar from 2010 to 2018. A total of 144 species comprised of 123 species of diatoms and 21 species of dinoflagellate were recorded in the Myeik Archipelago. Among them, the most number 93 species of phytoplankton was recorded in Done Pale Aw Station however the lowest 26 species found in Le' Al' Thal Tan Station. The common representative species were ten diatoms species such as Chaetoceros curvisetus, Ditylum sol, Lauderia annulata, Nitzschia longissima, Odotella sinensis, Pleurosigma normanii, Pseudo Nitzschia seriata, Rhizosolenia setigera, Thalassionema nitzschioides and T. frauenfeldii and then one of dinoflagellate, Ceratium furca. Moreover, the percentage of diatom (87%) was higher than the dinoflagellate (13%) during the study period. The temperature 25-30°C and salinity 4-34‰ was found in the Myeik Archipelago during the study period.

Tidal Influence on Nutrients Status and Phytoplankton Population of Okpoka Creek, Upper Bonny Estuary, Nigeria

Okpoka Creek of the Upper Bonny Estuary in the Niger Delta is a tidal creek receiving organic anthropogenic effluents from its environs. The study investigated the influence of tides (low and high) on the species composition, diversity, abundance, and distribution of phytoplankton. The surface water and phytoplankton samples were collected monthly from May 2004 to April 2006 at both tides from ten stations according to standard methods. Phytoplankton was identified microscopically. Species diversity was calculated using standard indices. Data analyses were done using analysis of variance, Duncan multiple range, and descriptive statistics. Phosphate and ammonia exceeded international acceptable levels of 0.10 mg/L for natural water bodies indicating high nutrient status, organic matter, and potential pollutants. A total of 158 species of phytoplankton were identified. Diatoms dominated the phytoplankton (62.9%). Diversity indices of diatoms were1.5±0.03(Margalef) and0.8±0.01(Shannon). Pollution-indicator species such asNavicula microcephala,Nitzschia sigma,Synedra ulna(diatoms),Cladophora glomerata(green alga),Euglena acus(euglenoid),Anabeana spiroides(blue-green alga), andCeratium furca(dinoflagellate) were recorded at either only low, high or both tides. Concerted environmental surveillance on Upper Bonny Estuary is advocated to reduce the inflow of pollutants from the Bonny Estuary into this Creek caused by tidal influence.