Abundance Of Phytoplankton Groups Research Articles

Distributions of Nutrients in Relation to Phytoplankton Community Heterogeneity in the Makassar Strait, Indonesia

The Monitoring of Indonesia Throughflow (MITF) with scientific cruise across the Indonesian waters that are connecting the islands of Kalimantan and Sulawesi or strait of Makassar. This cruise carried out in August 2015 in an area between 2° and 4° South and 118° and 119° East. This cruise aims to characterize the concentration of nutrients and abundance of phytoplankton groups as well as explain their distribution based on the environmental conditions. Nutrient concentrations consisting of Inorganic Dissolved Nitrogen (DIN), Inorganic Dissolved Phosphate (DIP) and Inorganic Dissolved Silicate (DSi) were measured at seven depth layers, i.e. 10, 30-60, 100-150, 300, 500, 750 and 1000 meters. The study showed that in the transitional season (August), the upper layer of study sites were characterized by salinity between 34.05 and 34.76 PSU, temperature between 26.85 and 29.88 °C, and relatively high nutrient concentration, i.e. DIN = 8.91 - 36.74 μM, DIP = 0.02 - 0.16 μM, and DSi= 31.88 - 249.49 μM. The phytoplankton community groups found were Cyanophyta, Bacillariophyta (Diatom), and Dinophyta, where the highest abundance was Cynophyta for the genus Trichodesmium sp. The composition of phytoplankton community in the surface layer is strongly influenced by sea surface temperature, salinity and nutrient concentration. We found that nutrient utilization in the surface layer is relatively high.

Influence of riverine connectivity on phytoplankton abundance and diversity of associated wetlands of River Ganga: A comparative study of an open and a closed wetland

AbstractRiver connectivity is often described as a key requirement for maintaining the health and biodiversity of associated wetlands of rivers. A comparative study was undertaken to understand the influence of river connectivity on plankton diversity and abundance in an open (Chharaganga Beel) and a closed wetland (Kalobaur Beel) situated on the banks of River Ganga in West Bengal, India. During the present investigation, data revealed that the major groups of phytoplankton recorded were Cyanobacteria (33.12%), Bacillariophyta (29.07%), and Chlorophyta (22.34%) from the open wetland, and Bacillariophyta (47.40%), Euglenozoa (30.68%), and Chlorophyta (10.12%) from the closed one. Shannon diversity (H’) and Margalef's species richness index indicate that phytoplankton diversity in the Chharaganga ecosystem was higher than in Kalobaur Beel. A one-way ANOVA showed significant station-wise difference for water turbidity (p <0.05) in both of the beels, and student t test revealed that differences in physico-chemical parameters between the studied beels was statistically significant (p <0.05) for depth, turbidity, conductivity, total hardness, nitrate, total N, phosphate-P, silicate, Ca²+, Mg²+and chlorophyll a,whereas abundance of phytoplankton groups was significantly different for Bacillariophyta (p <0.05) and Euglenozoa (p <0.05). The positive correlation of total N with Euglenozoa (r=0.496; p<0.05) might be the cause of favourable conditions for a higher abundance of Euglenozoa in the closed Kalobaur Beel,which is on the verge of partial eutrophication. The hydrological flushing by river water in the Chharaganga wetland maintains the ecological stability. Therefore, restoration of river connectivity is recommended to improve the health of the disconnected wetlands.

Impacts of land and water use on plankton diversity and water quality in small man-made reservoirs in the Limpopo basin, Zimbabwe: A preliminary investigation

This paper reports on a study carried out from February to April 2005 in the southern part of Zimbabwe in the Mzingwane catchment, Limpopo basin to investigate the impacts of land and water use on the water quality and ecosystem health of eight small man-made reservoirs. Four of the reservoirs of were located in communal lands while the remaining four were located in the National Park Estates, considered pristine. Plankton community structure was identified in terms of abundance and diversity as an indirect assessment of water quality and ecosystem health. In addition, phosphorus, nitrogen, pH, transparency, electric conductivity and hardness were analysed. The results obtained indicate that a significant difference in abundance of phytoplankton groups was found between the communal lands and the National Park Estates ( P < 0.01). Though the highest phytoplankton abundance was observed in April, February showed the highest number of taxa (highest diversity). Chlorophytes was the major group in both periods with 29 genera in February and 20 in April followed by Diatoms with 17 genera in February and 12 in April. The zooplankton community was less diverse and less abundant and did not show any seasonality pattern. Phosphorus (0.022 ± 0.037 mg/l) and nitrogen (0.101 ± 0.027 mg/l) had similar trends in the study area during the study period. Transparency of water was very low (ca. 27 cm secchi depth) in 75% of the reservoirs with communal lands’ reservoirs having a whitish colour, likely reducing light penetration and therefore photosynthetic potential. Evidence from the study indicates that, at this time, activities in the communal lands are not significantly impacting the ecosystem health of reservoirs, as water quality characteristics and plankton diversity on communal lands were not significantly different from the pristine reservoirs in National Park. However, water managers are urged to continuously monitor the changes in land and water uses around these multipurpose reservoirs in order to prevent possible detrimental land and water uses that might occur in the future.