Tiny Phytoplankton: The Most Powerful Organisms of the Oceans!

Although sharks, whales, and other large organisms come to mind when one thinks about the most important or most powerful organisms of the sea, in fact, the most powerful are the tiny phytoplankton. Phytoplankton, which are microscopic algae, hold this power because they harvest the light from the sun, making food for all other organisms. Phytoplankton are the foundation for the ocean ecosystem. Through the process of photosynthesis, they also make oxygen and are responsible for almost half of the oxygen in the world. However, some phytoplankton can also be harmful and can kill fish or damage ecosystems. These harmful phytoplankton can also make people sick. The phytoplankton are tiny but mighty!

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.

Bloom of Trichodesmium and seasonality of other potentially toxic and harmful phytoplankton in tropical San Pedro Bay, Leyte, Philippines in 2012-13

<p>Since 1983, San Pedro Bay in the Philippines had been reported to be the site of episodic <em>Pyrodinium bahamense </em>var. <em>compressum</em> blooms that cause paralytic shellfish poisoning in its nearby coastal communities. This bay is also subjected to numerous typhoons, the strongest of which was super typhoon Haiyan in November 8, 2013.<strong> </strong>Phytoplankton ecology of this bay must have unique characteristics. For the first time, the seasonal dynamics of potentially toxic and harmful phytoplankton in this bay is elucidated. This is also the first record of a bloom of the cyanobacteria, <em>Trichodesmium erythraeum</em> that reached 90,000 cells/L in April 2013. There were 19 other potentially toxic and harmful phytoplankton encountered during the sampling period. This consisted of a haptophyte, <em>Phaeocystis globosa, </em>the diatom <em>Pseudo-nitzschia</em> and 17 dinoflagellates. Seven of these harmful algae had densities high enough to be traced through time.<strong> </strong>Normally, diatoms abound during the dry season. But here, <em>Pseudo-nitzschia </em>increased in abundance during the wet season of 2012 and 2013. The dinoflagellates behaved as expected and exhibited a relative increase in cell density during the rainy season of both years. <em>Phaeocystis globosa</em> also increased during the wet season. High nutrient availability during this season must have influenced the behavior of the phytoplankton despite differences in temperature and light intensity among seasons. Other notable but rare harmful species found only in plankton net tows during the study were <em>Pyrodinium bahamense </em>var. <em>compressum, Alexandrium tamiyavanichii</em>, <em>Cochlodinium</em> <em>polykrikoides, </em>and <em>Noctiluca scintillans. </em> <strong></strong></p>

SPATIAL ANALYSIS ON PHYTOPLANKTON IN GREEN MUSSEL AQUACULTURE AREA, KAMAL MUARA, NORTH JAKARTA

<p>Research on the spatial distribution of phytoplankton was held in the green mussel aquaculture area, Kamal Muara, North Jakarta. The research aimed to obtain the abundance and spatial distribution of phytoplankton and the influencing environmental parameters. The study was necessary to conduct in order to determine the useful or harmful phytoplankton groups in the location, which will affect the quality of green mussel for consumption.Thalasiossira and Chaetoceros from Bacillariophyceae, which will be harmful in a bloom condition, were the most abundantly found phytoplankton in the area. Based on distribution maps, the abundance of Bacillariophyceae and Dinophyceae were highest at stations near the mainland, whereas Cyanophyceae was at farther stations. Spearman’s correlation values indicated that the abundance of Bacillariophyceae was most influenced by pH, Dinophyceae by salinity, whereas Cyanophyceae was influenced by phosphate.</p><p><br /><strong>Keywords</strong>: Kamal Muara, phytoplankton, spatial distribution.</p>

Modelling the dispersion of harmful algal bloom (HAB) in the Thermaikos gulf (NW Aegean Sea)

Coastal hydrodynamics are directly related to important environmental and ecological issues. This paper focuses on the study of harmful phytoplankton cells’ dispersion, after an episode of an algal bloom, based on mathematical modeling. The case of Thermaikos Gulf was used for the simulation. The necessary hydrodynamic information was obtained by the application of a 2D hydrodynamic model directly coupled with a transport model for the simulation of the harmful cells’ dispersion. The model describes hydrodynamic and biological processes such as advection, dispersion and cell growth and losses. The mechanical processes are described with the mass and momentum conservation equations while the movement of the particles is described with the Random Walk simulation. The biological processes of cell growth rate were described as a function of temperature light and nutrients, and embodied to the simulation as input data for the model runs while the biological losses are simulated by the removal of particles randomly selected from the field. The reliability of the model was tested using data of a real algal bloom episode. Finally the study is completed with the detection of the distribution of the harmful phytoplankton cells in Thermaikos for different wind conditions and different sources of algal bloom.