Agricultural Research Management Information System

Home
Research Summary
Search
About Us
- ARMIS
- Brochure
Contact Us
Report
User Request
Data Input
Help
- Operation Manual
  - PDF
  - Video
- Program Area & Commodity
We have reached 37600 number of research entries at this moment.

- Logout

Research Detail

Home
Research
Detail

Seasonal Variations in Phytoplankton and Zooplankton Population in Relation to Some Environmental Factors at the Tidal Sangu River in Chittagong of Bangladesh

A K M F Haque
Department of Coastal and Marine Fisheries, Sylhet Agricultural University, Sylhet-3100, Bangladesh

N Begum
Department of Coastal and Marine Fisheries, Sylhet Agricultural University, Sylhet-3100, Bangladesh

M S Islam*
Department of Coastal and Marine Fisheries, Sylhet Agricultural University, Sylhet-3100, Bangladesh

Abstract/ Executive Summary:

An experiment was carried out at two selected stations in the Sangu river estuary with the Bay of Bengal, Chittagong, Bangladesh to determine the abundance and monthly variations of phytoplankton and zooplankton communities as well as some physico-chemical parameters of water for a period of twelve months from August 2013 to July 2014. Water temperature, salinity and pH were recorded on the spot during each sampling. The NO₃-N and PO₄-P of the collected water samples were measured in the laboratory. The highest temperature (28.5⁰ C at station I and 29⁰ C at station II) was in September and the lowest (20⁰ C at station I and 21.20 C at station II) in January. Salinity fluctuated from 13.0 to 32.0 ppt at station I in July and February, respectively and 15.0 to 33.0 ppt at station II in July and February, respectively. The highest pH (8.45) was recorded at station I in October. The highest NO₃-N (2.3 mg l ^-1 and 2.1 mg l ^-1 at station I and II, respectively) and PO4-P (2.9 mg l^-1 and 2.5 mg l ^-1 at station I and II, respectively) was recorded in August. In total 97 phytoplankton species were identified and 2 types could not be identified. Among the phytoplankton, 58 species belonged to Bacillariophyceae, 14 to Dinophyceae, 11 to Chlorophyceae, 6 to Cyanophyceae, 4 to Polycystinea and 4 to Polyhymenophorea. The highest phytoplankton production (117.3 × 103 cells l ^-1 at station I and 104.7×103 cells l ^-1 at station II) was found in August and the lowest (28.77 × 103 cells l^-1 at station I and 29.6 × 103 cells l^-1 at station II) in January. Phytoplankton bloom was observed in the study area in August. A total of 16 different zooplankton genera were recorded of which 12 belonging to Copepoda, 3 Rotifera and 1 Decapoda. Copepoda was the dominant group followed by Rotifera and Decapoda. The highest number of zooplankton (1,466 cells l ^-1 at station I and 1,198 cells l^-1 at station II) was recorded in January and the lowest (280 cells l ^-1 at station I and 172 cells l^-1 at station II) in August. The highest number of phytoplankton was appeared in August, which may be due to higher level of nutrients and water quality like temperature, salinity and pH were also within the favorable ranges. But zooplankton population was comparatively lower at that period owing to phytoplankton bloom. Therefore, the findings of this study would be helpful for the conservation of plankton community, biodiversity of the waters and congenial environment of the tidal waters.

Keywords: Seasonal variations, Phytoplankton, Zooplankton, Nutrients, Water quality parameters

Location: Sangu river estuary at Chittagong

Start Date: 00-08-2013

End Date: 00-07-2014

Program Area: Animal Health and Management

Commodity: Plankton

Objectives:

The present study was undertaken to determine the seasonal variations in species composition, occurrence and abundance of different species of plankton in relation to environmental factors at the Sangu river in Chittagong of Bangladesh.

Methodology:

Study area: The Sangu river originates in the Alakan Hills of Myanmar and enters into Bangladesh near Remarki of Thanchi upazila of Bandarban district, and finally falls into the Bay of Bengal. The present study was carried out in the estuary of the Sangu river. Two spots /stations were selected in the Sangu river estuary at Chittagong for plankton sample. Samples were collected from the spots at day time. The experiment was carried out for a period of 12 months from August 2013 to July 2014. The necessary data were collected during the study period to fulfill the requirement of the research works. Measurement of water quality parameters: Water quality parameters such as surface water temperature, salinity and pH were recorded respectively using a Celsius thermometer, portable refractometer and digital pH meter on the spot at monthly intervals. All the physical water quality parameters were determined in the field. Other water parameters were measured in the laboratory of Institute of Marine Sciences and Fisheries of Chittagong University. Water samples were collected on each sampling day. Plastic bottles were filled up with water from various spots. The bottles were than carried to the laboratory and 100 ml of water sample from each bottle was filtered through glass fiber filter paper (Whatman GF/C) for its analysis. Nitrate-nitrogen and phosphate-phosphorus (mg l -1 ) were measured by an advanced Hach Kit (DR 4000, a direct reading spectrophotometer) using high range chemicals (Nitraver 5 Nitrate Reagent Powder Pillows for 25ml sample for NO₃-N and Phosver 3 Phosphate Reagent Powder Pillows for 25ml sample for PO₄-P analysis). Plankton estimation: Plankton samples were collected monthly from each of the study spots. Ten liter of water samples were collected from the spot and passed through fine meshed (25 µm) plankton net. Filtered samples were taken into a measuring cylinder and carefully measured. The volume of plankton samples were preserved in 10% buffered formalin in plastic bottles for subsequent analysis. From each of preserved samples, 1 ml sub-sample was examined for plankton estimation using Sedgewick-Rafter counting cell under a compound binocular microscope. The plankton liter^-1 of original water was estimated applying the following formula (Rahman, 1992). Identification of plankton was done according to Prescott (1962), Bellinger (1992), Needham and Needham (1962) and Davis (1955).

Source of Information: J. Sylhet Agril. Univ. 2(2):209-219, 2015 ISSN: 2308-1597

Article Link (Online Journal):

Funding Source:

Budget:

Total Budget (Tk.) :

Achievement/Findings:

The results of the present study on phytoplankton and zooplankton in the Sangu river estuary are very much important for the coastal waters. Efforts were made to retrieve data on the records of phytoplankton abundance, primary productivity and water quality parameters like water temperature, pH, salinity, nitrate nitrogen (NO₃-N) and phosphate phosphorus (PO₄-P) from the study area. The abundance of plankton was varied from one place to another. The abundance of plankton was also varied according to the water temperature, pH and other water quality parameters. These findings will be helpful for the conservation of plankton community, biodiversity of the waters and congenial environment of the Sangu river ecosystem and other tidal waters.

Knowledge Management: Journal