title: Characterization of blooming algae and bloom-associated changes in the water quality parameters of traditional pokkali cum prawn fields along the South West coast of India.
abstract: In tropical shrimp farms, especially in traditional pokkali shrimp ponds, poor water quality management can lead to serious threats like heavy algal blooms and frequent disease outbreaks. An investigation regarding the frequent disease outbreaks in selected pokkali shrimp pond adjoining the Cochin backwaters has been conducted. Water quality parameters were analyzed during the study period. Results indicate a considerable fluctuation in the concentration of dissolved oxygen (DO) in the study in the shrimp farm where the algal bloom was observed. Poor water exchange along with nutrient loading from adjacent housing areas resulted in heavy algal bloom in the pond which led to hypoxic conditions in early morning and supersaturation of DO in the afternoon. It also led to considerably high alkaline pH. High levels of total ammonia nitrogen (TAN) were recorded in the sampling sites. Heavy algal bloom was observed throughout the study period in the selected pond especially in the summer. Anabaenopsis elenkinii and Merismopedia elagans which were the dominant species from the culture pond caused the bloom. Characterization and percentage distribution of bacteria present in the water and those associated with the algal blooms were carried out. The algae were found to support greater diversity of bacteria when compared to water. Pathogenic species like Aeromonas hydrophila and Vibrio parahaemolyticus were encountered in the study. Experimental challenge studies using Artemia as a model showed that the V. parahaemolyticus isolates were highly pathogenic. Hence, this study reveals how algal growth supports opportunistic pathogens in great diverse in a shrimp pond and causes frequent disease outbreaks under favourable conditions.
authors: Department of Marine Biology, Microbiology and Biochemistry, School of Marine Sciences, Cochin University of Science and Technology, Fine Arts Avenue, Cochin, 682016, India. ajinmadhav89@gmail.com.
authors: A M
authors: AM
authors: Ajin
authors: Department of Marine Biology, Microbiology and Biochemistry, School of Marine Sciences, Cochin University of Science and Technology, Fine Arts Avenue, Cochin, 682016, India.
authors: Reshma
authors: R
authors: Silvester
authors: Department of Marine Biology, Microbiology and Biochemistry, School of Marine Sciences, Cochin University of Science and Technology, Fine Arts Avenue, Cochin, 682016, India.
authors: Deborah
authors: D
authors: Alexander
authors: Department of Marine Biology, Microbiology and Biochemistry, School of Marine Sciences, Cochin University of Science and Technology, Fine Arts Avenue, Cochin, 682016, India.|Nansen Environmental Research Centre, India (NERCI), 6A, Oxford Business Centre (6th Floor), Ravipuram, Kochi, Kerala, 682016, India.
authors: Nashad
authors: N
authors: M
authors: Department of Marine Biology, Microbiology and Biochemistry, School of Marine Sciences, Cochin University of Science and Technology, Fine Arts Avenue, Cochin, 682016, India.
authors: Mohamed Hatha
authors: MH
authors: Abdulla
mesh_terms: D000818:Animals; D017756:Aquaculture; D000458:Cyanobacteria; D004784:Environmental Monitoring; D005068:Eutrophication; D007194:India; D010100:Oxygen; D033561:Penaeidae; D061005:Ponds; D012621:Seasons; D014873:Water Pollutants / Q000032:analysis*; D060753:Water Quality / Q000592:standards
chemical_list: D014873:Water Pollutants; D010100:Oxygen
keywords: Algal blooms; Artemia; Disease outbreak; Pathogens; Shrimp ponds; V. parahaemolyticus; Water quality