Effect Of Water Quality And Marine Phytoplankton Community Structure On Shrimp Production In Tropical Ponds

Production of giant black tiger shrimp (Penaeus monodon) in earthen ponds in the tropical region may vary as the pond matures, depending on water quality and phytoplankton community structure. The objectives of the present study were to determine water quality and marine phytoplankton succession in ponds of different ages, to nutritional value of isolated species of a dominant cyanobacterium in the shrimp ponds in comparison with a beneficial diatom and green alga and to investigate how phytoplankton community structure could be affected by alteration of macronutrient concentrations in mixed cultures. The field study was carried out in an intensive shrimp farm in Kuala Selangor, Malaysia. Phytoplankton and water samples were collected from ponds of different ages categorized as new (<1yr), intermediate (2-5yrs) and old (>10yrs), for 16 weeks of shrimp culture. Fluctuation of nutrient and chlorophyll-a concentrations were not different from other tropical shrimp ponds in the region. Cyanobacteria (five genera), diatoms (24 genera), dinoflagellates (four genera) and green algae (three genera) were four dominant groups of phytoplankton found in all the shrimp ponds. Diatoms were dominant during the early stage of the culture in new ponds whilst blue–green algae dominated intermediate and old ponds throughout the culture period. Shrimp production in new ponds were significantly higher than intermediate and old ponds (p