Survey on Phytoplankton Biomass and Water Parameters in the Habitats of Invasive Tigers Shrimps (Penaeus Monodon) in Nigeria

Abstract

Penaeus monodon is an invasive species found in the coastal waters of Nigeria. Although widely exploited with significant economic importance, investigation into its adaptation and potential ecological impact in the newly found environment is poorly known. This survey provides baseline information on the phytoplankton community and physico-chemical parameters in ten selected stations from five states where they are exploited in Nigeria. These include: Ibeno (Akwa Ibom State), Bonny (Rivers State), Kaa (Rivers State), Brass (Bayelsa State), Aiyetoro (Ondo State), Makoko (Lagos state), Folu (Lagos state), Apapa (Lagos state), Tin Can Island (Lagos state) and Tarkwa Bay (Lagos state). Total of 147 species of phytoplankton from six classes were recorded during the survey with diatoms being the most prevalent (70.4%), green algae (20.4%), Blue-green algae (5.6%), Chrysophyceae (1.9%). Water parameters recorded temperature (range: 27.33 ± 1.53°C-29.00 ± 1.00°C), pH (7.39 ± 0.08-8.13 ± 0.14), dissolved oxygen (5.40 ± 3.22 mgL-1-8.00 ± 1.44 mgL-1), Conductivity (11.22 ± 10.03 μS/cm-39.33 ± 5.87 μS/cm) and salinity (11.02 ± 15.56% -25.98 ± 2.02%). Lowest values for phosphate, nitrate-nitrogen and sulphate were 0.11 ± 0.07mgL- 1, 0.10 ± 0.07 mgL-1 and 523.67 ± 880.21 mgL-1 respectively. Generally, ecological factors in their newly found environment are similar to their native range. However, negative impact as an invasive species most be checked.