Author(s): Muhammad Jawed Abbasi, Zarina Abbasi, Farah Naz Khokhar, Pervaiz Iqbal and Pirzada Jamal Ahmed Siddiqui

Abstract: The studies on zooplankton population structure, distribution and abundance are scare from Pakistani waters particularly from the near-shore waters off of Karachi. Most of the previous work is done on a few individual groups and species of zooplankton. The present study was proposed with an objective to assess the distribution and abundance of zooplankton from near-shore waters off of Karachi and also to correlate quantitative data with water quality parameters. This study showed higher population diversity of zooplankton groups. The seasonal abundance of zooplankton groups varied from station to station; the peak zooplankton abundance occurred in April (337.6 individuals/m³) at S2 and the lowest abundance was recorded in July (19.08 individuals/m³) at S1. In general, copepods (highest 67.74% at S1 and 73.51 at S3) always maintained dominance in the zooplankton population. Water parameters were variable through the year and showed low correlation with abundance data. The zooplankton population appears to be regulated by other factors (such as grazing pressure, etc.) and the water parameters had little contribution in controlling zooplankton population. For example, chlorophyll content (primary production) showed only weak positive correlation (r =0.170) with zooplankton abundance. The study area showed relatively stable environmental conditions and high zooplankton population which is beneficial for fisheries production. This study also provides the current and updated data, which helps to understand the marine ecosystem of coastal waters of Karachi coast of North Arabian Sea.

Pages: 241-249  |  1858 Views  282 Downloads

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