Sampling site: The sampling site “mangrove backwater area” at Sandspit is the largest on the coast of Karachi and is
located between latitudes 24° 50’34.7" N and longitudes 66° 53’08.2" E. It is covered by 400 ha of mangrove forest out
of which 307 ha is dense and 93 ha consist of sparse forest. The Sandspit backwater is connected to the northern Arabian
Sea through Karachi Harbor where the sea water enters the harbor from Southeast and travels through the Baba and Bhit
islands. The tide on the coast of Karachi is semidiurnal and range at Karachi port is 2.3 m high (Tariq et al., 2002). It is
densely populated by the mangrove species Avicennia marina.
The sampling area was divided into three transects lines. The first transect 1 was located just opposite to the shore
laboratory, Centre of Excellence in Marine Biology, University of Karachi. The second transect was at a distance of 1.5 km
away from transects 1 towards east and third transect was 1.5 km away from transects 2 or 3 km away from transects 1.
Each transect stretched over three tidal zones, i.e., low tide level (LTL), mid tide level (MLT) and high tidal level (HTL).