Inventory of Ichyofaunal Diversity, Fishing Gear and Craft in Turag River, Dhaka, Bangladesh

Naser Ahmed Bhouiyan,Mohammad Abdul Baki

doi:10.4172/2150-3508.1000165

Abstract

Biodiversity of many Bangladesh Rivers is seriously threatened by industrial and municipal pollution. The study was conducted in the Turag River starting from Amin Bazar bridge (23°47' N 90°20'E) to Kamarpara bridge (23°53' N 90°23'E). This inventory survey was sampled at a fortnightly interval usually between 7.00 am to 5.00 pm by a team using a boat from December 2012 to November 2013. Detailed information on catch by species, fish length & weight, different types of gear & craft were collected through direct observation. A total of 71 (65 indigenous and 6 exotic) fish species (under 25 families of 9 orders) have been identified. 17 different types of gears of two categories (active and passive gear) and 8 different types of crafts were observed to harvest fish in the study area. The survey revealed that rising floodwater stimulated an increase in fishing activities in the study area from July to October. Fish numbers were recorded lower from November to July (dry and pre-monsoon period) likely due to reduced water flow and adverse water quality of this river. A paired t-test indicate that fish species numbers were significantly difference between Dry and pre-monsoon (P=0.02), Dry and monsoon (P=0.02) and Dry and post-monsoon season (P=0.03) respectively. However, fisheries resources contribution is very limited for livelihood of the surrounding people.

Highlights

Population growth has resulted in increasing demand for the use of rivers to satisfy a diverse range of human needs, including solid waste disposal and the discharge of industrial, sewage and mining effluents
It has been established that pollution of the river impacts key physiochemical properties of water thereby causing reduced dissolved oxygen (DO) level [7]
The water quality improves moderately, but on the advent of the dry season, pollution concentration increases abruptly because the water level of the rivers reduces a lot at this time, but the rate of pollutants released into the rivers remains identical

Summary

Introduction

Population growth has resulted in increasing demand for the use of rivers to satisfy a diverse range of human needs, including solid waste disposal and the discharge of industrial, sewage and mining effluents. The modifications to rivers disrupt the aquatic ecosystem and diminish its integrity [1,2,3] affecting the capacity of fish and other organisms to survive. The large input of organic matter to aquatic flood plain habitats may reduce dissolved oxygen and result in the emigration or death of a great number of fishes [6]. The concept of using fish communities as biological indicator has been historically followed by several authors [8,9]. Their size, community composition and structure often reflect nutrient status of a water body. Fish health may reflect and give a good indication of the status of specific aquatic ecosystem [10,11]

Objectives

Methods

Results

Conclusion