A preliminary benthic macroinvertebrates survey of Gunung Belumut Recreational Forest, Kluang, Johor, Malaysia

The macroinvertebrate community in Sungai Dengar sub-catchment which is located at Gunung Belumut Recreational Forest in Kluang, Johor was surveyed in from 8th to 11thAugust 2009 by using Surber Net. River water quality and river characteristics were also recorded. The surface water dissolved oxygen (DO) content ranged from 7.11 mg/l to 8.06 mg/l. The maximum value of 8.06 dissolved oxygen content was recorded at site C (palm oil plantation area). The minimum value of 7.11 dissolved oxygen content was recorded at site A (Gunung Belumut). The pH values ranged from 7.47 to 7.89. The maximum value was recorded at site B (pristine area) while the minimum value was recorded at site A (Gunung Belumut). The surface temperature varied between 23.6 °C to 25.3 °C. The maximum temperature was observed at site C and the minimum temperature was noted at site A. The conductivity values varied between 27.4 µS/cm to 29.10 µS/cm. The maximum conductivity was recorded at site C and the minimum value at site B. The water turbidity ranged from 9.28 NTU to 22.85 NTU. The maximum turbidity values were recorded at site B and the minimum values were recorded at site A. The dissolved oxygen, pH, temperature and conductivity values did not show any distinct variation between stations except turbidity. Based on the result, it shows that Diptera particularly Chironomidae were abundant at the pristine site which is the most up-stream (undisturbed) located on the Gunung Belumut and also at the station B2 which was pristine station located at the foothill of Gunung Belumut but nevertheless the numbers of individual taxon are much higher at polluted sites (C1 & C2). Pristine site also recorded to have abundant Mollusca particularly from Atyiedae and Palaemonidae families. Results obtained also showed an abundant of the genus of Pseudocleon and Potamanthus from Ephermeroptera order at the polluted sites (C1 & C2), beside Chironomidae. Odonata, Trichoptera and Coleoptera were among the least order found at all the sampling stations. There were only five individual of Odonata taxon, 12 individual Trichoptera and ten individual Coleoptera collected. Only one family (Perlidae) and one genus (Neoperla) were found from Plecoptera order at all the sampling stations. Other than that, there were only one Mollusca from the family of Lymnaeidae collected at station B1. Based on the above results, it could be implied that, macro invertebrate community structure was not dependent solely on water quality of the river but it was also dependent on other factors such as habitat characteristics, river morphology, river riparian, canopy cover, etc., especially river substrate compositions.