HEWAN BENTOS SEBAGAI INDIKATOR EKOLOGI DI SUNGAI CIKAPUNDUNG, BANDUNG
T591. 526 32 RON
ABSTRAK
Penelitian tentang hewan bentos sebagai indikator ekologi di S. Cikapundung telah dilakukan dari tanggal 15 Agustus 1981 - 15 Nopember 1981. Perubahan faktor fisika-kimia air dari waktu ke waktu maupun dari hulu ke arah muara, ternyata mengakibatkan perubahan dan perbedaan komposisi dan keanekaragaman hewan bentos. Kualitas air S. Cikapdndung cenderung, menurun dari hulu ke arah muara. Di habitat jeram maupun lubuk dari hulu sampai daerah perladangan, larva Insekta merupakan komponen utama komunitas hewan bentos, sedangkan dari daerah pemukiman sampai muara, komunitas hewan bentos didominasi oleh Annelida. Berdasarkan hasil analisis dengan koefisien kesamaan menurut Bray dan Curtis, ternyata bahwa dari hulu hingga daerah perladangan komunitas hewan bentos di jeram maupun lubuk adalah berbeda. Dari daerah pemukiman sampai muara, ternyata hanya hewan bentos dari lubuk yang mempunyai komposisi yang relatif sama, sedangkan komposisi hewan bentos dari jeram yang relatif sama adalah antara daerah pemukiman, persawahan dan muara. Komposisi hewan bentos antara jeram dan.lubuk-dari hulu sampai muara sangat berbeda. Jumlah taksa di jeram dan lubuk cenderung menurun dari hulu ke arah muara, sebaliknya jumlah individu meningkat. Jumlah taksa hewan bentos di jeram umumnya lebih banyak dari pada di lubuk, tetapi sebaliknya jumlah individu di lubuk lebih tinggi dari pada
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di jeram. Indeks keanekaragaman (H') hewan bentos menurun dengan nyata (p «0 . 0 5 ) dari hulu ke arah muara mengikuti penurunan kualitas air. Indeks keanekaragaman hewan bentos di jeram lebih tinggi dari pada di lubuk (p 0.05). Berdasarkan penilaian kualitas air secara terpadu antara faktor fisika, kimia dan biologi (hewan bentos) ternyata S. Cikapundung dari hulu sampai muara berada dalam kisaran belum tercemar sampai tercemar parah. Species indikator dalam tiap tingkat pencemaran dikemukakan pula.
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ABSTRACT
A study on zoobenthos as ecological indicators of water quality of the River Cikapundung was conducted from August 15, 1981 to November 15, 1981. Physico-chemical changes of the water with time and along the course of the river, appeared to have caused changes and differences in the composition and the diversity of the zoobenthic animals. The water quality tends to decrease with the water course of the river. From the upper reaches down to the cultivation zone, the zoobenthic communities were dominated by insect larvae, whereas from the residential zone till the mouth of the river, they were dominated by the annelids. Analyses of coefficients of similarity of Bray and Curtis showed that the zoobenthic communities of both the riffles and the pools in the upper reaches till the cultivation zone have different compositions. From the residential zone till the mouth of the river, the commposition of the zoobenthic communities of the pool was relatively similar, whereas similar composition of zoobenthic communities of the riffles was found between those of the residential and rice field zones and the mouth of the river. At each zone and along the cource of the river the zoobenthic composition of the riffle was very different from that of the pool. In general the number of zoobenthic taxa of the riffles was higher than that of the pools, however, the number of individuals was
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higher in the pools than in the riffles. The diversity index ( H.') of benthic animals decreased significantly (p«0.05) with the water course and the decrease of water quality. The diversity index of the benthic animals of the riffles was significantly higher (p«0.05) than that of the pools. Based on the integrated assessment of physical, chemical and biological factors it was concluded that along the course of the River Cikapundung, the degree of water quality ranged from unpolluted to heavily polluted. Indicators species in each category of pollution were also discused.
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