Ranggeh River is one of the inlets of Lake Maninjau (West Sumatra, Indonesia), which has a vital role in supporting the life of native fish. Increasing anthropogenic activities (agriculture and human settlements) around the river can harm benthic macroinvertebrates as natural food for fish. Therefore, this study aimed to analyze and observe water quality changes and their impact on the benthic macroinvertebrate communities in the Ranggeh River. Sampling was conducted from February to August 2019 using the Hess Sampler tool. The results indicate that the anthropogenic impacts around the Ranggeh River on water quality has changed the macroinvertebrate benthic community structures (composition, abundance, and biological index). Furthermore, the Ephemeroptera Plecoptera and Trichoptera (EPT) number of taxa index were superior in reflecting disturbances in the Ranggeh River compared to the Family Biotic Index (FBI) and the Percent Model Affinity (PMA). In conclusion, the anthropogenic effect on the macroinvertebrate community in the Ranggeh River prominently was caused by habitat changes rather than enrichment by nutrients (TN and TP).

AbstrakKeberadaan logam berat di ekosistem akuatik telah sering dilaporkan menimbulkan masalah ke biota perairan. Salah satu biota perairan yang memiliki resiko untuk terpapar logam berat dari sedimen adalah organisme makrozoobentos. Penelitian ini bertujuan untuk mendeskripsikan pengaruh kontaminasi logam berat di sedimen pada struktur komunitas makrozoobentos yang berada di ekosistem lentik (situ dan waduk). Penelitian ini telah dilakukan pada bulan Juni 2009 -September 2011 di beberapa situ dan waduk yang berada di Provinsi Jawa Barat dan Jakarta. Sampel makrozoobentos dikumpulkan dengan menggunakan alat Ekman grab. Hasil penelitian menunjukkan bahwa terdapat korelasi antara indeks keanekaragaman makrozoobentos dengan kontaminasi logam arsen yang tinggi. Kontribusi logam Pb dan Cd dalam memberikan pengaruh pada indeks keanekaragaman relatif masih kecil. Keberadaan makrozoobentos Coleoptera (Simsonia sp.), lintah (Placobdella sp.), larva chironomid (Ablabesmyia sp.), dan (Tanytarsus sp.) relatif toleran dengan kontaminasi logam arsen di sedimen yang tinggi, pH dan suhu yang rendah. Penggunaan indeks keanekaragaman pada penelitian ini masih relatif sensitif dalam mencerminkan gangguan akibat kontaminasi logam berat di sedimen.Kata kunci: logam berat, makrozoobentos, sedimen, situ, waduk, polutan. Abstract Presence of heavy metals in aquatic ecosystems have been reported to cause problems in aquatic organisms. One of the aquatic organisms that have risk for exposure by heavy metals from sediments is macrozoobenthos. This paper aims to describe the influence of heavy metal contamination in sediments to the structure of macrozoobenthos communities in lentic ecosystem (small lakes and reservoirs). This study was conducted in

ABSTRAKKeberadaan logam merkuri pada ekosistem akuatik telah diketahui banyak menimbulkan dampak negatif bagi biota perairan. Salah satu biota akuatik (organisme makrozoobentos) yang terkena dampak kontaminan logam merkuri adalah larva insekta Trichoptera Cheumatopsyche sp. Tujuan dari penelitian ini adalah untuk mendeskripsikan adanya korelasi antara meningkatnya kontaminan logam merkuri di perairan dengan persentase terjadinya nekrosis insang larva Cheumatopsyche sp. di Sungai Ciliwung dan Cikaniki. Larva Trichoptera dikumpulkan dengan menggunakan alat jala surber dan dilakukan penggabungan menjadi satu sampel (komposit). Hasil penelitian ini menunjukkan adanya korelasi yang kuat antara kontaminan logam merkuri di sungai dengan persentase nekrosis larva Cheumatopsyche sp. (r = 0,8 untuk sungai Cikaniki dan r = 0,9 untuk Sungai Ciliwung). Disamping itu ada kecenderungan bioakumulasi logam merkuri di tubuh larva Cheumatopsyche sp. diikuti dengan meningkatnya kejadian nekrosis pada insang (r = 0,8 untuk sungai Cikaniki dan r = 0,88 untuk sungai Ciliwung). Penelitian ini menunjukkan potensi yang besar dari penggunaan insang larva Cheumatopsche sp. sebagai indikator terhadap stress oleh kontaminan toksik lainnya di ekosistem akuatik. Kata kunci: toksisitas kronis, logam berat, larva, bioindikator, bioakumulasi ABSTRACTMercury contamination in aquatic ecosystems has been reported to give many negative impacts for freshwater organisms. Cheumatopsychesp. (Trichoptera) is one of aquatic biota (macrozoobenthos organisms) affected by mercury contamination. The purpose of this study was to show a correlation between increasing mercury contamination in Ciliwung and Cikaniki rivers, with percentage of gill necrosis incidence in Cheumatopsyche sp. larvae. Trichoptera larvae was collected using Surber net and was composited. The results of this study showed a strong correlation between mercury contamination in the river with the percentage of larvae necrosis Cheumatopsyche sp. (r = 0. 8 for Cikaniki and r = 0.9 for Ciliwung). Besides, there was a tendency in the presence of metal bioaccumulation of mercury in the body of the larvae Cheumatopsyche sp.followed by the increasing incidence of necrosis in the gills (r = 0.8 for Cikaniki and R 2 =0.88 for Ciliwung river). Gill necrosis of Cheumatopsche sp. larvae has great potency tobe used as indicator of the contamination of other toxic pollutants in aquatic ecosystems.

<strong>Evaluation of Riparian Rehabilitation in River River Usingthe Macrozoobenthos Community Indicator. </strong>Macrozoobenthos organism is one of aquatic biota which is often used to assess the ecosystems health of river.The evaluation of riparian habitat rehabilitation using benthic macroinvertebrates has been commonly used in many countries. The purposes of this study were to evaluate the impact of Ranggeh river riparian rehabilitation and to determine environmental parameters that influenced benthic macroinvertebrate communities in Ranggeh River. This research was conductedfrom February to September 2019. Benthic macroinvertebrate Benthic macroinvertebrates, river, evaluation, EPT, rehabilitationsamples were collected using Hess Sampler in a sampling area of 0.2 m². This evaluation was carried out after two months since the rehabilitation of riparian habitat completed. The results show that rehabilitation of the riparian habitat has changed the community, in the aspects of biological metrics of taxa number, abundance, and taxa numbersof Ephemeroptera, Plecoptera, and Trichoptera (EPT). Furthermore, the taxa number and EPT metrics increased after habitat rehabilitation, however the abundance decreased slightly. In addition, the taxa number metric was positively correlated with conductivity parameter (r = 0.8), but negatively correlatedto turbidity (r = -0.91) and pH (r = -0.77). Meanwhile, the EPT metric was negatively correlated with turbidity parameters (r = -0.76) and  %<em>embeddedness</em> (r = -0.94). The total abundance metric was not sensitive to the parameters measured in this study. Meanwhile, biological metrics for taxa number and EPT can be used to assess rehabilitation success of river ecosystem habitats