SUMMARY
ABSTRACTTin mining in the coastal waters of West Bangka Regency is known to affect water quality, which has an impact on the phytoplankton community structure. This research aims to study phytoplankton communities in mining tin areas and outside of mining areas (non-mining areas). Sampling was carried out in 22 sampling stations with 7 stations in the tin mining area. Phytoplankton samples were taken by the vertical haul method. Zooplankton sampling and measurement of water parameters in the form of temperature, pH, and salinity were also conducted to determine the relationship of these parameters with the phytoplankton community. Based on the density of phytoplankton in the water column, the coastal waters of West Bangka are generally in the category of oligotrophic with cell densities ranging from 3.6 × 105 - 1.6 × 107 cells.m-3. The results of the IS-ID analysis showed a difference of 56% in phytoplankton community structures in the mining and non-mining areas of West Bangka coastal. Although no differences were found in the number of phytoplankton genus present, phytoplankton cell density in the waters around the tin mining area was found to be lower compared to the waters in the non-mining area. Differences in community structure and phytoplankton cell density in mining and non-mining areas are thought to be related to mining activities in the coastal. However, further studies are needed to study the magnitude of the influence and exact cause of the emergence of differences in community structure and phytoplankton density.Keywords: Tin mining, spatial distribution, phytoplankton community, Bray-Curtis clustering ABSTRAKPenambangan timah di perairan pesisir Kabupaten Bangka Barat diketahui dapat mempengaruhi kualitas perairan sehingga berdampak pada struktur komunitas fitoplankton. Penelitian ini bertujuan untuk mempelajari komunitas fitoplankton di kawasan tambang timah pesisir (mining) dan di luar area tambang (non-mining) di pesisir Bangka Barat. Pengambilan sampel dilakukan pada bulan Oktober 2012 di 22 stasiun sampling, termasuk 7 stasiun sampling yang berada di area penambangan timah. Sampel fitoplankton diambil dengan metode vertical haul menggunakan jaring Kitahara (mata jaring 80 µm). Pengambilan sampel zooplankton dan pengukuran parameter air berupa suhu, pH, dan salinitas juga dilakukan untuk mengetahui hubungan parameter tersebut dengan komunitas fitoplankton di area kajian. Berdasarkan densitas fitoplankton di kolom air, perairan pesisir Bangka Barat secara umum berada dalam kategori oligotrofik dengan densitas sel berkisar antara 3,6×105 – 1,6×107 sel.m-3. Komunitas fitoplankton di Bangka Barat terdiri atas 28 genus, mencakup 23 genus Diatomae dan 5 genus Dinoflagellata, dengan Bacteriastrum, Chaetoceros, Thalassiothrix, Rhizosolenia, dan Pseudo-nitzschia sebagai genera paling dominan di perairan. Hasil analisis IS-ID menunjukkan perbedaan sebesar 56% pada struktur komunitas fitoplankton di area mining dan non-mining perairan Bangka Barat. Meskipun tidak ditemukan perbedaan pada jumlah genus fitoplankton yang hadir, densitas sel fitoplankton di perairan sekitar kawasan mining timah ditemukan lebih rendah dibandingkan dengan perairan yang ada di kawasan non-mining Kabupaten Bangka Barat. Perbedaan struktur komunitas dan densitas sel fitoplankton di area mining dan non-mining diduga terkait dengan aktivitas penambangan di perairan pesisir Bangka Barat. Namun diperlukan kajian lebih lanjut untuk mempelajari besar pengaruh dan penyebab pasti munculnya perbedaan struktur komunitas dan densitas fitoplankton tersebut. Kata kunci: Tambang timah, distribusi spasial, komunitas fitoplankton, Bray-Curtis clustering