KEANEKARAGAMAN FITOPLANKTON DI PERAIRAN ESTUARI SEI TERUSAN, KOTA TANJUNGPINANG - Syafriani, Ria; Apriadi, Tri (LIMNOTEK - Perairan Darat Tropis di Indonesia, 2017)
Penelitian keanekaragaman fitoplankton dan beberapa parameter fisika dan kimia perairan perlu dilakukan untuk mengetahui kondisi suatu perairan. Penelitian keanekaragaman fitoplankton di perairan estuari Sei Terusan dilakukan pada bulan Desember 2016. Fitoplankton yang ditemukan di perairan Sei Terusan terdiri dari 3 kelas yaitu kelas Dinophyceae, Coscinodiscophyceae, dan Bacillariophyceae. Kelas Dinophyceae terdiri dari Ceratium sp., Protoperidinium sp.,dan Prorocentrum gracile. Kelas Coscinodiscophyceae terdiri dari Coscinodiscus sp., Skeletonema sp., dan Rhizosolenia sp. Kelas Bacillariophyceae terdiri dari Chaetoceros sp., Pleurosigma sp., Cylindrotheca closterium, dan Pseudo-nitzschia sp. Kelimpahan terbesar dari 4 stasiun pengamatan ditemukan pada kelas Dinophyceae yang mendominansi di semua stasiun pengamatan. Indeks keanekaragaman dari 4 stasiun pengamatan adalah 0,052 â 1,872, indeks keanekaragaman ini < 2,306 sehingga termasuk kategori keanekaragaman rendah dan kestabilan komunitas rendah. Indeks keseragaman fitoplankton di 3 stasiun dari 4 stasiun pengamatan cukup rendah berkisar 0,032 â 0,050 dengan indeks dominansi 0,975 â 0,986. Dengan rendahnya indeks keseragaman menyebabkan adanya dominansi spesies tertentu dan menunjukkan adanya tekanan ekologis perairan. Ceratium sp. dari kelas Dinophyceae mendominansi di semua stasiun pengamatan.Phytoplankton diversity research and some physical and chemical parameters of waters needs to be done to determine the condition of a body of water. Phytoplankton diversity research in waters of the Sei Terusan estuarine was conducted in December 2016. Phytoplankton were found in the waters of the Sei Terusan consists of three classes, namely Dinophyceae, Coscinodiscophyceae, and Bacillariophyceae. Dinophyceae class were consisted of Ceratium sp., Protoperidinium sp., and Prorocentrum gracile. Coscinodiscophyceae class consists of Coscinodiscus sp., Skeletonema sp., and Rhizosolenia sp. Bacillariophyceae class consists of Chaetoceros sp., Pleurosigma sp., Cylindrotheca Closterium, and Pseudo-Nitzschia sp. The higest phytoplankton abundance were found in Dinophyceae that dominated at all observation stations. Shannon Diversity indice of four observation stations was 0.052-1.872, this diversity indice < 2.306 thus categorized low diversity and community stability was low. Eveness indice of phytoplankton in three stations of four observation stations was low enough ranged from 0.032-0.050 with dominance index from 0.975- 0.986. The low Eveness indice due to dominance of certain species and indicate their ecological pressure waters. Ceratium sp. (Dinophyceae) was dominate at all observation stations.Â