STRUKTUR KOMUNITAS PLANKTON DAN KONDISI LINGKUNGAN PERAIRAN DI TELUK JAKARTA

Fitoplankton dan zooplankton merupakan pakan alami bagi biota laut termasuk ikan. Tujuan penelitian adalah mengetahui struktur komunitas fitoplankton dan zooplankton serta kondisi lingkungan perairan di Teluk Jakarta. Penelitian dilakukan pada bulan April, Juni, Agustus dan Oktober 2009, pengamatan di 5 stasiun TJ1, TJ2, TJ3, TJ4 dan TJ5. Parameter yang di ukur adalah: kelimpahan fitoplankton dan zooplankton, suhu air, kecerahan, oksigen terlarut, pH, salinitas,. Hasil penelitian menunjukkan bahwa fitoplankton yang ditemukan 5 kelas meliputi: Cyanophyceae (6 spesies), Chlorophyceae (4 spesies), Bacillariophyceae (37 spesies), Dinophyceae (14 spesies) dan Euglenophyceae (1 species). Zooplankton yang ditemukan 10 kelas meliputi : Crustacea (16 spesies), Holothuroidea (3 spesies), Ciliata (5 spesies), Sagittoidea (2 spesies), Sarcodina (3 spesies), Rotatoria (4 spesies), Echinodermata (1 spesies), Polychaeta (1 spesies), Urochordata (1 spesies) dan Hydrozoa (1 spesies). Kelimpahan fitoplankton berkisar antara 1.587.086 - 3.799.799 sel/l. Kelimpahan zooplankton berkisar antara 922.010 - 3.834.261ind/l. Indeks keanekaragaman (=H) fitoplankton berkisar antara 1,74 – 3,64;indeks dominansi (=D) berkisar antara 0,04-0,40 dan indeks keseragaman (=E) berkisar antara 0,08-0,34. Indeks biologi zooplankton menunjukkan nilai (=H) berkisar antara 0,22-3,70; nilai (=D) berkisar antara 0,18-0,79; dan nilai (=E) berkisar antara 0,01-0,37. Suhu air berkisar antara 29,5-31,6oC, pH berkisar antara 4,96-7,38 dan salinitas berkisar antara 12,0-31,5 o/oo. Teluk Jakarta diindikasikan mengalami tekanan lingkungan sehingga hanya beberapa spesies plankton mampu beradaptasi, yaitu dari kelas Bacillariophyceae (Chaetoceros sp) dan Crustaceae (Calanus sp dan Acartia sp). Phytoplankton and zooplankton is a natural food for other marine life including fish. Growth and development are supported by condition of aquatic environment. The research objective was to determine the community structure of phytoplankton and zooplankton and aquatic environments as a factor in supporting the management of fish resources in the Jakarta Bay. The research was conducted in April, June, August and October 2009 at five stations were : TJ1, TJ2, TJ3, TJ4 and J5 . The parameters measured were: phytoplankton and zooplankton abundance, water temperature, brightness, dissolved oxygen, pH and salinity,. The results show that there were 5 classes of phytoplankton found in Jakarta Bay consisting of: Cyanophyceae (6 species), Chlorophyceae (4 species), Bacillariophyceae (37 species), Dinophyceae (14 species)and Euglenophyceae (1 species). Zooplankton were found 10 classes consisting of Crustacea (16 species), Holothuroidea (3 species), Ciliata (5 species), Sagittoidea (2 species), Sarcodina (3 species), Rotatoria (4 species), Echinodermata (1 species), Polychaeta (1 species), Urochordata (1 species) dan Hydrozoa (1 species). Phytoplankton abundance was between 1.922.010 - 3.834.261 cell/ l. Zooplankton abundance was between 2.764 - 2.849.066 ind/l. Analysis on biological index of phytoplankton showed that the diversity indeces ranged between 1,74 – 3,64; dominance indeces (=D) ranged between 0,04-0,40 and similarity indeces (=E) ranged between 0,08- 0,34. Biological index of zooplankton showed that the diversity indeces (= H) ranged between 0,22-3,70; dominance indeces (=D) ranged between 0,18-0,79, and similarity indeces (= E) ranged between 0,01-0,37. Water temperature ranged between 29.5 - 31.6o C, pH ranged between 4.96 - 7.38 and salinity ranged between 12.0 - 31.5 o / oo . Jakarta Bay is experienced environmental pressures so that only several species plankton are capable of adapting, that is from class Bacillariophyceae (Chaetoceros sp.) and class Crustaceae (Calanus sp. and Acartia sp)