Hasil Pencarian  ::  Simpan CSV :: Kembali

"Plankton berperan penting dalam ekosistem perairan, karena kehadirannya dapat mempengaruhi komunitas lain. Penurunan populasi ikan dipengaruhi oleh beberapa faktor yaitu faktor kondisi lingkungan dan ketersediaan makanan. Penelitian ini bertujuan menganalisis kondisi perairan Pandeglang dilihat dari parameter fisika suhu, kecerahan, kecepatan arus , kimia salinitas, pH, DO, nitrat, fosfat dan biologi klorofil-a , menganalisis struktur komunitas plankton di perairan Pandeglang, menganalisis hubungan antara parameter fisika-kimia perairan dengan struktur komunitas plankton, menganalisis ketersediaan makanan ikan dan kebiasaan makan ikan kembung terhadap fitoplankton di perairan Pandeglang. Penelitian dilaksanakan dari bulan September-Oktober 2017. Pengambilan sampel fitoplankton menggunakan plankton net 80 m dengan penarikan horizontal dan zooplankton menggunakan plankton net 133 m dengan penarikan vertikal. Komposisi fitoplankton terdiri dari 37 genus dengan 4 filum yaitu Bacillariophyta, Miozoa, Cyanophyta dan Euglenophyta dengan kelimpahan berkisar pada 2,785-29,425 ind/liter. Indeks keanekaragaman fitoplankton rata-rata sebesar 1,62, indeks keseragaman 0,65, dan indeks dominansi sebesar 0.29. Komposisi zooplankton terdiri dari 35 genus dengan 12 filum dengan kelimpahan berkisar pada 279-480 ind/liter. Indeks keanekaragaman zooplankton rata-rata sebesar 1.69, indeks keseragaman sebesar 0.72, indeks dominansi sebesar 0.27. Hubungan parameter lingkungan perairan terhadap kelimpahan fitoplankton : berkorelasi positif [kecepatan arus 0.793 , fosfat 0.122 ] dan sangat signifikan [kecepatan arus ?

---

Plankton play an important role in aquatic ecosystems, because its presence can affect other communities. The decrease of fish population is influenced by several factors, namely environmental condition and food availability. This study aims were to analyze the condition of Pandeglang waters viewed from the physics parameters temperature, brightness, current velocity , chemistry salinity, pH, DO, nitrate, phosphate and biology chlorophyll a , analyzing the plankton community structure in Pandeglang waters, between water physics chemical parameters and plankton community structure, analyzing the availability of fish food and feeding habits of Indian Mackerel on phytoplankton in Pandeglang waters. The study was conducted from September to October 2017. Phytoplankton sampling using 80 m plankton net with horizontal drag and zooplankton using 133 m net plankton with vertical drag. The phytoplankton composition consists of 37 genera with 4 phyla namely Bacillariophyta, Miozoa, Chyanophyta and Euglenophyta with abundance ranging from 2,785 29,425 individu liter. The phytoplankton diversity index was 1.62, the evenness index was 0.65, and the dominance index was 0.29. The composition of zooplankton consists of 35 genera with 12 phyla with abundance ranging from 279 480 individu liter. The zooplankton diversity index of 1.69, evenness index of 0.72, the dominance index of 0.27. The relation of environmental parameters to phytoplankton abundance positively correlated current velocity 0.793 , phosphate 0.122 and strong significant current velocity "

"Hurun Gulf waters including Fisheries Management Area (WPP) and the Java Sea in the area of Lampung Bay waters. Hurun Bay around many ponds, sights, and karamba Floating Net, so the activities carried out at sea and on land can have a negative effect on this region, especially the quality of aquatic environment. Therefore, to study the depth of the plankton community structure that can be used as the basis of information in monitoring the condition of the waters. This research was conducted during two weeks in January, February, and March. Defined 15 stations taking measurements and water and plankton samples, with two replications, from each station. Determination of the station based on the condition of the area. Sampling for phytoplankton taken with a Kitahara net cone with diameter 31 cm, length 100 cm and eye net size for surface and vertical net 80 m. Zooplankton sampling with a NORPAC net with diameter 45 cm, 180 cm length and eye net size for surface and vertical net 300 m. These samples were preserved with formalin 4 then analyzed in the laboratory using the method of sub-samples. Plankton was observed and analyzed using a microscope binoculars. The instrument used for measuring chemical and physical parameters are thermometer, refraktometer, Secchi disc, and bathymetrimeter. Vehicle used was 40 HP fishing boat. Phytoplankton species identification results of the surface are 50 genera, including in the class 3 or Diatoms Bacillariophyceae (36 genera), Cyanophyceae (3 genera) and Dinophyceae (11 genera) and the vertical is 56 genera which are 36 genera composition classes Bacillariophyceae, 4 genus 16 genus of Cyanophyceae and Dinophyceae. The dominant genus of the class is Bacillariophyceae Chaetoceros, Thalassiosira, Thalassionema and Biddulphia and three genera of the class Dinophyceae is Ceratium, Noctiluca and Protoperidinium. Diversity index values range in the surface 1.50 (Station 15) - 0.59 (Station 10), while the vertical 1.79 (Station 9) - 0.78 (Station 15). The range of values of surface uniformity index 0.47 (Station 15) - 0.17 (Station 10), whereas the vertical range of values uniformity index 0.64 (Station 9) - 0.16 (Station 15). Dominance is the highest index of 0.83 indicates that dominance is. Total abundance of phytoplankton ranged from the lowest 750 cells / l until the highest 192750 cells / l. The dominant zooplankton obtained from the class Crustacea, which is taking 24 genera in the genus 19 surface and vertically, Protozoa class (on the surface of genus 17 and 18 are vertical), Annelida (on the surface of genus 7 and 6 are vertical), Protochordata (there are two genus on the surface or vertical), molluscs (two genera), and Rotifera Echinodermata one genus. Diversity index values range in the Surface, 2.27 (Station 4) - 0.64 (Station 3) and the Vertical 2.33 (Station 1) -0.82 (Station 15). The range of surface uniformity index value, 0.99 (Station 2) -0.42 (Stasiun12), whereas the vertical range of values uniformity index 0.95 (Station 4) -0.54 (Station 14). Dominance is the highest index of 0.66, indicating that dominance was.The lowest surface abundance of 6750 ind / l (Station 14), the highest 144000 ind / l (Station 3). Phytoplankton relationships with environmental factors, phytoplankton abundance parameters are influenced by phosphate and brightness, but the most affecting is phosphate, when viewed between phytoplankton abundance parameters week has a close affinity with salinity, DO, depth and pH. Zooplankton relationships with environmental factors seen in between stations have a close connection with the phosphate and brightness, and when viewed from the inter-week zooplankton abundance parameter has a close affinity with salinity, DO, phosphate and pH. Relationships of phytoplankton-zooplankton abundance correlated positively linear in time corresponding to the regression equation Y = 0,502X – 8226. The results showed that herbivorous zooplankton feed speed is proportional to the speed increase phytoplankton populations."

"Penelitian hubungan kuantitatif antara fitoplankton dan zooplankton herbivor di Teluk Jakarta telah dilakukan pada Agustus dan September 2009. Sampel pada 10 stasiun diambil secara horizontal menggunakan jaring Kitahara untuk sampel fitoplankton dan jaring NORPAC untuk zooplankton. Tabulasi data disajikan dalam bentuk tabel dan grafik serta dianalisis secara deskriptif. Kelimpahan kelompok Diatom, Dinoflagellata, dan Cyanophyta memiliki korelasi negatif terhadap kelimpahan zooplankton herbivor pada bulan Agustus 2009. Kelimpahan zooplankton herbivor dapat dijelaskan sebesar 23,4% dengan persamaan regresi linear yang terbentuk pada bulan Agustus 2009. Kelimpahan kelompok Diatom, Dinoflagellata, dan Cyanophyta memiliki korelasi positif terhadap kelimpahan zooplankton herbivor pada bulan September 2009. Kelimpahan zooplankton herbivor dapat dijelaskan sebesar 88,8% dengan persamaan regresi linear yang terbentuk pada bulan September 2009.

---

Research on quantitative relationship between phytoplankton and herbivore zooplankton in Jakarta Bay was conducted on August and September 2009. Sample at 10 stations was taken horizontally by Kitahara net for phytoplankton and NORPAC net for zooplankton. The data tabulation are showed in tables and graphs and also analyzed descriptively. Abundance of Diatom, Dinoflagellate, and Cyanophyta have negative correlation for herbivore zooplanktons on August 2009. Abundace of herbivor zooplankton can explain 23,4% by regression linearity on August 2009. Abundance of Diatom, Dinoflagellat, and Cyanophyta have positive correlation for herbivore zooplanktons on September 2009. Abundace of herbivor zooplankton can explain 88,8% by regression linearity on September 2009."

"Zooplankton merupakan komponen penting pada ekosistem perairan yang memiliki sebaran dalam skala ruang dan waktu. Sebaran dan keanekaragaman zooplankton merupakan salah satu indikator biologis kualitas suatu perairan.Kajian mengenai sebaran dan kelimpahan zooplankton di Danau Maninjau, Sumatera telah dilakukan Desember 2005

---

"

"Penelitian ini bertujuan mengkaji aspek biologi panjang, bobot ikan, dan tingkat kematangan gonad ikan kembung lelaki terkait dengan parameter fisika suhu permukaan laut, kecerahan, dan arus dan kimia salinitas serta kesuburan perairan klorofil-a pada daerah penangkapan/fishing ground dalam upaya pengelolaan penangkapan ikan kembung di Kabupaten Pandeglang. Penelitian dilaksanakan dari bulan Desember 2016-April 2017. Pengambilan sampel dilakukan di tiga titik fishing ground yaitu Batu Hideung, Sumur dan Panaitan. Pengukuran panjang, berat ikan, pembedahan untuk mengamati tingkat kematangan gonad serta pengukuran parameter fisika kimia perairan dilakukan secara in situ. Suhu permukaan laut pada lokasi penelitian berkisar antara 28.20-29.700C, Kecepatan arus 0.6-0.8 m/det, kecerahan 6-9 m, dan salinitas 30-32g/l. Nilai klorofil-a bulan Desember 0.13 mg/m3 kondisi fishing ground kurang subur, Februari-April nilai klorofil-a 0.9-2.0 mg/m3 yang mengindikasikan bahwa area fishing ground Batu Hideung dan Sumur dalam kondisi subur. Ikan kembung lelaki yang tertangkap dengan jaring rampus diperoleh nilai fork length antara 14-22 cm modus 18.3 cm. Ukuran ikan pertama kali tertangkap Lc adalah 17.17 cm. Hasil analisis hubungan panjang berat diperoleh nilai slope b ikan kembung jantan dalam kategori allometrik negatif dan ikan betina allometrik positif. Ukuran panjang pertama kali ikan matang gonad Lm sebesar 17.91 cm. Hasil analisis nilai Lc lebih rendah dibanding nilai Lm, hal ini berdampak negatif bagi kelestarian ikan kembung. Upaya pengelolaan sumberdaya ikan kembung perlu dilakukan dengan cara mengatur dan mengawasi operasi penangkapan berdasarkan siklus pola pemijahan ikan kembung.

---

The aim of this research was to study the relationship between biological aspects length, weight and gonad maturity level of Indian Mackerel and physical sea surface temperature, transparency, and current velocity , chemical parameters salinity and chlorophyll a of the fishing grounds in Pandeglang regency. The research was conducted from December 2016 to April 2017. Samplings were taken at three sites within the fishing grounds in Batu Hideung, Sumur and Panaitan. The measurement of length, weight, and surgery for gonad maturity level observation as well as physical chemical waters parameters measurement were conducted in situ. The sea surface temperature at the study site ranged from 28.20 29.700C, current velocity 0.6 0.8 m s, transparency 6 9 m, and salinity 30 32 g l. While the value of chlorophyll a in December was 0.13 mg m3, at which the fishing ground conditions were less fertile, the chlorophyll a value in February April ranged from 0.9 to 2.0 mg m3, indicating that the fishing grounds within Batu Hideung and Sumur were in fertile condition. The fork length Indian mackerel caught by a bottom gillnet was about 14 22 cm mode 18.3cm. The length of fish at first capture Lc was 17.17 cm. The value of slope b in the length weight relationship revealed that male Indian mackerel was in negative allometric while female Indian mackerel was still positive. Length at first maturity Lm was 17.91 cm. The value of Lc is lower than Lm, revealed that the fishing activity has negative impacts on sustainability of Indian mackerel. Efforts including arrangement and supervision of fishing operations based on the spawning patterns are needed to manage Indian mackerel resources."

"Penelitian mengenai hubungan struktur terhadap parameter fisika dan kimia di Situ Puspa, Universitas Indonesia, Depok, Jawa Barat telah dilakukan pada bulan April hingga Juni 2022. Penelitian ini bertujuan untuk mengetahui hubungan kelimpahan fitoplankton terhadap parameter fisika dan kimia di Situ Puspa UI. Sampel yang digunakan dalam penelitian ini adalah fitoplankton dari perairan Situ Puspa UI. Hasil penelitian menunjukkan bahwa jenis fitoplankton di Situ Puspa UI ditemukan 24 marga dari 9 kelas dan kelimpahannya berkisar 121-4.167 plankter/liter. Fitoplankton yang hidup di Situ Puspa UI memiliki produktivitas, ekosistem, kestabilan, dan keanekaragaman fitoplankton sedang, tidak ada jenis yang mendominasi, kemerataan cukup dan hampir merata, dan Situ Puspa mengalami pencemaran sedang. Kelimpahan fitoplankton pada bagian inlet berkorelasi positif dengan oksigen terlarut, kecepatan arus, dan fosfat. Kelimpahan fitoplankton pada bagian midlet berkorelasi positif dengan nitrat dan pH serta kelimpahan fitoplankton pada bagian outlet berkorelasi positif dengan suhu, turbiditas, dan kedalaman air.

---

Research on the relationship of structure to physical and chemical parameters at Situ Puspa, Universitas Indonesia, Depok, West Java was carried out from April to June 2022. This study aimed to determine the relationship between abundance of phytoplankton while physical and chemical parameters at Situ Puspa UI. The sample used in this study was phytoplankton from the waters of Situ Puspa UI. The results showed that the types of phytoplankton in Situ Puspa UI found 24 genera from 9 classes and their abundance ranged from 121-4,167 plankter/liter. Phytoplankton that lived in Situ Puspa UI has moderate productivity, ecosystem, stability, and phytoplankton diversity, no species dominates, evenness were sufficient and almost evenly distributed, and Situ Puspa UI was moderately polluted. The abundance of phytoplankton at the inlet were positively correlated with dissolved oxygen, current velocity, and phosphate. The abundance of phytoplankton in the midlet were positively correlated with nitrate and pH and the abundance of phytoplankton at the outlet were positively correlated with temperature, turbidity, and water depth."

"Penelitian mengenai studi struktur komunitas fitoplankton di Sungai Ciliwung dilakukan di tiga stasiun yang merepresentasikan bagian yang masih alami Jembatan Panus, area penataan Srengseng Sawah, dan area betonisasi T.B Simatupang. Penelitian dilakukan pada bulan Oktober hingga November 2017. Penelitian ini bertujuan untuk mengetahui perbedaan struktur komunitas fitoplankton pada tiga stasiundi Sungai Ciliwung dengan melihat perbedaan nilai kelimpahan, H, E, dan D. Hasil penelitian menyatakan bahwa keanekaragaman di setiap stasiun tergolong rendah dengan kemerataan yang tidak merata dan tidak adanya dominansi. Hal tersebut menggambarkan kondisi struktur komunitas fitoplankton di Sungai Ciliwung tidakstabil dengan keragaman yang rendah dan kondisi lingkungan yang kurang mendukung kehidupan fitplankton.

---

The research of the phytoplankton community structure in the Ciliwung River was conducted in three stations that representing the unspoiled area Jembatan Panus, settlement area Srengseng Sawah, and sheet pile area T.B Simatupang. The studywas conducted from October to November 2017. The purpose of this research was toknow the difference of phytoplankton community structure at three stations inCiliwung River by looking at the difference of abundance index, H 39, E, and D values. The research results stated that the diversity in each station was low with evenness evenly and the absence of dominancy. This result illustrated that the phytoplankton rsquo community structure in the Ciliwung River was unstable with low diversity and unsuitable environmental conditions for phytoplankton."

"Penelitian ini dilakukan untuk mengetahui struktur komunitas filoplankton serta hubungannya lerhadap kondisi fisiko-kimia perairan di Waduk Krenceng Cilegon. Kelimpahan fitoplankton dihitung dengan lackey drop microlransect method, keanekaragaman jenis dengan indeks Shannon Wiener, kesamarataan jenis dengan indeks Evenness. Hubungan anlara fitoplankton dengan lingkungan menggunakan analisis regresi berganda. Hasil identifikasi ditemuka 26 jenis fitoplankton yang termasuk dalam 4 klas dengan kelimpahan tertinggi jenis Microcysiis aeroginasa. Hasil analisa regresi menunjukkan faktor lingkungan yang berpengaruh terhadap kelimpahan fitoplankton pada bulan Nopember adalah: kecerahan, suhu, pH, oksigen terlarut, nitrat, dan orthofosfat. Sedangkan pada bulan Marel faktor-faktor lingkungan seperti keceraahan, suhu, pH, oksigen terlarut, nitrtal, dan CO; lebih berpengaruh.

---

This research was carried out lo know the structure of the phytoplankton communities as well as his relations lo the physical and chemical water conditions in the Krenceng Reservoir, Cilegon. The phytoplankton abundance, diversity and evenness were counted. Relations between the phytoplankton and the environment were calculated with regression. We identified 26 species of the phytoplankton that including in four classes with the highest abundance of the Microcystis aeroginosa. The analysis of regression pointed out that the environmental factors such as brightness, temperature, pH, dissolve oxygen, nitrate, and orthophosphates influence the phytoplankton abundance in November, whereas in March the influenced factors are brightness, temperature, pH, dissolve oxygen, nitrates, and CO2."

"ABSTRAKPerairan Teluk Jakarta sangat subur karena banyak sungai besar maupun kecil yang mengalir ke perairan ini dengan membawa nutrien atau zat-zat hara dari daratan kota Jakarta sehingga menjadi tempat yang sangat baik untuk para nelayan menangkap ikan. Dengan bertambahnya penduduk maka hasil buangan juga akan meningkat, sehingga akibatnya perairan akan cenderung mengalami kondisi eutrofik. Eutrofikasi merupakan suatu proses pengayaan perairan oleh zat-zat hara yang berlebihan dan berlangsung terus menerus dan ditandai oleh blooming satu jenis fitoplankton dan kekurangan zat oksigen di dekat dasar perairan. Akibat dari kondisi eutrofik ini maka sering kita jumpai kematian ikan atau biota dasar perairan secara masal.Untuk mengantisipasi masalah ini kepada masyarakat perlu digalakkan kesadaran lingkungan seperti tidak membuang sampah langsung ke badan-badan air. Perlu pula dimasyarakatkan budidaya ikan dan biota seperti kerang-kerangan.Lokasi penelitian: yaitu perairan-perairan estuarin Teluk Jakarta. Pengamatan dilakukan pada 6 titik wilayah dari barat ke timur yaitu Cengkareng, Muara Angke, Marina, Sampur, Blencong, dan Muara Gembong. Dilakukan pengambilan sampel fitoplankton dan pemeriksaan beberapa parameter hidrologi seperti suhu, salinitas, oksigen, pH, fosfat, dan nitrat. Analisis semua data dilakukan di Laboratorium Puslitbang Oseanologi-LIPI, Jakarta.Hipotesis yang diajukan adalah:1. Keragaman kelimpahan fitoplankton secara spasial dan temporal adalah sangat besar.2. Keragaman kelimpahan fitoplankton dipengaruhi oleh faktor -faktor suhu, salinitas, pH, oksigen, nitrat, dan fosfat, atau oleh kombinasi dari faktor-faktor lingkungan tersebut, dan nutrien merupakan faktor paling dominan dalam mempengaruhinya.3. Keragaman fitoplankton sangat ditentukan oleh dominasi dari marga-marga yang dominan.Ringkasan hasil penelitian adalah sbb.:Reragaman kelimpahan fitoplankton sangat bervariasi.Pada keragaman secara temporal, kelimpahan pada bulan Juli, September, dan Februari tinggi, sedangkan pada bulan Mei dan Mopember relatif rendah.Pada keragaman secara spasial, kelimpahan tinggi terjadi pada wilayah Muara Angke, Marina, dan Sampur, sedangkan kelimpahan rendah terjadi pada wilayah Cengkareng, Blencong, dan Muara Gembong.Pada setiap pengamatan terjadi blooming fitoplankton yang didominasi oleh beberapa marga yang bergantian.Pada bulan Mei 1993 kelimpahan mencapai 6,34 juta sel/m3 yang didominasi oleh Skeletonema (39 %) dan Thalassiosira (36%). Pada bulan Juli kelimpahan mencapai 22,4 juta sel/m3dimana saat itu sedang terjadi blooming Skeletonema (51%) dan blooming Thalassiosira (49%). Pada bulan September kelimpahan mencapai angka tertinggi selama penelitian yaitu 62,6 juta sel/m3. Pada saat itu terjadi blooming oleh Chaetaceros (99 %). Pada bulan Nopember kelimpahan paling rendah selama penelitian yaitu 1,5 juta sel/m3. Pada saat itu sebenarnya sedang terjadi ledakan populasi Noctiluca. Walaupun jumlahnya kecil tetapi karena ukuran setiap sel nya adalah besar yaitu dapat mencapai 2 mm maka kondisi demikian sesungguhnya sedang terjadi blooming oleh Noctiluca (58%) dan Chaetviceros sebesar 42%. Pada bulan Februari 1994 kelimpahan mencapai 14 juta sel/m3. Pada saat itu sedang terjadi blooming oleh Skeletonema {99,8 %) dan Noctiluca sebesar 0,2 %.Pola kelimpahan tampak berlawanan dengan pole curah hujan maupun pola kelimpahan di perairan P. Pari dan Teluk Jakarta secara umum. Pola kelimpahan mempunyai 2 puncak yaitu puncak ke 1 terjadi pada periode Mei-September dimana titik puncak terlihat pada bulan September (tertinggi), dan puncak ke 2 terjadi pada bulan Februari.Hubungan kelimpahan fitoplankton terhadap parameter-parameter hidrologi menunjukkan hubungan yang sangat erat (p<0,01) pada pengamatan-pengamatan bulan-bulan Mei, Nopember, dan Februari; dan hubungan erat (p<0,05) pada bulan-bulan Juli dan September. Interaksi fosfat dengan nitrat berpengaruh kuat terhadap kelimpahan fitoplankton pada bulan Mei, Nopember, dan Februari. Interaksi suhu dengan oksigen mempunyai korelasi terhadap kelimpahan fitoplankton pada bulan Juli. Interaksi suhu dengan salinitas berkorelasi kuat terhadap kelimpahan pada bulan September.Dengan tingginya limbah domestik yang masuk ke perairan Teluk Jakarta dan terbukti perairan ini selalu mengalami blooming dan bahkan kematian ikan sering terjadi menuniukkan bahwaperairan ini telah cenderung mengaiami kondisi eutrofik. Hal ini berarti di perairan sedang terjadi penurunan kualitas air karena sedang menghadapi tekanan-tekanan yang datang dari daratan.

---

ABSTRACT

Spatial and Temporal Variations of The Structures of Phytoplankton Communities at The Estuary of The Jakarta BayJakarta Bay is very rich of nutrient due to many rivers which bring the nutrients to the waters from the land of Jakarta. Therefore this area become a good place for fisheries. The increasing of the domestic wastes because of the population growth, will result the tendency of the eutrophication condition. Due to this condition, sometime we face the mass mortality of fish due to the oxygen depletion condition at the bottom of the water.

In anticipation of this problem, the public should be made aware of the environmental condition: not throwing away the wastes directly to the water, and fish and benhic fauna cultures i. e. mussels, etc. should be also introduced to them.

The location of the research: are at 6 locations along the coast from the west to the east of the Jakarta Bay, namely Cengkareng, Muara Angke, Marina, Sampur, Blencong, and Muara Gembong. The samples were studies for phytoplankton and temperature, salinity, oxygen, pH, phosphate, and nitrate. All samples were analyzed at the Laboratory of Puslitbang Oceanology - LIPI, Jakarta.

The Hypothesis are

Spatial and temporal variations of phytoplankton densities were high.

The variations were influenced by temperature, salinity, pH, oxygen, nitrate, and phosphate, and the inter-action of the factors. The nutrient is the main factor for phytoplankton growth.

The variations were also strongly influenced by the dominant genera.

The summary :

The variations of phytoplankton densities were high.

For the temporal variatons, the phytoplankton densities in July, September, and February were high, while in May and November were relatively low.

For the spatial variations, the densities at Muara Angke, Marina, and Sampur were high, while at the other areas: Cengkareng, Slencong, and Muara Gembong were low.

There were always blooming which were dominated by some genera. In May, the average phytoplankton density was 6,34 million cells/.m3 where the community was dominated by Skeletonema {39%) and Thalassiasira (36%). In July, the density reached 22,4 million cells/m3 where the phytoplankton communities were dominated by Skeletonema (51%) and Thalassiosira (49%). In September, the density reached the highest value i. e. 62,6 million cell/m3. At that time Chaetoceras outbreak was occurred (99%). In November, the phytoplankton density reached the lowest value, i. e. 1,5 million cells/m3. At that time Noctiluca outbreak was occurred. Although the density was low, the size of Nactiluca is quite big (2mm in diameter).

Therefore Noctiluca outbreak (58%) occurred and was reached 14 million cells/m0. At that time the blooming of Skeletonema occurred (99,8 %) and Noctiuca was only reached 0,2 %.

The pattern of the densities of phytoplankton were in opposite to the pattern of the densities in this bay in general and the pattern of the rain fall.

The relationship of densities and environmental condition were very significant (p<0,01) in May, November, and February; and were significant (p<0,05) in July and September. Nitrate was much influenced the phytoplankton densities, while phosphate was not so. The inter-action of nitrate-phosphate was significantly influenced and positive to the growth of phytoplankton in May and February, while in November was significant and negative. The interaction temperature-oxygen was significant and negative to the phytoplankton growth in July. In September, the inter-action temperature-salinity was significant and positive to the phytoplankton growth.

As the result of high influx of domestic wastes to the water of the Jakarta Bay, the fact that the water was always in bloom condition and fish and benthic animals mortalities frequently occurred. This condition reflects the tendency of the eutrophic process. This means that the

As the result of high influx of domestic wastes to the water of the Jakarta Bay, and the fact that the water was always in bloom condition, and fish and benthic animals mortalities frequently occurred, reflects the tendency of the eutrophic process. This means that the quality of the water is worsening due to the pressure coming from the land.

References : 64 books and papers (1925-1994)."

"The aims of the study were a ) to determine the affect of offshore distant to the density and diversity of phytoplankton b) to determine the distribution pattern of density and diversity of phytoplankton...."