scholarly journals POTENSI BUDIDAYA IKAN BANDENG SEBAGAI PEMANFAATAN PLANKTON DI PERAIRAN BATU NAMPAR

2021 ◽  
Vol 1 (1) ◽  
pp. 41-48
Author(s):  
Nanda Diniarti ◽  
Muhammad Junaidi ◽  
Baiq Hilda Astriana
Keyword(s):  
Skeletonema Costatum ◽  
Coscinodiscus Granii

Perairan Teluk Ekas telah memiliki konsentrasi nutrien yang di atas ambang batas. Nutrien berasal dari pakan ikan rucah yang diberikann oleh pembudidaya ikan sistem Karamba jaring Apung. Nutrien yang berlebihan di perairan akan memicu pertumbuhan besar-besaran plankton atau yang dikenal dengan blooming. Blooming plankton akan berdampak buruk pada biota yang dibudidayakan serta untuk semua organisme yang mendiami perairan tersebut. Plankton yang tumbuh dapat dikendalikan dengan memberikan organisme yang dapat memanfaatkan keberadaannya sebagai pakan. Bandeng banyak digunakan sebagai pemanen /pemanfaatan plankton baik di perairan tawar maupun laut. Bandeng merupakan ikan euryhalin atau memiliki rentang salinitas yang luas. Selain itu ikan bandeng merupakan ikan ekonomis penting. Namun sebelum mengintroduksi ikan bandeng di KJA Batu Nampar perlu dilakukan analisa kesesuaian beberapa parameter lingkungan dan yang tidak kalah pentingnya adalah jenis plankton yang bisa dimanfaatkan oleh bandeng. Oleh karena itu tujuan penelitian ini adalah mengiventaris/mendata jenis plankton di perairan Batu Nampar serta melihat kesesuaian jenis plankton yang ada dengan yang menjadi pakan ikan alami Bandeng. Metode yang digunakan dalam penelitian ini adalah metode survey. Pengamatan lebih dititikberatkan pada pendataan jenis plankton. Pengambilan contoh air dan pengamatan terhadap parameter-parameter kualitas air lainnya dilakukan pada tiap bulan selama 3 kali. Jenis plankton yang teriventarisir pada saat penelitian adalah: Synedra ulna, Fragilaria, Hemiaulus sinensis, Skeletonema costatum, Triceratium taves, Coscinodiscus granii, Pseudo nitzschia, Dytilum sol, Cerataulina smithii, Clamydocapsa sp, Navicula elegans, Aulacodiscus gracilis, Cydotella sp., Globorotolia pumilio, Ceratium sp.,larva crustacean, Pontellina plumata. Plankton yang terdapat lebih banyak dari Bacillariophyceae yang merupakan jenis pakan dari ikan bandeng sehingga perairan KJA Batu Nampar berpotensi digunakan untuk budidaya Bandeng

Effects of resuspension of eastern oyster Crassostrea virginica biodeposits on phytoplankton community structure

2020 ◽  
Vol 640 ◽  
pp. 79-105
Author(s):  
ET Porter ◽  
E Robins ◽  
S Davis ◽  
R Lacouture ◽  
JC Cornwell
Keyword(s):  
Water Quality ◽  
Community Structure ◽  
Crassostrea Virginica ◽  
Skeletonema Costatum ◽  
Eastern Oyster ◽  
Energy Dissipation Rate ◽  
Negative Effects ◽  
Cell Densities ◽  
Sediment Bottom ◽  
Nitrite Nitrate

Anthropogenic disturbances in the Chesapeake Bay (USA) have depleted eastern oyster Crassostrea virginica abundance and altered the estuary’s environment and water quality. Efforts to rehabilitate oyster populations are underway; however, the effect of oyster biodeposits on water quality and plankton community structure are not clear. In July 2017, we used 6 shear turbulence resuspension mesocosms (STURMs) to determine differences in plankton composition with and without the daily addition of oyster biodeposits to a muddy sediment bottom. STURM systems had a volume-weighted root mean square turbulent velocity of 1.08 cm s-1, energy dissipation rate of ~0.08 cm2 s-3, and bottom shear stress of ~0.36-0.51 Pa during mixing-on periods during 4 wk of tidal resuspension. Phytoplankton increased their chlorophyll a content in their cells in response to low light in tanks with biodeposits. The diatom Skeletonema costatum bloomed and had significantly longer chains in tanks without biodeposits. These tanks also had significantly lower concentrations of total suspended solids, zooplankton carbon, and nitrite +nitrate, and higher phytoplankton carbon concentrations. Results suggest that the absence of biodeposit resuspension initiates nitrogen uptake for diatom reproduction, increasing the cell densities of S. costatum. The low abundance of the zooplankton population in non-biodeposit tanks suggests an inability of zooplankton to graze on S. costatum and negative effects of S. costatum on zooplankton. A high abundance of the copepod Acartia tonsa in biodeposit tanks may have reduced S. costatum chain length. Oyster biodeposit addition and resuspension efficiently transferred phytoplankton carbon to zooplankton carbon, thus supporting the food web in the estuary.

Modeling of photosynthesis light curves by linear splines

2019 ◽  
pp. 20-29
Author(s):  
Alexander S. Lelekov ◽  
Rudolf P. Trenkenshu
Keyword(s):  
Experimental Data ◽  
Chlorophyll A ◽  
Skeletonema Costatum ◽  
Light Flux ◽  
Photosynthesis Rate ◽  
Light Curves ◽  
External Irradiation ◽  
Exchange Reactions ◽  
Cell Adaptation ◽  
Linear Splines

The paper presents an example of the linear splines use to describe the photosynthesis light curves for microalgae culture. The main mathematical models of the relationship between photosynthesis rate and light are listed. Based on the previously formulated basic principles of modeling microalgae photobiosynthesis, a mathematical model is proposed that describes the dependence of the assimilation number of chlorophyll a on the value of the light flux by linear splines. The advantage of the proposed approach is a clear definition of the point of change of the limiting factor. It is shown that light-limited photosynthesis rate is determined not only by external irradiation, but also by the concentration of chlorophyll a. The light-saturated rate depends on the amount of a key enzyme complex, which limits the rate of energy exchange reactions in the cell. Verification of the proposed model on the example of the diatom microalgae Skeletonema costatum was carried out. It is shown that the higher the degree of cell adaptation to high irradiation, the better the photosynthesis curve is described by linear splines. If S. costatum cells are adapted to low irradiation, deviations of experimental data from the idealized broken line are observed, which are caused by changes in the pigment composition. When the experimental data are normalized, the cell adaptation factor is reduced, all points are described by a single broken line, which indicates the universality of the proposed approach.

ẢNH HƯỞNG MỘT SỐ ĐIỀU KIỆN NUÔI TRỒNG ĐẾN SINH TRƯỞNG CỦA TẢO SILIC Skeletonema costatum (Greville) Cleve

2015 ◽  
Vol 108 (9) ◽  
Author(s):  
Nguyễn Thị Thu Liên
Keyword(s):  
Skeletonema Costatum

Tảo Skeletonema costatum là một trong các loài tảo silic được sử dụng phổ biến để làm thức ăn cho thủy sản ở nhiều cơ sở sản xuất giốn. Bài báo này trình bày một số kết quả bước đầu thăm dò điều kiện nhân nuôi một chủng tảo silic Skeletonema costatum SKVT phân lập từ vùng biển Vinh Thanh. Các kết quả nghiên cứu này sẽ làm cơ sở cho những nghiên cứu tiếp theo phát triển nuôi trồng loài tảo này trên quy mô lớn đáp ứng nhu cầu cung cấp thức ăn cho nuôi trồng thủy sản ở vùng Thừa Thiên Huế.Qua một số khảo nghiệm bước đầu cho thấy chủng tảo S. costatum SKVT sinh trưởng tốt ở điều kiện pH 8,0; độ mặn 30 phần nghìn; cường độ ánh sáng là 3000-3500 lux và chiếu sáng liên tục; sục khí liên tục 24/24h. Mật độ tảo giống ban đầu ảnh hưởng đến thời gian sinh trưởng cực đại: mật độ càng cao thì thời gian đạt cực đại càng ngắn. Trong cùng điều kiện môi trường , nhân nuôi sinh khối tảo S. costatum trong túi nilon thu được sinh khối cao hơn so với trong thùng xốp.

ENERGY TRANSFER EFFICIENCIES ON LOWER TROPHIC LEVELS WITH INTENSIVE OYSTER FARMING IN HIROSHIMA BAY, JAPAN

2017 ◽  
Author(s):  
Akira Umehara ◽  
Akira Umehara ◽  
Satoshi Asaoka ◽  
Satoshi Asaoka ◽  
Naoki Fujii ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Primary Production ◽  
Skeletonema Costatum ◽  
Warm Season ◽  
Nutrient Supply ◽  
Trophic Levels ◽  
Phytoplankton Primary Production ◽  
Mean Values ◽  
Hiroshima Prefecture ◽  
Study Species

In enclosed water areas, organic matters are actively produced by phytoplankton due to abundant nutrient supply from the rivers. In our study area of the semi-enclosed Hiroshima Bay, oyster farming consuming high primary production has been developed since the 1950s, and the oyster production of Hiroshima prefecture have had the largest market share (ca. 60%) in Japan. In this study, species composition of phytoplankton, primary production, and secondary production of net zooplanktons and oysters were determined seasonally at seven stations in the bay between November 2014 and August 2015. In the bay, diatoms including Skeletonema costatum dominated during the period of the study. The primary productions markedly increased during summer (August), and its mean values in the northern part of the bay (NB) and the southern part (SB) were 530 and 313 mgC/m2/d, respectively. The productions of net zooplankton and oyster increased during the warm season, and its mean values in the NB were 14 and 1.2 mgC/m2/d, and in SB were 28 and 0.9 mgC/m2/d, respectively. The energy transfer efficiencies from the primary producers to the secondary producers in the NB and SB were 2.8% and 9.1%, respectively. However, the transfer efficiency to the oysters was approximately 0.3% in the bay. This study clearly showed the spatial difference of the productions and transfer efficiencies, and the low contribution of the production of oysters in secondary productions in Hiroshima Bay.

Development of QSAR models for evaluating pesticide toxicity against Skeletonema costatum

Chemosphere ◽  
2021 ◽  
pp. 131456
Author(s):  
Lu Yang ◽  
Cuihong Sang ◽  
Yinghuan Wang ◽  
Wentao Liu ◽  
Weiyu Hao ◽  
...  
Keyword(s):  
Skeletonema Costatum ◽  
Pesticide Toxicity ◽  
Qsar Models

A unique hexaene hydrocarbon from a diatom (Skeletonema costatum)

1970 ◽  
Vol 202 (2) ◽  
pp. 386-388 ◽  
Author(s):  
Richard F. Lee ◽  
Judd C. Nevenzel ◽  
G.-A. Paffenhöfer ◽  
A.A. Benson ◽  
Stuart Patton ◽  
...  
Keyword(s):  
Skeletonema Costatum ◽  
Diatom Skeletonema Costatum

Influence of the Insecticide Diflubenzuron (Dimilin) on the Growth of Marine Diatoms and a Harpacticoid Copepod in Culture

1985 ◽  
Vol 42 (7) ◽  
pp. 1272-1277 ◽  
Author(s):  
N. J. Antia ◽  
P. J. Harrison ◽  
D. S. Sullivan ◽  
T. Bisalputra
Keyword(s):  
Skeletonema Costatum ◽  
Harpacticoid Copepod ◽  
Adult Survival ◽  
Thalassiosira Weissflogii ◽  
Marine Diatoms ◽  
Tigriopus Californicus ◽  
Per Se ◽  
Juvenile Development ◽  
Cyclotella Cryptica ◽  
Injurious Effects

Diflubenzuron (Dimilin) was tested, in the concentration range 0.1–5000 μg∙L−1, for possible injurious effects on the growth and photosynthesis of three chitin-producing (Thalassiosira weissflogii, T. norden-skioldii, Cyclotella cryptica) and one nonchitinaceous (Skeletonema costatum) diatoms. For comparison, the effects of the pesticide were also examined on adult survival and juvenile development of the harpacticoid copepod Tigriopus californicus. While the development of the copepod was hindered at concentrations of the order of 1–10 μg∙L−1, the diatoms were barely affected by Dimilin even at the highest concentration tested (5 mg∙L−1). We conclude that Dimilin acts specifically on insects and crustaceans as a larvicide by interfering with chitin deposition into cuticles during juvenile development through ecdysis. The lack of effect from Dimilin on the chitin-producing diatoms has suggested that the insecticide may not inhibit chitin biosynthesis per se as was previously believed, but that it presumably deregulates one or more of the larval postsynthetic processes responsible for chitin integration into cuticles.

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