scholarly journals ABSOLUTE GROWTH AND BIOMASS OF Gracilaria sp. THAT CULTIVATED UNDER DIFFERENT DEPTHS

Author(s):  
Nurlaila Ervina Herliany ◽  
Z Zamdial ◽  
Rahma Febriyanti

<p>There is significant increasing of seaweeds demand over the years that affect the development of seaweeds farming in Indonesia. <em>Gracilaria </em>sp. is one of the species that cultivated in Indonesia. There are some factors that affect the successful of seaweeds cultivation, one of them is cultivation depth. The research was carried out to study the effect of different depth on absolute growth and biomass of <em>Gracilaria </em>sp. <em>Gracilaria </em>sp. was cultivated under three different depths (30, 45 and 60 cm). The result shows that absolute growth and biomass were influenced by cultivation depth. The best treatment was cultivation at 30 cm of depth. Water quality measurements shows that research location is suitable for the growth of seaweeds.</p><p><strong><em>Keywords</em></strong><em> : Absolute growth, Biomass, Cultivation depths, Gracilaria </em>sp</p>

2019 ◽  
Vol 7 (1) ◽  
pp. 266
Author(s):  
Pitjont Tomatala ◽  
Petrus P. Letsoin ◽  
Evangelin M.Y. Kadmaer

Sandfish (Holothurai scabra) and seaweed Gracilaria sp are marine commodities that have economic value and have good prospects in the market. These two commodities, if rearing together, will certainly provide added value to farmers. This research aims to determine the potential of sea cucumber polyculture, (H. scabra) and Gracilaria sp. which is maintained in culture. This research was conducted in April - May 2018 in the coastal of Rat village, Southeast Maluku Regency. Sea cucumbers are weighed and stocked on Pen-culture (measuring 4 x 3 meters) with a density of 40 individuals / Pen-culture. Gracilaria seeds are taken from young thallus which are tied into one clump and ditagging. After that, Gracilaria was weighed and spread in Pen-culture of 20 clump / Pen-culture. Observation of growth and survival of sandfish and Gracilaria sp done once a week. At the same time, predator control is carried out on pen-culture and water quality measurements. The results showed that sea cucumbers experienced absolute growth and survival rates of 18.20 g and 92.5% respectively. Gracilaria sp which is maintained does not experience growth, while the percentage of survival of Gracilaria sp is 20%. Based on the results of the research it can be concluded that Polyculture of sandfish, H. scaba and seaweed, Gracilria sp is not effective if Gracilria sp is stocked on the basis of Pen-culture.Keyword : Sandfish, Gracilaria, PolycultureABSTRAKTeripang pasir (Holothurai scabra) dan rumput laut Gracilaria sp merupakan komuditi laut yang bernilai ekonomis dan mempunyai prospek yang baik dipasaran. Kedua komuditi ini, jika dipelihara bersama tentunya akan memberikan nilai tambah bagi pembudidaya. Penelitian ini bertujuan untuk mengetahui potensi polikultur teripang pasir, (H. scabra) dan Gracilaria sp. yang dipelihara pada pen-culture.Penelitian ini dilaksanakan pada bulan April – Mei 2018 di perairan desa Rat, Kabupaten Maluku Tenggara. Teripang pasir ditimbang dan ditebar pada Pen-culture berukuran 4 x 3 meter dengan kepadatan 40 individu/Pen-culture. Bibit Gracilaria diambil dari thallus muda yang diikat menjadi satu rumpun dan ditagging. Setelah itu, Gracilaria ditimbang dan ditebar pada Pen-culture sebanyak 20 rumpun/ Pen-culture.Pengamatan pertumbuhan dan kelangsungan hidup teripang pasir dan Gracilaria sp. dilakukan  seminggu sekali. Pada waktu yang bersamaan, dilakukan juga pengontrolan predator pada Pen-culture dan pengukuran kualitas air. Hasil penelitian diketahui bahwa teripang mengalami rata-rata pertumbuhan mutlak dan kelangsungan hidup, masing-masing sebesar 18.20 g dan 92.5 %. Gracilaria sp yang dipelihara tidak mengalami pertumbuhan, sedangkan presentase kelangungan hidup Gracilaria sp sebesar 20 %. Berdasarkan hasil penelitian dapat disimpulkan bahwa Polikultur teripang pasir, H. scaba dan rumput laut, Gracilria sp tidak efektif jika Gracilria sp ditebar pada dasar Pen-culture. Kata kunci : Teripang pasir, Gracilaria, Polikultur


1998 ◽  
Vol 37 (1) ◽  
pp. 251-257 ◽  
Author(s):  
Torben Larsen ◽  
Kirsten Broch ◽  
Margit Riis Andersen

The paper describes the results of measurements from a 2 year period on a 95 hectare urban catchment in Aalborg, Denmark. The results of the rain/discharge measurements include 160 storm events corresponding to an accumulated rain depth of totally 753 mm. The water quality measurements include 15 events with time series of concentration of SS, COD, BOD, total nitrogen and total phosphorus. The quality parameters showed significant first flush effects. The paper discusses whether either the event average concentration or the accumulated event mass is the most appropriate way to characterize the quality of the outflow.


2021 ◽  
Vol 13 (22) ◽  
pp. 12377
Author(s):  
Wen-Cheng Liu ◽  
Hong-Ming Liu ◽  
Rita Sau-Wai Yam

In this study, a coupled three-dimensional hydrodynamic-ecological model was developed to comprehensively understand the interaction between the hydrodynamics and ecological status of a lake. The coupled model was utilized to explore the hydrodynamics, water quality, and ecological status in an ecologically rich subalpine lake (i.e., Tsuei-Feng Lake (TFL), located in north-central Taiwan). The measured data of water depth, water temperature, water quality, and planktonic biomass were gathered to validate the coupled model. The simulated results with a three-dimensional hydrodynamic and water quality-ecological model reasonably reproduced the variations in observed water depth, water temperature, water quality, and phytoplankton and zooplankton biomass. Sensitivity analysis was implemented to determine the most influential parameter affecting the planktonic biomass. The results of sensitivity analysis indicated that the predation rate on phytoplankton (PRP) significantly affects the phytoplankton biomass, while the basal metabolism rate of zooplankton (BMZ) importantly affects the zooplankton biomass. Furthermore, inflow discharge was the most important environmental factor dominating the phytoplankton and zooplankton biomass of TFL. This implies that the runoff in the catchment area caused by rainfall and the heavy rainfall induced by climate change may affect the planktonic biomass of the lake.


2021 ◽  
Vol 21 (2) ◽  
pp. 89-104
Author(s):  
Riska Puluhulawa ◽  
Tatag Budiardi ◽  
Iis Diatin ◽  
Irzal Effendi

Efforts to improve the production performance of clown loach in recirculate aquaculture system can be done by increasing stocking density and water discharge. This study aimed to analyze the effect of increasing stocking density and water discharge on production performance, stress response and water quality in order to obtain the best stocking density and water discharge to obtain maximum profit in a short time. A factorial completely randomized design with two factors, i.e. the stocking density of 1, 2, and 3 fish L-1 and the water discharge of 0,05; 0,10; 0,15 L s-1 was performed. The volume of water used in each aquarium was 48 L and using a ½ inch faucet stop to regulate the water discharge from the inlet pipe. Clown fish fed Tubifex sp. with a feeding frequency of two times a day according to the treatment for 60 days. The result indicates that there was no interaction between the two factors on production performance, payback period, and R/C ratio. Stocking density has a significant effect on specific growth rate, absolute growth rate of individual weight, feeding consumption rate and R/C ratio of clown loach. Stocking density and water discharge had an interaction on the visual color of pectoral and caudal fins of clown loach. Different stocking densities with the combination of water discharge in this study resulted that the water quality were within tolerable range for clown loach so that they did not experience stress, as well as high production and business performance. It is recommended to intensify clown loach with a stocking density of 3 fish L-1 and 0,15 L s-1‑ of water discharge.


Author(s):  
Steven E. Suttles ◽  
Neil K. Ganju ◽  
Sandra M. Brosnahan ◽  
Ellyn T. Montgomery ◽  
Patrick J. Dickhudt ◽  
...  

2020 ◽  
Vol 7 (1) ◽  
pp. 75-87
Author(s):  
Ummi Suraya ◽  
Lilia Lilia

This study aims to determine the water condition of Lake Pampait, KamelohBaru Village, Sebangau District, Palangka Raya City, measured from physical and chemical water quality as a measure of the condition of the water quality in Lake Pampait. The study was conducted for approximately 2 (two) months, namely from June to July 2018. Sampling was carried out in 3 (three) stations, namely inlet (station I), middle section (station II) and outlets (station III). The physical and chemical water quality measurements are carried out directly, namely temperature, brightness, depth, pH (Degrees of Acidity) and DO (Dissolved Oxygen) while indirectly or analyzed in the laboratory are PO4 (Phosphate), NO3 (Nitrate) and NH3 (Nitrate) Ammonia). The results of research on physical and chemical water quality is an average temperature of 23.7 oC. Brightness 28.75 cm, Depth 4.25 m, Degree of Acidity (pH) with an average of 6.03, and Dissolved Oxygen (DO) 2.93 mg/L, Phosphate (PO4), Nitrate (NO3), and Ammonia (NH3) ) 0.932 mg/L, it can be concluded that Lake Pampait can be said to be still not polluted and is still considered good for the life of fish and other aquatic organisms.


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