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Sampling of Jala
Jala is mean fish casting net

This sampling is commonly implemented for shrimp with more 2.5 gram weight with the result that trapped on it mesh. In addition to used for regularly sampling, jala also to be used for incidentally sampling.

Equipment/Tools

Jala with 6 meter diameter size, length 3 - 4 meter, with mesh size depend on location and who it made (mesh size is to be appropriated with shrimp size that become as sampling target).Viewed as sampling equipment, the function of jala is tool for shrimp samples taking.
Plastic bucket that contained water for place of shrimp that will be sampling.
Weight measure equipment ('sit' or 'hang on' model) with 6 kgs capacity as tool for measuring shrimp average body weigth.
Calculator for calculated average body weigth.
Writing kit for documentation of shrimp number and average body weight calculating results and others.

Sampling Stages

Prepared all equipments that to be need like mentioned above in order to sampling process can be implemented with effective.
Fixed one location point as place to throwing jala (on one sampling of jala activity, commonly using several locations in order to get optimal result that hope can be representative of shrimp population on its location.
Throwed jala with opened perfectly, thats mean jala can be open with maximal when it throwed and then wait for the moment in order to jala can reach out at the bottom.
Lift up jala and entry the body of jala with its catched on plastic bucket that contained water. In this moment, the important matter that need to be viewed is impurity profil as bottom indikator.
Detached shrimp from jala mesh at that bucket carefully in order to no happen shrimp physically broken that influence on shrimp quality.
Separating with other water biotas that brought at jala. These water biotas can become indicator of density level and kind of shrimp competitor/predator on the pond.
After detaching process, take litle bucket that contained shrimp samples on weight measure tool ('sit' or 'hang on' model) (make sure that tool on normal condition).
Measure and record total weight of shrimp samples based on weight measure tool.
Measure weight of plastic bucket that contained water in order to know the real total weight of shrimp sample with this manner : result weight of item 8) above minus weight of item 9). For example if weight of item 8) = 3.5 kgs, and weight of item 9) = 1.5 kgs, then real total weight of shrimp sample = 3.5 kgs - 1.5 kgs = 2.0 kgs.
Count total number of shrimp on that buckets and at the same time monitoring in line with condition/quality of shrimp. If fined shrimp with trouble indication, record the problem as decision making matters related with shrimp culture technically or other aspects. The shrimps that have been counting as soon as get back on pond water in order to avoid decreased shrimp samples quality.
Count average body weigth (ABW) with formula : shrimp total weight devide shrimp total number. Example : if shrimp total weight = 2000 grs (2.0 kgs), shrimp total number = 200 pcs, then ABW = 2000 grs : 200 pcs = 10 grs/pcs.
Repeat that above process at several point location on one pond.
Record calculated and monitoring resultas base of decision making process.

Notes :

Throwing jala process on the wter bottom is better implemented by person who have skill/clever to do it with the result that sampling process can be effectively
Sampling jala process is better to be implemented about 2.5 - 3 hours after feeding in order to the shrimp numbers that will be take can effectively because the shrimps still spreading on feeding area with the result that it still on reach out of jala.
Sampling process is better to implemented not on water circulation condition and it good idea for minimalized waterwheel operation with the result jala can opening perfectly because not disturbed water current.
Sampling process is better to implemented as fastly in order to decreasing quality of shrimp samples.

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