• Journal of the Korean Society for Marine Environment & Energy
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• v.12 no.2
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• pp.96-103
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• 2009

The biodegradability in water of the artificial baits for blue crab pots which were made of intestines of mackerel, tuna and grinded krill were studied. The biodegradability of artificial bait was evaluated with the effective capacity of 10L water tank which was made of acryl pipe at the velocity of 1m/d and hydraulic retention time of 12 hours. For the 23 days operation time, all artificial baits were degraded fast at the early stage of operation time and stabilized within 5 days after start up. The rates of biodegradation were different depending on the raw materials of artificial baits. In terms of degradation rate of organic matter which can be expressed as COD, artificial bait made of tunas intestine showed the fastest degradation rate. On the other hand, in terms of degradation rate of nitrogenous matter which can be expressed as ammonia nitrogen, artificial bait made of mackerels intestine showed the fastest degradation rate. In order to evaluate the effect of artificial bait on marine ecosystem, seawater qualities including SS, COD, DO, nitrogen, phosphorus were determined depending on depth and location during 2 days test operation period. It is apparent that the effect of artificial bait on seawater quality was negligible when comparing seawater quality of test operation area with control area.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.44 no.1
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• pp.20-30
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• 2008

In order to evaluate the biodegradability of bait used in the pot for swimming crab, water tank experiments were conducted. Mackerel is the most commonly used natural form of bait to catch the swimming crabs, and therefore was used in this experiment for the biodegradability according to the manufacturing process of the bait. From the biodegradability test on chemical oxygen demand(COD), total nitrogen(T - N), total phosphorus(T - P), ammoniac nitrogen, nitrite nitrogen and nitrate nitrogen per unit weight of the bait based on the production rate and the accumulated amount of pollutants, it was concluded that the smaller the size of the mackerel pieces, the higher the production rate and accumulated amount of organic matter and nutrients which was unfavorable to water pollution. The amount of pollutants released from the intestine of the tuna was similar with that from the whole mackerel. For the operation period of 111 days, the accumulated concentrations of tested pollutants from the tuna which were 67.3 mgCOD/g d, 86.4 mgT N/g d, 3.1 mgT - P/g d, were almost half comparing with those from the mackerel which were 65.7 - 94.4 mgCOD/g d, 83.8 - 109.4 mgT - N/g d, 3.1 - 5.2 mgT - P/g d. The amount of pollutants released from the intestine of the tuna was slightly less than that from the mackerel that was cut into 8 pieces. but more than that from the mackerel which was not cut into pieces. Therefore, it can be concluded that the key factor in determining water pollution potential is not the kind of bait, but the processing or preparation method used.