Study On The Annual Variation Of The Sea Cucumber Ponds Water In The Estuary

The sea cucumber breeding pond is the main way in the sea cucumber aquaculture,however,The sea cucumber breeding in estuary is on a big scale,and that accounted for 30% of all the sea cucumber breeding area.But in recent years, the diseases of sea cucumber in estuary had happened frequently and always with high mortality.This kind of situation has very bad affect on the healthy development of the estuary sea cucumber breeding pond.so,Study the sea cucumber pond water environment characteristics play an important role in reducing the incidence of the region trepang, and improving the survival rate and yield.This paper studies the waters characteristics of the pond water temperature, salinity, dissolved oxygen, p H and the sea cucumber breeding pond in Qing Dui Zi and the characteristics of tidesi off the coast, in order to understand the change characteristics of the region water environment, provide theoretical basis for the health of the sea cucumber breeding in the region.1. The water temperature characteristics of sea cucumber ponds in estuaryWe analysis the reason of high mortality and lower productivity in the sea cucumber through monitoring periodic change of temperature at the bottom of the pond and water temperature of the sea.The research found that blue waters of trepang pond water temperature variation in the short time within the scope of 10 ~ 20 ℃(only in April, may and October), and within 10 ~ 15 only in April and October, and the pond water temperature is greater than 20 to long(6 ℃ ℃~ 9 months).In this research, the pond water surface and the bottom in February, April, June appear obvious stratification phenomenon.2. The salinity characteristics of sea cucumber ponds in estuary.By monitoring the pond table underlying the salinity and the salinity off the coast of anniversary of changes to the analysis result in the region sea cucumber mortality is high, the reasons for the low yield.The study found that the pond surface for the whole year average salinity is between 17.3 ~ 29.3.Salinity minimum annual August, with an average of 17.3, the following January the highest water temperature, an average of 29.3.Among them, August, September, October salinity is lower than 23.Surface salinity is lower than the bottom, throughout the year in February, march and June table bottom salinity is large, there is an obvious stratification, the most strong stratification, February 2.7, next June, 2.5.3. The dissolved oxygen and p H characteristics of sea cucumber ponds in estuary.Pond in test cycle the mass concentration of dissolved oxygen on the whole, the seasonalchange rule, surface is greater than the underlying dissolved oxygen dissolved oxygen, but both the changing rule of the overall agreement.Dissolved oxygen concentration change between 5.04 ~ 18.56mg/L, the maximum value appeared in the following year in January, the minimum value in the following year in August, the mass concentration of dissolved oxygen present after the first rise to reduce overall trends.Starting in August, the dissolved oxygen concentration increased gradually, in the following peaked in January, and then gradually reduce, in July to reach the lower.p H in a periodic variation on the whole, usually p H greater than the underlying surface.Surface p H range of 7.60 ~ 8.92, the underlying changes in p H range of 7.43~ 8.91, the maximum p H was in October, the following year, the minimum in September.4. The pond farming related tidal estuary sea cucumber featuresAnalyzed the green features of the tide of the, the study found that spring day, February to July, the tidal range is higher than the first half of the second half a month, September to December, the first half of the tidal range is greater than the second half a month;Neap tide, a ~ April and December, tidal range is higher than the first half of the second half a month, five ~ November, the first half of the tidal range is greater than the second half a month.Spring tide during tidal range is big, neap tidal range small during the day.Research shows that the analysis of the study are that the long dormancy time and the short growth time is the one of the reasons that lead the sea cucumber production low in this place. High temperature and low salinity, and the water stratification are the reasons that result sea cucumber in disease frequently in the area. Do not understand the changes of tidal estuary is the primary cause that lead to the above problems happened.