| Building stock enhancement areas is a perfect method to improve the fisheryresource and fishery yield on the base of ecology principles and natural environment.This paper focuses on the sediment characteristic and supplemental feed to growth ofsea cucumber cultured in artificial reef or seagrass bed stock enhancement areas,probe the matter cycle energy flow characteristic of Apostichopus japonicas in foodchain at artificial reef or seagrass bed. Reveal the relationship between the feed ofsea cucumber and environment in the stock enhancement areas. Evaluate the stockenhancement effects of the two typical stock enhancement areas for selecting thebetter site of stock enhancement areas and a better release time or size. The mainresearch results are as follows:Based on the sediment characteristic at artificial reef or seagrass bed stockenhancement areas in Rongcheng Weihai, the difference in total organic carbon(TOC), total nitrogen (TN) content of the sediment before or after aestivation (Juneand December) were compared. While this paper analysis the moisture content,carbonate percentage composition, Chlorophyll a concentration and Spectralcharacteristics. Above all, the paper discussed the bio-availability of the sediment atLidao and Swanlake. We can conclude that, the A. japonicas is animal who has aselected ability to the high content TOC and TN sediment. As illustrated， theorganic content is much higher on June than December, it can make sure the A.japonicas can get a perfect feed then and improve the survival rate after released.Through the TOC/TN ratio, it indicated that the sediment of the two marine ranchingmay main derive from marine algae, the animal can get similar kinds of feed from thesediment on June and December. Spectral characteristics indicated the sediment at two stock enhancement areas was benthic diatom and bacteria bloomed, which willprovide an available food for stocked animals.Stable isotope ratios were used to estimate the diets contribution of sea cucumbercultured in the different stock enhancement areas as the time which is before or afteraestivation (June and December). Research on the δ13C characteristics of thepotential diets resource indicate that the δ13C of zoster marina was changedsignification as the season changed. The δ13C of POM illustrate that the POM inartificial reef area is consist of plankton and macrophyte, and the biomass of theplankton is higher than macrophyte. The computation by the IsoSource softwareindicated that, there were significant changes of the diets in the artificial reef betweenspring and autumn. The main diets contribution of sea cucumber cultured in theartificial reef on June is Epiphyte, zostera marina and macrophyte. The contributionof the three is about18%respectively. But the main diets contribution of seacucumber cultured in the artificial reef on December is zostera marina，which take upabout40%in the diets. The sea cucumber would like to inhabit in the seagrass tofeed the large number of epiphyte attached on the leaves. The main dietscontribution of sea cucumber cultured in the seagrass bed on June is epiphyte andsediment. When the zostera marina and macrophyte come into being degeneratingstage, the A. japonicas main feed zooplankton and sediment.Stable isotope ratios were used to estimate the diets contribution of juvenile seacucumber cultured in the pool, at the same time, the diets contribution of adult seacucumber cultured in the stock enhancement area is estimated. The computation bythe IsoSource software indicated that, the bacteria occupy the highest rate in thejuvenile sea cucumber cultured period. The following is sargassum thunbergii,which contribution is about22.9%. It was significant higher than the compoundfeed. Account for the A. japonicas can digest and feed more sargassum thunbergiithan compound feed. Juveniles actual digestion and absorption proportion ofnutrients from the EM, sargassum thunbergii, compound feed, sea mud is4:2.5:1.The main diets contribution of sea cucumber cultured in the stock enhancement area is Epiphyte, zostera marina and macrophyte. Above all, there were significantchanges of the diets in the pool and stock enhancement area.This paper assesses the ecosystem health to the stock enhancement artificial reefand seagrass bed at Lidao, Rongcheng in accordance with the ecosystem synthesizeassessment model. This is based on the survey dates of each month between years2010to2011in the Lidao Rongcheng artificial reef areas and seagrass bed. Theassessment system of stock enhancement area ecosystem is built on three aspects: theeco-environmental effects, the biology community effects and the ecosystemfunctional effects. The Analytical Hierarchy Process is used to determine the weightof each indicator. The ecosystem health assessment model is built by the SyntheticalIndex Method. The result showed that the ecosystem health index of the artificialreef area and the seagrass bed were0.647and0.563; the artificial reef area isSub-Healthy, the seagrass bed area is in sub-health.In summary, the paper evaluated composition characteristics of sediment in twostock enhancement zone, confirmed the sea cucumber diets mainly come from algaldetritus, benthic diatoms and bacteria; this study confirmed bacteria and algae withhigh contribution rate for growth on juvenile sea cucumber in artificial cultivationstage, tracked and monitored Apostichopus japonicus food composition and source inthe spring or autumn changed with growth of macroalgae (grass) in the two stock ofresources area, pointed out that it is important to artificial cultivation of juvenile in thediet acclimation before releasing. In addition, this paper constructed comprehensiveindex of ecosystem health evaluation model, the comprehensive evaluation resultsshow that, the ecosystem of Lidao artificial reefs and Swan lake seagrass stockenhancement zone are both in good health, we should continue to carry out regulationand conservation method to the artificial stock enhancement zone, for sustainablyproviding a good stock environment for the sea cucumber. |
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