Yellow River Delta Spartina Invasion Of Large Benthic Invertebrates Influence

In recent years,mutually spent Spartina and the rice grass is introduced a finevariety to the Yellow River delta,mainly distribute in the area between the Xianhetown and the fifth stake ofthe Dongying city,the bayou ofsmall limpid river,and thetideland of Wudichajian.In the Yellow River delta exposed salt desolate beach theinvasion of the mutually spent Spartina and the rice grass result in the variety oftideland entironment.The variety has obviously effected the large-scale benthos.Take the Yellow River delta as the investigation and study area,take 2005 as theinvestigation datum year.Different seasons and sampling area effect the vertebrate'spopulation structure , density distribution , biomass distribution and speciesmultiplicity,according to this reason,discuss the influence of large-scale benthoscaused byinvasion of the rice grass.Analysis the water quality and bottom quality on the physics and chemistry.Theresult shows that the water quality of three sampling areas neither conform to therequirement the second kind seawater quality standard.The water quality of starfishand seashell breed aquatics spot in Dongying is mainly polluted by oil,the waterquality of Chajian,Wudi is polluted by sulphide and phosphate,and the pollution ofthe water quality of the the Xiao Qing River is the heaviest,the contamination mostlyis oil,sulphide,phosphat and COD,the dissolved oxygen did not conform to therequirement either.Especially the concentration of phosphate has exceeded four timesOf the founh kind seawater standard.The result'shows that kalium of starfish andseashell breed aquatics spot.in Dongying superpass the standard,and plumbum,cadmium,zinc,arsenic of the bottom of the Xiao Qing River is overstep the standard.By sampling for three times in a year,collecting 21 kinds of large-scale benthosaltogether which belong to 15 family,9 order,5 class 4 phylum.The number ofmOllusk,the arthropod partly take the first and the second part in the number ofall thelarge-scale benthos. Starfish and seashell breed aquatics spot in Dongying is the area which isinvaded by mutually spent Spartina,and the large-scale benthos in it is Gastropda andPolychaeta,the relativly excessiveness is partly 79 percent and 13.5percent.The dominance community is Cerithidea cingulata(Gmelin),therelativly excessiveness is 70 percent.The Ps ofthe invasion area and thecontrastarea is 0.09,it shows that the bottom-inhabit community is notsimilar.The invasion species in the sampling area of the Xiao Qing Rivermainly is the rice grass,the dominance community of bottom-inhabitinvertebra community is Gastropda and Crustacea,the the relativlyexcessiveness partly is 81.7 percent and 16.2 percent.The dominancecommunity of the large-scale benthos is Umbonium thomasi(Crosse),Assiminea sp . and Helice tientsinensis Rathbum , the relativlyexcessiveness is 62.8 percent,18.8 percent,14.1 percent.The Ps ofthe invasion area and tlle contrast area is 0.04,it shows that thelarge . scale benthos is not similar . The annual average densitydistribution of the large-scale benthos in the three sampling area havedifferent character,annual average density of the invasion area and thecontrast area in seashell breed aquatics spot in Dongying partly is 1 78per square meter and 456 per square mete, and the invasion area isobviously lower than the contrast area.The annual average density of theinvasion area and the contrast area in the Xiao Qing River partly is 272.7per squaremeter and 47.3 per square meter.The annual average densityof the invasion area and the contrast area in Chajian partly is 63.7 persquare meter and 29.3 per square meter, and the invasion area is obviouslyhigher than the contrast area.The distribution of biology quantity hassome relativity of the distribution of biology density.It shows that themutually spent Spartina and the rice grass which invade in the Yellow Riverdelta effects the commumty structure and variety of the large-scalebenthos indifferent degree.