조류는 동물플랑크톤 분포에 다양한 영향을 미치고 있으나 황해처럼 조류가 빠른 곳에서 동물플랑크톤 분포를 조사하는 경우에도 조류의 영향을 무시하고 하는 경우가 많았다. 뿐만 아니라 황해에서 조류의 영향에 따른 동물플랑크톤의 개체수 변화 자료는 많지 않다. 본 연구에서는 강한 조류의 영향을 받는 소난지도 인근해역에서 시간에 따라 동물플랑크톤 가운데 우점하는 Acartia, Calanopia, Calanus, Centropages, Corycaeus, Lab

Three embankments, namely Changpo, Bokkil and Guil, in Chunggye Bay were investigated to assess the influence of environmental changes to phytoplankton size structure, distribution of species and standing crops. Three stations was sampled near at each embankment in Nov. 2006, Feb. 2007, May 2007 and Aug. Phytoplankton were classified into net-size (>20㎛) and nano-size (<20㎛). In summer, the freshwater discharge seemed to have influence in the decrease of salinity and in the increase of turbidity, ammonium and phosphorus concentrations. Chl a concentration and phytoplankton abundance in Feb. 2007 were observed to be generally higher in all stations compared to other periods. Net-size phytoplankton was observed to be higher in Feb. 2007 and May 2007 compared to nano-sized phytoplankton. However, there was shift in phytoplankton composition in Nov. 2006 and Aug. 2007. Phytoplankton under seven class (Bacillariophyceae, Chlorophyceae, Chrysophyceae, Cryptophyceae, Cyanophyceae, Dinophyceae, Euglenophyceae) was identified during the study period. It was found out that the major phytoplankton class was Bacillariophyceae. Phytoplankton was more diverse in autumn compared to any other season. Cyanophyceae was increased in summer. In rainy season, change in physical factors (salinity, transparency) seemed to have more influence on phytoplankton growth compared to inorganic nutrients.

In this paper, the individual number of the future has depended not only upon the present individual number but upon the present individual age, considering the stochastic process model of individual number when the life span of each individual number and the individual age as a set, this becomes a Markovian. Therefore, in this paper the individual is treated as invariable, without depending upon the whole record of each individual since its birth. As a result, suppose N(t), t〉0 be a counting process and also suppose Zn</Tex> denote the life span between the (n-1)st and the nth event of this process, (ngeq1〈/TEX〉) : that is, when the first individual is established at n=1(time, 0), the ZZn</Tex> at time nth individual breaks, down. Random walk Zn〈/Tex〉 is Zn=X1+X2+·s·s+XA, Z0=0</Tex> So, fixed time t, the stochastic model is made up as follows ; A) Recurrence (Regeneration)number between(0.t) Nt=maxn ; Zn≤t B) Forwardrecurrence time(Excess life) T-It=ZNt+1-t C) Backward recurrence time(Current life) T-t=t-ZNt