长江口中华绒螫蟹蟹苗资源的数量波动及其合理利用

本大根据1972年至1997年长江口中华绒螫蟹的成蟹和蟹苗生产统计资料和径流量、温度等环境因子资料,用简单的里克繁殖模型拟合得出其亲体量与补充量的关系为：R＝9．583Pexp(－0．001406P),其最大补充量听对应的亲体量指数为711．2,用考虑环境条件变化的里克繁殖模型拟合得出补充量与环境条件指数、亲体量的关系如下式：Rt＝(55．847－16．122X1－32．1X2－56．46X3＋29．471X4)Ptexp(－0．001406Pt),Rt、Pt分别代表t年的蟹苗产量指数、亲体量指数,X1、X2、X3、X4依次代表当年5月份平均水温指数、当年3月至5月份平均水温指数、前一年12月至当年3月份平均径流量指数、当年5月份平均径流量指数。文中着重指出目前由于过度捕捞所造成的长江口中华绒螫蟹的成蟹和蟹苗资源衰退的严重程度,并为恢复和保护成蟹资源、合理利用长江口天然河蟹蟹苗资源、振兴长江口河蟹渔业,提出看法和建议。

THE ALTERATION AND RATIONAL UTILIZATION OF MEGALOPA RESOURCES OF ERIOCHEIR SINENSES POPULATION IN CHANGJIANG RIVER ESTUARY

On the basis of investigated data of crab and megalopa yield and of environ mental factors, the simple Ricker stock-recruitment model, R = 9. 583P exp (-0.001406P) was obtained. The optimum index of spawning stocks is 711. 2. In the meantime, the Ricker model including variation of environmental factors was given below. Rt = (55. 847 -1 6. 122X,1(t ) - 32. 100X2 (t ) - 56. 460X3 (t ) 29. 471X4 (t) )Pt exp (- 0.001406Pt), Where Rt as index of recruitment, Pt as index of spawning stock, X1 as index of average water temperature in May, X2 as index of average water temperature from March to May, X3 as index of average runoff from last December to March in this year , and X4 as index of average runoff in May. The seriousness of present resources of Chinese mitten-handed crab and its megalopa was discussed. Some regulatory methods of resuming and protecting the crab resources,making rational utilization of resources of nature megalopa and prospering this fishery in Changjiang river estuary were suggested.