報告書番号

V13019

タイトル（和文）

ミズクラゲの個体数変動機構と発生量予測手法に関する文献調査

タイトル（英文）

Literature surveys on moon jellyfish Aurelia aurita s.l. bloom dynamics

概要 （図表や脚注は「報告書全文」に掲載しております）

日本沿岸ではミズクラゲによる臨海発電所の取水障害が生じている．臨海発電所における既往対策の効果向上に資するため，ミズクラゲ個体群変動機構および発生量予測に関する既存知見を整理した．その結果，増殖機構については，主に飼育下で多くの知見が得られているのに対し，減耗機構については知見が乏しいことが明らかとなった．また，既存の発生量予測手法は予測に用いる変数に着目すると大きく2分類できたが，いずれの手法も理論的な裏づけが不十分であり，個体数変動に関する長期の観測データも極めて限られていることから，妥当性や適用性の検証は困難であった．今後，ミズクラゲの発生予測手法を開発するためには，知見の限られているストロビラ～エフィラ期といった初期成長段階における増殖・減耗機構の解明とミズクラゲ個体数の長期データの取得が不可欠である．

概要 （英文）

Moon jellyfish Aurelia aurita s.l. (Cnidaria, Scyphomedusae) blooms have resulted problems at electric power plants in Japanese coast through clogging the cooling water intake systems. Thus, understanding the mechanism of their population dynamics and construction of the predictive models of their blooms is important to prevent the damage of Japanese coastal power plants. We conducted literature surveys mainly on the production and mortality mechanisms of moon jellyfish and the population dynamics of scyphomedusae. As the result, it is revealed the mortality mechanisms of moon jellyfish is poorly understood, especially about their ephyrae stage when they are suggested to survive at a low rate, while the mechanisms of their production have been well researched. In addition, there are few long-term time-series records of the population dynamics of scyphomedusae while more than 10 years is proposed to be necessary for the jellyfish population dynamics analysis, thus robust predictive models of their blooms have not been constructed yet. To understand the mechanisms and construct predictive models of moon jellyfish population dynamics, it requires to elucidate the production and mortality mechanism of moon jellyfish in coastal ocean, especially about their early life stages, and to obtain long-term time-series data records of their population dynamics.

報告者

キーワード