所屬科目:水產資源學
2.(20 分 ) The Kobe plot describes statuses of four fish stocks. Please fill in the blank circles with the English letters of A-D. Among the four fish stocks, which one is in the rebuilding condition? Please cxplain why.
3.(20分)The figure below shows the recruitment and stock biomass data (black circles) of a fish stock and a Ricker stock-recruitment curve. Please explain the definitions of"stock biomass" and "recruitment". Why does the recruitment data vary so largely given a fixed stock size? Please explain the biological mechanisms of why the recruitment reaches a maximum before decreasing at higher levels of stock biomass in the Ricker stock-recruitment curve.