Such forage fish already account for nearly a fifth of the world's total annual catch;

这样的饲料鱼已经差不多占每年世界总捕鱼量的五分之一；

Such forage fish already account for nearly a fifth of the world’s total annual catch; another fifth goes to feed pigs and poultry.

这样的饲料鱼已经差不多占每年世界总捕鱼量的五分之一；另有五分之一被用于喂猪和家禽。