为研究低氧对海洋浮游生物关键种存活、繁殖等的影响,作者采用了实验室模拟低氧环境的方法,研究了低溶解氧(dissolved oxygen,DO)浓度对中华哲水蚤(Calanus sinicus)致死率、产卵和孵化的影响。研究发现,中华哲水蚤对低氧环境比较敏感,当DO质量浓度为2 mg/L左右时,中华哲水蚤会在1h内全部死亡;当DO质量浓度为3 mg/L左右时,中华哲水蚤会在96 h内全部死亡;当DO质量浓度为4-6 mg/L时,基本无死亡,但对中华哲水蚤的产卵有明显抑制作用,首次产卵时间推迟,产卵周期缩短。当DO质量浓度为4 mg/L时,基本不产卵,当DO质量浓度为6 mg/L时,产卵量也仅为常氧组的15%左右。当DO质量浓度为4-6 mg/L时,中华哲水蚤所产卵的孵化率为常氧组的60%左右,但差异不显著。可见,低氧对中华哲水蚤的存活和繁殖均有抑制作用,长时间低氧很可能会降低中华哲水蚤的种群数量,甚至改变海洋生态系统结构。
The mortality rates and reproduction of Calanus sinicus at different concentration of dissolved oxygen(DO) were investigated.The results showed that when DO declined to 2 mg/L,C.sinicus all died in 1 h.When DO declined to 3 mg/L,C.sinicus all died in 96 h.When DO was 4-6 mg/L,basically there was no death.But the spawning rate of C.sinicus could be significantly inhibited under this hypoxia condition.When DO was 4 mg/L,almost no spawn.When DO was 6 mg/L,the total spawning amount was only 15% of nornoxic group.When DO was 4-6 mg/L,the hatching rate was 60% of nomixic group.Therefore,hypoxia inhibits both survival and reproduction of C.sinicus.Long time hypoxia would reduce the population quantities of C.sinicus and even change the structure of ecosystem.