Effects of oxygen depletion on field distributions and laboratory survival of the marine copepod Calanus pacificus
Effects of oxygen depletion on field distributions and laboratory survival of the marine copepod Calanus pacificus
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缺氧对海洋桡足类太平洋哲蚌野外分布和实验室生存的影响
DOI：
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
J. Keister
中科院分区：
文献类型：
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作者：
Matthew A. Grodzins;P. Ruz;J. Keister
桡足类在浮游动物中占主导地位，但令人惊讶的是，人们对它们对日益严重的缺氧威胁的耐受性知之甚少。我们测量了花椒类桡足动物Calanus paci fi cus的丰度与田间氧气浓度的关系，并在实验室中确定了其对低溶解氧（DO）的耐受性。在华盛顿州普吉特海湾的季节性缺氧次河口胡德运河，采用深度层网取样法评价了太平洋梭鲈雌蚊的原位分布。没有观察到明显避免DO水平从过饱和降至2.0 mg DO L−1；在我们的采样中，DO水平< 2 mg L−1是罕见的。在实验室中，在13°C下，当DO水平降至1.7 mg DO L−1时，雌性太平洋绒螯蟹的24小时存活率为100%；低于1.5 mg DO L−1时，存活率急剧下降，1.2 mg L−1时存活率为25%，0.9 mg L−1时1小时内完全死亡。太平洋螯虾（Calanus paci fi cus）是北太平洋大部分地区的优势桡足类之一，是生态系统的重要营养环节。我们的测量表明，它们的氧耐受性有一个陡峭的阈值，这与其他类calanoid桡足类动物的测量值相似，这可能会限制它们在严重缺氧的年份的栖息地。
Copepods dominate the zooplankton, but surprisingly little is known of their tolerance to the increasing threat of hypoxia. We measured abundances of the calanoid copepod Calanus paci fi cus in relation to oxygen concentrations in the fi eld and established its tolerance to low dissolved oxygen (DO) in the laboratory. In situ distributions of female C. paci fi cus were assessed with depth-strati fi ed net sampling in Hood Canal, a seasonally hypoxic sub-estuary of Puget Sound, Washington. No clear avoidance of DO levels from supersaturated down to 2.0 mg DO L − 1 was observed; DO levels < 2 mg L − 1 were rare in our sampling. In the lab, at 13 ° C female C. paci fi cus exhibited 100% 24-h survival at DO levels down to 1.7 mg DO L − 1 ; below 1.5 mg DO L − 1 , survival sharply declined, with 25% survival at 1.2 mg L − 1 and complete mortality within 1 h at 0.9 mg L − 1 . Calanus paci fi cus is one of the dominant copepods throughout much of the North Paci fi c and an important trophic link in the ecosystem. Our measurements indicate that they have a steep threshold in oxygen tolerance that is similar to those measured for other calanoid copepods and which could limit their habitat in years of severe oxygen depletion.