企鵝的主要食物是小魚和磷蝦,。中國科學(xué)技術(shù)大學(xué)教授孫立廣等人通過分析過去8000年企鵝食譜變化發(fā)現(xiàn)，由于近幾百年人類對海豹和鯨的獵殺,，磷蝦在企鵝食譜中的比重顯著增加,，南極生態(tài)系統(tǒng)正承受人類活動和全球變暖帶來的雙重壓力。這一研究成果9月30日發(fā)表在國際權(quán)威學(xué)術(shù)期刊《自然》子刊《科學(xué)報告》上,。
南極磷蝦是南大洋食物鏈中的關(guān)鍵物種,，對氣候海冰變化極為敏感，氣候溫暖時期數(shù)量偏低,，偏涼時則增加,，間接影響企鵝食譜的變化。
中科大孫立廣,、黃濤研究小組通過分析古今企鵝的骨骼,、羽毛、糞土沉積物等發(fā)現(xiàn),，現(xiàn)代企鵝的氮同位素比值顯著虧損,，表明磷蝦數(shù)量豐富。雖然近百年來全球氣候變暖,，但人類對南極海豹和鯨的獵殺使磷蝦天敵減少,，磷蝦種群密度不降反增。這是人類活動影響海洋生態(tài)系統(tǒng)的典型案例,。
南大洋磷蝦生物量達(dá)10億噸以上,，是人類蛋白質(zhì)資源的重要寶庫。該項研究表明,，自然氣候變化和人類活動都曾對南極磷蝦及海洋食物鏈變化產(chǎn)生過深刻影響,，這對評估未來南極氣候變化下磷蝦的種群動態(tài)及南大洋生物資源保護具有重要科學(xué)價值（生物谷Bioo.com）。
生物谷推薦的英文摘要
Scientific Reports doi:10.1038/srep02807
Penguin tissue as a proxy for relative krill abundance in East Antarctica during the Holocene
Tao Huang,，Liguang Sun,，Nanye Long，Yuhong Wang & Wen Huang
Antarctic krill (Euphausia superba) is a key component of the Southern Ocean food web. It supports a large number of upper trophic-level predators,， and is also a major fishery resource. Understanding changes in krill abundance has long been a priority for research and conservation in the Southern Ocean. In this study,， we performed stable isotope analyses on ancient Adélie penguin tissues and inferred relative krill abundance during the Holocene epoch from paleodiets of Adélie penguin (Pygoscelis adeliae)， using inverse of δ15N (ratio of 15N/14N) value as a proxy. We find that variations in krill abundance during the Holocene are in accord with episodes of regional climate changes,， showing greater krill abundance in cold periods. Moreover,， the low δ15N values found in modern Adélie penguins indicate relatively high krill availability， which supports the hypothesis of krill surplus in modern ages due to recent hunt for krill-eating seals and whales by humans.
