Ocean acidification but not nutrient enrichment reduces grazing and alters diet preference in Littorina littorea
Ocean acidification but not nutrient enrichment reduces grazing and alters diet preference in Littorina littorea
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DOI：
10.1007/s00227-022-04099-8
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发表时间：
2022-08
期刊：
影响因子：
2.4
通讯作者：
Gordon T. Ober;C. Thornber;J. Grear
中科院分区：
文献类型：
--
作者：
Gordon T. Ober;C. Thornber;J. Grear
海洋酸化和富营养化对许多海洋巨藻的生长具有直接的积极影响，可能导致巨藻繁殖和生态系统结构和功能的转变。然而，大型藻类的生长可能受到食草动物的控制。虽然海洋酸化和富营养化条件下的放牧有不同的响应，但有证据表明这些因素间接增加了消耗。我们测试了一种常见的海洋草食性蜗牛Littorina littorea是否会在海洋酸化（二氧化碳分压增加）和/或富营养化条件下增加大型藻类（UlvaandFucus）的消耗率，通过对活的和重组的藻类菌体进行喂养试验。我们发现，二氧化碳浓度的增加导致蜗牛对活菌的取食率降低，蜗牛几乎只吃ulva。然而，富营养化并不影响活组织的消耗率。此外，在所有处理中，重组藻和褐藻组织消耗的相似性表明，藻类组织的物理特性，而不是组织化学，可能驱动气候变化中的饮食变化。在这个系统中，消耗的减少加上大型藻类生长的增加，最终可能会促进藻类的生长和扩散。
Ocean acidification and eutrophication have direct, positive effects on the growth of many marine macroalgae, potentially resulting in macroalgal blooms and shifts in ecosystem structure and function. Enhanced growth of macroalgae, however, may be controlled by the presence of grazers. While grazing under ocean acidification and eutrophication conditions has variable responses, there is evidence of these factors indirectly increasing consumption. We tested whether a common marine herbivorous snail,Littorina littorea, would increase consumption rates of macroalgae (UlvaandFucus) under ocean acidification (increased pCO2) and/or eutrophication conditions, via feeding trials on live and reconstituted algal thalli. We found that increased pCO2resulted in reduced grazing rates on live thalli, with snails feeding almost exclusively onUlva. However, eutrophication did not impact consumption rates of live tissues. In addition, similarity in consumption of reconstitutedUlvaandFucustissues across all treatments indicated that physical characteristics of algal tissues, rather than tissue chemistry, may drive dietary shifts in a changing climate. In this system, decreased consumption, coupled with increased growth of macroalgae, may ultimately enhance algal growth and spread.