How do coral energy strategies influence their survival?

大多数造礁珊瑚通过光合作用的藻类内共生体获得自养营养，并通过捕食浮游生物利用异养营养。这种灵活的营养策略被认为加强了它们在一系列深度、生境和海洋环境中殖民的能力，这些深度、生境和海洋环境在能量资源供应方面存在差异(Williams等人)。2018年3月生物；福克斯等人。2018当代生物学)。实验室实验表明，异养摄食可能解释了一些珊瑚在具有挑战性的环境中坚持下来的能力，包括高度浑浊的珊瑚礁，那里的阳光迅速减弱。这是因为异养提供了一种有价值的营养来源，支持珊瑚的生长，尽管藻类内共生体对自养的贡献减少了(Grotolli等人。2006自然)。由于近岸水域日益浑浊，海岸变暗，正在影响世界各地的珊瑚礁。然而，我们对珊瑚营养策略如何随着资源可获得性的时空梯度而变化，以及营养可塑性是否使一些珊瑚能够在这些日益具有挑战性的沿海条件下存活下来，知之甚少。确定能够使珊瑚在资源可获得性的梯度上存活的机制是理解珊瑚礁是否以及如何随着我们的沿海水域逐渐变暗而适应的关键(Williams&Graham 2019 Funct Eol)。

Most reef-building corals harness autotrophic nutrition from their photosynthetic algalendosymbionts and heterotrophic nutrition via predation of plankton. This flexible trophic strategyis thought to underpin their ability to colonise a range of depths, habitats and oceanographiccontexts that vary in energetic resource supply (Williams et al. 2018 Mar Biol; Fox et al. 2018Current Biology). Laboratory experiments suggest heterotrophic feeding might explain the abilityof some corals to persist in challenging environments, including highly turbid reefs where sunlightis rapidly attenuated. This is because heterotrophy provides a valuable nutritional source thatsupports coral growth despite reduced autotrophic contributions from the algal endosymbionts(Grotolli et al. 2006 Nature). Coastal darkening, a consequence of increasingly turbid nearshorewaters, is impacting coral reefs worldwide. Nevertheless, we know very little about how coraltrophic strategies vary in response to spatial and temporal gradients in resource availability andwhether trophic plasticity enables some corals to persist under these increasingly challengingcoastal conditions. Identifying mechanisms that enable coral survival across gradients in resourceavailability is key to understanding whether and how coral reefs will adapt as our coastal waterssteadily grow darker (Williams & Graham 2019 Funct Ecol).