University of Oxford, Department of Zoology, Oxford OX1 3PS, UK; Operation Wallacea, Spilsbury, UK.
University of Oxford, Department of Zoology, Oxford OX1 3PS, UK.
Mar Environ Res. 2018 Mar;134:37-43. doi: 10.1016/j.marenvres.2017.12.013. Epub 2017 Dec 18.
Mesophotic Coral Ecosystems (MCEs) may act as a refuge for impacted shallow reefs as some of the stressors affecting tropical reefs attenuate with depth. A less impacted population at depth could provide recruits to recolonise shallow reefs. Recently, disturbance has been reported on several mesophotic reefs including storm damage, biological invasions, and coral bleaching; calling into question the extent of deep reef refuges. We report on a reciprocal transplant experiment between shallow and mesophotic reefs in the Caribbean, which occurred during a period of coral bleaching. 102 fragments of Agaricia lamarcki were collected down a continuous depth gradient at two sites to a maximum depth of 60m. Fragments were transplanted to either a shallow or mesophotic station at a third site, with controls. This allowed the disaggregation of the effect of the disturbance experienced during the observation period, and any potential acclimation resulting from the historical location of a fragment. Mortality and bleaching were quantitatively assessed. We found the relocation depth of a coral fragment had the strongest effect on both survival and the degree of bleaching recorded. The site a fragment was collected from, and the original collection depth, failed to explain mortality or bleaching with statistical significance. This experiment provides support for the assumption that mesophotic corals may be protected in comparison to shallow reefs, in spite of the potential effects of differing susceptibilities to stress.
中层珊瑚礁生态系统（MCE）可能成为受影响浅海珊瑚礁的避难所，因为一些影响热带珊瑚礁的压力因素随着深度的增加而减弱。在较深的地方，受影响较小的种群可能会为重新殖民浅海珊瑚礁提供新兵。最近，在包括风暴破坏、生物入侵和珊瑚白化在内的几个中层珊瑚礁中都报告了干扰；这使得深层珊瑚礁避难所的范围受到质疑。我们报告了在加勒比地区进行的一次浅海和中层珊瑚礁之间的互惠移植实验，该实验发生在珊瑚白化期间。在两个地点沿着连续的深度梯度采集了 102 块 Agaricia lamarcki 碎片，最大深度达到 60m。将碎片移植到第三个地点的浅水区或中层区，同时设置对照。这使得可以分解在观察期间经历的干扰的影响，以及碎片的历史位置可能导致的任何潜在适应。定量评估了死亡率和白化程度。我们发现珊瑚碎片的重新定位深度对存活率和记录的白化程度有最强的影响。从碎片采集的地点和原始采集深度，无法用统计学意义解释死亡率或白化程度。该实验支持这样的假设，即中层珊瑚可能比浅海珊瑚礁受到保护，尽管存在对压力不同敏感性的潜在影响。
