Stressor-response research on stony corals in the laboratory relies on detecting relatively small changes in the size of coral fragments throughout the course of an experiment. Coral colonies are complex, three-dimensional (3D) communities of organisms, so small changes in size are best detected by changes in 3D surface area. Traditional methods to estimate 3D coral surface area commonly require destruction of the sample, thereby eliminating repeat measurements and the ability to calculate growth rate. However, non-destructive two-dimensional (2D) photogrammetry can be used if defensible relationships with 3D surface area can be established. In this study, 165 coral skeletons representing four stony coral species (Pocillopora damicornis, Madracis mirabilis, Orbicella faveolata, Porites porites) were photographed in 2D (top and side views) and then imaged with 3D laser scanning. Significant linear relationships were found between the 3D surface areas (laser) and the sum of various combinations of top and side view surface areas captured by 2D digital photography. The relationships were very strong for simple colony shapes and more variable as coral fragments increased in size and complexity. This study demonstrates an efficient method for obtaining estimates of 3D coral surface area from non-destructive 2D photogrammetry, allowing measurement of growth rate throughout experimental exposure periods.

中文翻译：

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估计小Scleractinian珊瑚的3维表面积。

在实验室中，对石质珊瑚的应激反应研究依赖于在整个实验过程中检测珊瑚碎片大小的较小变化。珊瑚菌落是复杂的生物的三维（3D）群落，因此最好通过3D表面积的变化来检测大小的微小变化。估计3D珊瑚表面积的传统方法通常需要破坏样品，从而消除重复测量和计算生长速率的能力。但是，如果可以建立与3D表面积的可靠关系，则可以使用非破坏性二维（2D）摄影测量。在这项研究中，代表四种石质珊瑚物种（Pocillopora damicornis，Madracis mirabilis，Orbicella faveolata，用2D（俯视图和侧视图）拍照，然后用3D激光扫描成像。发现3D表面积（激光）与2D数字摄影所捕获的顶视图和侧视图表面积的各种组合之和之间存在显着的线性关系。对于简单的殖民地形状，这种关系非常牢固，随着珊瑚碎片的大小和复杂性的增加，它们之间的关系也更加可变。这项研究演示了一种从无损2D摄影测量获得3D珊瑚表面积估计值的有效方法，从而可以测量整个实验暴露时间段的生长速率。对于简单的殖民地形状，这种关系非常牢固，随着珊瑚碎片的大小和复杂性的增加，它们之间的关系也更加可变。这项研究演示了一种从无损2D摄影测量法获得3D珊瑚表面积估计值的有效方法，从而可以测量整个实验暴露时间段的生长速率。对于简单的殖民地形状，这种关系非常牢固，随着珊瑚碎片的大小和复杂性的增加，它们之间的关系也更加可变。这项研究演示了一种从无损2D摄影测量法获得3D珊瑚表面积估计值的有效方法，从而可以测量整个实验暴露时间段的生长速率。