Fricke H W, Knauer B
Max-Planck-Institut für Verhaltensphysiologie, 8131, Seewiesen, Germany.
Heizz-Steinitz-Marine Laboratory, Eilat, Israel.
Oecologia. 1986 Dec;71(1):29-37. doi: 10.1007/BF00377316.
This is the first study based on numerical analysis of the abundance of 11 scleractinian corals of depths at between 100-210 m in the Red Sea twilight zone. Two distinct coral communities were found: a Leptoseris fragilis community at a depth of 100-130 m (zone 1) and a Dendrophillia horsti community below 130 m (zone 2, 3). Population densities and coral coverage are very low; distribution of individuals is highly clumped. Highest observed densities on 100 m were 2720 individuals for L. fraglis, 2720 for D. horsti and 2260 for Javania insignis. Calculated coverage rates were maximally 3.6% (L. fragilis), 0.08% (D. horsti) and 0.11% (J. insignis). L. fragilis, the only symbiont bearing coral, was very abundant. It has an unusual depth range for a photosynthesising coral. Coral density is only weakly correlated with hard bottom coverage. Species diversity with an average of 8 species is highest at 120-170 m and decreases in shallower and deeper water. The study depth range is a transient zone for coral distribution. It contains the upper distribution limits of a few "deep sea" corals and the lower ones of several shallower water species. Ahermatypic corals, collected at 160-170 m depth, were transplanted from their original depth to 159, 118, 70 and 40 m; after one year most species survived transplantation far beyond their upper distributional limits. The symbiotic L. fragilis, collected at 120 m, survived transplantation to deep water (159 m) as well as shallow zones (90, 70 and 40 m). The study demonstrates the feasibility of line-transect methods for coral community studies with a submersible.
这是第一项基于红海暮光区100 - 210米深度的11种石珊瑚丰度数值分析的研究。发现了两个不同的珊瑚群落：一个是100 - 130米深度的脆弱细薄星珊瑚群落（区域1），另一个是130米以下的霍氏树珊瑚群落（区域2、3）。种群密度和珊瑚覆盖度非常低；个体分布高度聚集。在100米处观察到的最高密度，脆弱细薄星珊瑚为2720个个体，霍氏树珊瑚为2720个，无显著爪哇珊瑚为2260个。计算得出的覆盖率最高分别为3.6%（脆弱细薄星珊瑚）、0.08%（霍氏树珊瑚）和0.11%（无显著爪哇珊瑚）。脆弱细薄星珊瑚是唯一有共生体的珊瑚，数量非常多。它对于进行光合作用的珊瑚来说，深度范围不寻常。珊瑚密度与硬底覆盖度仅呈弱相关。平均有8个物种的物种多样性在120 - 170米处最高，在较浅和较深水域则降低。研究深度范围是珊瑚分布的一个过渡区域。它包含一些“深海”珊瑚的上部分布界限以及几种浅水物种的下部分布界限。在160 - 170米深度采集的非造礁珊瑚被从其原始深度移植到159米、118米、70米和40米；一年后，大多数物种在远超其分布上限的移植后存活了下来。在120米处采集的共生脆弱细薄星珊瑚，移植到深水（159米）以及浅水区（90米、70米和40米）后均存活。该研究证明了使用潜水器进行珊瑚群落研究的断面线方法的可行性。
