Incident light on mesophotic corals is constrained by reef topography and colony morphology
| Autor: | Curtis D. Mobley, Michael P. Lesser, John D. Hedley, Marc Slattery |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
0106 biological sciences
geography geography.geographical_feature_category Ecology 010604 marine biology & hydrobiology fungi technology industry and agriculture Colony morphology biochemical phenomena metabolism and nutrition Aquatic Science Light attenuation 010603 evolutionary biology 01 natural sciences Ray Oceanography population characteristics Reef geographic locations Ecology Evolution Behavior and Systematics Geology |
| Zdroj: | Marine Ecology Progress Series. 670:49-60 |
| ISSN: | 1616-1599 0171-8630 |
| DOI: | 10.3354/meps13756 |
| Popis: | Mesophotic coral reefs, generally defined as deep reefs between 30 and 150 m, are found worldwide and are largely structured by changes in the underwater light field. Additionally, it is increasingly understood that reef-to-reef variability in topography, combined with quantitative and qualitative changes in the underwater light field with increasing depth, significantly influence the observed changes in coral distribution and abundance. Here, we take a modeling approach to examine the effects of the inherent optical properties of the water column on the irradiance that corals are exposed to along a shallow to mesophotic depth gradient. In particular, the roles of reef topography including horizontal, sloping and vertical substrates are quantified, as well as the differences between mounding, plating and branching colony morphologies. Downwelling irradiance and reef topography interact such that for a water mass of similar optical properties, the irradiance reaching the benthos varies significantly with topography (i.e. substrate angle). Coral morphology, however, is also a factor; model results show that isolated hemispherical colonies consistently ‘see’ greater incident irradiances across depths, and throughout the day, compared to plating and branching morphologies. These modeled geometric-based differences in the incident irradiances on different coral morphologies are not, however, consistent with actual depth-dependent distributions of these coral morphotypes, where plating morphologies dominate as you go deeper. Other factors, such as the cost of calcification, arguably contribute to these differences, but irradiance-driven patterns are a strong proximate cause for the observed differences in mesophotic communities on sloping versus vertical reef substrates. |
| Databáze: | OpenAIRE |
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