Deep down on a Caribbean reef: lower mesophotic depths harbor a specialized coral-endosymbiont community
Bongaerts, P.; Frade, P.R.; Hay, K.B.; Englebert, N.; Latijnhouwers, K.R.W.; Bak, R.P.M.; Vermeij, M.J.A.; Hoegh-Guldberg, O. (2015). Deep down on a Caribbean reef: lower mesophotic depths harbor a specialized coral-endosymbiont community. NPG Scientific Reports 5(7652): 9 pp. http://dx.doi.org/10.1038/srep07652 In: Scientific Reports (Nature Publishing Group). Nature Publishing Group: London. ISSN 2045-2322; e-ISSN 2045-2322, more |   |
| Authors | | Top | - Bongaerts, P.
- Frade, P.R.
- Hay, K.B.
- Englebert, N.
| - Latijnhouwers, K.R.W.
- Bak, R.P.M., more
- Vermeij, M.J.A.
- Hoegh-Guldberg, O.
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| Abstract | The composition, ecology and environmental conditions of mesophotic coral ecosystems near the lower limits of their bathymetric distributions remain poorly understood. Here we provide the first in-depth assessment of a lower mesophotic coral community (60–100 m) in the Southern Caribbean through visual submersible surveys, genotyping of coral host-endosymbiont assemblages, temperature monitoring and a growth experiment. The lower mesophotic zone harbored a specialized coral community consisting of predominantly Agaricia grahamae, Agaricia undata and a “deep-water” lineage of Madracis pharensis, with large colonies of these species observed close to their lower distribution limit of ~90 m depth. All three species associated with “deep-specialist” photosynthetic endosymbionts (Symbiodinium). Fragments of A. grahamae exhibited growth rates at 60 m similar to those observed for shallow Agaricia colonies (~2–3 cm yr-1), but showed bleaching and (partial) mortality when transplanted to 100 m. We propose that the strong reduction of temperature over depth (?5°C from 40 to 100 m depth) may play an important contributing role in determining lower depth limits of mesophotic coral communities in this region. Rather than a marginal extension of the reef slope, the lower mesophotic represents a specialized community, and as such warrants specific consideration from science and management. |
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