Publications:

Bongaerts et al. 2015


scientific article | Sci Rep | open access

Deep down on a Caribbean reef: lower mesophotic depths harbor a specialized coral-endosymbiont community

Bongaerts P, Frade PR, Hay KB, Englebert N, Latijnhouwers KRW, Bak RPM, Vermeij MJA, Hoegh-Guldberg O



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 (Δ5°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.

Research sites

Keywords
Meta-data
Depth range
60- 100 m

Mesophotic “mentions”
94 x (total of 6374 words)

Fields
Community structure
Biodiversity
Ecology
Molecular ecology

Focusgroups
Scleractinia (Hard Corals)
Symbiodinium (zooxanthellae)

Locations
Curaçao

Platforms
Manned Submersible
Diving - Regular Open-Circuit

Author profiles
Rolf Bak ( 17 pubs)
Pim Bongaerts ( 29 pubs)
Norbert Englebert ( 8 pubs)
Pedro Frade ( 6 pubs)
Mark Vermeij ( 8 pubs)