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This content will become publicly available on March 1, 2025

Title: Light‐use efficiency for coral reef communities and benthic functional types
Abstract

Coral reef metabolism is dominated by benthic photoautotrophic communities that comprise varying combinations of algae, coral, and sand. Rates of daily gross primary production (GPP) for these benthic functional types (BFTs) are remarkably consistent across biogeographical regions, supporting the idea that reefs exhibit modal metabolism. Most variability in reported rates likely arises from differences in light availability. In fact, GPP is a linear function of incident photosynthetically active radiation (PAR), the fraction of PAR absorbed (fAPAR) by photoautotrophic organisms or communities, and light‐use efficiency (ε), which parameterizes photosynthesizers' biochemical capacity for CO2fixation: GPP = ε × fAPAR × PAR. On time scales of days to weeks, fAPAR andεare far more stable than PAR.εis a critical parameter, because it represents productive response integrated across all environmental conditions, other than light. If BFTs exhibit consistent GPP across wide geographic ranges, then theirεs must also be consistent. The aim of this study was to estimateεfor algae, coral, and sand. Using data collected during NASA's CORAL mission in 2016–2017,εwas calculated for 32 mixed communities at Lizard Island, Australia (10); Kāne'ohe Bay, Hawai'i (8); Guam (6); and Palau (8). Nonnegative least squares was used to solve forεof each BFT, producing values of 0.038, 0.060, and 0.016 C photon−1for algae, coral, and sand, respectively. These values can be used in light‐driven models of reef metabolism. Further work is necessary to refine these estimates and, importantly, to explore howεis affected by environmental conditions.

 
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Award ID(s):
2224354
NSF-PAR ID:
10515864
Author(s) / Creator(s):
; ; ;
Publisher / Repository:
https://mcr.lternet.edu/bibliography
Date Published:
Journal Name:
Limnology and Oceanography
Volume:
69
Issue:
3
ISSN:
0024-3590
Page Range / eLocation ID:
712 to 722
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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