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Title: Fish feces reveal diverse nutrient sources for coral reefs
Abstract Consumers mediate nutrient cycling through excretion and egestion across most ecosystems. In nutrient‐poor tropical waters such as coral reefs, nutrient cycling is critical for maintaining productivity. While the cycling of fish‐derived inorganic nutrients via excretion has been extensively investigated, the role of egestion for nutrient cycling has remained poorly explored. We sampled the fecal contents of 570 individual fishes across 40 species, representing six dominant trophic guilds of coral reef fishes in Moorea, French Polynesia. We measured fecal macro‐ (proteins, carbohydrates, lipids) and micro‐ (calcium, copper, iron, magnesium, manganese, zinc) nutrients and compared the fecal nutrient quantity and quality across trophic guilds, taxa, and body size. Macro‐ and micronutrient concentrations in fish feces varied markedly across species. Genera and trophic guild best predicted fecal nutrient concentrations. In addition, nutrient composition in feces was unique among species within both trophic guilds (herbivores and corallivores) and genera (AcanthurusandChaetodon). Particularly, certain coral reef fishes (e.g.,Thalassoma hardwicke,Chromis xanthura,Chaetodon pelewensisandAcanthurus pyroferus) harbored relatively high concentrations of micronutrients (e.g., Mn, Mg, Zn and Fe, respectively) that are known to contribute to ocean productivity and positively impact coral physiological performances. Given the nutrient‐rich profiles across reef fish feces, conserving holistic reef fish communities ensures the availability of nutritional pools on coral reefs. We therefore suggest that better integration of consumer egestion dynamics into food web models and ecosystem‐scale processes will facilitate an improved understanding of coral reef functioning.  more » « less
Award ID(s):
2224354 1547952
PAR ID:
10437556
Author(s) / Creator(s):
 ;  ;  ;  ;  ;  ;  ;  ;  ;  
Publisher / Repository:
Wiley Blackwell (John Wiley & Sons)
Date Published:
Journal Name:
Ecology
Volume:
104
Issue:
8
ISSN:
0012-9658
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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