Data for: Fish feces reveal diverse nutrient sources for coral reefs

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-nutrients (calcium, copper,
iron, magnesium, manganese, zinc) 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 (Acanthurus
and Chaetodon). Particularly, certain coral reef fishes (e.g., Thalassoma
hardwicke, Chromis xanthura, Chaetodon pelewensis and Acanthurus
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.