Nutrient recycling by fish can be an important part of nutrient cycles in both freshwater and marine ecosystems. As a result, understanding the mechanisms that influence excretion elemental ratios of fish is of great importance to a complete understanding of aquatic nutrient cycles. As fish consume a wide range of diets that differ in elemental composition, stoichiometric theory can inform predictions about dietary effects on excretion ratios.
We conducted a meta-analysis to test the effects of diet elemental composition on consumption and nutrient excretion by fish. We examined the relationship between consumption rate and diet N : P across all laboratory studies and calculated effect sizes for each excretion metric to test for significant effects.
Consumption rate of N, but not P, was significantly negatively affected by diet N : P. Effect sizes of diet elemental composition on consumption-specific excretion N, P and N : P in laboratory studies were all significantly different from 0, but effect size for raw excretion N : P was not significantly different from zero in laboratory or field surveys.
Our results highlight the importance of having a mechanistic understanding of the drivers of consumer excretion rates and ratios. We suggest that more research is needed on how consumption and assimilation efficiency vary with N : P and in natural ecosystems in order to further understand mechanistic processes in consumer-driven nutrient recycling.
Details
- Diet Composition Affects the Rate and N:P Ratio of Fish Excretion
- Moody, Eric (Author)
- Corman, Jessica (Author)
- Elser, James (Author)
- Sabo, John (Author)
- College of Liberal Arts and Sciences (Contributor)
- School of Life Sciences (Contributor)
- Julie Ann Wrigley Global Institute of Sustainability (Contributor)
- Digital object identifier: 10.1111/fwb.12500
- Identifier TypeInternational standard serial numberIdentifier Value0046-5070
- Identifier TypeInternational standard serial numberIdentifier Value1365-2427
- This is the peer reviewed version of the article, which has been published in final form at http://dx.doi.org/10.1111/fwb.12500
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Moody, Eric K., Corman, Jessica R., Elser, James J., & Sabo, John L. (2015). Diet composition affects the rate and N:P ratio of fish excretion. FRESHWATER BIOLOGY, 60(3), 456-465. http://dx.doi.org/10.1111/fwb.12500