Meta-analysis about the temperature influence on nitrogen excretion rates of freshwater fish

This dataset was used to conduct a meta-analysis on the effects of temperature on the nitrogen excretion rates of freshwater fish. 

Our results show that increases in temperature leads to increases in nitrogen excretion, however the magnitude of this effect presents high variablility, possibly due to methodological differences between studies.

We found that the range of temperature tested significantly influenced how excretion was affected by temperature increase, with fish that were exposed to the highest temperature differences presenting the highest excretion rates.

Also, the fish feeding status (starved or fed) influenced the effect of temperature increase, with starved fish showing higher excretion rates than fish that were fed before the experiment.

Methods
We conducted a search at the online database ASFA (Aquatic Science and Fisheries Abstracts), Web of Science and Scopus, with the keywords: (warming OR temperature) AND fish* AND freshwater AND (excretion OR excretion rate*), filtering the results for the English language and for Scholarly Journals.

We selected the articles using the following criteria: 1) the study had to be experimental, 2) it had to study at least one species of freshwater fish and 3) it had to measure nitrogen and/or phosphorus excretion under different temperatures.

We reached a total of 27 publications, but because of 1) missing information on the type of error used (standard error or standard deviation), 2) two publications were about the same experiment, so we included only one of them, and 3) one study did not present a means comparison, a total of 24 publications were included in the meta-analysis.