fishThe RF models were evaluated with fivefold cross validation. The RF models were evaluated with fivefold cross validation. After the division and reservation of the test data, the information for every class used for modeling were randomly duplicated to reach the greatest sample number for categories 1 to 4 to eliminate bias. The generated data with equal sample numbers for every class were used as the modeling data. RF calculations were performed 5 times each with the test data for k1 to k5. The result files of RF prediction accuracy and significant variables diagnosed by the Gini index were generated, and the common values of RF1 to RF5 were calculated and used as the final RF effects.