Heat Index Effect on the Fecundity and Growth of Decapterus macrosoma in the Selected Fishing Waters of Caraga Region, Philippines

The fecundity of fish can be utilized to predict the fish catch in the future becoming to be the most vulnerable to the negative impact of global warming. This study aimed to determine the effect of heat index on the growth and fecundity of D. macrosoma “Budloy” from the selected locations of marine waters in the Caraga region. The study was conducted at Buenavista, Agusan del Norte, Placer Surigao del Norte, and Tandag Surigao del Sur, where Shortfin scad is common. This study used Stratification random sampling to collect the samples. To calculate the present heat index of the sampling areas, present temperature, and humidity during the capture of fish samples were determined. To determine the fecundity, six parameters of D. macrosoma were calculated: length, body weight, total weight of ovary, weight of ovary samples, number of eggs, and maturity stage of D. macrosoma ovaries. In terms of the correlational analysis between heat index and length of D. macrosoma, results showed that there is a moderate positive correlation, with r = .55, p = .000, for heat index and weight, results were found to have a strong positive correlation, with r = .71, p = .000. Based on the findings on the correlation between heat index and fecundity, with r =.007, p = .959, results indicate that although there is a positive correlation between heat index and growth, there is no significant relationship between heat index and fecundity. Based on the computed values of the heat index, growth, and fecundity of D. macrosoma samples in all sites, it is concluded that Buenavista waters have the highest numerical value of the reproductive potential of D. macrosoma as the basis for predicting the fish catch in the future.