Length-Weight Relationship and Population Dynamics of Fringescale Sardinella Sardinella fimbriata (Clupeiformes, Clupeidae) from Malampaya Sound, Palawan, Philippines

The study investigated the growth, mortality, exploitation rate and recruitment of Fringescale sardinella (Sardinella fimbriata Valenciennes, 1847) found in Malampaya Sound, Palawan, Philippines. A total of 1200 samples were collected from April 2023 to March 2024. The relationship between length and weight was expressed as y = 0.0291 x 2.561 for combined sex, y = 0.0404 x 2.4254 for males, and y = 0.0355 x 2.4856 for females. The resulting b values pinpoint to a negative allometric growth. The calculated regression model showed a significant association during which the p-values were below 0.0000 and the r2 values ranged between 0.76 and 0.79. Estimation using the FISAT II software resulted in an asymptotic length (L∞) = 16.28 cm, growth rate (K) = 0.68 yr-1, maximum length (Lmax) = 15.78 cm, theoretical age at birth (t0) = –0.5515 years and growth performance index (ɸ’) = 2.256. The estimated average total mortality rate (Z), natural mortality (M), and fishing mortality (F) were 2.69, 1.68, and 1.01 per year, respectively. Recruitment occurs throughout the year and peaks in June. It can be noted that the exploitation is calculated as 0.38, which is considered lightly exploited. To have a sustainable population and avoid overfishing, an optimum total yield (E50) can be set at an exploitation rate of 0.278. The maximum yield (Emax) is at an exploitation rate of 0.421.