Data collection was conducted in four (4) pre-identified fish landing sites in Zamboanga City. Sampling was conducted every other two days of the month with the third day as a rest day. The strategies used included interviews with fishers and/or boat captains to determine fishing grounds, type of gear used, total catch, and the number of fishing days. Two data collectors per site determine the species, length (total length if small, and fork length on larger fish), and the weight measurements from the one kilo of samples extracted from the total catch. Results show that the CPUE for the whole commercial fisheries subsector averaged 10,890.5 kg/day while the purse seine, which is the most prevalent gear employed, had a higher average CPUE of 14,142 kg/day. Its monthly CPUE was highest in April at 19,800.28 kg/day and lowest in December at 9,624.83 kg/day. The total catch of the commercial subsector for 2013 was 22,855,452.85 kg with April registering the highest at 4,116,650.9 kg and lowest in December at 313,980 kg. Overall, Sardinella lemuru constituted 45.89% of the total commercial sector production for 2013, followed by Amblygaster sirm at 13.19%, Selar crumenophthalmus at 8.93%, Rastrelliger kanagurta at 8.81% and Decapterus macrosomaat 8.17%. The most exploited species was Decapterus macrosoma caught by Purse Seine with an E value of 0.71, followed by Sardinella lemuru with 0.59, Amblygaster sirm with 0.57, and Rastrelliger kanagurta with 0.51. The species Selar crumenophthalmus has the lowest E value at 0.38. The maximum length (Lmax) of S. lemuru, A. sirm, R. kanagurta, and D. macrosoma are much higher than the published values of length at first maturity of subject species. Decapterus macrosoma, S. lemuru, A. sirm, and R. kanagurta all have higher fishing mortality than natural mortality suggestive of overexploitation. Amblygaster sirm and Rastrelliger kanagurta caught by purse seine were both captured before maturity with L25 values of 15.0 cms and 19.0 cm respectively while Sardinella lemuru and Decapterus macrosoma were already matured when captured with values of 15.0 cm and 19.0 cm, respectively. Fishing pressure on the most dominant species, S. lemuru, is high and its maximum length has gone down by as much as 23% over the past decade.
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