Komba Jossie KONOYİMA, Percival Arthur Timothy SHOWERS

Sierra Leone'de Karides Balıkçıları Tarafından Avlanan Pembe Karides, Farfantepenaeus notialis İçin Biyolojik Referans Noktalarının Tahmin Edilmesi

Av (ton) ve bolluk verilerinden (t/gün) stok tahmini için veri sınırlı durum-alan Bayesian Av-maksimum Sürdürülebilir Ürün (CMSY) yöntemi kullanılarak, Farfantepenaeus notialis’in av ve çaba verilerinin zaman serileri 'R'de analiz edildi. Çalışma, F.notialis'in durumunu sırasıyla I. dönem (1981-1996) ve II. dönem (2008-2018) olarak belirtilen iki kategoride karşılaştırmıştır. I. dönemde Bayesian Schaefer modeli (BSM) analizine dayalı yönetim için sonuçlar (önceki nisbi biyokütle (B/k) = 0,06; MSY = 2,25t , %95 CL = 1,98 - 2,56; Fmsy = 0,379 yıl-1, %95 CL = 0,29 - 0,495; Bmsy = 5,94t , %95 CL = 4,69 - 7,51; Biyokütle = 4,78t; B/Bmsy = 0,806; Balıkçılık ölüm oranı = 0,583yıl-1 ve Yararlanma oranı, F/Fmsy = 1,54) verirken, II. dönem için sonuçlar (önceki nisbi biyokütle (B/k) = 0,35; MSY = 0,662t, %95 CL = 0,567 - 0,773; Fmsy = 0,421yıl-1, %95 CL = 0,314 - 0,563; Bmsy = 1,58t, %95 CL = 1.22 - 2.04; Biyokütle = 1.09t; B/Bmsy = 0.69; Balıkçılık ölüm oranı = 0.532yr-1 ve Yararlanma oranı, F/Fmsy = 1.27) göstermiştir. Sonuç olarak, tüm tahmini biyolojik referans noktaları, 1989-1996 ve 2008-2018 yıllarında F.notialis'in aşırı avcılık durumunu göstermiştir. Sierra Leone'deki stoklar için stok iyileştirme önlemleri şiddetli olarak tavsiye edilmektedir.

Anahtar Kelimeler:

Bayesian, Yararlanma oranı, Avcılık baskısı, Referans noktası, Stok, Sürdürülebilirlik

Estimating Biological Reference Points of the Pink Shrimp, Farfantepenaeus notialis (Perez-Farfante, 1967) Targeted by Shrimp Trawlers in Sierra Leone

Time series of catch and effort data for Farfantepenaeus notialis were analysed in ‘R’ using a data limited state-space Bayesian Catch-maximum Sustainbale Yield (CMSY) method for stock assessment from catch (tonnes) and abundance data (t/day). The study categorically compared the status of F.notialis in two periods (1981-1996) and (2008-2018) denoted as periods I and II, respectively. Results for management based on Bayesian Schaefer model (BSM) analysis for Period I gave (Prior relative biomass (B/k) = 0.06; MSY = 2.25t , 95% CL = 1.98 - 2.56; Fmsy = 0.379 yr-1 , 95% CL = 0.29 - 0.495; Bmsy = 5.94t , 95% CL = 4.69 - 7.51; Biomass = 4.78t; B/Bmsy = 0.806; Fishing mortality = 0.583yr-1 and Exploitation rate, F/Fmsy = 1.54) while that of Period II showed (Prior relative biomass (B/k) = 0.35; MSY = 0.662t, 95% CL = 0.567 - 0.773; Fmsy = 0.421yr-1 , 95% CL = 0.314 - 0.563; Bmsy = 1.58t , 95% CL = 1.22 - 2.04; Biomass = 1.09t; B/Bmsy = 0.69; Fishing mortality = 0.532yr-1 and Exploitation rate, F/Fmsy = 1.27). By implications, all estimated biological reference points portrayed an overfished status of F.notialis in 1989-1996 and in 2008-2018. Stock recovery measures are strongly advised for the stock in Sierra Leone.

Keywords:

Exploitation, Fishing Pressure, Stock, Sustainability, Bayesian, Referance point,

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