Orta ve Doğu Karadeniz'deki çaça balığı (Sprattus sprattus (L. 1758)) stoklarının değerlendirilmesi
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Tarih
2024
Yazarlar
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Cilt Başlığı
Yayıncı
Sinop Üniversitesi
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Bu araştırmada, Orta ve Doğu Karadeniz'deki çaça balığı (Sprattus sprattus (L. 1758)) stokları akustik yöntem ile izlenmiş ve bilimsel olarak kabul görmüş güncel stok değerlendirme modelleri XSA ve SAM ile stokun durumu özetlenmiştir. Elde edilen sonuçlara göre von Bertalanffy büyüme parametreleri 2016-2022 yılları ortalaması L∞=13,40 cm, k=0,43, t0 = -1,370 olarak bulunmuştur. İlk üreme boyu dişiler için 5,99 cm, erkek bireyleri için ise 5,74 cm olarak tahmin edilmiştir. Örneklenen balıkların içerisinde 5,74 cm'den küçük balıkların oranı %0,65 olarak belirlenmiştir. Akustik yöntemle elde edilen veriler incelendiğinde ortalama balık boyları 2016, 2017, 2018, 2019, 2021 ve 2022 yılları için sırasıyla 7,1±1,95 cm, 7,6 ±2,22 cm, 5,8±1,41 cm, 6,9±1,31 cm, 7,2±1,82 cm ve 6,9±1,63 cm olarak belirlenmiştir. Çaça balığı stoklarının 1 mil2 deki biyokütleleri yıllara göre sırasıyla 1,24 ton/nm2, 2,03 ton/nm2, 3,28 ton/nm2, 14,11 ton/nm2, 1,4 ton/nm2 ve 0,76 ton/nm2 olarak tahmin edilmiştir. Modellerin çıktıları incelendiğinde 2022 yılında XSA ve SAM'a göre sırası ile yumurtlayan stok (SSB) 100 994 ile 80 615 ton, stoka katılım 81 761 452 ile 56 543 214 adet ve avcılık baskısı Fbar 0,42 ile 0,8 yıl-1 olarak hesaplanmış, XSA'e göre stoktan yararlanma referans seviyesinde, SAM'a göre ise stokların kullanımı referans seviyesinin (Ebar) üzerine çıkmıştır. 2016-2022 yılları süresince avcılığa bağlı olarak SSB'de ve avlarda dalgalı düşüşler yaşanmış, çaça balığının yaşam periyodu boyunca her 5 yılda bir döngüsel salınım yaptığı görülmüştür. Bu durum ekolojik parametreler ve balıkçılık faaliyetleri kapsamında stokun kendini yenileme periyodu olarak değerlendirilebilir. Ancak, son yıllardaki stok durumu ve avlanma dikkate alındığında, stoktan yararlanma oranı referans seviyesinin altında tutulmalıdır.
In the study, the stocks of sprat (Sprattus sprattus (L. 1758)) in the Central and Eastern Black Sea region were monitored by the acoustic method and the stock status was summarized with the accepted stock evaluation models. According to the results, the growth parameters of the von Bertalanffy as average of the years 2017-2022 were found as L∞=13.40 cm, k=0.43, t0 = -1.370. First breeding length was estimated as 5.99 cm for females and 5.74 cm for males. The percentage of fish smaller than 5.74 cm among the sampled fish was determined as 0.65%. The average fish lengths determined by acoustically recorded data according to years (2016, 2017, 2018, 2019, 2021, 2022) was determined respectively as 7.1±1.95 cm, 7.6 ±2.22 cm, 5.8±1.41 cm, 6.9±1.31 cm, 7.2±1.82 cm and 6.9±1.63 cm. The biomass of sprat stocks in 1 mile2 was predicted according to years respectively as 1.24 tons/Nm2, 2.03 tons/ Nm2, 3.28 tons/ Nm2, 14.11 tons/ Nm2, 1.4 tons/ Nm2 and 0.76 tons/ Nm2. When the outputs of the models are examined, the spawning stock (SSB) for the year 2022 was calculated with XSA and SAM as 100 994 and 80 615 tons, the participation in the stock was 81 761 452 and 56 543 214 units, and the fishing pressure was calculated Fbar 0.42 and 0.8 year-1, and overfishing increased the use of the stocks above the reference level (Ebar). During 2016-2022, there were fluctuating decreases in RCC and prey due to fishing, and it was observed that the sprat made a cyclical oscillation every 5 years during its life period. This situation can be evaluated as the self-renewal period of the stock within the scope of ecological parameters and fishing activities. However, taking into account the stock situation and fishing in recent years, the stock utilization rate should be kept below the reference level.
In the study, the stocks of sprat (Sprattus sprattus (L. 1758)) in the Central and Eastern Black Sea region were monitored by the acoustic method and the stock status was summarized with the accepted stock evaluation models. According to the results, the growth parameters of the von Bertalanffy as average of the years 2017-2022 were found as L∞=13.40 cm, k=0.43, t0 = -1.370. First breeding length was estimated as 5.99 cm for females and 5.74 cm for males. The percentage of fish smaller than 5.74 cm among the sampled fish was determined as 0.65%. The average fish lengths determined by acoustically recorded data according to years (2016, 2017, 2018, 2019, 2021, 2022) was determined respectively as 7.1±1.95 cm, 7.6 ±2.22 cm, 5.8±1.41 cm, 6.9±1.31 cm, 7.2±1.82 cm and 6.9±1.63 cm. The biomass of sprat stocks in 1 mile2 was predicted according to years respectively as 1.24 tons/Nm2, 2.03 tons/ Nm2, 3.28 tons/ Nm2, 14.11 tons/ Nm2, 1.4 tons/ Nm2 and 0.76 tons/ Nm2. When the outputs of the models are examined, the spawning stock (SSB) for the year 2022 was calculated with XSA and SAM as 100 994 and 80 615 tons, the participation in the stock was 81 761 452 and 56 543 214 units, and the fishing pressure was calculated Fbar 0.42 and 0.8 year-1, and overfishing increased the use of the stocks above the reference level (Ebar). During 2016-2022, there were fluctuating decreases in RCC and prey due to fishing, and it was observed that the sprat made a cyclical oscillation every 5 years during its life period. This situation can be evaluated as the self-renewal period of the stock within the scope of ecological parameters and fishing activities. However, taking into account the stock situation and fishing in recent years, the stock utilization rate should be kept below the reference level.
Açıklama
Anahtar Kelimeler
Balıkçılık Teknolojisi, Fisheries Technology
