Potential Effects of Different Selectivity Analysis Methods on Selectivity Parameters for Some Fish Species in Gillnet Fishing

Çağdaş Demirdak; Adnan Ayaz

Makale detayları

Potential Effects of Different Selectivity Analysis Methods on Selectivity Parameters for Some Fish Species in Gillnet Fishing

Yazarlar:

Çağdaş Demirdak | Adnan Ayaz

Yayıncı:

Çanakkale Onsekiz Mart University

Ana Başlıklar:

Su Ürünleri Teknolojileri

Dergi:

Çanakkale Onsekiz Mart University Journal of Marine Sciences and Fisheries Vol.7 Issue 1, pp.30-43

Belge Tipi:

Makale

Yayın Tarihi:

10/2024

Belge Dili:

Türkçe

Document ID (Org No.):

2001322765

pISSN:

2651-5326

Anahtar kelimeler:

Özet:

 In this study, the effects of different selectivity analysis methods on selectivity parameters in gill net fishing were investigated. Thirty-one operations were carried out in commercial fishing areas on the coast of Çanakkale. In the trials four different gill nets with mesh sizes of 20, 22, 23 and 25 mm were used. The selectivity analysis was performed for bogue Boops boops and saddled seabream Oblada melanura using both Holt and SELECT methods and the differences in the selectivity parameters were compared. Using Holt selectivity analyses method, modal lengths were calculated as 20,50, 22,55, 23,57 and 25,62 cm for bogue and 9,65, 10,61, 11,09 and 12,06 cm for saddled seabream for the nets with mesh sizes 20, 22, 23 and 25 mm, respectively. Modal lengths of SELECT method were calculated as 19,89, 21,88, 22,87 and 24,86 cm for bogue and 13,55, 14,91, 15,58 and 16,94 cm for saddled seabream for the nets with mesh sizes 20, 22, 23 and 25 mm, respectively. In order to compare Holt and SELECT methods, areas under the selectivity curves SEA and selectivity ranges were calculated. SEA values for bogue indicated that, selectivity curves of Holt method were 37, 25, 20 and 10 bigger than of those of SELECT method for mesh sizes 20, 22, 23 and 25 mm, respectively. Similarly, for the saddled seabream we have found that selectivity curves of Holt method were 41, 29, 24 and 14 bigger than those of SELECT method, for mesh sizes 20, 22, 23 and 25 mm, respectively. As a result, it was determined that different selectivity analysis methods resulted in up to 40 differences, especially for the saddled seabream.

 In this study, the effects of different selectivity analysis methods on selectivity parameters in gill net fishing were investigated. Thirty-one operations were carried out in commercial fishing areas on the coast of Çanakkale. In the trials four different gill nets with mesh sizes of 20, 22, 23 and 25 mm were used. The selectivity analysis was performed for bogue Boops boops and saddled seabream Oblada melanura using both Holt and SELECT methods and the differences in the selectivity parameters were compared. Using Holt selectivity analyses method, modal lengths were calculated as 20,50, 22,55, 23,57 and 25,62 cm for bogue and 9,65, 10,61, 11,09 and 12,06 cm for saddled seabream for the nets with mesh sizes 20, 22, 23 and 25 mm, respectively. Modal lengths of SELECT method were calculated as 19,89, 21,88, 22,87 and 24,86 cm for bogue and 13,55, 14,91, 15,58 and 16,94 cm for saddled seabream for the nets with mesh sizes 20, 22, 23 and 25 mm, respectively. In order to compare Holt and SELECT methods, areas under the selectivity curves SEA and selectivity ranges were calculated. SEA values for bogue indicated that, selectivity curves of Holt method were 37, 25, 20 and 10 bigger than of those of SELECT method for mesh sizes 20, 22, 23 and 25 mm, respectively. Similarly, for the saddled seabream we have found that selectivity curves of Holt method were 41, 29, 24 and 14 bigger than those of SELECT method, for mesh sizes 20, 22, 23 and 25 mm, respectively. As a result, it was determined that different selectivity analysis methods resulted in up to 40 differences, especially for the saddled seabream.

 In this study, the effects of different selectivity analysis methods on selectivity parameters in gill net fishing were investigated. Thirty-one operations were carried out in commercial fishing areas on the coast of Çanakkale. In the trials four different gill nets with mesh sizes of 20, 22, 23 and 25 mm were used. The selectivity analysis was performed for bogue Boops boops and saddled seabream Oblada melanura using both Holt and SELECT methods and the differences in the selectivity parameters were compared. Using Holt selectivity analyses method, modal lengths were calculated as 20,50, 22,55, 23,57 and 25,62 cm for bogue and 9,65, 10,61, 11,09 and 12,06 cm for saddled seabream for the nets with mesh sizes 20, 22, 23 and 25 mm, respectively. Modal lengths of SELECT method were calculated as 19,89, 21,88, 22,87 and 24,86 cm for bogue and 13,55, 14,91, 15,58 and 16,94 cm for saddled seabream for the nets with mesh sizes 20, 22, 23 and 25 mm, respectively. In order to compare Holt and SELECT methods, areas under the selectivity curves SEA and selectivity ranges were calculated. SEA values for bogue indicated that, selectivity curves of Holt method were 37, 25, 20 and 10 bigger than of those of SELECT method for mesh sizes 20, 22, 23 and 25 mm, respectively. Similarly, for the saddled seabream we have found that selectivity curves of Holt method were 41, 29, 24 and 14 bigger than those of SELECT method, for mesh sizes 20, 22, 23 and 25 mm, respectively. As a result, it was determined that different selectivity analysis methods resulted in up to 40 differences, especially for the saddled seabream.

 Bu çalışmada voli yöntemiyle uygulanan uzatma ağlarıyla avcılık sonucunda farklı seçicilik analiz yöntemlerinin seçicilik parametrelerine etkisi araştırılmıştır. Çanakkale kıyılarında farklı ağ göz genişliğindeki 20, 22, 23 ve 25 mm uzatma ağlarıyla toplamda 31 operasyon yapılmıştır. Operasyon sonucunda avlanılan kupes Boops boops ve melanur Oblada melanura balıklarının hem Holt hem de SELECT yöntemiyle seçicilik analizi yapılmış ve seçicilik parametrelerinin farklılıkları karşılaştırılmıştır. Seçicilik analizleri sonucunda tüm ağ göz genişlikleri için Holt yöntemi sonucunda hesaplanan optimum yakalama boyları kupes balıkları için sırasıyla 20,50, 22,55, 23,57 ve 25,62 cm, melanur balıkları için sırasıyla 9,65, 10,61, 11,09 ve 12,06 cmdir. SELECT yöntemiyle yapılan analizler sonucunda tüm ağ göz genişlikleri için hesaplanan optimum yakalama boyları sırasıyla kupes balıkları için 19,89, 21,88, 22,87 ve 24,86 cm, melanur balıkları için 13,55, 14,91, 15,58 ve 16,94 cmdir. Seçicilik analiz yöntemlerinin karşılaştırılması için Holt ve SELECT yöntemiyle oluşturulan seçicilik eğrilerinin altında kalan alanlar SEA ve seçicilik aralığı değerleri hesaplanmıştır. Kupes balıklarının 20, 22, 23 ve 25 mm ağ göz genişliğinde Holt yöntemiyle oluşturulan seçicilik eğrilerinin SEA değerleri, SELECT yöntemi ile oluşturulan seçicilik eğrisinden sırasıyla 37, 25, 20 ve 10 daha büyük olduğu hesaplanmıştır. Melanur balıklarının 20,22,23 ve 25 mm ağ göz genişliğinde Holt yöntemiyle oluşturulan seçicilik eğrilerinin SEA değerleri, SELECT yöntemi ile oluşturulan seçicilik eğrisinden sırasıyla 41, 29, 24, 14 daha büyük olduğu hesaplanmıştır. Çalışma sonucunda farklı seçicilik analiz yöntemlerinin analiz sonuçlarında farklılıklara neden olduğu özellikle melanur gibi yassı balıkların seçicilik parametrelerini 40 kadar değiştirdiği belirlenmiştir.

Makale detayları

Potential Effects of Different Selectivity Analysis Methods on Selectivity Parameters for Some Fish Species in Gillnet Fishing

Yazarlar:

Çağdaş Demirdak | Adnan Ayaz

Yayıncı:

Çanakkale Onsekiz Mart University

Ana Başlıklar:

Su Ürünleri Teknolojileri

Dergi:

Çanakkale Onsekiz Mart University Journal of Marine Sciences and Fisheries Vol.7 Issue 1, pp.30-43

Belge Tipi:

Makale

Yayın Tarihi:

10/2024

Belge Dili:

Türkçe

Document ID (Org No.):

2001322765

pISSN:

2651-5326

Selectivity

Bogue

Saddled seabream

Holt

SELECTSeçicilik

Kupes

Melanur

Holt

SELECT

Sayı

Makale detayları

Yazarlar: Çağdaş Demirdak | Adnan Ayaz

Yayıncı: Çanakkale Onsekiz Mart University

Ana Başlıklar: Su Ürünleri Teknolojileri

Dergi: Çanakkale Onsekiz Mart University Journal of Marine Sciences and Fisheries Vol.7 Issue 1, pp.30-43

Belge Tipi: Makale

Yayın Tarihi: 10/2024

Belge Dili: Türkçe

Document ID (Org No.): 2001322765

pISSN: 2651-5326

Sayı

Yazarlar:

Çağdaş Demirdak | Adnan Ayaz

Yayıncı:

Çanakkale Onsekiz Mart University

Ana Başlıklar:

Su Ürünleri Teknolojileri

Dergi:

Çanakkale Onsekiz Mart University Journal of Marine Sciences and Fisheries Vol.7 Issue 1, pp.30-43

Belge Tipi:

Makale

Yayın Tarihi:

10/2024

Belge Dili:

Türkçe

Document ID (Org No.):

2001322765

pISSN:

2651-5326