Ozan SOYKAN, Cemil SAĞLAM, İlker AYDIN, Hasan Tuncay KINACIGİL

Ege Denizi dip paragat balıkçılığında iğne ve yem tipinin birim çabada av miktarına etkisi

Bu çalışmada iğne ve yem türlerinin, avlanan balık av kompozisyonu ve birim çabada av miktarı (BÇAM) üzerindeki etkisinin belirlenmesi amaçlanmıştır. İğne ve yem türlerinin av miktarına, birim çabada av miktarına (BÇAM), boy ve ağırlık dağılımlarına etkisi, Ege Denizi’nde kullanılan deneysel dip paragatları ile saptanmıştır. Toplam 12 adet tekrar ile 4800 adet iğne kullanılarak Nisan 2014 ve Eylül 2014 ayları arasında örnekleme yapılmıştır. İki yem tipi olarak Sardalya (Sardina pilchardus Walbaum, 1972) ve Sülünez (Solen marginatus Pulteney, 1799) ve iki iğne tipi olarak J-iğne ve C-iğne test edilmiştir. BÇAM her tür için ve farklı iğne-yem tiplerine göre hesaplanmıştır. 3 aileye ait farklı 9 türden 623 adet balık yakalanmıştır. Toplam avın %60’ından fazlasının sülünez ve %50’den fazlasının J tipi iğne ile yakalandığı bulunmuştur. BÇAM için J tipi iğne ile avcılık istatistiksel olarak önemli değere yakın (p=0.06) ve sülünez ile avcılık istatistiksel olarak önemli (p=0.02) bulunmuştur. Yem türünün BÇAM ve balık boyutu üzerindeki etkisi, iğne türünden daha önemli bulunmuştur. İğne-yem kombinasyonu türlere göre farklılık göstermektedir ve sardalya ile yemlenen C tipi iğne, çalışma alanında en çok hedeflenen balık olan Sparus aurata için en iyi kombinasyon olarak belirlenmiştir. Toplanan veriler için ıskarta oranı ağırlığa göre % 34.0 toplam tür sayısı açısından% 42.5 olarak hesaplanmıştır. Türlerin kondüsyon değeri (K) 1.05 ile 1.68 arasında değişmekte ve yem türüne göre farklılık göstermektedir. Bu çalışmada kullanılan iğne-yem kombinasyonu ile yakalanmış yüksek ticari değeri bulunan türlerin çoğu, yasal avlanma boyu ve cinsi olgunluk çalışmalarına göre, minimum avlanma boyundan büyüktür.

Effect of hook and bait type on catch per unit effort in the Aegean Sea demersal longline fishery

This study aimed to determine the impact of hook and bait type on the catch composition and catch per unit effort. Effects of hook and bait types on catch composition, catch per unit effort (CPUE), length and weight distributions in demersal longline fishery were determined by experimental surveys on demersal longline sets in the Aegean Sea. A total of 12 samplings corresponding to 4800 hook fishing effort were performed between April 2014 and September 2014. Two bait types; sardine (Sardina pilchardus) and grooved razor shell (Solen marginatus) and two hook types; J-hook and C-hook were tested. CPUE values were calculated for each species and assessed between different hook-bait combinations. A total of 623 individuals were captured belonging to 3 families and 9 species. It was found that more than 60% of total catch was captured by grooved razor shell and more than 50% of the total catch was caught with J type hook. J hook was found to be close to significant (p=0.06) and grooved razor shell was found significant (p=0.02) for CPUE. The effect of bait type was found to be more significant than that of hook type for CPUE and length distribution. Hookbait combination differed according to species and C hook baited with sardine was determined to be the best combination for Sparus aurata as the most targeted fish in the study area. Discard ratio was calculated to be 34% in terms of weight and 42.5% in terms of total number of individuals for pooled data. The condition value (K) of the species ranged from 1.05 to 1.68 and differed according to bait type. Most of the high commercial value species caught with any hook-bait combination experimented within this study are larger than minimum fishing length according to minimum landing size regulations of Turkish fishery and maturity studies.

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