Celalettin Aydin

Celalettin Aydin
Ege University · Faculty of Fisheries

Professor

About

90
Publications
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722
Citations
Introduction
Fisheries, Selectivty, Sustainibilty

Publications

Publications (90)
Article
Sustainability of natural stocks of crayfish is critical because of their economic and ecological importance. Crayfish (Pontastacus leptodactylus), one of the most important species in Turkish inland fisheries, has been facing serious threats recently. One threat the species faces is high landed bycatch of undersized crayfish because of selective f...
Article
Full-text available
Context Owing to the use of fyke-nets with poor size selectivity in crayfish fishery, 40.7% of the landed undersized catch is discarded as bycatch. Aims This study investigated the effects of using hexagonal mesh (Hex34) instead of diamond nets (Com34) in the traditional crayfish fyke-net and the application of a sorting-grid (SG20, SG25, SG30) an...
Article
Donanımlı dalış, her geçen gün daha da yaygınlaşan bir aktivite olmasına rağmen, gerekli tedbirler alınmadığı takdirde yaralanma veya ölüme neden olabilecek potansiyel riskleri içermektedir. Bu çalışmada İzmir İl’inde donanımlı dalış faaliyetlerinde bulunan eğitmen ve dalgıç profilinin belirlenmesi amaçlanmıştır. Eğitmenlerin ve dalgıçların ortalam...
Article
Full-text available
The narrow-clawed crayfish (Pontastacus leptodactylus) is one of the most ecologically and economically important freshwater species in Turkey. However, the harvest of this species has declined from 7937 t in 1984 to 696 t in 2019. One of primary reasons for this decrease in stock is the use of fishing gears with poor size selectivity. In this stud...
Article
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Discard mortality of European anchovy (Engraulis encrasicolus) and European pilchard (Sardina pilchardus) was investigated during commercial purse seine fishing operations off İzmir Bay, Turkey. In total, 6703 anchovy and 2545 sardine individuals were observed for seven days in five survival experiments carried out from March to October 2019. Only...
Article
Bu çalışma, Norveç ıstakozunun (Nephrops norvegicus) morfolojik özelliklerinden yararlanılarak dip trol balıkçılığında kullanılan farklı torba ağ göz açıklıkları için elde edilebilecek olası L50 seçicilik parametresinin önceden tahmin edilebilmesine yönelik bir ön çalışmayı kapsamaktadır. Laboratuvarda yapılan morfolojik tespit çalışmaları ve sonra...
Article
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In this study, it was investigated that to determine the selectivity of 40 mm square (40S) and 90º turned mesh (40T90) codend for the european hake (Merluccius merluccius) and blue whiting (Micromesistius poutassou). Fishing experiments were conducted on the international waters of the Aegean Sea by using 1200 mesh tailored trawl. Codends have knot...
Article
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European pilchard Sardina pilchardus (Walbaum, 1792) is one of the most dominant small pelagic landed by purse seine in Turkey as well as Mediterranean. In this study, we aimed to identify relationships between the seasonally adjusted CPUE and changes of the sea surface temperature (SST), fishing area, moon phase, and light used in the purse seine...
Article
Full-text available
Balıkçılık kaynaklarının iyi yönetilebilmesi için stok ve avlanan balık miktarı kadar, balıkçılık filosunun ve kullanılan av araçlarının karakteristik yapısının da iyi derecede bilinmesine gereksinim vardır. Bu çalışma, Fethiye Körfezi’nde kullanılan uzatma ağlarının mevcut durumunu ve teknik yapısını ortaya koymayı amaçlamaktadır. Bu sayede ülkemi...
Article
In this study, the catch performance and remaining ratio on fishing hooks of natural alive mud shrimp (Upogebia pusilla) (CCK), siliconized mud shrimp (SCK) and siliconized pellet (SP) were investigated in a longline. The trials were carried out monthly between May 2016 and April 2017 in Zeytinlikuyu district of Kıyıkislacik Village – Milas-Mugla p...
Article
Full-text available
Bu çalışmada, Fethiye Körfezi’nde faaliyet gösteren S.S. Fethiye ve S.S. Göcek-İnlice Su Ürünleri Kooperatiflerine kayıtlı teknelerde kullanılan paraketa ve bazı ticari olta takımının teknik özellikleri, operasyon yöntemleri ve av kompozisyonlarının tespit edilmesi amaçlanmıştır. Takımların teknik özellikleri, donam ve operasyonel özellikleri, avcı...
Article
Full-text available
Sand smelt (Atherina boyeri Risso, 1810), which is an exotic species with invasive character, is the third most caught species in the small-scale fisheries among the inland fisheries in Turkey. The fact that it has become an important source of income for the fishermen with low income due to its export potential has led to the maintenance of its st...
Article
Full-text available
In this study, changes in crayfish production and global production proportion over years were evaluated. In addition, some recommendations were made to increase the yield capacity. According to 2016 FAO data, the world's freshwater crayfish production based on fishing was 15 782 tons and the USA is the first with 5460 tonnes. However, Turkey was l...
Article
The aim of this study was to determine the growth and reproduction characteristics of Upogebia pusilla in the central Aegean Sea. This species is widely used by the commercial and amateur bait fisheries in Turkey. A total of 1949 U. pusilla individuals were taken from İzmir Bay between April 2014 and March 2015. Their total length ranged between 16...
Article
Full-text available
In this study, the level of knowledge of the sea turtles that encounter fishing gears from time to time and the attitudes of fishermen on the Turkish coast of the Aegean Sea to these living beings were investigated. Data were collected from a total of 404 fishermen in 98 fisheries cooperatives in 5 provinces (Çanakkale, Balıkesir, İzmir, Aydın and...
Article
Full-text available
Türkiye’nin Akdeniz sularında 1980’lerin ortalarından beri demersal trol torba seçiciliği üzerine elliden fazla çalışma yürütülmüştür. Bu çalışmada Ege Denizi trol balıkçılığında 3 türün boy seçiciliğini geliştirmek için 3 farklı döndürülmüş ağ göz torbaları araştırılmıştır. Denemeler Doğu Akdeniz’de bulunan Kuşadası Körfezi’nde 19 Ocak ve 29 Mart...
Presentation
Full-text available
It is well known that Mediterranean bottom trawl fisheries is typical multispecies fisheries. And in multispecies fisheries, where several species are caught simultaneously, it is difficult to define the effect of a minimum codend mesh size for towed nets. Historically inadequate (trawl) selection pattern results in high amount of unwanted catches...
Data
Bu çalışmada farklı kokuların balıkları cezbedip etmediği sepet avcılığı ile test edilmiştir. Saha çalışmaları Haziran 2014 ile Mayıs 2016 tarihleri arasında, İzmir Körfezi’nde gerçekleştirilmiştir. Örneklemelerde ülkemizde geleneksel olarak kullanılan üstten girişli metal davul sepetler ve metal gergili yandan girişli ağ sepetler kullanılmıştır. S...
Data
ABSTRACT: In this study; the catching performance and catching efficiency of alive natural mud shrimp, siliconized mud shrimp and siliconized pellet were investigated into fishing with handline and longline fishery. The catching performance and catching efficiency of alive mud shrimp were studied for the first time in Turkey. Moreover, it is also f...
Article
Full-text available
This study investigated the selectivity of 90o turned meshes of 40 mm mesh size with 165 meshes around codend circumferences (40T1), 44 mm meshes size with 300 meshes around codend circumferences (44T1) and 44 mm mesh sizes with 150 meshes around codend circumferences (44T2). Experiments were carried out in the Kuşadası Bay of the Eastern Mediterra...
Article
Full-text available
This paper compares the selectivity of 44 mm diamond mesh codend used in commercial fisheries (D44) and alternative codends 50 mm diamond (D50), a 40 mm square (S40) and a 40 mm 90° turned mesh (T40) for red mullet Mullus barbatus, European hake Merluccius merluccius, Morocco dentex Dentex maroccanus, Atlantic horse mackerel Trachurus trachurus in...
Article
Mortality of non-target flatfishes that had escaped from various sizes (40, 44 and 50 mm) of codend meshes was determined by capturing and holding the escapees in cages for 7 days. Although three flatfish species were studied, sufficient data for detailed analyses were obtained only for Buglossidium luteum (Risso, 1810) (solenette). Trawl hauls (48...
Article
Full-text available
This study was aimed to estimate the selectivity properties of multifilament trammel and gillnets for common carp (Cyprinus carpio L., 1758) in Marmara Lake in Manisa, Turkey. Trammel and gillnets of 4, 6, 8, and 10 cm stretched mesh size and 210 d/2 no twine thickness were tested in the Marmara Lake. In addition, selectivity parameter of 11, 12, 1...
Article
Full-text available
In this study, the selectivity of commercial and alternative (experimental) codends for the deep-water rose shrimp, Parapenaeus longirostris, in the Aegean Sea demersal trawl fishery was investigated. Tested were the 44-mm diamond mesh codend as used in commercial fisheries (D44), in addition to a 50 mm diamond (D50), a 40 mm square (S40), and a 40...
Article
Red mullet (Mullus barbatus) is one of the most important commercial species for the multi-speciesMediterranean demersal trawl fisheries. Several experimental studies have been carried out to assess thecodend size selectivity for red mullet in the last two decades. However, while the number of experiment-based selectivity studies on red mullet are...
Article
Red mullet (Mullus barbatus) is one of the most important commercial species for the multi-species Mediterranean demersal trawl fisheries. Several experimental studies have been carried out to assess the codend size selectivity for red mullet in the last two decades. However, while the number of experiment-based selectivity studies on red mullet ar...
Article
Full-text available
Square mesh windows (SMWs) with 75 (75SMW; 37.5 mm bar length) and 90 mm (90SMW; 45 mm bar length) nominal mesh size were tested for determining size selectivity in dhow prawn fisheries of the Persian Gulf (Hormuzgan province). Fishing trials were conducted on the commercial fishing grounds of Hormuzgan province of the northern Persian Gulf by comm...
Article
Full-text available
Background. Bottom trawling is an important fishing technique for catching demersal fish, and selectivity is one of the most important tools for fishery management. This study aimed to determine the selectivity of 40 mm square- (40S) and 90º turned-mesh (40T90) codend for the deepwater rose shrimp, Parapenaeus longirostris, and greater forkbeard, P...
Article
Full-text available
Improvement of size selectivity of bottom trawl nets by using grid systems. Sorting grids used at length and species selection for experimental purpose can contribute to length selection at bottom trawl fishing. For this aim, sorting grids which has a grid bar space 20 and 15mm, were installed 60 o and 120 o angle attach at the part of cod-end of t...
Article
Full-text available
Araştırmada, sürükleme av araçları grubunda yer alan algarna takımlarının av kompozisyonunun incelenmesi ve bu av takımının balıkçılık ortamında yarattığı etkilerinin belirlenmesi amaçlanmıştır. İzmir Körfezi, Gülbahçe açıklarında birer saatlik 14 geçerli av operasyonu sonucu 21 türün yakalandığı tespit edilmiştir. Bu türlerden ekonomik değere sahi...
Article
A male specimen of Alpheus lobidens De Haan, 1849 was collected on the Aegean coast of Turkey. It is the second Lessepsian species belonging to the genus Alpheus from the Turkish coast of the Aegean Sea.
Book
Full-text available
SÜR-KOOP'un maddi katkılarıyla basılan bu kitap, Ege Üniversitesi Su ürünleri Fakültesi, İzmir Su Ürünleri Kooperatifleri Birliği, Foça Merkez Su Ürünleri Kooperatifi ve Foça Belediyesi'nin desteğiyle organize edilmiş, " Ege Denizi Balıkçılığı ve Balıkçılarımız " konulu çalıştayın sunumlarını, metinlerini ve sonuçlarını içermektedir.
Article
Full-text available
This study investigated the effect of the number of meshes in the protective bag circumference on size selectivity of a demersal trawl codend. Circumferences of 50-mesh (NMPB50) and 215-mesh (NMPB215) protective bags rigged on the 44 mm diamond mesh codend were tested. Fishing experiments were carried out on the commercial trawler ‘Hapuloğlu’ betwe...
Article
Full-text available
On 17 October 2012, an abnormally pigmented specimen of the surmullet Mullus surmuletus L. with a standard length of 164 mm was caught off the coast of Urla in İzmir Bay (Aegean Sea). This is the first report of abnormal pigmentation of the surmullet in the Mediterranean Basin. The sample fish had a patterned blue color on the back and its flanks w...
Article
Full-text available
Seasonal changes in the selectivity of a 40 mm polyethylene trawl codend for common pandora (Pagellus erythrinus) were tested under similar fishing conditions in spring, summer and autumn 2002, and winter 2003. Data were obtained using the covered codend technique and analyzed using a logistic model fitted with the maximum likelihood method. Parame...
Article
The study aimed to evaluate sorting grids of 10 and 15 mm bar spacing specifically for separation of deep water rose shrimp, but including other species, in a Mediterranean multispecies demersal trawl fishery. Data were collected 15–25 October 2008 in Sığacık Bay, Eastern Aegean Sea with the commercial trawler, ‘Hapuloğlu’, using a modified bottom...
Data
Full-text available
Capture Efficiency and Hook Selectivity in Longline: In this study, capture efficiency in longline with straight and reversed fish hook and different bait types were investigated. The data were collected from Bodrum (Muğla) and Urla (İzmir) between July 2007 and June 2011. Experimental longline consisted of 635 m total main line length with made of...
Article
Full-text available
The objective of this study was to determine the length-length, length-width and length-weight relationships in Nephrops norvegicus as a basis for conversions. A total of 659 specimens were collected with trawl gears from the commercial trawler Hapulo lu between the 17th and 21st August 2008 in international waters of the middle Aegean Sea. Morphom...
Article
Full-text available
In this study, the variation of Caulerpa racemosa density depending on different depths and its effects on the diversity of some fish species in catch composition were investigated. The quadrate method was used by divers to determine the variation of density of C. racemosa depending on depth and its possible effects on fish species diversity was de...
Article
Full-text available
The study was aimed to determine length-weight relationship of Eriphia verrucosa (Forskal, 1775) as a basis for conversions. The study was carried out in Izmir Bay, the middle of Aegean sea between October 2008 and January 2009. The experiments were collected by skin divers between. All sampled individuals were sorted according to sex by checking t...
Article
Full-text available
The aim of this study was to determine the selectivity of 40 mm square (40S) and 50 mm diamond (50D) mesh codend for five species, red mullet (Mullus barbatus), annular sea bream (Diplodus annularis), common Pandora (Pagellus erythrinus), axillary sea bream (Pagellus acarne) and blotched picarel (Spicara maena) in the Eastern Mediterranean. Selecti...
Article
Full-text available
This study aimed to determine the survival rates of three fish species, the brown comber (Serranus hepatus), black goby (Gobius niger) and annular seabream (Diplodus annularis), after their escape from a 40 mm stretched diamond mesh polyethylene (PE) codend. Experiments were carried out in the eastern Mediterranean in September 2007 using a convent...
Article
We investigated the survival of red mullet (Mullus barbatus), annular seabream (Diplodus annularis), and blotched picarel (Spicara maena) escaping from 40mm square and 40mm diamond mesh codends in the Aegean Sea. A low mortality for red mullet and blotched picarel was observed, and annular seabream had no mortality for two different codends. Red mu...
Article
Scientific studies have been conducted on size selectivity of trawls with grids in the Mediterranean; however, none has focused on species selectivity. The aim of the present study was to analyze the value of sorting grids with 20 mm bar spacing for species separation, in a demersal trawl fishery mainly targeting deep water rose shrimp (Parapenaeus...
Article
Full-text available
Knowledge on selectivity is considered essential for an adequate management of the trawl fishery. This paper compares the selectivity of conventionally used codends of 44 mm diamond mesh, 40 mm square, and hexagonal mesh for Atlantic horse mackerel, European hake and greater forkbeard in the eastern Mediterranean. Data were collected using the cove...
Article
Full-text available
Temporal variabilities of demersal fish species were analaysed in terms of their numerical abundance in the Izmir Bay. A total of 545559 specimen belonging to eight different families were caught in 2005, covering all the year using a R/V trawl. The contribution of each family was Sparidae (34.38%), Serramdae (22.25%), Bothidae (15.09%), Mullidae (...
Article
Undersized and immature commercially important cephalopods are often inadvertently caught by trawlers in the eastern Mediterranean. To evaluate the effectiveness of different mesh codends (diamond, hexagonal and square) to reduce bycatch of juvenile commercially important Mediterranean cephalopods (European squid Loligo vulgaris, broadtail shortfin...
Article
This study investigates the differences in selectivity of commercially used 44 mm mesh size single and double codends for the deep-water rose shrimp, Parapenaeus longirostris by using the covered codend method. Experiments were conducted on the commercial fishing grounds of Kuşadası Bay and Sığacık Bay of the eastern Aegean Sea, between 3 and 27 Oc...
Article
This study aims to assess the selectivity of square and hexagonal mesh codends for the deep water rose shrimp, Parapenaeus longirostris. Experiments were conducted in Kusadasi Bay and Sigacik Bay, eastern Aegean Sea, between 30 September and 25 October 2007 with a commercial stern trawler. The covered codend technique was used for controlling the e...
Article
Full-text available
This research investigated effects of changing the diamond mesh size on codend selectivity in Mediterranean fisheries. The selectivity of a typical 50-mm diamond knotless polyethylene (PE) codend used in the Turkish fishery in the Aegean Sea was measured for commercially important species, in particular hake (Merluccius merluccius), horse mackerel...
Article
This research investigated effects of changing the diamond mesh size on codend selectivity in Mediterranean fisheries. The selectivity of a typical 50-mm diamond knotless polyethylene (PE) codend used in the Turkish fishery in the Aegean Sea was measured for commercially important species, in particular hake (Merluccius merluccius), horse mackerel...
Article
Sorting grids with two different bar spacings (12 mm and 14 mm) were tested to improve size selectivity of the commercially important fish species, red mullet (Mullus barbatus) and annular sea bream (Diplodus annularis), in Turkish bottom trawl fishery. Fishing trials were carried out with R/V ‘Egesüf’ between April and May 2003 in Izmir Bay, Aegea...
Article
In this study, cod end mesh selectivity of braided polyethylene for the deep-water rose shrimp, Parapenaeus longirostris was investigated in the Aegean Sea. Fishing trials were carried out on the commercial trawler, "Hapuloğlu" between 9 and 12 December 2006. Data were collected by a diamond mesh cod end of the 1200 mesh trawl net commercially used...
Conference Paper
The fish composition of three different depth stratas around Uzunada located in the Izmir Bay (Aegean Sea) were studied by means of monthly trawl surveys between January and December 2005. Samplings were carried out onboard R/V Egesuf (27 m LOA, 500 hp main engine) by employing a conventional bottom trawl commercially used in Turkish waters during...
Article
Full-text available
Poor selectivity of conventional trawl codends has recently been a serious concern in Turkish fisheries. Modification of the codends to reduce the capture of juvenile fish has been one of the management tools for sustainable fisheries. This study investigates effect of square mesh escape window installation on selectivity of bottom trawl codends fo...
Article
Full-text available
The selectivity of 3 trawl codends, (1) a commercially used standard codend, (2) a narrow codend (100 meshes on its circumference instead of 200) and (3) a square mesh top panel codend, was tested for hake (Merluccius merluccius) and poor cod (Trisopterus minutus capelanus) between 8 and 24 October 2003, in the Aegean Sea. Data were collected using...