Akın Türker İLKYAZEge University · Faculty of Fisheries
Akın Türker İLKYAZ
Professor
About
74
Publications
28,887
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
633
Citations
Introduction
Additional affiliations
March 2017 - March 2017
January 1995 - present
Publications
Publications (74)
In this study, age, growth, and sex ratio of 342 golden grey mullets, which were caught in fish traps during fishing season were determined. The samples were between 7.5 and 39.5 cm in length and were between 1 and 4 years old. The length-weight relationship for this population was calculated as W=0.01*L2.93, L∞=43.2 cm, K=0.33 yr-1, and to=-0.30 y...
Length-weight relationships were estimated for 11 elasmobranch and 51 teleost fish species caught in Izmir Bay, Turkey. Sampling was carried out from June 2005 to May 2006 at monthly intervals using a bottom trawl net. The mean b-value was calculated as 3.10 (SE = +/- 0.03) and only three species were out of range between 2.5 and 3.5.
A computer program about the calculation of the selectivity parameters in towed fishing gear illustrated with cover cod-end method (L50 Version: 1.0.0): In this study, a computer program, using the statistical methods which use the data that obtained by cover cod-end method, is written to calculate selectivity parameters. L50 selectivity parameter,...
Age estimations were made using otolith length and weight measurements from 3 goby species in the central Aegean Sea: the four-spotted goby (Deltentosteus quadrimaculatus Valenciennes, 1837), the black goby (Gobius niger Linnaeus, 1758), and Fries's goby (Lesueurigobitts friesii Maim, 1874). A total of 266 individual four-spotted gobies, 283 black...
Age, growth, spawning period and maturity of the solenette (Buglossidium luteum Risso, 1810) were studied in the central Aegean Sea to provide fisheries managers with essential data for science-based management. A total of 1220 samples were collected by trawl hauls from July 2004 to June 2007 in İzmir Bay (Turkey). Sample sizes ranging from 5.3 to...
This study exhibits relationships between length-weight and length-length for 21 fish species caught in Izmir Bay. Coefficients a and b for the length-weight relationships (LWRs) and length-length relationships (LLRs) were calculated with W=aLb formulae and as equations of TL=a+bFL and TL=a+bSL respectively. Equations of length-length for convertin...
This study exhibits relationships between length-weight and length-length for 21 fish species caught in Izmir Bay. Coefficients a and b for the length-weight relationships (LWRs) and length-length relationships (LLRs) were calculated with W=aLb formulae and as equations of TL=a+bFL and TL=a+bSL respectively. Equations of length-length for convertin...
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...
ABSTRACT:
The objectives of the present study were to determine length-weight and length-length relationship, and spawning period of blue crab (Callinectes sapidus Rathbun, 1896) in Köyceğiz Lagoon. Sampling period of the study was between June 2017 and May 2018. A total of 1,277 blue crab individuals were sampled. It was determined 67% (n=860) of...
In this study, findings of morphological deformation observed on a blue crab sampled in Köyceğiz Lagoon (Muğla, Turkey) are presented. The deformation is in the left lateral spine. It has been observed that this spine, which normally should have been one, developed as two independent spines. Due to this abnormality observed in the individual, the i...
The goal of this work was to study the influence of dynamite used for blast fishing from July 2006 to July 2007 on marine applications and determine the physico-chemical parameters of seawater before and after blasting off the coast of Hekim Island located in İzmir Bay, Turkey. Field applications consisted of four steps; these were blast operations...
The dataset of the study consists of total length, fork length, head girth, maximum girth and weight measurements of 136 bluefish. The relationship between the total length and fork length of the product was TL=1.1348×FL-0.8184; the relationship between the total length and weight was W=0.0103×L2.97. The relationships between the total length and h...
The aim of this study was to determine the spawning season and length and ages at first maturity lengths of demersal fish species in the central Aegean Sea. Fish samples were collected by bottom trawling in İzmir Bay. Sampling was carried out at monthly intervals over a three-year period. The sample size of 21 species was sufficient to estimate the...
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...
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...
Background. In Turkey, the Mediterranean scaldfish, Arnoglossus laterna (Walbaum, 1792), is a discard fish species and it has a ‘least concern’ status on the IUCN Red List which indicates a low extinction risk. Although there are some studies investigating biology of this species, the knowledge of the mortality rates, spawning period, first maturit...
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...
120 pre-schoolers at 5-6 ages were trained on aquatic animals in various activities which were sponsored by Tübitak. The aim of the project was to determine contribution of the training to children’s awareness of aquculture and fisheries including two questionnaires such as pre and post -studies in tests. Percentage ratios for the first and the las...
Determining the Effects of Aquatic Animals Training on Building Awareness of Pre-school Children
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.
Specimens of European hake were collected by a traditional demersal trawl between July 2004 and June 2007 from İzmir Bay, Central Aegean Sea. A total of 2108 individuals were sampled during the study and the female: male sex ratio of the stock was 1:0.89. The length–weight relationship was W=0.00341L3.24 (R2=0.994) for all individuals. A high gonad...
Background. The bogue, Boops boops (Linnaeus, 1758); large-eye dentex, Dentex macrophthalmus (Bloch, 1791); common two-banded seabream, Diplodus vulgaris (Geoffroy Saint-Hilaire, 1817); and axillary seabream, Pagellus acarne (Risso, 1827) are four commercially important sparid species which are distributed in the Mediterranean. Although they are ve...
The growth and reproduction of brown comber (Serranus hepatus Linnaeus, 1758) were studied using specimens collected from the central Aegean Sea between July 2004 and June 2007. A total of 2410 specimens were analyzed, and of those, 2290 individuals were mature and 120 individuals were juvenile. Analyses covered all individuals because the species...
Determination of Demersal Fish Abundance Distribution of Commercial Fishing Zones and By-catch Amounts of Aegean Sea: In this study it was aimed to determine the distribution of demersal fish abundance and by-catch characteristics of trawl fishery in Aegean Sea. Research was conducted by 9 trawlers and 1200 meshes trawl net. Furthermore sampling pe...
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...
Length distribution, sex ratio, length-weight relationship, age, growth, spawning period, age, and length at first maturity of four-spotted goby inhabiting Izmir Bay were investigated. A total of 1696 four-spotted goby were collected by trawl hauls between July 2004 and June 2007. The size of the fish sampled ranged from 3.1 to 9.2 cm total length....
We investigated the length distribution, sex ratio, sex inversion length, length-weight relationship, age, growth, spawning period, age and length at first maturity of the common pandora inhabiting Izmir Bay. A total of 2654 common pandora were collected by trawl hauls of Izmir Bay (Turkey) between January 2002 and June 2007. The size of the sample...
Growth and reproduction of the blotched picarel, Spicara maena (Linnaeus, 1758), were determined based on specimens (n = 2547) collected from the central Aegean Sea between July 2004 and June 2007. The samples consisted of 71.9% females, 16.2% males, and 11.9% immature individuals. The sex ratio of females to males was 1:0.23. The length-weight rel...
Age, growth, and reproduction of the large-scaled gurnard were studied in the central Aegean Sea to provide fisheries managers with the essential data for science-based management. A total of 2342 samples were collected by trawl hauls between July 2004 and June 2007 from Izmir Bay (Turkey). The size of the samples ranged from 3.4 to 15.2 cm total l...
This study presents the data from a morphologic deformation diagnosis of a speckled ray (Raja polystigma Regan, 1923) individual which was sampled from Izmir Bay. Deformation was located on the head part of the specimen and no deformation was observed in other body regions.
Totally 189 poor cod (Trisopterus minutus Linn., 1758) specimens were collected by trawling in the central Aegean Sea between April 2001 and March 2002. The relationship of the otolith length and weight with the age of poor cod was investigated, as the age determination is relatively difficult by otolith readings. There was a linear relationship be...
A total of 1527 of poor cod (Trisopterus minutus Linn., 1758) were collected by trawl hauls between April 2001 and March 2002 from lzmir Bay (central Aegean Sea). The size of the fish (total length) ranged from 10.6 cm (minimum. September) and 24.8 cm (April). The population was composed of 53% males, 41% females, and 6% immature individuals, with...
Reproduction Characteristics and Determination of Minimum Landing Size of Caramote Prawn (Melicertus kerathurus Forskål, 1775)
In this study, reproduction characteristics and first reproduction length of Caramote Prawn (Melicertus kerathurus Forskål, 1775) were determined. A total of 1663 individuals were sampled during the study. Length and weight...
Determination of the First Maturity Length/Age and Growth Parameters of Demersal Fish Stock in the Aegean Sea from the Fishery Management Point of View:
This study is carried out in İzmir Bay, in between July 2004 and June 2007. Sampled specimens were collected by trawl from Foça, Gülbahçe Bay and northwest of Uzunada. Length measurements and weigh...
Species Identification by Morphological Differences for Picarels (Spicara smaris, S. flexiosa and S. maena) Living Aegean Sea.
Growth Parameters and Mortality Rates of Common Pandora (Pagellus erythrinus Linn., 1758) in İzmir Bay (Aegean Sea).
Age Determination for Common Pandora (Pagellus erythrinus Linn., 1758) with Otolith Cutting Method and Otolith Length - Age and Otolith Weight - Age Relationship.
An Example of Deformation in Rajidae Family.
Gökova Bay, which is located in Mugla in Turkish Aegean Sea, has total area of 52000 hectares, including 24500 hectares territorial waters. This area is one of the eight protected marine areas in Turkey which has been protecting since 1989. This study reports an investigation carried out on set net fishery in two main fishing ports, Akyaka and Akça...
A total of 1527 specimens of poor cod, Trisopterus minutus, was collected by trawl fishing between April 2001 and March 2002 from the Izmir Bay (Middle Aegean Sea). Fish size ranged from 10.6 cm total length (TL, minimum) in September to 24.8 cm TL in April. Of the sampled population 53% were males and 41% females (sex ratio female : male = 1 : 1.3...
In this study, selectivity parameters of 36 and 44 mm mesh sized gill nets were calculated for red mullet (Mullus barbatus Linn., 1758) and annular sea bream (Diplodus annularis Linn., 1758) by using direct estimation method. Alive specimens were collected monthly with trawl nets in between June 2004 –May 2005, from the Middle Aegean Sea. Optimum c...
In this study selectivity parameters of annular sea bream (Diplodus annularis Linn., 1758), common two-banded sea bream (Diplodus vulgaris (Geoffroy Saint-Hilaire, 1817), striped red mullet (Mullus surmuletus Linn., 1758), blotched picarel (Spicara maena flexuosa afinesque,
1810), picarel (Spicara smaris Linn., 1758) and painted comber (Serranus s...
Çalışmanın materyalini oluşturan tavuk balığı (Trisopterus minutus capelanus Lacepède, 1800) örnekleri Nisan 2001 – Mart 2002 tarihleri arasında, Orta Ege Denizi’nden trol avcılığı ile toplanmıştır. Araştırmada toplam 189 bireye ait; total boy, otolit boyu ve otolit ağırlığı ölçümü yapılmıştır. Yaş tayini; otolitlerin kesilmesi, zımparalanması ve p...
An equation aimed at appropriateness to our country's conditions for L50 parameter one of the performance criterian of towed fishing gear and to estimate the total fish catch under legal size. The L50 parameter, is one of the major parameter which uses in determination of the codend selectivity parameters in towed fishing gear. Theorically, 50% of...
TÜBİTAK Project Report / TÜBİTAK Proje Raporu
Fish behaviour in relation to bottom trawling: It is now well established that a trawl net does not simply act as a mechanical sieve, sampling only the volume of the water through which it is towed. A given fish, reacts according to its size and species specific behaviour to stimuli presented by various components of the gear. Both fishermen and sc...
Turkish pelagic fish production is 448.500 ton and 30200 ton of this production is obtained from the Aegean Sea and the Mediterranean. While 7% of the Turkish pelagic fish is obtained from these seas, 60% of this production is sardine (Sardina sp.) and 22% is anchovies (Engraulis sp.). To increase the density of the pelagic fish schools living in t...
Survival of Fish After Escape from a Trawl Codend
Red mullet is one of the most important species due to its highly economical value in Turkish fishery. The individuals obtained from Izmir Bay in the study are between I-III age year classes and fork length are 10.3, 13.4 and 15.4 cm by age, respectively. Weight - length relationship of the male+female specimen was W=0.0071L3.29. Von Bertalanffy gr...
Daily growth of otoliths on gilthead sea bream (Sparus aurata L.) larvae: In this study, daily growth of otoliths was observed on gilthead seabream larvae when 1-65 days old, under the controlled conditions. In daily sampling, standart length of larvae and two different otolith, sagittae and lapillus, lengths were measured. Power regression analysi...
In the present study, that carried out in the coastal areas of Izmir Bay in Aegean Sea, totally 1000 metres gillnet were used which are 18, 18, 20, 22, 24, 25, 28, 30, 32, 36 and 38 mm mesh sizes. At the end of the study, 41 different fish species were caught with the nets that has the same hanging ratio but different mesh sizes. Selectivity parame...
A study about evaluation of some growth parameters in fish with a MS-Windows Computer Program (BBP Ver:1.00): This study is a computer program in order to calculate some growth parameters in fish. The program’s name is BBP Ver: 1.00. The program is using of von Bertalanffy Growth Equation (VBGE) to calculate the growth parameters in fish. It calcul...
A preliminary study on the shrimp trawling bycatch in Taşucu Bay (Northeastern Mediterranean): Globally, the highest bycatch and discard rates have been obtained shrimp trawling. It’s known that shrimp trawls that used especially in Eastern Coast of Mediterranean (Turkey) caused to significant discard and bycatch rates, but there is no scientific a...
Bycatch problems in fisheries: Untargeted species or individuals caught during fishing operations have been a cause of loss of income and even danger for fishermen for centuries. Recently, the magnitude of the problem has been brought to the forefront of fisheries science. Unwanted individuals caught during fishing have been defined by “discard”, “...
The selectivity of gill net in different mesh size for Diplodus annularis (Linn., 1758) and Spicara flexuosa (Rafinesque, 1810): In this study, the size selectivitiy of gill nets for D. annularis and S. flexuosa was estimated from samples collected with nets of 18, 20, 22 mm mesh size (nominal bar lenght). Selectivity parameters were estimated usin...
This research was realized in İzmir Bay by the fishing vessel is called Murat Kaptan II from December 1996 to March 1997. In this study, the bottom trawl had used and the codend divided to two panels like trousers. The selectivity effects of the diamond and square mesh are 40 and 44 mm mesh size had examined. In this study, red mullets' and hakes'...
Sea Fishery in Aegean Sea: Nine percent of the Turkish sea fish production is obtained from the Aegean Sea. There are three main types of fisheries, inshore, coastal and lagoon fisheries, in the Aegean Sea. Which is known to have a rich variety of fish species. In this study, problems of the regional fishery as well as the problems between types of...
In this research, computer technology was used in order to make the studies easier for the people related to fish systematic which is one of main subjects about fish products.
For this purpose, a 100% IBM adapted PC/XT computer were used. The computer language used in this study was Turbo Pascal Ver:5.5.
This program may be sufficient for all kinds...
