scholarly journals Species diversity and dominancy indexes in Izmir Bay (Aegean Sea) purse seine fishery

2020 ◽  
Vol 37 (4) ◽  
pp. 353-356
Author(s):  
Ahmet Mert Senbahar ◽  
Özlem Güleç ◽  
Zafer Tosunoglu
Keyword(s):  
Dominant Species ◽  
Diversity Index ◽  
Aegean Sea ◽  
Purse Seine ◽  
Total Biomass ◽  
Sardina Pilchardus ◽  
Izmir Bay ◽  
Bony Fishes ◽  
Sardinella Aurita ◽  
Purse Seine Fishery

To determine the diversity index values of species caught by purse seine, all samplings were carried out between September 2, 2017, and April 6, 2018 in Izmir Bay. As a result, a total of 17 fish species (Osteichthyes) belonging to 11 families and also 2 species from invertebrates (Cephalopoda and Arthropoda) were determined. Bony fishes and invertebrates consist of 99.9% and 0.1% of the total biomass, respectively. Sardina pilchardus was the most dominated species that occupied as 80.2% of the overall bony fishes followed by Engraulis encrasicolus (14.6%) and Sardinella aurita (1.5%). Diversity index values of species were found-1.026 by Shannon-Weaver and 0.63 by Simpsons, respectively. The highest dominancy was found for S. pilchardus with 71.1%. Overall final results indicate that the diversity of species in Izmir Bay purse seine fishery is very low and also S. pilchardus is the most over-dominant species.

scholarly journals Effects of Lunar Phases and Other Variables on CPUE of European Pilchard, Sardina pilchardus, Caught by Purse Seine in the Eastern Mediterranean

2021 ◽  
Vol 21 (06) ◽  
pp. 283-290
Author(s):  
Zafer Tosunoglu ◽  
Tevfik Ceyhan ◽  
Ozlem Gulec ◽  
Faik Ozan Duzbastilar ◽  
Muharrem Hakan Kaykac ◽  
...  
Keyword(s):  
Eastern Mediterranean ◽  
Aegean Sea ◽  
Purse Seine ◽  
Sardina Pilchardus ◽  
Lunar Phases ◽  
Pelagic Fishes ◽  
The Mean ◽  
The Impact ◽  
Fishing Area ◽  
Purse Seine Fishery

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 fishery to understand the impact of changes on the CPUE of pelagic fishes, especially S. pilchardus, by a total of 214 operations in Izmir Bay, Aegean Sea. The effect of the parameters on the Sardine CPUE, expressed in terms of kg (haul day)–1, was examined by means of the Generalized Additive Modelling (GAMs) techniques. The CPUE values for S. pilchardus were between 0 – 16 800 kg (haul day)–1 and the mean CPUE was 1 844.3±176.6 kg (haul day)–1 . The smallest median was 441 kg (haul day)–1 for full moon and the differences between the CPUE values of lunar phases were statistically significant (p<0.05). Furthermore, there is a linear relationship between CPUE and SST. In conclusion, the CPUE varied under hydrographic variables mostly SST for sardine purse seine fishery in the Aegean Sea.

scholarly journals Retention probability of purse seine grating sieve based on fish morphology

2021 ◽  
Vol 38 (2) ◽  
pp. 173-180
Author(s):  
Zafer Tosunoğlu ◽  
Sinan Mavruk ◽  
Nazlı Kasapoğlu
Keyword(s):  
Simulated Data ◽  
Aegean Sea ◽  
Purse Seine ◽  
Maximum Height ◽  
Sardina Pilchardus ◽  
Maximum Width ◽  
Engraulis Encrasicolus ◽  
Sardinella Aurita ◽  
First Maturity ◽  
Boops Boops

The retention-releasing patterns of the double-grid grating sieve placed on the deck of the purse seiners were revealed for four case species (Sardina pilchardus, Sardinella aurita, Engraulis encrasicolus and Boops boops) using a simulated data predicted from total length (TL) – maximum height (Hmax) and TL – maximum width (Wmax) regressions. To calculate these relationships, samples were collected during commercial purse seine operations between 3 April 2017 and 21 March 2018 in Izmir Bay, Aegean Sea (Turkey). Optimal Bar Spacing (OBS) values corresponding to minimum landing sizes or the length at first maturity were calculated separately for each species. OBS values were found 10.97 mm for sardine (Sardina pilchardus), 11.29 mm for round sardine (Sardinella aurita), 7.78 mm for anchovy (Engraulis encrasicolus) and 17.89 mm for bogue (Boops boops). The bar spacing regulations may constitute a promising management measure to release undersized fish for the purse seine fishery in the Aegean Sea.

scholarly journals Feeding and ecomorphology of three clupeoids in the N Aegean Sea

2013 ◽  
Vol 15 (1) ◽  
pp. 9 ◽  
Author(s):  
P. K. KARACHLE ◽  
K. I. STERGIOU
Keyword(s):  
Trophic Level ◽  
Feeding Habits ◽  
Aegean Sea ◽  
Life Cycles ◽  
Mouth Area ◽  
Morphological Features ◽  
Sardina Pilchardus ◽  
Intestine Length ◽  
Sardinella Aurita ◽  
The Individual

The present study examines the feeding habits of anchovy (Engraulis encrasicolus), sardine (Sardina pilchardus) and round sardinella (Sardinella aurita). The results are combined with previously published information on feeding-related morphological features (i.e. mouth area, intestine length and tail area) in order to explore morphological affinities between species and the effect of ecomorphology on their co-existence. These species were mainly zooplanktivorous and no dietary differences were found with sex and season. Anchovy preyed mainly on Crustacea larvae, whereas sardine and round sardinella on Copepoda. In the majority of cases (>90%), the individual fractional trophic level of all species ranged between 3.0 and 3.5, classifying them as omnivores with preference to animals. The feeding-related morphological features differed between anchovy and the two other species, whereas only intestine length differed between sardine and round sardinella. The fact that round sardinella’s diet and morphology show a greater resemblance to those of sardine, further support the hypothesis that is a particulate feeder as sardine. Hence the three species tend to exploit the same food resources differently throughout the year. Thus, they make best use of the environment and its resources, in order to avoid competition and achieve optimum feeding conditions throughout their life cycles

Soft-bottom crustacean species from Izmir Bay, Aegean Sea, Turkey, with a new alien decapod

Crustaceana ◽  
2016 ◽  
Vol 89 (10) ◽  
pp. 1213-1227
Author(s):  
Alper Doğan ◽  
Kerem Bakir ◽  
Fevzi̇ Kirkim ◽  
Tuncer Katağan
Keyword(s):  
Dominant Species ◽  
Aegean Sea ◽  
Soft Bottom ◽  
Grab Sampling ◽  
Crustacean Species ◽  
Izmir Bay ◽  
Single Station ◽  
De Man ◽  
Number Of Individuals ◽  
First Time

The soft-bottom crustacean fauna from Izmir Bay was studied semi-annually between September 2014 and April 2016. Benthic samples were collected by means of a Van Veen grab, sampling ca. 0.1 m2 area, at 4 stations in the inner (3 stations) and middle (a single station) parts of the bay. Forty-one species and 999 individuals belonging to seven crustacean orders (Sessilia, Mysida, Amphipoda, Cumacea, Tanaidacea, Isopoda, Decapoda) were identified. Amphipoda were represented with the highest number of species (21 species) followed by Isopoda (7) and Decapoda (6). Among the species encountered, Phtisica marina was the most dominant species with an average 90.6 individuals (27.22% of the total number of individuals) while Iphinoe douniae was the most frequent species (occurring in 50% of the samples). Eurycarcinus integrifrons De Man, 1879 is an alien decapod herein reported for the first time from the Aegean Sea.

Crustacea associated with Mytilus galloprovincialis Lamarck, 1819 and Mytilaster minimus (Poli, 1795) (Mollusca, Bivalvia) beds from Izmir Bay, Aegean Sea, Turkey

Crustaceana ◽  
2015 ◽  
Vol 88 (7-8) ◽  
pp. 857-866 ◽  
Author(s):  
Alper Doğan ◽  
Kerem Bakir ◽  
Tuncer Katağan
Keyword(s):  
Dominant Species ◽  
Mytilus Galloprovincialis ◽  
Aegean Sea ◽  
Crustacean Species ◽  
Izmir Bay ◽  
Mussel Beds ◽  
Single Station

The crustacean fauna associated with Mytilus galloprovincialis and Mytilaster minimus (Mollusca, Bivalvia) beds from Izmir Bay was investigated spatially in autumn 2014. Samples were collected by means of a quadrate sampler covering 400 cm2 at four intertidal stations from the inner (3 stations) and outer (a single station) parts of the bay. A total of 831 individuals belonging to 16 species of crustaceans, were collected and identified. Among these, the isopod Paradella dianae was the most dominant species represented with 227 individuals. Paradella dianae and the amphipod Hyale crassipes were the most frequent crustacean species on the mussel beds with 58.33% occurrence. The maximum crustacean biomass (306.29 g/m2) was calculated at station 4. The amphipods Stenothoe gallensis and Elasmopus pectenicrus, and the isopod P. dianae were the alien crustaceans encountered in the present study.

Spatial segregation by size of billfishes bycaught by the tuna purse-seine fishery in the Eastern Pacific Ocean

2021 ◽  
Vol 241 ◽  
pp. 106001
Author(s):  
Osman Crespo-Neto ◽  
Eric Díaz-Delgado ◽  
Tatiana A. Acosta-Pachón ◽  
Raúl O. Martínez-Rincón
Keyword(s):  
Pacific Ocean ◽  
Spatial Segregation ◽  
Eastern Pacific ◽  
Purse Seine ◽  
Eastern Pacific Ocean ◽  
Purse Seine Fishery
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