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 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 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

scholarly journals An analysis of historical landing data of some pelagic species caught by purse seines in the Aegean Sea

2021 ◽  
Vol 38 (4) ◽  
pp. 417-426
Author(s):  
Zafer Tosunoğlu ◽  
Tevfik Ceyhan
Keyword(s):  
Sustainable Use ◽  
Aegean Sea ◽  
Pelagic Fish ◽  
Historical Period ◽  
Scomber Japonicus ◽  
Sardina Pilchardus ◽  
Fishing Activity ◽  
Pelagic Species ◽  
Almost All ◽  
Boops Boops

The fishing activity with purse seines in the Aegean Sea accounts for almost half of the pelagic fish excluding anchovy (Engraulis encrasicolus Linnaeus, 1758) in Turkey. In this study, we aimed to analyse the catch amounts of some important pelagic species caught by Aegean purse seiners between 1973 and 2019. While mid-1990s are the most captured years for the European pilchard (Sardina pilchardus Walbaum, 1792) in Aegean Sea and also Turkish Seas, this amount has decreased at the level of 10000 mt in the mid-2000s and remained similar amounts up to now. Though European pilchard was the most caught species in the Aegean until 2011, this has changed in favour of anchovy in the last decade. Recently, almost all pelagic species such as mackerel (Scomber scombrus Linnaeus, 1758), chub mackerel (Scomber japonicus Houttuyn, 1782) and bogue (Boops boops Linnaeus, 1758) have been caught from the Aegean Sea in Turkey. In the study, the production of these species in the historical period was tried to be associated with the regulations implemented with circulars and notifications, and the problems preventing the sustainable use of these species that were caught by purse seiners were determined and solutions were proposed for the future.

scholarly journals Gospodarenje sitnom plavom ribom analizom uzoraka ribarskih lovina istočnog dijela Jadranskog mora

2016 ◽  
Vol Special edition (1) ◽  
pp. 245-252
Author(s):  
Bosiljka Mustać ◽  
Lorana Marić
Keyword(s):  
Scomber Japonicus ◽  
Sardina Pilchardus ◽  
Trachurus Trachurus ◽  
Engraulis Encrasicolus ◽  
Sardinella Aurita ◽  
Belone Belone

Plan upravljanja ribolovom se dijelom temelji i na poznavanju bioloških parametara ribljih vrsta. Sitna plava riba je gospodarski iznimno značajna za RH. S obzirom na već zabilježene fluktuacije pojedinih vrsta, preporuča se učestali monitoring populacija svih vrsta sitne plave ribe, uz analizu njihovih ihtioloških parametara. U ovom radu su prikazani rezultati analiza uzoraka ribarskih lovina sitne plave ribe u razdoblju od 2. lipnja 2014. do 22. travnja 2015. godine iz Jadranskog mora. Ukupno je obrađeno 17 uzoraka (N=2377) koji su potjecali iz sljedećih ribolovnih zona (podzona): A (a3), B (b2 i b3), C (c1),E (e2, e5 i e6) i F (f1 i f2) . Promatrajući zastupljenost vrsta u uzorcima, utvrđeno je da je srdela Sardina pilchardus (64,79%) bila najzastupljenija vrsta. Po zastupljenosti je slijedio inćun Engraulis encrasicolus (28,82%), zatim šarun (šnjur) Trachurus trachurus (3,11%), plavica (lokarda) Scomber japonicus (1,73%), srdela golema Sardinella aurita (1,05%), papalina Sparttus sprattus (0,46%) i iglica Belone belone (0,05%). Uredbom vijeća (EZ-a) br. 1967/2006 o mjerama upravljanja za održivo iskorištavanje ribljih resursa u Sredozemnom moru, dane su minimalne lovne dužine za sitnu plavu ribu. Prema podacima ovog istraživanja, nisu uočena prekoračenja minimalnih dozvoljenih lovnih dužina najzastupljenijih vrsta: srdele i inćuna

scholarly journals Reconstructing discards profiles of unreported catches

2018 ◽  
Vol 82 (S1) ◽  
pp. 39 ◽  
Author(s):  
Francisco Leitão ◽  
Vânia Baptista ◽  
Karim Erzini
Keyword(s):  
Purse Seine ◽  
Artisanal Fisheries ◽  
Sardina Pilchardus ◽  
Merluccius Merluccius ◽  
Liza Aurata ◽  
Scomber Colias ◽  
Boops Boops ◽  
Trawl Fisheries ◽  
Belone Belone ◽  
Unreported Catches

In Portugal it has been estimated that unreported catches represent one third of total catches. Herein, information on landings and total unreported catches (discards) by commercial métier were disaggregated into high taxonomic detail using published scientific studies. Fish accounted for 93.5% (115493 t) of overall unreported catches per year, followed by cephalopods (2345 t, 1.9%) and crustaceans (1754 t, 1.4%). Sharks accounted for 1.3% of total unreported catches in weight (1638 t/y). Unreported taxa consisted mostly of the commercial landed fish species: Scomber colias, Boops boops, Trachurus picturatus, T. trachurus, Merluccius merluccius, Sardina pilchardus, Liza aurata and Micromesistius poutassou, which together accounted for 70% of the unreported discarded catches. The number of unreported/discarded species was highest in artisanal fisheries, followed by trawl and purse seine. In artisanal fisheries, L. aurata, S. colias, S. pilchardus, Trachinus draco and B. boops accounted for 76.4% of the unreported discards. B. boops, S. colias and S. pilchardus were also among the most discarded purse seine species, together with Belone belone accounting for 79% of the unreported catches. In trawl fisheries, T. picturatus (16%), M. merluccius (13%), S. colias (13%) and M. poutassou (13%) accounted for 55% of the trawl discarded unreported catches. The discarded species that most contribute to overall unreported catches are those that are most frequently landed and that most contribute to overall landings in weight.

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.

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