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Çanakkale Onsekiz Mart University Journal of Marine Sciences and Fisheries
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This is an Open Access Journal

Open Access journal
ISSN (Online) 2651-5326
Published by Canakkale Onsekiz Mart University

[2 journals]

Spatial and Temporal Characteristics of Demersal Assemblages in Sığacık
Bay, Central Aegean Sea, Turkey
- Authors: Hakkı DERELİ; M. Alp SALMAN, Okan ÖZAYDIN, Zafer TOSUNOĞLU
  Abstract: This study aimed to determine the spatial and temporal variation of species diversity and CPUE in trawl fisheries in the Central Aegean Sea (Sığacık Bay). The study also aimed to evaluate changes in some biometric parameters (mean and frequency of length) depending on the season and depth for three important commercial species (Parapenaeus longirostris, Nephrops norvegicus and Illex coindetii). Monthly trawl samplings were carried out in three depth strata (0-200; 201-400 and 401-600 m) between May 2008 - April 2009. A total of 111 species were identified including 74 Osteichthyes, 13 Chondrichthyes, 18 Cephalopods and 6 Crustaceans. The highest species diversity and catch per unit effort (CPUE) values were obtained at 201-400 m strata. Among these, Osteichthyes had the highest frequency and CPUE values in all strata and seasons. Summer was the season with the highest CPUE in all groups followed by a decrease until winter due to openning of trawl fisheries in the Autumn. The mean carapace length of P. longirostris, the target species in Sığacık Bay trawl fisheries, increased with depth and this species was more abundant at the 201-400 m strata.
  PubDate: Wed, 29 Dec 2021 00:00:00 +030
Occupational Health and Safety in Fishing Boats in Çanakkale Province
- Authors: Hüseyin Gökhan AYTEPE; Orkun DALYAN, Mehmet PİŞKİN
  Abstract: In this study, the attitudes of fishermen in Çanakkale region towards occupational health and safety measures have been investigated. For this purpose, a questionnaire consisting of 26 questions was conducted in June 2021 with fishermen working in fishing boats registered to Çanakkale Central Port Authority. Data obtained from responses of 103 randomly selected fishermen indicated that 99 participants (96.1%) were male and 63 (61.2%) were married. Fifty two of the participants (50.5%) were between the ages of 25-35. Only 26 (25.2 %) of the participants received higher education. 55 (53.4%) of the participants had 1-5 years of professional experience. Fishermen between the ages of 19-24, with an associate degree and less than 1 year of professional experience gave more positive answers regarding the occupational health and safety efforts in fishing activities compared to those expressed by the personnel in other groups. There was a significant difference between the occupational health and safety perception and age and professional experience variables in fishing activities. The data obtained indicated insufficient efforts on fishing activities by the authorized public organizations and institutions, docking problems of fishing boats, lack of OHS service in fishing activities. Involvement of fishermen in the planning of fisheries related programs and informing employers about the necessity of mandatory OHS services provided by the Ministry of Labor and Social Security may solve identified problems.
  PubDate: Wed, 29 Dec 2021 00:00:00 +030
Ecological Gradients of Epimegafaunal Distribution along The Sectors of
Gulf of İzmir, Aegean Sea
- Authors: Erhan MUTLU
  Abstract: During 2009-2010 epifaunal materials were collected seasonally with a beam trawl from seven fixed stations in the infralittoral of Gulf of Izmir to study spatiotemporal distribution of megabenthic fauna and their ecology. A total 153 megafaunal species were identified belonging to nine phyla, comprised mostly of 54 molluscans, 43 chordates (mostly fish), 20 arthropods, and 18 echinoderms. Nine alien species were recorded. Four species (two fish species, one gastropod and one Asteroidea species) were constant species and 16 species were common species in the study area. Lesueurigobius friesii, Buglossidium luteum, Turritellinella tricarinata and Astropecten irregularis were the most frequently occurred, and Lesueurigobius friesii, Varicorbula gibba, Anomia ephippium, Turritellinella tricarinata and Dentalium sp were the most abundantly occurred species. Excluding the evenness index, faunistic characteristics tended to increase as a factor of depth. Seasonal density (abundance and biomass) was minimal in April and maximal in February, followed by November having 2-fold higher abundance than that inJuly. Faunal assemblages were correlated with regions of the gulf and habitat type. Buglossidium luteum overspread the entire gulf excluding the inner gulf. Varicorbula gibba and Fulvia fragilis, a pollution indicator predominated the inner gulf. Hydrographical parameters and depth were associated to dictate faunal assemblages with difference among the sectors and habitats.
  PubDate: Wed, 29 Dec 2021 00:00:00 +030
Determination of Mortality Rates in Pinna nobilis (Linnaeus, 1758)
Population in The Çanakkale Strait
- Authors: Ata AKSU; Uğur ALTINAĞAÇ, Tekin DEMİRKIRAN
  Abstract: The population of ecologically important Pinna nobilis (Linneaus, 1758), the largest bivalve species of the Mediterranean, has been under serious threat since 2016 as a result of both anthropogenic effects and the epidemic caused by Haplosporidium pinnae. In addition, in recent years P. nobilis mortalities caused by Vibrio sp. infections in the North Aegean Sea have been reported. In this study, the effects of the mass mortalities of P. nobilis observed in the Mediterranean were investigated in the populations in the Dardanelles. For this purpose, P. nobilis populations in 30 different stations were observed and counted along transects between June 2020 and September 2021. Underwater observations were carried out either by scuba diving or free diving depending on the underwater characteristics of the region. Observations based on a total of 2183 minutes of bottom time indicated that mortality rate of pen shells increased to 94.67% in 2021 as compared to 81.15% in 2021. In addition, in a period 1 year, the number of stations with 100% mortality increased from 11 to 14 and the number of stations with no presence of pen shells increased from 3 to 5. The decrease in the total number of live pen shells from 1108 to 207 and the consequent reduction of pen shell density (individual/100 m2) from 13.15 to 9.2 in a period of one year indicate the imminent threat of extinction for P. nobilis in this region. In addition to monitoring studies, aquaculture of pen shells and their transplantation to affected areas should be carried out to mitigate the effects of mass mortalities observed in this region.
  PubDate: Wed, 29 Dec 2021 00:00:00 +030
Evaluation of Sediment Dredging on Heavy Metal Concentrations in Mogan
Lake’s Sediment (Ankara, Turkey)
- Authors: Arzu BİNİCİ; Serap PULATSÜ, Nurbanu BURSA
  Abstract: Sediment dredging (removal), a lake management method, is performed on a regular basis to improve the recreational value of Mogan Lake. The aim of the study is to a) determine heavy metal concentrations (Hg, As, Cd, Cr, Pb, Ni, Cu, and Zn) in the sediment after dredging and make evaluations based on the sediment quality criteria, b) define the potential sources of heavy metals by multivariate analyses, c) shed light on the effectiveness of the dredging in the context of current data. As indicated by the findings from two stations under the influence of mineral processing facilities (station I) and domestic wastewater discharges (station II) taken in May and November, 2020, the mean heavy metal concentrations in the sediment in decreasing order were Cr>Cu>Zn>Ni>Pb>As>Cd>Hg. Cr, Ni, and As levels were found to exceed the probable effect level (PEL) and therefore, the lake sediment was classified as heavily polluted in terms of Cr, Ni, Cu and As. Based on the Spearman’s correlation analysis, Cu-Cd, Zn-Pb, and As-Cd were found to have similar anthropogenic sources. Three main components determined by the principal component analysis also support this result; the differences in heavy metals originating from different anthropogenic sources reflect the environmental pollution diversity and pressure related to the heavy metal accumulation in the lake sediment. Based on our findings, sediment removal in Mogan lake can not be considered as effective intervention. As anthropogenic pollutants persist in the lake basin, sediment should be routinely monitored for heavy metal levels to ensure the lake's sustainable use.
  PubDate: Wed, 29 Dec 2021 00:00:00 +030
Comparison of The Selectivity of Diamond and Square Mesh Codends for Red
Mullet Mullus Barbatus in The Antalya Bay
- Authors: Mehmet Cengiz DEVAL
  Abstract: In this study, the selectivities of commercial 44 mm nominal polyethylene (PE) diamond mesh (PE44DM) and square mesh (PE44SM) codends for red mullet Mullus barbatus fisheries in Antalya Bay, Eastern Mediterranean, were compared and modelled. For this purpose, a conventional bottom trawl of 600 meshes was operated onboard R/V “Akdeniz Su” during night time at 25-50 m depths for a total of 21 hauls. Data were collected using the covered codend technique, and analysed using a logistic equation with maximum likelihood by SELNET software. The PE44DM codend had a higher catch rate (89.6%) and 32.5% of M. barbatus were below the minimum landing size whereas catch rates decreased to 42.1% and 9.9%, respectively, in the PE44SM codend. Changing from the diamond mesh to square mesh codend increased the mean L50 and SA values from 8.2 to 13.2 cm and from 2.11 to 2.87 cm, respectively. Both L50 and SA values obtained in the present study show a statistically significant increase (no overlap in 95% confidence limits) with a change in the same mesh size codends from diamond to square for M. barbatus. The use of the PE44SM codend resulted in a significant improvement in the selectivity of M. barbatus compared to the currently used PE44DM codend with a very low escape ratio (10%).
  PubDate: Wed, 29 Dec 2021 00:00:00 +030
The Effects of Some Physico-Chemical Parameters and Seasons on Fish
- Authors: Cemil SAĞLAM; Okan AKYOL
  Abstract: The study was carried out monthly between 2014 and 2016 in Akköy Lagoon, Southern Aegean Sea. Experimental beach seine net was used to determine the species diversity in the lagoon. Fishing operations were carried out in triplicate at two different stations. Sea surface temperature (°C), salinity (‰), dissolved oxygen (mg.l-1) and pH were measured. Abundance, species richness (S) and Shannon (H) index values were computed to determine species diversity. A total of 1878 fish specimens from 17 species belonging to 9 families were captured by the beach seine net. The Mugilidae family with five species was represented by the highest catch rates among all the families. According to Canonical Correspondence Analysis (CCA), the diversities of fish species were strongly influenced by environmental parameters. Results indicated that Chelon ramada, Mugil cephalus and Chelon saliens were dominant in the winter and autumn and showed positive correlation with DO. Chelon auratus and Sparus aurata were dominant in the spring and Solea solea, Chelon labrosus, Lithognathus mormyrus, Sardina pilchardus, Boops boops, Zosterisessor ophiocephalus, Mullus spp. and Syngnathus spp. were dominant in the summer and showed positive correlation with SST, pH and salinity. Atherina boyeri, Aphanius fasciatus, Blennius spp. and Pomatoschistus spp. were present in all seasons.
  PubDate: Wed, 29 Dec 2021 00:00:00 +030
A Review of the Research on Reproductive Biology of Turkish Marine Fishes
- Authors: İsmail Burak DABAN
  Abstract: The teleost fish stocks distributed in Turkish seas are threatened due to overfishing, pollution, global warming and increasing food competition. There is a need to provide scientific knowledge on reproductive traits of commercial species in order to ensure the sustainability of fish stocks. Parameters related to reproductive biology of fishes such as sex ratio, first sexual maturity length, gonadosomatic index, fecundity and reproductive period are rather effective constituents that should be taken into consideration in the decision making process by fisheries managers. In this study, studies on reproductive biologies of teleost fishes from Turkish waters have been reviewed. A total of 177 studies were compiled that focused on 91 species belonging to 41 families. Reviewed data indicated that existing studies focused on certain fishing areas in the Turkish seas and no information were provided on reproductive biologies of some species. In some species, important parameters such as first sexual maturity length, reproductive period, gonadosomatic index and fecundity were not available.
  PubDate: Wed, 29 Dec 2021 00:00:00 +030
Range Extension of Priacanthus sagittarius Starnes, 1988 Southeastern
Mediterranean Coast of Turkey
- Authors: Mevlüt GÜRLEK; Deniz ERGÜDEN, Cemal TURAN
  Abstract: A single specimen of Priacanthus sagittarius Starnes, 1988 has been captured in the Iskenderun Bay (Konacık, Turkey), at a depth of 80 m in February 2021. This species represents the second record from Turkish waters and the first record from southeastern Mediterranean coast of Turkey. Besides, this species is the fifth successive record from the. The presence of P. sagittarius in the Mediterranean coast of Turkey is evidently due to migration from the Red Sea through the Suez Canal. On the other hand, available records show that this species is gradually expanding its distribution in the Mediterranean.
  PubDate: Wed, 29 Dec 2021 00:00:00 +030
Investigation of Microplastic Pollution Along the Dalyan-Iztuzu (Eastern
Mediterranean) Coastline
- Authors: Aytuğ ZİLİFLİ; Sezginer TUNCER
  Abstract: In the present study, 14 sampling stations along the Dalyan-Iztuzu beach were sampled in June and July 2019 for the examination of microplastics. Samples were taken from surface waters (0-15 cm) using a manta trawl with a towing speed of 2 knots/h and a towing duration of 20 minutes. Microplastics were separated according to their shapes, types and sizes under a binocular stereo microscope. Results indicated that, the average density of microplastics were 0.148 ±0.07 particles/m2. Microplastic densities in the present study were lower compared to those of earlier studies carried out in the other parts of Mediterranean coasts and the Sea of Marmara.
  PubDate: Wed, 29 Dec 2021 00:00:00 +030
Biodiversity and Abundance of Phytoplankton from Auranga Estuary, Valsad
District, Gujarat, India
- Authors: Shefali S. PATEL; Susmita SAHOO
  Abstract: This study describes phytoplankton abundance and diversity from site 1 (downstream) and site 2 (upstream) of Auranga Estuary (20˚63’ N and 72˚82’ E). A Total of 44 species of phytoplankton were recorded, 35 species from downstream and 24 species from upstream. The assessed abundance was 129 cells/mL and 86 cells/mL from the downstream and upstream, respectively. Bacillariophyceae (19) was the dominant group followed by Chlorophyceae (10), Cyanobacteria (07), Dinophyceae (07), and Chrysophyceae (01). Nitzschia, Coscinodiscus and Ceratium were abundant genera at site 1 and Spirogyra, Microcystis, Chlorella and Oscillatoria were abundant at site 2. Nitzschiaceae and Zygnemataceae had highest family contribution at the downstream and upstream, respectively. Members of Bacillariophyceae and Cyanobacteria were present in high numbers throughout the year. The abundance of Chlorophyceae did not fluctuate greatly. Chrysophyceae (Chromulina pascheri) was observed during the summer period. Spatially, downstream had higher species diversity and abundance than upstream whereas winter season was favorable for plankton growth compared to summer and monsoon. Species dominance (Site 1: 0.238; Site 2: 0.257) richness (Site 1: 1.13; Site 2: 1.36), evenness (Site 1: 0.88; Site 2: 0.79) and diversity were assessed using alpha biodiversity indices. The Shannon diversity index was 1.417 and 1.268 for downstream and upstream, respectively. It indicates less diversity level in this estuary.
  PubDate: Wed, 29 Dec 2021 00:00:00 +030
The Effect of Different Solvents on Antioxidant Properties of Gongolaria
barbata (Phaeophyceae)
- Authors: Melis YILMAZ; Gülen TÜRKER, İlknur AK
  Abstract: In this study, the antioxidant activities, total polyphenolic contents of algal extracts from Gongolaria barbata were examined by using ethyl acetate (AcOEt), water(W), and phosphate buffer (PH) as solvents. According to the results, EtOH, W, and PB showed medium antioxidant potential with low IC50 values. The highest total flavonoid content was detected in W (6.91±0.09 mg/g Ext., and PB showed the maximum phenolic content (2.29±0.01 mg GAE/g ext.). The chlorophyll a and total carotenoid contents were detected as 40.5±1.20 and 29.13±1.12 (mg/g DW), respectively. Phycoerythrin was 0.002±0.001 (mg/g DW), while phycocyanin content was found as0.04 ±0.01 (mg/g DW). Our results show that PB could be used as an extraction solvent for determining the antioxidant properties of G. barbata instead of ethanol.
  PubDate: Wed, 29 Dec 2021 00:00:00 +030
The Growth and Survival of The European lobster (Hommarus gammarus) Larvae
in Pseudo-Green Water and Clear Water Under Low Density Conditions
- Authors: Umur ÖNAL; Hakan BAKİ
  Abstract: The European lobster, Hommarus gammarus, is a commercially important species in Europe. Despite successful stock enhancement programs during the last two decades, culture methods of H. gammarus are still in progress. In this study, the effects of pseudo-green water technique and clear water technique with lower stocking densities on the growth and survival of H. gammarus larvae during stages I-IV were investigated. All larvae were reared in 800 L cylindro-conical tanks with a stocking density of 1.25 larvae/L at a temperature of 17.1±1 oC and a salinity of 32±1 ppt. Lobster larvae were fed with enriched Artemia at a density of 3-5 naupli/ml for a period of 10 (09:30 am- 19:30 pm) hours. Daily additions of concentrated algae increased turbidity and reduced visibility in tanks compared to clear water conditions. Results showed that growth of lobster larvae were not significantly different among treatments during planktonic stages I-IV (p>0.05). Overall mean survival rate was only 3% with no significant differences between treatments. Increased turbidity and lower stocking density did not improve survival rates. Further studies are required to develop methods that will promote higher survival rates during the pelagic stages of lobster larvae.
  PubDate: Wed, 29 Dec 2021 00:00:00 +030