An analysis on the statistics of occupational accidents in Turkish fisheries and aquaculture sector; 2013-2019 period

This study was carried out to make a holistic evaluation on the occupational health and safety (OHS) of fisheries and aquaculture sector with its subsectors and to reveal the actual situation of fisheries and aquaculture sector by comparing relevant OHS statistics reported in Turkey. Annual average of accidents in the fisheries and aquaculture sector was found to be 312 (± 147.6), of which 2.14 (± 1.57) resulted in permanent incapacity and 1.57 (± 1.51) of them with fatality. While general incidence rate, fatal incidence rate, permanent incapacity incidence rate and work accident frequency rate were calculated as 2211.8 (±574) 103.6 (±13.4), 5.88 (±2.41) ve 8.36 (±1.93), these values for fisheries and aquaculture sector were determined to be 3579.1 (±1549.3) 175.65 (±152.34), 240.67 (154.62) ve 13.65 (±5.84), respectively. In 2019, the fatal accident rate in Turkey was found to be 0.27% in general, 0.34% in the mining sector, 0.77% in construction and 0.80% in transportation. This ratio was calculated as 1% in the fisheries and aquaculture sector. It was determined that there were more work accidents and fatal incidents in fisheries and aquaculture activities in the seas than in fresh water. Difference between number of work accidents and the duration of temporary incapacity as a result of work accidents in fisheries and aquaculture activities in marine and fresh waters were also significant (p<0.05). Number of fatal accidents in aquaculture sector was found to be more than 4 times than in fisheries. It was determined that the all types of incident rates, work accident frequency rates and fatality rates per work accident in fisheries and aquaculture sector were higher than that of Turkey in general. Evaluation of occupational accidents in the fisheries and aquaculture activity was found to be riskier than expected. Although some evaluations and suggestions are put forward to reduce the number of accidents and the severity of these accidents, a systematic and legislative approach will be more effective. Therefore, it would be a suitable approach to raise the hazard classes of fisheries and aquaculture economic activity to the “very dangerous” class. In this way, the training period of the sector employees on occupational risks and the titles and numbers of OHS professionals working in the sector will be increased, a more qualified specialization will be realized, and control and audit activities will be more frequent.

Bioaccumulation of heavy metals in the water, sediment and the tissues of Carassius gibelio (Bloch, 1782) from Eber Lake

In this research, in order to observe the seasonal change between April 2014 and February 2015, heavy metal contents in the water, sediment and the Carassius gibelio (Bloch, 1782) tissues (muscle, gill and liver) growing in Eber Lake were determined. The obtained results showed that trace elements were founded in water, sediment and fish tissues. Among the average annual concentrations of water samples, the highest concentration was found for Mn (0.1584 mg/L) element and the lowest concentration was found for Pb element in the spring season. the maximum Average annual concentration was calculated for Mn (0.1584 mg/L, Spring) and the minimum was determined for Pb in water. In the sediment, Fe (16245.84 mg/kg, Spring) was found to be maximum and Co was the minimum. In fish, the highest concentrations were found in liver (Mo, Ni, Pb, Co, Cu, Fe), while the lowest concentrations were found in gill (Mn, Zn) and muscle (Cd, Cr, Se) tissues While the highest heavy metal concentrations were observed in the sediment, the minimum was found in the fish tissues (the ranking was the following; liver, gill and muscle). It was concluded that the heavy metal levels measured in the Lake Eber have no risk to the environment and to the public health.

The effect of mercury, copper, and zinc on paraoxonase (PON) enzyme activity in Bonito (Sarda sarda) fish

Since heavy metal dirtiness, which we frequently encounter in environmental pollution causes harmful effects on the organism through biochemical enzyme reactions, in this study, the effects of mercury (Hg+2), copper (Cu+2), and zinc (Zn+2) heavy metal ions, which are common in environmental pollution, on PON (paraoxonase) enzyme activity in muscle tissue of bonito (Sarda sarda) were investigated. In the study, 25 bonito (S. sarda) fish muscle tissues freshly obtained from the Samsun region sea were used. The changes in PON enzyme activity were determined by adding different volumes of heavy metal solutions. PON enzyme activities of Hg+2 heavy metal ion used in different volumes were calculated as 30.9383 U/mLdak, 29.0598 U/mLdak, 26.3799 U/mLdak, 23.9443 U/mLdak, 20.6725 U/mLdak, PON enzyme activities of Cu+2 heavy metal ion used in different volumes were calculated as 19.7949 U/mLdak, 19.4807 U/mLdak 19.1864 U/mLdak, 19.1200 U/mLdak, 18.9037 U/mLdak and PON enzyme activities of Zn+2 heavy metal ion used in different volumes were calculated as 23.8305 U/mLdak, 23.0781 U/mLdak, 22.9073 U/mLdak, 22.4324 U/mLdak, 21.8159 U/mLdak. As a result of these obtained data, activity (%) values were calculated and activity (%) graphs were drawn. As a result of the study, it was determined that increasing concentrations of Cu+2 and Zn+2 heavy metal ions caused a decrease in PON enzyme activity, but there was no statistically significant difference between the different concentrations used. It was determined that increasing concentrations of Hg+2 heavy metal ion inhibited the PON enzyme activity, caused a statistically significant decrease between the activities depending on the different concentrations used (p < 0.05).

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

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.

Preliminary study on otolith chemistry and otolith morphology of two demersal fish species, European hake Merluccius merluccius (Linnaeus, 1758) and striped red mullet (Mullus surmuletus, Linnaeus, 1758) in the Sea of Marmara

Otoliths are calcium carbonate (CaCO3) accumulations. Under the influence of different ecosystems morphological and chemical composition change. In this study, economically important two demersal fish species; European hake Merluccius merluccius (Linnaeus, 1758) and Stripet red mullet (Mullus surmuletus Linnaeus, 1758) was examined. Otoliths (Sagitta) belonging to these two species have been studied both chemically and morphologicall. Morphometric measurements of otoliths (length, mm; width, mm; area, mm2; perimeter, mm) in the sagittal of each species was made by the Leica M125 tri-ocular microscope. In the chemical analysis of otoliths, strontium (Sr), magnesium (Mg) and calcium (Ca) trace element amounts, the ratios of Sr and Mg trace elements to Ca element (Sr/Ca and Mg/Ca) were determined. For the micro-chemical analysis of otoliths ICP-MS was used. The highest magnesium (24.92±9.57 mmol/mol) and strontium (26.17±1.81 mmol/mol) element values were found in the otolith of red mullet. The difference between strontium (Sr) and magnesium (Mg) amounts for two fish species was found to be significant (P<0.05). In addition to it was found that the difference between them in the amount of calcium is significant (P<0.001). The shape indexes of otoliths are significantly different between the two fish species. Especially in terms of roundness (RD) and aspect ratio (AR) (P<0.001). The results of this study provide information about the habitats of two economic importance demersal fish species. Since such studies can give information about the habitat areas of fish species, they are important for tracking stocks, migration routes and sustainable fisheries.

About the identity of Granulina pusaterii Smriglio & Mariottini, 2003 (Volutoidea: Granulinidae) from the Tunisian Plateau

On the ground of an extensive study of topotypes and of the shell morphology documented in comparable Mediterranean populations, Granulina pusaterii Smriglio & Mariottini, 2003 described from the Tunisian Plateau is proved to belong to the natural variability of G. melitensis Smriglio, Mariottini & Rufini, 1998 and it is proposed as junior synonym name of the latter.

Length-weight relationship and condition factor of three endemic fish species, Ponticola bathybius, Neogobius caspius and N. pallasi (Perciformes: Gobiidae) from the Southern Caspian Sea basin, Iran

In this study, the length-weight relationships (LWRs) and condition factors were estimated for 445 specimens belonging to three gobiid species viz. Ponticola bathybius (Kessler, 1877), Neogobius caspius (Eichwald, 1831) and Neogobius pallasi (Berg, 1916) from the Southern Caspian Sea basin. Total length and total weight of the examined specimens ranged 4.9-28.3 cm and 0.64-263.4 g, respectively. The length-weight parameter b of the studied species found between 2.47 (N. caspius) and 3.45 (N. pallasi) with r2 ranging 0.831 to 0.988. LWR and K parameters are reported first time for N. pallasi from the Caspian Sea basin. The condition factor estimated was calculated from 0.94 (N. pallasi) to 0.98 (N. caspius) and 1.00 (P. bathybius). The basic biological information on the LWRs of these three gobies will be useful as baseline information for further biological research in the region.

Diversity of benthic macroinvertebrates and water quality of Karasu Stream (Black Sea)

The study was conducted in Karasu Stream (Sinop Province, Black Sea Region of Turkey). The purpose of this study is, to determine the benthic macroinvertebrate composition of the stream, together with some of its environmental characteristics (water temperature, pH and dissolved oxygen) to evaluate the trophic level of the stream. Samplings of benthic macroinvertebrates and environmental variables were performed monthly at ten stations between February 2013 and January 2014. As a result, 18260 specimens were investigated and 175 taxa were determined. Chironomidae and Oligochaeta were the higher groups in terms of species richness with 48 and 38 taxa, respectively. The BMWP and ASPT indices indicate that all the stations belong to “slightly polluted (Class II)” or “unpolluted (Class I)” water quality levels.

A preliminary study of the effects of cold, frozen, or room temperature storage of commercial feeds on growth performance and feed consumption of juvenile rainbow trout (Oncorhynchus mykiss)

The storage of commercial feeds in a cool and dry place is a prerequisite management strategy to minimize the deterioration of commercial feeds. This study investigated the effects of feed storage conditions on feed intake and growth performances of juvenile rainbow trout (Oncorhynchus mykiss). A total of 240 juvenile rainbow trout, weighing 8.7–10.5 g, were randomly distributed into four groups. Each group was further subdivided into three replicates with 20 fish in each. The experimental fish were fed to apparent satiation twice daily over a 35-days period using four commercial feeds previously kept at different storage conditions, i.e., room temperature storage (20.8°C), cold storage (10°C), or frozen storages (-1.1°C and -15°C). The feed utilization was assessed by relative feed intake (RFI%) and feed conversion rate (FCR), while growth performance was evaluated by the thermal-unit growth coefficient (TGC) and specific growth rate (SGR). The preliminary findings suggest that the food storage conditions did not significantly affect feed intake and growth performance in juvenile rainbow trout. The findings provide practical information for fish farmers in the management of feed storage, which covers a remarkable proportion of the total production costs in aquaculture facilities.

Size and structure of the Mediterranean medicinal leech, Hirudo verbana populations inhabiting wetlands around Lake Eğirdir, Turkey

In the present study size and structure of the Mediterranean medicinal leech (Hirudo verbana Carena, 1820) populations inhabiting wetlands around Lake Eğirdir (Turkey) were investigated. Population size was estimated by removal methods, age classes were estimated for the first time in leeches (Hirudinea) using “Modal Progression Analysis” of body length frequencies using Bhattacharya's method. The population size and biomass of medicinal leeches around Lake Eğirdir were estimated to be 1,562,696 ± 805,613 leeches and 467.26 ± 172.91 kg, respectively. Three age classes were identified; the age group of 0+ was dominant with 78.6%. While 89.9% of the individuals weighed less than 1 g, whereas the broodstock was estimated to represent only 7%. Body weight, body length and condition factor were found to be 0.52 ± 1.19 g, 4.5 ± 2.4 cm and 0.620 ± 0.123, respectively. This study reveals that the population size of H. verbana in the wetlands around Lake Eğirdir is relatively well preserved and there is no significant threat to the sustainability of the exploitation of the medicinal leech populations. It is concluded that the stability of the lake's water budget, the variety and abundance of the host in the undamaged wetlands, the socioeconomic structure of the leech collectors, the sales policies, and the effective activities of conservation and control units might affect conservation status of the medicinal leech populations inhabiting wetlands around Lake Eğirdir.