State of the pacific oyster Crassostrea gigas (Thunberg, 1793) population in the Losos Bight (Sakhalin Island) in 2013–2020

The state of the aggregation of Pacific oyster Crassostrea gigas (Thunberg, 1793) in the Losos Bight (Aniva Bay) in 2013–2020 was assessed. For now, this aggregation has been in depression as a result of intense fishing. The abundance of the aggregation of commercial individuals (shell height >120 mm) was poor two recent years. The total stock estimated is 31.5 t; the commercial stock – 4.7 t.

Comparative assessment of amateur fishing influence on water bioresources of Lake Tsatsa in Volgograd region

The paper presents the results of research conducted in 2020 on the impact of amateur fishing on the aquatic bioresources of Lake Tsatsa, which is part of the Sarpin Lakes located in the Volgograd region. On the basis of field studies (direct accounting), the number of amateur fishermen who visited the lake, as well as the qualitative and quantitative composition of their catches, was established. According to the data obtained, the total catch of fish by amateur fishermen, as well as the average catch per fisherman, was estimated. The size and weight composition of amateur fishing catches was determined based on the analysis of 2912 fish species. During the observation period 9 fish species were marked as part of amateur fishermen’s catches. The assessment of compliance of aquatic biological resources catch by amateur fishermen with the norms of the current Fishing Regulations was carried out. An assessment of the scale of amateur fishing impact on the aquatic bioresources of Lake Tsatsa is given, according to the analysis of the collected data. The catch of amateur fishermen in 2020 in Lake Tsatsa is amounted to 8.8232 tons, which can account for up to 15% (about 65-70 tons) of the total stock of commercial fish species in the lake. The forecast values of the production volume for industrial fisheries, for which the total allowable catch (TAC) is established and the species for which the recommended catch is determined, are 5.9 and 18.6 tons, respectively. Out of the forecast volumes amateur fishermen additionally catch fish species for which the total allowable catch (TAC) is established (carp, bream, pike) in the amount of 2.858 tons, and species for which the recommended catch value is determined as 5.643 tons.

ANALISIS PERSEDIAAN KEBUTUHAN GALANGAN (PLAT KAPAL) DENGAN METODE EOQ PADA PT PENGERUKAN INDONESIA

Inventory is one of the fundamental problems in a business. Without inventory, a business will be faced with a variety of problems, for example, not having the option to fulfill client orders that lead to loss of client trust, inhibiting interaction creation, etc. Therefore, this study will analyze the management of ship plate inventory at PT Pengerukan Indonesia. There is a technique used to control the supply of stock, namely the"Economic Order Quantity" (EOQ) method. The method used is quantitative by using two types of data, namely primary data and secondary data. The results of this study can produce efficiency of inventory costs where the total stock of uk plate 5mm company as much as 399 sheets and plate uk 12mm 419 sheets and companies make orders as much as 110 times a year. While using the EOQ method the company only orders the purchase of plates as many as 35 times a year with a 10-day message period with a total requirement when ordering as much as 11 pieces for uk 5mm and 12 sheets for uk 12mm and experience cost efficiency of Rp37,280,302. for uk 5mm plates and Rp37,673,245 for uk 12mm plates.

Quantitative and qualitative characteristics of forests in the Baikal Mountain Forest region

The article considers modern approaches to the study of the state of forests of the Baikal Mountain Forest region. All the obtained results of field studies are confirmed by a 13-year period of observations of the changes in the quantitative and qualitative indicators of growth and development of forests, the selected object. During the research, about 17 thousand ha of forest area were surveyed, 1570 permanent test areas were laid. According to the sanitary condition, the share of healthy plantings (class 1) accounts for 76.5%, the 2nd class of resistance (with the presence of small damage and signs of weakening) – 11.1% the indicators of other classes of resistance of plantings vary from 0.5% to 2.6%. The main sign of damage and weakening of forests are grass-roots fires – 60.3%. The total stock of wood according to the GIL is 2568.9 million m3. Coniferous species have the largest share of the stock of business trees – 94.3%, a smaller share of the stock – soft-leaved – 5.6%. The obtained data allow us to develop measures for rational forest management for part of the forests of the Republic of Buryatia, the Trans-Baikal Territory and the Irkutsk Region.

Long-term interplay between harvest regimes and biophysical conditions may lead to persistent changes in age-at-sexual maturity of Northeast Arctic cod (Gadus morhua)

This investigation commenced by constructing principal maturation schedule equations as a function of fishing mortality (F), key biophysical factors and a term attributed to fisheries-induced adaptive change (FIAC). Following the onset of industrial trawl fishery on the model stock, Northeast Arctic cod (NEAC) (1934-2020), F on immature age groups 5-8 years (F5-8) increased and mean age at 50% maturity (A50) decreased from ≈10 years in the late 1940s to ≈7 years today. Large annual fluctuations in total stock biomass (TSB), sea temperature (KolaT) and F5-8 were used to better understand A50 responses. In the model, the annual accumulation of F5-8 drives FIAC. The model includes the option that NEAC may sustain F5 8 up to a certain level (F_bal) before FIAC becomes statistically evident, with F_bal falling between 0.00 and 0.40 for A50. This dynamic range in F_bal indicates a sophisticated, underlying adaptive response. Independent of F_bal, our analysis clarifies that FIAC is necessary to explain the observed changes in A50.

Comparative analysis of Scots pine homogeneous stands bioenergetic productivity in European North

The bioenergetic productivity of artificial pine stands is considered. It was found that in 30-year-old artificial pine coenoses, the lowest amount of energy associated with the tree layer is observed in the lichen type of growing conditions (443,1 GJ/ha), the highest — in the blueberry (1915,1 GJ/ha). Bioenergetic productivity occupies an intermediate position (1210,7 GJ/ha) in the cranberry-type forest culture phytocenoses. It is shown that the accumulated energy reaches the highest relative value in such a component of aboveground phytomass as trunk wood. For this fraction, the variation is observed from 50.2% in the lichen type of growing conditions to 65.8% in the blueberry type, based on the total stock of phytomass of forest crops. It is established that the secondary position relative to this indicator is occupied by woody greens. The share of the energy productivity of needles in the total aboveground phytomass decreases with the improvement of forest growing conditions. An approximately equal ratio of energy deposition in the studied types of artificial pine forests by the fractions of bark and live branches (7,2...11,7%) was determined, and the smallest share of accumulated energy falls on the fraction of dry branches (5,3...7,0 %).

Development of the Organized Securities Market in Uzbekistan

The development trends of the organized securities market in Uzbekistan, the main factors influencing the development of the organized market, as well as the trend of joint-stock companies, their issue, existing problems and ways of solving them are described. Based on the data, it can be said that the unorganized securities market in the country is developing better than the organized securities market. The size of the organized stock market does not match the expected share of the total stock market. This, in turn, requires a radical development of this market.

Obstacles and ways of forming effective protection of rice crops from weeds

Goal. Assessment of the current level of soil contamination in rice checks with weed seeds and determination of the reasons for insufficient efficiency of herbicide application to ensure high yields of rice sown in the south of our country. Research methodology: Field small-site experiments were conducted in crops (rice checks) of the Institute of Rice of NAAS of Ukraine (Antonivka village, Skadovsk district, Kherson region). The size of the sown experimental plot is 66 m2, the accounting area is 50 m2. The experiments were repeated 4 times. Placement of plots is regular in two tiers. Accounting and analysis were performed in accordance with the specifics of the requirements «Methods of testing and application of pesticides» edited by Professor S.O. Tribel, and Methods of research in beet growing. The level of yield of rice crops was determined by continuous harvesting of accounting plots on all repetitions of variants by a special selection combine «Sampo-2000» with the subsequent conversion into t/ha. Results. Washing of soil samples from rice checks and analysis of washed seeds and organs of vegetative reproduction revealed that the largest stocks of live seeds are present in the horizon 0—10 cm, and average 1310.0 pieces/ m2 of rooster millet. The total stock of seeds of different types of weeds that retained the ability to germinate in the soil was 12987.8 pieces/ m2. The number of weed seedlings in weed control crops (option 1) averaged 894.8 pcs/m2. In crops of option 2 after application of soil herbicide Kommand 48, KE (Clomazon, 480 g/l) with a concentration of working solution — 0.25%, at the rate of consumption of 0.5 l/ha before germination, the number of weed germs decreased to 550.5 pcs/ha or by 38.5%. Spraying of crops of rice of sowing in the period of formation — 3 leaves with a norm of expenses of working liquid of 200 l/hectare, herbicide Topshot, 113 OD of m.d. normal sow 3.0 l/ha with a concentration of working solution — 1.5%, further reduced the number of weeds in crops. The overall decrease in the number of weed plants in rice crops averaged 90.2%. Seedlings of acute plague died by 91.0%, rooster millet by 97.1%, bitter gourd by 96.3%. At the same time, the seedlings of Korsakov’s monochoria died out by 79.4% of the compact reed tuber by 77.1%, and the spreading plague by 76.2%. In crops of sown rice, 59.5 pcs/ m2 of weed plants of different species still remained to grow. Surviving plants were formed in rice crops on average 1452 g/m2 weight or 39.5% of its maximum volume in the experiments (option 1). The main part of the mass of weed plants was monocotyledonous species — 73.9%. The yield of rice crops was 5.12 t/ha or 44.8% of the maximum in the experiments (option 3). Conclusions: Systems of measures to protect rice crops should be aimed primarily at reliable and systematic control of seedlings and seedlings of the most numerous and problematic weed species: members of the botanical families Osokov and Tonkonogov.

THE EXPANSION OF THE BIVALVE ANADARA KAGOSHIMENSIS (TOKUNAGA, 1906) IN THE SEA OF AZOV

The dispersion of the Asian bivalve Anadara kagoshimensis in the Sea of Azov continues for more than 30 years. The study of the expansion of A. kagoshimensis is based on the materials of annual bottom grab surveys performed in the Sea of Azov in 1989-2018. The process of dispersion of the mollusk is considered through the changes of the range area, the indicators of abundance (specific abundance, biomass, total stock) and the structure of the population. The main stages of the invasion process are highlighted and discussed. The influence of various environmental factors on the distribution and quantitative indicators of the development of the mollusk population is estimated. It is shown that salinity is the key factor determining the expansion of the mollusk in the Sea of Azov.

Estimation of coarse woody debris stocks in forest ecosystems of Slobozhansky national nature park

Dead wood is an important component of forest ecosystems. It performs a number of environmental functions. Coarse woody debris includes standing dead trees, fallen dead trees, fragments of fallen trees (trunks), branches (fragments of branches), and rough tree roots. It is a substrate and habitat for living organisms, including a number of species of mosses, lichens, fungi, invertebrates, as well as birds and mammals. Woody detritus plays an important role in the biological cycle of substances and energy, and carbon deposition, is a source of nutrients. Therefore, the study of quantitative and qualitative features of dead wood, in particular on protected areas, is a considerable nowadays problem. The aim of the work is to estimate identified by forest inventory stocks of dead wood in forest ecosystems of Slobozhansky NNP by categories, as well as to analyze the distribution of its volumes in stands of dominant tree species and forest types. The estimation of coarse woody debris stocks was performed based on forest inventory data of Slobozhansky National Nature Park conducted by Ukrainian State Project Forestry Production association “Ukrderzhlisproekt”. Data from 493 forest stands of nine tree species were analyzed. The stock of the following fractions of coarse woody debris was studied: standing dead wood, fallen (downed) dead wood. Data analysis was performed using MS Excel 2016 software. It was found that the total area of forest stands in which standing or downed dead wood was found during forest inventory was 2149.8 ha, or 47.5% of the total forest area of NNP. The total stock of coarse woody debris was 19478 m3, more than 95% of which is concentrated in the stands of Scots pine (Pinus sylvestris L.) (78.8%) and pedunculate oak (Quercus robur L.) (16.6%). Standing dead wood prevailed (62.1%) fallen dead wood (37.9%) in the structure of dead wood volume. The volume of dead wood was in the range of 5–50 m3∙ha–1, and on average in studied forest ecosystems in which it was found was 9.1 m3∙ha–1. In Scots pine forest stands coarse woody debris was found on an area of 1703.5 hectares with total stock of 15355 m3, consists of standing dead trees (9952 m3, 64.8%) and fallen dead wood (5403 m3, 35.2%). The volume of dead wood in forest stands was 5–50 m3∙ha–1, on average – 9.0 m3∙ha–1. In pedunculate oak stands coarse wood debris was found on an area of 384.7 hectares with a total stock of 3224 m3, consists of standing dead wood (1469 m3, 45.6%) and fallen dead wood (1755 m3, 54.4%). The volume of dead wood in forest stands was 5–20 m3∙ha–1, on average – 8.4 m3∙ha–1.