The subject of the article is to establish the relationship between trophic functions as properties of interacting populations as a whole and the characteristics of individual foraging behavior of consumers. The article classifies general predator-prey models and trophic functions as integral components of these models. It is shown that simple assumptions about the individual behavior of predators and prey lead to a specific type of trophic function - the piecewise linear Arditi-Ginzburg dependence or its "smoothed" version. The obtained theoretical results are verified using an original simulation model representing the interaction between the consumer and food objects at the individual level.

Systematic studies of the western (Okhotsk-Korean) population of the Gray Whale, listed in the Red Book of the Russian Federation, have been carried out since 1997. Since the early 2000s, these studies have been of a monitoring nature and are carried out by a group of oil producing companies active on the Sakhalin shelf. To date, a large amount of information has been accumulated relating to various aspects of the life of the gray whale. Estimates of the population size of the gray whale were obtained, its size and sex composition was studied, as well as the feeding and migratory behavior of these animals off the coast of Sakhalin. Previously, we analyzed monitoring materials relating to 2001–2012. The work done was aimed at assessing the spatial contingency in the dynamics of the distribution of gray whales and their food items. A GIS project was created, with the help of which approaches to assessing the spatial correspondence of elements of the whales-benthos system were tested and implemented. The analysis showed that the most attractive for whales are vast fields lying at shallow depths with a high, relatively evenly distributed amphipod biomass. The whale feeding area is adjacent to areas where oil production platforms and elements of the hydrocarbon transport system are installed. The activities of engineering systems can have a negative impact on animals, disorient them, scare them away, disrupt communications and even lead to physical damage. Continuous acoustic monitoring data was included in a previously created GIS to assess the impact of industrial noise on whale behavior. The results obtained do not allow us to consider acoustic impact as a significant factor influencing the spatial distribution of the feeding gray whale population in the Piltun area.

Distribution of children with congenital clefts of lip and/or palate (CCL, CCP and CCLP) by local administrative-territorial units of the Krasnodarskij kraj has been studied from clinical data base of the chair of child stomatology, odontology and orofacial surgery of KGMU for the period from 1985 to 2010 (N=1745). The average frequency of clefts in Krasnodar region is 1,15:1000, and proved to be respectively stable during the total period of monitoring. Frequency in different administrative-territorial units of Krasnodarskij kraj varies of from minimum value 1:2000 to maximum 1:500. Dynamics of proportions of diagnosis CCL, CCP and CCLP for the 25-year period has been considered separately for two sexes.

We previously applied simple analytical models to show that a community structure may be disrupted if interspecific food relations are disregarded. The primary goal of multispecies modeling is to insure the sustainable existence of a community or ecosystem, and, if possible, to increase its production level, which entails a higher catch level. The potential of the two major multispecies models—the cohort model, MSVPA, and the mass-balance production model, ECOPATH/ECOSIM—have been analyzed. The first model needs more structured feeding data (by species and age for both predators and preys), while the second requires only trophic level data. The MSVPA model involves only fishing species and external predators; the second model considers matter flows among all levels of the food web, although it disregards seasonal and interannual variability in feeding. The identification of parameters for a multispecies model involves labor-intensive trophological research. V.S. Ivlev, one of the first Russian trophology scientists, set up a number of experiments to identify the consumption rates among fish. Experiments on the estimation of the rates of the digestion of various prey species in the stomachs of particular predator species are also of particular importance. Our estimates of mortality from predation for the fish community of the Barents Sea obtained with MSVPA show that mortality from predation is sometimes higher than that of fishing mortality. Another important factor contributing to recruitment into the northeast Arctic cod stock (the major one in the Barents Sea) is cannibalism. In studies on the dynamics and sustainability of aquatic communities and in the formation of advice for fishery management, it is particularly important to consider the predation mortality in stocks of prey species, such as capelin, which is the most preferable food item for many predatory fish, mammals, and birds.

A generalized model of recruitment formation in exploited fish populations is introduced, which provides a full description of the class of 'stock-recruitment' relationships based on the conception of density-dependent regulation of population dynamics. The results are presented of the analysis of the deterministic model version that includes five control parameters. The proposed unified model, as being derived ab initio, provides the possibility for quantitative comparison (at the level of parameter values) of qualitatively different descriptions of recruitment processes based on alternative hypotheses about the mechanisms and factors of the processes in question. The generality of the model formulation enables transition from deterministic version to stochastic one, which may include, at the same time, the effects of environmental factors.

Васильев П.В. 1 , Чистов С.В. 2 , Криксунов Е.А. 3 , Бобырев А.Е. 4 КАРТОГРАФИЧЕСКОЕ МОДЕЛИРОВАНИЕ ПРОСТРАНСТВЕННО-ВРЕМЕННОЙ ДИНАМИКИ ПОПУЛЯЦИЙ РЫБ ПСКОВСКОГО ОЗЕРА АННОТАЦИЯ В статье авторы излагают экспериментальную методику построения серии карт численности промысловых видов рыб на основе данных их траловых учетов в акватории Псковского озера.За последние полтора десятка лет для линий траления помимо параметров ресурсного и гидролого-климатического характера стали фиксировать еще и координаты начальной и конечной точек, что создало предпосылки для разработки серии картографических моделей.На основе специализированного ГИС-проекта выполнено картографическое моделирование пространственно-временной динамики ряда видов рыб в акватории Псковского озера за 2003, 2006 и 2008 гг., различающиеся режимом водности.В результате впервые выполнена попытка определения связей между распределением в различные сезоны года видов ихтиофауны (присутствовавших в составе улова экспериментального трала: окунь, лещ, судак, плотва, щука, ерш, густера) и градиентами гидрологических факторов (температура, водность, глубина), влияющими на поведение и перемещения рыб.По результатам картографирования в акватории озера выявлены и оценены зоны высокой продуктивности ихтиофауны как по отдельным промысловым видам, так и по их комплексам, а также дана оценка эколого-географических параметров, определяющих акватории различной продуктивности с учетом сезонной ритмики и тенденции изменений состава улова на протяжении последних лет.Установлено, что для разных видов рыб связь плотности скоплений с гидрологическими условиями не выражена, максимальные и минимальные значения плотности для каждого из видов, в достаточном количестве присутствующих в уловах экспериментального трала, фиксируются при разных параметрах водности, температуры и глубины.Авторы предполагают, что включение в анализ других факторов (в том числе гидрохимических и гидробиологических) позволит уточнить причины, определяющие пространственно-временную динамику каждого из исследуемых видов.Полученные результаты подтверждают перспективность применения картографического метода в изучении пространственно

The dynamics of the population of pikeperch Sander lucioperca in lakes Pihkva and Peipsi in 1980−2009 has been studied based on cohort models. The conducted analysis indicates a weak relationship of the recruitment abundance with the spawning stock biomass and average annual level, temperature, and transparency of water in the lake. One of the main factors of dynamics of the pikeperch population is the rate of recruitment. Significant recruitment pulses occur synchronously in both lakes, which indicates the generality of the population of this species and a weak isolation of groupings that inhabit different parts of Lake Peipsi-Pihkva. The current state of pikeperch fishing in Lake Peipsi-Pihkva provides an annual yield close to the maximum level.

We present the results of a mathematical model for the aquatic communities which include zooplankton, planktivorous fish and predator fish. The aquatic populations are considered to be body mass- and agestructured, while the trophic relations between the populations to be correspondingly status-specific. The model reproduces diverse dynamic regimes as such steady states and oscillations in the population size. Oscillations in the fish population size are shown to be both regular and irregular. We show that the period of the regular oscillations can be up to decades. The irregular oscillations are shown to be both chaotic and non-chaotic. Analyzing the dynamics in the model parameter space has enabled us to conclude that predictability of fish population dynamics can face difficulties both due to dynamical chaos and to the competition between various dynamical regimes caused by variations in the model parameters, specifically in the zooplankton growth rate.

Among the most important ecological challenges of the modern age is maintaining the current level of biodiversity. The subject of this research is the gray whale (Eschrichtius robustus) that inhabits the northern parts of the Pacific Ocean. The gray whale of the Okhotsk–Korean or the Western Gray Whale (WGW) population is classified as critically endangered according to criteria of the International Union for Conservation of Nature (IUCN); current estimate of the total population numbers is approximately 150 individuals. The main feeding area where western gray whales spend their summer-fall period, constitutes a narrow (with depths no greater than 50 m) sea area that runs alongside the coastline over approximately 100 km, and is located in the north-eastern part of the Sakhalin Island. Unlike other cetaceans, the gray whale feed on benthic organisms — the primary components of their diet are bottom-dwelling crustaceans belonging to the groups of Amphipoda and Isopoda. Systematic research into the western gray whale, initiated by a group of oil companies working offshore Sakhalin, has been going on since 1997. We analyzed the associativity between the spatial distributions of the western gray whales and the biomass of the benthic organisms serving as their food source over the period of 2002–2011. The analysis was conducted using GIS technologies. Cartographic alignment of whale occurrence distribution and the abundance of food benthos demonstrate the high degree of their spatial associativity, thus indicating the important role of the food factor in the formation of the whale spatial distribution. Maximum values of cumulative yearly estimates of sighted gray whales are associated with the areas with the maximum density of benthos. The analysis of the associativity dynamics shows that most attractive for whales are shallow vast fields with high and relatively evenly distributed Amphipoda biomass.

Dynamics of eight commercial populations of fish from Pskov-Chudskoe Lake forming the main bulk (up to 80%) of annual catch was analyzed using an ADAPT-VPA model making it possible to reconstruct the dynamics of the total stock biomass and fishing mortality. The populations of five species (European smelt Coregonus albula, whitefish C. lavaretus maraenoides, perch Perca fluviatilis, roach Rutilus rutilus, ruffe Gymnocephalus cernuus) in the present period demonstrate a tendency for a decrease in biomass while the stocks of two species (bream Abramis brama and zander Sander lucioperca) beginning from the 1980s considerably increased. A particularly drastic (multifold) increase in biomass is recorded in zander population. The causes of the observed population changes are related mainly to ecosystemic transformations taking place in the water body; only with respect to two species-perch and roach-can one state that the decrease in stocks is determined in part by the fishery impact. The increase in zander population is, in all probability, the result of the combined effects of eutrophication forming favorable conditions for the feeding and survival of its juveniles and fishery that led to the decrease in the biomass of one of its main food competitors-perch. The drastic increase in zander numbers in turn promoted the decrease in the biomass of species being objects of its feeding.

We present a mathematical model of an aquatic community, where the size-and-age structure of hydrobiont populations is taken into account and the corresponding trophic interactions between zooplankton, peaceful fish, and predatory fish are described. We show that interactions between separate components of the aquatic community can give rise to long-period oscillations in fish population size. The period of these oscillations is on the order of decades. With this model we also show that an increase in the zooplankton growth rate may entail a sequence of bifurcations in the fish population dynamics: steady states → regular oscillations → quasicycles → dynamic chaos.