Individual variation in seasonal movements and foraging strategies of a land-locked, ice-breeding pinniped

Marine mammal satellite telemetry studies can provide important tests of movement and foraging theory. Here we present the first satellite tracking study of Caspian seals (Pusa caspica), an endangered, ice-breeding phocid seal, endemic to the Caspian Sea. The Caspian Sea is one of the most variable habitats inhabited by any pinniped species, and lacks competing large piscivores. Under such conditions foraging theory predicts individual variation in foraging strategy may develop to reduce intra-species competition. We deployed 75 Argos satellite tags 2009-2012 on adult seals of both sexes, and used State Space Modelling to describe movement, and behavioural states. During winter in all years most individuals were mobile within the icepack, making repeated trips into open water outside the ice field, with only brief stationary periods that may be related to breeding activity. During summer 2011, 60% of tagged animals migrated into the mid and southern Caspian, while the remainder spent the ice free season in the north. Summer foraging locations were not restricted by proximity to haul out sites, with animals spending more than 6 months at sea. Maximum dive depths exceeded 200m, and maximum duration was greater than 20 minutes, but 80% of dives were shallower than 15m and shorter than 5 minutes. Hierarchical cluster analysis identified 3 distinct groups of summer dive behaviour, comprising shallow, intermediate and deep divers, which were also spatially exclusive, suggesting potential niche partitioning and individual specialisation on prey or habitat types. The results can contribute to assessment of impacts from anthropogenic activities and to designation of protected areas encompassing critical habitats

Breeding behavior and pup development of the Caspian seal, Pusa caspica

The Caspian seal, Pusa caspica, is an ice-breeding phocid endemic to the Caspian Sea. The breeding behavior of this species is poorly documented. Here, we report behavioral observations of 518 mother-pup pairs and 210 lone pups, made from the bridge of icebreakers traversing seal breeding grounds while servicing oil installations in the northeastern Caspian Sea, during 34 trips from late January to early March, 2006-2012. The breeding habitat of Caspian seals is land-fast or drift ice, usually at least 20 cm thick, overlying water 3–5 m deep. Pregnant females formed pairs or small groups. They were not observed to use lairs, but preferentially pupped beside ice ridges or ice-slab piles that afforded shelter to pups. In years when there were few natural leads into the ice-field, females often gave birth on the edge of artificial leads formed by shipping channels. Pups were categorized into stages from newborn (1), white-coat (2), molting (3), and molted (4), with Stage 3 and 4 pups appearing from mid to late February. The nursing period lasted at least 3 weeks and neighboring mother-pup pairs appeared to be mutually tolerant. Mothers left their pups alone or at nursery sites, presumably to forage. Most white-coat pups moved over the ice while avoiding water in response to disturbance from vessels. Mother-pup pairs maintained contact while moving across the ice by a combination of the pup’s following response and diligent chaperoning by the mother. During disturbances some lone pups sought refuge in shelters under ice slabs, whereas others followed a neighboring mother-pup pair away from the vessel. Male-female pairing occurred in late season with no male-male competition observed on the ice. While breeding and pup rearing behavior of Caspian seals has some features in common with that of other Holarctic seals, it is largely distinct and adapted to the unique conditions of the Caspian environment, in particular the paucity of snow cover on the ice

Inter-year variation in pup production of Caspian seals (Pusa caspica) 2005-2012 determined from aerial surveys

Assessing species abundance and reproductive output is crucial for evaluations of population dynamics, conservation status and the development of management objectives. The Caspian seal (Pusa caspica) is a key predator in the Caspian Sea ecosystem and is listed as “Endangered” by IUCN. Here we report on fixed-wing aerial strip transect surveys of the breeding population on the Caspian Sea winter ice field carried out in February 2005-2012. Potential detection biases were estimated by applying a Petersen mark-recapture estimator to the counts from double photographic observations. We also tested for effects of weather conditions on count results, and for correlations between pup production and ice conditions and net primary productivity (npp). Fluctuations in pup production estimates were observed among years, ranging from 8,200 pups (95% CI 7,130-9342) in 2010 to 34,000 (95% CI 31,275-36,814) in 2005. Total adults on the ice ranged from 14,500 in 2010 to 66,300 in 2012. We did not detect significant associations between pup production and either ice summary data (ice season length, and ice area) or npp. The observed inter-year variation may be partly due to underlying biological drivers influencing the fecundity of the population, although measurement errors arising from observation bias, plus variation in survey timing and weather conditions may also have contributed. Identifying the potential drivers of Caspian seal population dynamics will require extending both the survey time series and the quality of supporting data. However, inter-year fluctuations should still cause concern that the population may be vulnerable to environmental variability and ecosystem dynamics

Exposure of wild Caspian seals (Pusa caspica) to parasites, bacterial and viral pathogens, evaluated via molecular and serological assays

Disease surveillance of marine mammal populations is essential to understand the causes of strandings, identify potential threats to animal health, and to support development of conservation strategies. Here we report the first large multi-pathogen screening of prevalence for viruses, bacteria and parasites in a sample of 177 live, healthy, wild Caspian seals (Pusa caspica), captured and released during satellite telemetry studies 2007-2017. Employing molecular and serological assays we assess prevalence of pathogens known to be of significance for marine mammal health worldwide, and evaluate the results in relation to Caspian seal health and conservation. RT-PCR, and PCR assays find evidence for infection by Canine Distemper Virus (CDV), Phocine herpes virus, phocine adenovirus and Influenza A at prevalences of 5%, 6.4%, 21.7%, and 4% respectively. The genomes of CDV isolates collected in 2008 showed 99.59% identity with the 2000 Caspian seal CDV epizootic strain. A partial coding sequence for the Us2 gene from the Caspian seal herpes virus was identical to PhHV-1 isolate PB84, previously reported from a harbor seal (Phoca vitulina), while amplicon sequences for the adenovirus polymerase gene indicated a novel strain. ELISA assays detected exposure to Influenza A (55% of tested samples), adenovirus (25%), coronavirus (6%), CDV (8%), herpes virus (94%), Toxoplasma gondii (2.6%) and heartworm (1%). Hemagglutination inhibition (HI) tests detected exposure to Influenza B at a prevalence of 20%, and Leptospira microscopic agglutination tests detected suspected exposure to Leptospira serovars in 9% of tested samples. Overall, the risks, profile and prevalence of pathogens in Caspian seals appear comparable to other wild phocid seal populations. Our results suggest Caspian seals have exposure pathways to pathogens with epizootic potential or ability to cause significant morbidity, and that disease impacts could reduce the resilience of the population to other conservation threats. Caspian seals are listed as Endangered by the International Union for Conservation of Nature (IUCN), and we recommend that resources are invested to support further surveillance programs and to understand how anthropogenic pressures may influence future disease risks. A translated version of this abstract is available in Russian and Kazakh in the Supplementary Material (Presentation 1 and Presentation 2

The functional condition of left atrium during the endovascular treatment of atrial fibrillation

The atrial fibrillation causes structural and functional changes of atriums. In this case, the remodeling of left atrium increases the risk of AF. One of the treatment strategy is catheter isolation of the pulmonary veins. However, the effectiveness of these operations does not exceed 70% in most of the cases that may be due to remodeling of left atrium. In this regard, the assessment of the condition of left atrium is actual for the optimization of treatment tactics and improvement of effectiveness rate.Фибрилляция предсердий вызывает структурные и функциональные изменения предсердий. При этом ремоделирование левого предсердия увеличивает риск возникновения ФП. Одна из стратегий лечения - катетерная изоляция легочных вен. Однако эффективность данных операций в большинстве случаев не превышает 70%, что может быть обусловлено, в том числе, ремоделированием левого предсердия. В связи с этим, актуальна оценка состояния левого предсердия для оптимизации тактики лечения и улучшения показателей эффективности

Condition of bream Abramis Brama and roach Abramis Brama и плотвы Rutilus Rutilus populations infected with Poslhodiplostomosis in Imantau lake

Исследования ихтиофауны оз. Имантау выявили очаг постодиплостомоза (Poslhodiplostomosis) в популяциях леща Abramis brama и плотвы Rutilus rutilus. Первый вид характеризуется многочисленностью, низким темпом роста, истощенностью и высокой степенью инвазии постодиплостомозом – экстенсивность доходит до 100%. В меньшей степени указанная инвазия затронула и оказала негативное воздействие на популяцию плотвы. С целью борьбы с эпизоотией, во избежание массовой гибели популяций рекомендуется мелиоративный отлов леща и плотвы и изъятие биомассы рыб, потерявших товарную ценность. Отсутствие промыслового рыболовства на оз. Имантау со дня образования национального парка (1996 г.) принесло отрицательный результат, т. к. большая численность леща – чужеродного вида в экосистеме водоема, ведет к развитию эпизоотии и тугорослости особей. Данное обстоятельство сдерживает развитие других, более ценных (в т. ч. и для развития любительского (спортивного) рыболовства) видов рыб аборигенной ихтиофауны, к примеру, линя, а также мешает натурализации карпа.The research of Imantau Lake fish fauna discovered a nidus of posthodiplostomosis in populations of bream Abramis brama and roach Rutilus rutilus. Bream of Imantau Lake shows multiplicity, low growth rate, atrophy and high degree of posthodiplostomosis invasion – up to 100%. The invasion affected and had a negative impact on the roach population to a smaller degree. Ameliorative bream and roach fishing is recommended to protect against epizootic, as well as to remove excessive biomass that lost market quality and to avoid the fish kill. The lack of commercial fishing in Imantau Lake since the time of National Park establishment in 1996 paid off negatively, as large numbers of bream: foreign species in the lake ecosystem – lead to epizootic and stunted fish. This circumstance prevents the population increase of others, more valuable (for development of sport fishery as well) fish species of local fish fauna, like tench, as well as acclimatization of carp

To the fishery assessment оf the lake Sarykopa and the river Uly-zhylanshyk, entering the state natural reserve «Altyn-Dala» (Republic of Kazakhstan)

В пределах буферной зоны государственного природного резервата «Алтын-Дала» располагаются водоемы, которые могут быть использованы для любительского (спортивного) рыболовства. Но данных о состоянии биоразнообразия водоемов ранее не было. Исследования проводились на двух водоемах: оз. Сарыкопа и р. Улы-Жыланшык, относящихся к Тобол-Торгайскому водохозяйственному бассейну Казахстана. Был применен комплексный подход, предусматривающий проведение гидрохимических, гидрологических, гидробиологических и ихтиологических изысканий. Проведенный анализ видового разнообразия рыб на основе специальной литературы и собственных данных показал, что в водоемах резервата обитают 13 видов, из которых два вида относятся к интродуцентам, все остальные – аборигенные виды. Занесенных в Красную книгу Казахстана рыб среди указанных видов рыб нет. В результате исследований в 2013 году. подтверждено обитание 8 видов рыб, обнаружено обитание речного рака. На основе собственных материалов приведен аннотированный список видов рыб, произведена оценка возможности проведения любительского (спортивного) рыболовства в каждом водоеме.Within a buffer zone of the state natural reserve «Altyn-Dala» reservoirs which can be used for amateur (sports) fishery settle down. Researches were done on two reservoirs: the Lake of Sarykopа and the river Uly-Zhylanshyk which relating to the Tobol-Torgay water management basin of Kazakhstan. At researches the integrated approach was applied, which providing hydrochemical, hydrological, hydrobiological and ichthyological researches are holding. The carried-out analysis of a specific variety of fishes on the basis of literary and own data showed that 13 species of fish from which two look belongs to introduced species, all others – native types live in reservoirs of the reserve. In the middle of the specified species of fish in the Red List of Kazakhstan aren't include. As a result of researches of 2013 dwelling of 8 species of fish is confirmed, dwelling of a crawfish is revealed. On the basis of own materials the annotated list of species of fish is provided, the assessment of possibility of carrying out amateur (sports) fishery in each reservoir is made

Exposure of wild Caspian seals (Pusa caspica) to parasites, bacterial and viral pathogens, evaluated via molecular and serological assays

Disease surveillance of marine mammal populations is essential to understand the causes of strandings, identify potential threats to animal health, and to support development of conservation strategies. Here we report the first large multi-pathogen screening of prevalence for viruses, bacteria and parasites in a sample of 177 live, healthy, wild Caspian seals (Pusa caspica), captured and released during satellite telemetry studies 2007-2017. Employing molecular and serological assays we assess prevalence of pathogens known to be of significance for marine mammal health worldwide, and evaluate the results in relation to Caspian seal health and conservation. RT-PCR, and PCR assays find evidence for infection by Canine Distemper Virus (CDV), Phocine herpes virus, phocine adenovirus and Influenza A at prevalences of 5%, 6.4%, 21.7%, and 4% respectively. The genomes of CDV isolates collected in 2008 showed 99.59% identity with the 2000 Caspian seal CDV epizootic strain. A partial coding sequence for the Us2 gene from the Caspian seal herpes virus was identical to PhHV-1 isolate PB84, previously reported from a harbor seal (Phoca vitulina), while amplicon sequences for the adenovirus polymerase gene indicated a novel strain. ELISA assays detected exposure to Influenza A (55% of tested samples), adenovirus (25%), coronavirus (6%), CDV (8%), herpes virus (94%), Toxoplasma gondii (2.6%) and heartworm (1%). Hemagglutination inhibition (HI) tests detected exposure to Influenza B at a prevalence of 20%, and Leptospira microscopic agglutination tests detected suspected exposure to Leptospira serovars in 9% of tested samples. Overall, the risks, profile and prevalence of pathogens in Caspian seals appear comparable to other wild phocid seal populations. Our results suggest Caspian seals have exposure pathways to pathogens with epizootic potential or ability to cause significant morbidity, and disease impacts could reduce the resilience of the population to other conservation threats. Caspian seals are listed as Endangered by the International Union for Conservation of Nature, and we recommend that resources are invested to support further surveillance programmes and to understand how anthropogenic pressures may influence future disease risks