Search

Many environmental flow (e-flow) studies and applications have predominantly used state—(i.e., at a single time point) and rate—(i.e., temporal change) based demographic characteristics of species representing lower trophic levels (e.g., fish communities) to build flow-ecology relationships, rather than using a process that incorporates population dynamics. Recent studies have revealed the importance of incorporating data on species traits when building flow-ecology relationships. The effects of flow on keystone megafauna species (i.e., body mass ≥ 30 kg) reverberate through entire food webs; however, the relationships between flow and these species are not well understood, limiting the scope of the relationships used in flow management. Here, we fill this gap by incorporating the habitat selection traits at different flows of a freshwater apex predator, Ganges River dolphin (GRD, Platanista gangetica gangetica), which plays a significant role in maintaining the structure, functions and integrity of the aquatic ecosystem. Using temporally and spatially measured GRD habitat selection traits, we quantified flow-ecology responses in the Karnali River of Nepal during the low-flow season when habitat was heavily reduced and water demand was highest. We define ecological responses as suitable habitat templates with enough usable surface area to support GRD fitness by improving reproduction and survival. We measured the available and occupied habitats to develop flow-ecology responses. Variation in flow resulted in substantial differences in the ecological response across time and space, suggesting that aquatic species adjusted in a variety of habitats to support their life histories and maintain viable populations. The limited availability of suitable habitats combined with uninformed water regulations by humans likely places GRDs under severe physiological stress during low-water seasons (i.e., January–April), suggesting that reduced flows contribute to the process of endangering and extirpating highly sensitive endemic aquatic biodiversity. Our study reveals that ad hoc or experience-based flow management is no longer tenable to maintain the integrity and functionality of aquatic ecosystems. We stress that quantifying the flow-ecology relationships of foundational species, particularly megafauna, in response to flow variation is crucial for monitoring the effects of water alterations and determining the minimum flows needed for maintaining healthy and functional freshwater ecosystems in the Anthropocene.

Environmental DNA (eDNA) is increasingly popular as a useful non-invasive method to monitor and study biodiversity and community structure in freshwater and marine environments. To effectively extract eDNA from the filter surface is a fundamental factor determining the representativeness of the samples. We improved the eDNA extraction efficiency of an established Sterivex method by 12- to 16-fold using a larger volume of lysis buffer mix coupled with backflushing the cartridges. The DNeasy extraction column could be overloaded when the environmental sample input is high, possibly due to a higher nonspecific binding present in environmental samples, thus resulting in a relatively lower quantity measured. Therefore, we included an internal control DNA in the extraction to monitor the extraction and purification efficiencies in field samples, which is crucial for quantification of original eDNA concentration. The use of Takara Probe qPCR Mix supplemented with protein-based additives improved the robustness of the real time PCR assay on inhibitor-rich environmental samples, but prior purification by Qiagen PowerClean Pro Cleanup kit could be essential for inhibitor-rich water samples, even though the recovery rate was unexpectedly low (average 33.0%). The improved extraction and quantification complement the qualitative analyses including metabarcoding and metagenomics in field application.

Studying the spatial management scope of the river ecological corridor is a crucial step in effectively managing river health problems. For various purposes and needs, human beings intervene excessively in the river, resulting in the problems of unclear spatial scope, unclear ownership, and unreasonable functional utilization of the river ecological corridor. However, there is scarce research on the management scope of the river ecological corridor at present, and on the coordination relationship with territorial spatial protection planning. Therefore, in order to solve this key problem, this paper reviews and summarizes the current research status and development trends in terms of the concept, components, and other basic theories of the river ecological corridor, as well as relevant policy regulations. The relationship between the spatial scope of the river ecological corridor and the territorial spatial control line is analyzed, including the relationship with the river shoreline, aquatic ecological redline, “three control lines” and other control lines. Accordingly, this study reviewed the spatial management and control scope of the river ecological corridor. It also determined that the boundary line of the river shoreline management is the minimum line, the aquatic ecological redline, and the “three control lines” are the outermost boundary lines, in which the aquatic ecological redline has priority over other control lines. It also points out the thinking of determining the management scope in the protection and restoration of the river ecological corridor in the future. Our findings can provide a decision-making basis for the management of river ecological space.

В работе кратко рассмотрена эволюция подхода к оценке воздействия ионизирующей радиации на живые организмы. На примере черноморских гидробионтов показана возможность применения концептуальной радиохемоэкологической модели зональности действия хронического облучения ионизирующих излучений в природе Г. Г. Поликарпова для оценки уровня экологического воздействия ионизирующего излучения от техногенных радиоизотопов на водную биоту. Эта модель может служить в прикладной гидробиологии основой комплексного подхода к оценке экологического состояния водной биоты и его прогноза для широкого диапазона концентраций активности 239,240Pu в морской воде. Подчёркивается необходимость совместного применения биогеохимического и эквидозиметрического показателей поведения радиоизотопов в водоёме. В частности, для прогнозных дозиметрических оценок важно учитывать количественные характеристики концентрирующей способности черноморских гидробионтов и тип биогеохимического поведения радиоэлемента, отражающие особенности биогеохимической миграции плутония в морской экосистеме.

The article presents the results of research on the ecological conditions of carp farming in feeding ponds, which were carried out on the basis of the fishery “Yaniv”, which is part of PrJSC “Lviv Regional Fish Production Plant”. The research was carried out during the vegetation period of 2019 in accordance with the methods adopted in hydrobiology and fish farming. The hydrochemical state of the studied reservoirs and their biotic component, in particular zooplankton and zoobenthos, were analyzed. The results of studies of water quality of feeding ponds of the fishery “Yaniv” show that the hydrochemical parameters during the study period in the vast majority were within the maximum permissible concentrations set for fish farms; sometimes were registrated some indicators which slightly exceeded the normative limits, in particular permanganate oxidation, nitrites, phosphates, chlorides. The study of the natural forage base by zooplankton and zoobenthos revealed that the values of development of the studied aquatic organisms corresponded to the limits of development, which are characteristic of the ponds of the studied type of the Forest-Steppe zone. The values of zooplankton biomass in the experimental ponds were in the range of 5.3–12.5 g/m3. The dynamics of zooplankton development in feeding ponds shows its maximum development in early summer and some decrease in the second half of the vegetation season. In general, the basis of its biomass was consisted of Cladocera (Daphnia magna Straus, Bosmina longirostris, Daphnia cucullata Sars, Ceriodaphnia quadrangula OF Müller, Moina rectirostris Leydig), representatives of Copepoda (Thermocyclops crassus Fischer), Calanoida (Diaptomus castor Jurine, Eudiaptomus coeruleus Fischer) and Rotatoria (Brachionus diversicornis Daday, B.calyciflorus Pallas, Filinia longiseta Ehrb., Keratella cochlearis Gosse). Cladocera and Copepoda made the largest contribution to biomass, while Rotatoria had almost twice less share of total biomass. Indicators of zoobenthos biomass in ponds were in the range of 4.9–6.8 g/m2. The maximum development of benthic organisms was observed in late spring. The basis of biomass of zoobenthos was mainly consisted of insect larvae and oligochaeta.

Citizen science data (CSD) have the potential to be a powerful scientific approach to assess, monitor and predict biodiversity. Here, we ask whether CSD could be used to predict biodiversity of recently constructed man-made habitats. Biodiversity data on adult dragonfly abundance from all kinds of aquatic habitats collected by citizen scientists (volunteers) were retrieved from the Swedish Species Observation System and were compared with dragonfly abundance in man-made stormwater ponds. The abundance data of dragonflies in the stormwater ponds were collected with a scientific, standardized design. Our results showed that the citizen science datasets differed significantly from datasets collected scientifically in stormwater ponds. Hence, we could not predict biodiversity in stormwater ponds from the data collected by citizen scientists. Using CSD from past versus recent years or from small versus large areas surrounding the stormwater ponds did not change the outcome of our tests. However, we found that biodiversity patterns obtained with CSD were similar to those from stormwater ponds when we restricted our analyses to rare species. We also found a higher beta diversity for the CSD compared to the stormwater dataset. Our results suggest that if CSD are to be used for estimating or predicting biodiversity, we need to develop methods that take into account or correct for the under-reporting of common species in CSD.

The enigmatic and poorly studied sturgeon genus Pseudoscaphirhynchus (Scaphirhynchinae: Acipenseridae) comprises three species: the Amu Darya shovelnose sturgeon (Pseudoscaphirhynchus kaufmanni (Bogdanow)), dwarf Amu Darya shovelnose sturgeon P. hermanni (Kessler), and Syr Darya shovelnose sturgeon (P. fedtschenkoi (Bogdanow). Two species – P. hermanni and P. kaufmanni – are critically endangered due to the Aral Sea area ecological disaster, caused by massive water use for irrigation to support cotton agriculture, subsequent pesticide pollution and habitat degradation. For another species – P. fedtschenkoi – no sightings have been reported since 1960-s and it is believed to be extinct, both in nature and in captivity. In this study, complete mitochondrial (mt) genomes of these three species of Pseudoscaphirhynchus were characterized using Illumina and Sanger sequencing platforms. Phylogenetic analyses showed the significant divergence between Amu Darya and Syr Darya freshwater sturgeons and supported the monophyletic origin of the Pseudoscaphirhynchus species. We confirmed that two sympatric Amu Darya species P. kaufmanni and P. hermanni form a single genetic cluster, which may require further morphological and genetic study to assess possible hybridization, intraspecific variation and taxonomic status and to develop conservation measures to protect these unique fishes.

���������������������� ��������������, ���������������������������� ���������������������������� ���� ������������ �� ������������ ������������������������������ ��������������. ������������ �������� ������������������������ ������������������ �������������������������� �� ���������������������������� ���������������� �������������������������� �� ������������ ���� ������������������ �� ����������������, ���������������� ���������������� �������������������� ��������., The reports presented by hydrobiologists at the First and Second Hydrological Congresses are discussed. This kind of retro-chronicle allows one to get acquainted with the domestic leaders of hydrobiology during their youth and maturity, to show the development of the ideas presented.

Ūdens ekosistēmās zooplanktons ir vidusposms, kas darbojas kā enerģijas pārneses starpnieks starp producentiem (mikroskopiskajām aļģēm jeb fitoplanktonu) un gala konsumentiem (zivīm), tādejādi nodrošinot pelaģiāles barības tīkla funkcionēšanu. Šajā promocijas darbā analizēta zooplanktona daudzveidība saistībā ar vides faktoriem. Kopumā plašā empīriskā informācija sniedz vispārīgu izpratni par mezozooplanktona un tā daudzveidības dinamiku iesāļūdens ekosistēmā, atļaujot pilnvērtīgi izvērtēt tās potenciālo pielietojumu vides stāvokļa novērtēšanā, identificējot gan iespējas, gan izaicinājumus turpmākajam darbam šajā virzienā. Promocijas darba galvenie rezultāti publicēti četrās SCOPUS indeksētās publikācijās. Darbā iekļauti arī nepublicēti dati. Galvenie rezultāti norāda, ka mezozooplanktona funkcionālo daudzveidību kontrolē abiotiskie faktori, ja dzīvotne ir homogēna vertikālajā dimensijā (kā tas novērots Rīgas līča piekrastē). Savukārt, ja dzīvotne ir heterogēna, sadalīta vairākās mikrodzīvotnēs jeb nišās (kā tas novērots Rīgas līča atklātajos ūdeņos), noteicošie ir biotiskie faktori, piemēram, plēsonība un konkurence. Mezozooplanktona funkcionēšanu aprakstošais indikators, kas testēts šajā darbā, uzrāda pārliecinošus rezultātus tieši Rīgas līča atklātajos ūdeņos, kur, kā jau minēts, zooplanktona daudzveidība lielā mērā ir biotisko mijiedarbību kontrolēta. Līdz ar to secinu, ka mezozooplanktona daudzveidības dinamika sniedz informāciju par atklāto ūdeņu pelaģisko barības tīklu kopumā, un to var izmantot, lai novērtētu vides stāvokli tajos. Savukārt piekrastes ūdeņu funkcionēšana krasi atšķiras no atklātajiem ūdeņiem. Vides stāvokļa novērtēšana piekrastē, pamatojoties uz mezozooplanktona cenozes daudzveidības parametriem, ir apgrūtināta spēcīgas un mainīgās abiotisko faktoru ietekmes dēļ. Atslēgas vārdi: funkcionālā daudzveidība; Baltijas jūra; zooplanktons; pelaģiāle; vides stāvoklis, Zooplankton are an essential component in the pelagic food web, linking primary production to higher trophic levels, thereby playing a key role in the functioning of aquatic ecosystems. Here, in the doctoral thesis, I analyse zooplankton diversity in relation to environmental factors. The extensive empirical information provides a general understanding of the dynamics of mesozooplankton and its diversity in the brackish water ecosystem, allowing to evaluate the potential in assessing the environmental status, identifying both opportunities and challenges for further work in this field. The main results of the doctoral thesis are published in four SCOPUS publications. Unpublished data are also included in the dissertation. The main results indicate that the functional diversity of mesozooplankton is primarily controlled by abiotic factors if the habitat is homogeneous along the vertical dimension (as observed in the coastal regions of the Gulf of Riga). On the other hand, if a habitat is heterogeneous – divided into several microhabitats or niches – (as observed in the open waters of the Gulf of Riga), biotic factors, such as predation and competition, are decisive. The indicator describing the functioning of mesozooplankton shows convincing results in the open waters of the Gulf of Riga, where, as already mentioned, the diversity of zooplankton is largely controlled by biotic interactions. Therefore, I conclude that the dynamics of mesozooplankton diversity provide information on the pelagic food web in open water regions thus they can be used to assess the environmental status there. The functioning of coastal waters, on the other hand, is very different from that of open waters. The environmental status assessment based on the diversity parameters of mesozooplankton for the coastal environments is difficult due to the strong and variable influence of abiotic factors. Key words: Functional diversity; Baltic Sea; zooplankton; palagia; environmental status

В статье впервые предпринята попытка изложить биографию М.М. Ивановой-Берг и рассказать о ее работе на педагогическом поприще и научных трудах в области ихтиологии. Ее жизнь пришлась на тот период, когда в обществе изменялось положение женщин и они все увереннее доказывали свое право и возможность работать научно наравне с мужчинами. Этот процесс получил дополнительный импульс в годы социалистического строительства в условиях декларированного социального равенства. М.М. Иванова-Берг, еще в предреволюционные годы окончившая один из лучших вузов столицы, внесла существенный вклад в становление ленинградской высшей и профессиональной школы, активно участвовала в экскурсионном и краеведческом движении, вписала свою главу в изучение водной фауны Северо-Запада России. Значительную поддержку в научных исследованиях ей оказал муж — зоолог Л.С. Берг, в известной степени руководивший ее работой. Ранее автором было сделано сообщение, посвященное М.М. Ивановой-Берг1. Его содержание в настоящей статье значительно расширено, прежде всего за счет привлечения материалов из архивов Санкт-Петербурга., The article attempts first to discover the biography of M.M. Ivanova-Berg and to narrate her pedagogical activities as well as scientific research in ichthyology. During her life, there was huge social change in the status of women; as a result, they worked as successful as men, including scientific sphere. In the age of building socialism, the officially declared social equality gave further impetus to the process. Yet before the revolution, M.M. Ivanova-Berg finished one of the best higher educational institutions of St. Petersburg, and in after years she significantly contributed to the formation of the higher and professional education in Leningrad, actively developed excursion activities and regional studies, added value to the research into the aquatic fauna of Northwestern Russia. It was her husband L.S. Berg, a zoologist and geographer, who highly supported and even directed her research works. The author has already written a short report on M.M. Ivanova-Berg. Now the article broadens its scopes, thanks to the documents of St. Petersburg archives.

Статья посвящена жизни и деятельности выдающегося организатора науки, зоолога и гидробиолога, заведующего гидробиологическим отделом Зоологического института АН СССР, профессора Владимира Ивановича Жадина во время Великой Отечественной войны. Описан предвоенный период времени, жизнь в блокадном Ленинграде в первый, самый сложный год войны, эвакуация в Сталинабад и научная работа в Таджикистане в 1942–1945 гг. В основе работы — неизвестные материалы Научного архива Зоологического института РАН (НА ЗИН РАН) и Санкт-Петербургского филиала Архива РАН (СПбФ АРАН). Документы, впервые введённые в научный оборот, позволяют яснее представить и глубже понять причины тех или иных действий учёных в сложный военный период времени, оценить их способность приспособиться к новым условиям жизни и быстро перестроиться в переломные моменты. Проанализирована роль В.И. Жадина как организатора научных работ, необходимых для народного хозяйства в данный момент и в данном месте. Умение находить выход из сложившейся ситуации и принимать правильное решение в том или ином случае способствовало как обеспечению научного процесса, так и личному благосостоянию его семьи. Энергия, работоспособность и целеустремлённость В.И. Жадина позволили ему достойно пройти сложнейший период в жизни нашей страны., This article is devoted to the professional and personal life of Professor Vladimir Ivanovich Zhadin, an outstanding research organiser, zoologist and hydrobiologist, head of the Department of Hydrobiology and its malacological section at the Zoological Institute of the USSR Academy of Sciences, during the Great Patriotic War. It describes the pre-war period, his life in the besieged Leningrad in the first and the most difficult year of the War, evacuation to Stalinabad, and his research conducted in Tajikistan in 1942–1945. The unknown materials from the Scientific Archive of the Zoological Institute of the Russian Academy of Sciences (NA ZIN RAS) and the St. Petersburg Branch of the Archive of the Russian Academy of Sciences (SPbF ARAN) were used in this article. The documents, for the first time introduced for scientific use, allow us to better understand the reasons behind some of the scientists’ actions during the difficult wartime period and appreciate their ability to adapt to new circumstances and quickly adjust themselves during critical moments. In this biographical sketch, we highlight the role of V.I. Zhadin as an organiser of scientific research when and where necessary for the country’s national economy. His ability to find a solution in a difficult situation and make the right decision helped him to secure both the research process and his family’s well-being. V.I. Zhadin’s energy, hard work and determination allowed him to go through the country’s most difficult period with dignity.

The study of Avilés Canyon System has been done within the framework of the EU-funded Nature + LIFE INDEMARES (07/NAT/E/ 000732) and INTEMARES (LIFE15 IPE ES 012) projects; ST received funding from the grant PID2020-117115GA-100 funded by MCIN/AEI/10.13039/50110001103 (...), Ríos, P., Altuna, Á., Frutos, I., Manjón-Cabeza, E., García-Guillén, L., Macías-Ramírez, A., Ibarrola, T.P., Gofas, S., Taboada, S., Souto, J., Álvarez, F., Saiz-Salinas, J.I., Cárdenas, P., Rodríguez-Cabello, C., Lourido, A., Boza, C., Rodríguez-Basalo, A., Prado, E., Abad-Uribarren, A., Parra, S., Sánchez, F., Cristobo, J.

В 2021 г. мировая экология отметила сразу несколько знаменательных дат. Прежде всего, исполнилось 155 лет с того момента, когда сама эта наука получила своё наименование. На фоне такого глобального события, как рождение новой науки, юбилеи отдельных учёных неизбежно хочется соотнести с её развитием. И экология в этом отношении оказывается крайне благодатным материалом. Имя Владимира Ивановича Жадина, проработавшего в стенах Зоологического института РАН (ЗИН) в Санкт-Петербурге 40 лет, сегодня в основном связывают с такими классическими для любого зоолога и гидробиолога пособиями, как «Моллюски пресных и солоноватых вод СССР» и многотомная «Жизнь пресных вод СССР». Между тем научное наследие учёного включает множество теоретических вопросов современной экологии. Среди них особое место занимает его теория биологической продуктивности водоёмов (1940 г.)., In 2021, the world ecology celebrated several significant dates at once. First of all, 155 years have passed since the moment when this science itself received its name. Against the backdrop of such a global event as the birth of a new science, the anniversaries of individual scientists inevitably want to be correlated with its development. And ecology in this respect is extremely fertile material. The name of Vladimir Ivanovich Zhadin, who worked within the walls of the Zoological Institute of the Russian Academy of Sciences (ZIN) in St. Petersburg for 40 years, today is mainly associated with such classic textbooks for any zoologist and hydrobiologist as "Mollusks of fresh and brackish waters of the USSR" and the multi-volume "Life of Fresh Waters THE USSR". Meanwhile, the scientific heritage of the scientist includes many theoretical issues of modern ecology. Among them, a special place is occupied by his theory of the biological productivity of water bodies (1940).

A espécie Cyanocyclas brasiliana (Deshayes, 1854) é endêmica da América do Sul e ocorre no norte do Brasil, nos estados do Amazonas, Pará e Piauí. O presente estudo foi realizado no estuário do Rio Parnaíba, Piauí, Brasil. O limite de tolerância e a sobrevivência do bivalve de água doce Cyanocyclas brasiliana, submetido a um gradiente de salinidade crescente, foi avaliado em condições de laboratório. Os espécimes (19,49 a 26,47 mm) foram mantidos em recipientes com 2 litros de água com aeração constante e densidade de 2,5 animais por litro. Foram realizados 7 tratamentos (salinidades de 0, 1, 2, 3, 4, 5 e 6) com 5 repetições por tratamento. Nas primeiras 36 horas não houve óbito de nenhum indivíduo; a mortalidade iniciou após 48 horas em 3, 4, 5 e 6‰; foi mais significativo de 72 a 96 horas para tratamentos variando de 2 a 6‰ e todos os espécimes para tratamentos de 2 e 3‰ morreram de 120 a 144 horas. A CL50 varia de 3,1 às 72 h e 3,3 às 84 h, portanto a salinidade média limitante foi de 3,2‰ e essa espécie é caracterizada como estenohalina. O tempo letal de morte (LT50) foi: 81,8; 82,3; 78,5; 61,1 e 63,5 h para salinidades de 2, 3, 4, 5 e 6‰, respectivamente. Essa espécie não suporta grandes variações de salinidade em condições experimentais, estando bem adaptada para sobreviver em salinidades entre 0 e 1., SI

The paper deals with the main historical moments of the Caspian sturgeon population dynamics and the formation of their stocks. The participation of researchers of the Department of Ichthyology and Hydrobiology of Saint-Petersburg State University in creating the concept of sturgeon conservation in the Caspian Sea and the specialized institute of sturgeon farming in Astrakhan was highly appreciated. The materials on the contribution of the Department’s researchers to the study of the physiological state of sturgeon producers, improving their quality, survival and safety in the conditions of artificial breeding of these species are presented. The data on the reduction of the sturgeon abundance reared and released into the Caspian Sea by the Caspian littoral states are presented. A description of the current state of the sturgeon of the Caspian basin is given. The data on changes in stocks, the structure of the spawning part of the population and reproduction of the beluga, Russian sturgeon and stellate sturgeon in the Volga-Caspian basin under the conditions of the prohibition of their commercial fishing are analyzed. It was shown that during the years of the ban, the abundance and stocks of sturgeon and biological indicators of breeding migrants to spawn in the Volga continued to decrease and the proportion of females among them, which is associated with the illegal catch of sturgeon, comparable in scale to the commercial fishery before the ban was introduced. Reduced natural (up to its complete cessation in the Beluga) and artificial reproduction of sturgeons are stated. Only observing the moratorium on sturgeon fishing in all the Caspian littoral states, strengthening the protection of fish at feeding grounds and spawning migrations can preserve and restore their unique Caspian populations.

The present article is dedicated to the 90th anniversary of the foundation of the Department of Ichthyology and Hydrobiology in Saint-Petersburg State University, as well as to the formation of ichthyological school by talented scientist and bestow teacher Professor Nikolai Lvovich Gerbilcky. The results of fundamental works which were fulfilled during much time when using the principle of ecological histophysiological analysis laid by N.L. Gerbilsky are shown in this article. Also the results of the analysis of species adaptations connecting with the reproduction of fishes and with survival of its progeny when using this new method were presented. The basic principles of the biotechnology of fish reproduction in industrial conditions were created because of these results. The sphere of the principles of morphological-physiological analysis were expended and continued by following leaders of the Department and Laboratories – the schoolers and the followers of N.L. Gerbilsky. The mechanisms of hormonal regulation of fish’s gametogenesis were studied and the patterns of phase changes in the regulation and ecological – physiological staging of fish’s gametogenesis were opened by B.N. Kazansky. Fundamental investigations of osmotic and ionic regulation in different species of acipenserids and salmonids from the perspective of ecological morphological physiology when using present experimental methods leaded up to the creation of new direction in the study of fish osmoregulation and its adaptation to water with different salinity by L.S. Krayushkina and her pupils and colleagues. The mechanisms of regulation of the gametogenesis and the functions of sex gonads, the differentiation of fish sex and the influence of extremal factors on the process of gameto- and gonad genesis in different fishes were investigated by G.M. Persov and his Laboratory of Experimental Ichthyology. The use and the development of the principle of Gerbilsky’s method outside the Department by his pupils were presented: in the creation of the theory of functional basis of fish migrations, in the studies of endocrine regulation of reproductive cycle in acipenserids and salmonids by I.A. Barannikova and colleagues of her Laboratory. Structural and functional peculiarities of hypothalamic-hypophysial neurosecreting system of fishes were studied by A.L. Polenov. The continuation of traditional ruse to the analysis of different fish adaptations were demonstrated in the investigations of the ichthyologists at present time.

The aquatic ecological health status was focused on the Huai River Basin (HRB) from the aspects of water quantity, water quality, water ecology, river connectivity, and riparian habitat environment. Ten monitoring sections were set up in the middle and upper reaches of HRB, and 5 experiments of each section were conducted in July and December from 2012 to 2014. Thus, relevant data on the species, the density of phytoplankton, zooplankton and benthic animals, the concentration of water physicochemical variables, and riparian habitat quality were obtained. Eleven key impact factors were chosen using frequency statistics, theoretical analysis, and correlation analysis methods, forming the evaluation index system of aquatic ecological health. Then, the indicator weight value was determined by the combined weight method, and the health degree was evaluated by the comprehensive index method. On the whole, the aquatic ecological health degree of the upper sections (D1 ~ D3) of the Shaying River ranges from 0.334 to 0.927, which is generally in a "sub-healthy" state. The aquatic ecological health degree of the main section of the Huai River (D8 ~ D10) ranges from 0.362 to 0.777, which is in the "critical" or "sub-healthy" state. The Huaidian Sluice (D5) and Fuyang Sluice (D6) in the middle and lower reaches of the Shaying River had the worst aquatic ecological health. Its water ecological health range is 0.283-0.523, and most of them are under "sub-pathologic." The research results have important theoretical and practical significance. They can enrich the evaluation theories and methods of river aquatic ecological health, help to grasp the aquatic ecological health status in HRB, and provide basic support for aquatic ecological protection and water pollution control in sluice-controlled rivers.

A variety of mammals suppress reproduction when they experience poor physical condition or environmental harshness. In many marine mammal species, reproductive impairment has been correlated to polychlorinated biphenyls (PCBs), the most frequently measured chemical pollutants, while the relative importance of other factors remains understudied. We investigate whether reproductively active females abandon investment in their foetus when conditions are poor, exemplified using an extensively studied cetacean species; the harbour porpoise (Phocoena phocoena). Data on disease, fat and muscle mass and diet obtained from necropsies in The Netherlands were used as proxies of health and nutritional status and related to pregnancy and foetal growth. This was combined with published life history parameters for 16 other areas to correlate to parameters reflecting environmental condition: mean energy density of prey constituting diets (MEDD), cumulative human impact and PCB contamination. Maternal nutritional status had significant effects on foetal size and females in poor health had lower probabilities of being pregnant and generally did not sustain pregnancy throughout gestation. Pregnancy rates across the Northern Hemisphere were best explained by MEDD. We demonstrate the importance of having undisturbed access to prey with high energy densities in determining reproductive success and ultimately population size for small cetaceans.

The family Marnaviridae comprises small non-enveloped viruses with positive-sense RNA genomes of 8.6–9.6 kb. Isolates infect marine single-celled eukaryotes (protists) that come from diverse lineages. Some members are known from metagenomic studies of ocean virioplankton, with additional unclassified viruses described from metagenomic datasets derived from marine and freshwater environments. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the family Marnaviridae, which is available at ictv.global/report/marnaviridae.

Jargon is the specialised vocabulary of any science: it allows the creation of new terms to define concepts and it removes ambiguity from scientific communication. Yet, it may also hinder understanding for a broader audience. Given that the Journal of Limnology has jargon in its title, we here investigate the impact of the term ‘limnology’ on the way limnologists work, publish their research, and attract the interest of other scientists. We do so by comparing scientometric features of papers published from 1965 to 2020 that used the term ‘limnology’ against papers on similar topics but that used the term ‘lake ecology’ or ‘hydrobiology’, and to the marine counterpart of papers that used the term ‘oceanography’. We found that papers using the term limnology score worse than those of the other topics in terms of both publication output and scientific impact. Limnologists may need to use other terms in addition to ‘limnology’ to reach a broader scientific audience.

While satellite remote sensing of ocean color is a viable tool for estimating large-scale patterns of chlorophyll-a (Chl-a) and global ocean primary production, its application in coastal waters is limited by the complex optical properties. An exploratory study was conducted in the Gulf of Trieste (Adriatic Sea) to assess the usefulness of Sentinel-3 satellite data in the Slovenian national waters. OLCI (Ocean and Land Colour Instrument) Chl-a level 2 products (OC4Me and NN) were compared to monthly Chl-a in-situ measurements at fixed sites from 2017 to 2019. In addition, eight other methods for estimating Chl-a concentration based on reflectance in different spectral bands were tested (OC3M, OC4E, MedOC4, ADOC4, AD4, 3B-OLCI, 2B-OLCI and G2B). For some of these methods, calibration was performed on in-situ data to achieve a better agreement. Finally, L1-regularized regression and random forest were trained on the available dataset to test the capabilities of the machine learning approach. The results show rather poor performance of the two originally available products. The same is true for the other eight methods and the fits to the measured values also show only marginal improvement. The best results are obtained with the blue-green methods (OC3, OC4 and AD4), especially the AD4SI (a designated fit of AD4) with R = 0.56 and RMSE = 0.4 mg/m³, while the near infrared (NIR) methods show underwhelming performance. The machine learning approach can only explain 30% of the variability and the RMSE is of the same order as for the blue-green methods. We conclude that due to the low Chl-a concentration and the moderate turbidity of the seawater, the reflectance provided by the Sentinel-3 OLCI spectrometer carries little information about Chl-a in the Slovenian national waters within the Gulf of Trieste and is therefore of limited use for our purposes. This requires that we continue to improve satellite products for use in those marine waters that have not yet proven suitable. In this way, satellite data could be effectively integrated into a comprehensive network that would allow a reliable assessment of ecological status, taking into account environmental regulations.

In some cases, wildlife management objectives directed at multiple species can conflict with one another, creating species trade-offs. For managers to effectively identify trade-offs and avoid their undesirable outcomes, they must understand the agents involved and their corresponding interactions. A literature review of interspecific trade-offs within freshwater and marine ecosystems was conducted to illustrate the scope of potential interspecific trade-offs that may occur. We identified common pitfalls that lead to failed recognition of interspecific trade-offs, including, single-species management and limited consideration of the spatial and temporal scale of ecosystems and their management regimes. We devised a classification framework of common interspecific trade-offs within aquatic systems. The classification can help managers determine whether the conflict is species based through direct relationships (i.e., predator-prey, competition, other antagonistic relationships) or indirect relationships involving intermediate species (i.e., conflict-generating species) or whether the conflict is driven by opposing management objectives for species that would otherwise not interact (i.e., nontarget management effects). Once the nature and scope of trade-offs are understood, existing decision-making tools, such as structured decision-making and real-options analysis, can be incorporated to improve the management of aquatic ecosystems. Article Impact Statement: A synthesis of interspecific trade-offs in aquatic ecosystems supports their identification and resolution.Un Marco de Clasificación para Compensaciones Interespecíficas en Ecología Acuática Resumen En algunos casos, los objetivos del manejo de fauna dirigidos a muchas especies pueden entrar en conflicto entre sí creando compensaciones entre las especies. Para que los manejadores identifiquen efectivamente estas compensaciones y eviten sus resultados no deseados, deben entender a los agentes involucrados y sus interacciones correspondientes. Se realizó una revisión literaria de las compensaciones interespecíficas dentro de los ecosistemas marinos y de agua dulce para ilustrar el alcance de las compensaciones interespecíficas que pueden ocurrir. Identificamos dificultades comunes que llevan al reconocimiento fallido de las compensaciones interespecíficas, incluyendo el manejo de una sola especie y sus regímenes de manejo. Diseñamos un marco de clasificación de compensaciones interespecíficas comunes dentro de los ecosistemas acuáticos. La clasificación puede ayudar a los manejadores a determinar si el conflicto está basado en las especies por sus relaciones directas (es decir, depredador-presa, competencia, otras relaciones antagonistas) o por relaciones indirectas que involucran a otras especies (es decir, efectos del manejo de especies que no son el objetivo). Una vez que se entiende la naturaleza y el alcance de las compensaciones, las herramientas de toma de decisión existentes, como la toma estructurada de decisiones y el análisis de opciones reales, pueden incorporarse para mejorar el manejo de los ecosistemas acuáticos.

On January 6, 2020, Lyudmila Vasilyevna Ilyash, an outstanding hydrobiologist, Doctor of Biological Sciences, professor of the Department of General Ecology and Hydrobiology of the Biological Faculty of Lomonosov Moscow State University. Research interests L.V. Ilyash covered a wide range of issues and topics related to the ecology of marine planktonic and ice algae, patterns of formation of the structure and functioning of phytocenoses in marine ecosystems

The length-weight relationships (LWRs) of Clupeonella cultriventris and Clupeonella muhlisi were analysed. Fish samples were collected gill nets (10 mm mesh sized) from the Buyukcekmece Reservoir and Kucukcekmece Lagoon April and June 2016. Samples from Durusu Reservoir and Uluabat Lake were obtained from Istanbul University Science Faculty Hydrobiology Museum. The values of parameter b in the LWR equations varied from 3.177 (Kucukcekmece Lake population) to 3.496 (Buyukcekmece Reservoir population) for C. cultriventris and 3.258 (Uluabat Lake) for C. muhlisi.

In current paper we presented the dynamics of the macrozoobenthos in Eastern Sivash depending on temporal and spatial salinity fluctuations from pleiomesohaline to polyhaline and hyperhaline. We shown that the highest species richness and biomass were observed in polyhaline conditions at the lowest salinity values, and the maximum density was in pleiomesohaline conditions. The lowest species riches and biomass were observed in hyperhaline conditions. Keywords: Eastern Sivash; macrozoobenthos; distribution; abundance; biomass References Almazov, O.M. (1960). Hydrochemical characteristic of eastern Sivash: Biological substantiation of the development of the mullet farming of Eastern Sivash and Molochnyi Estuary. Proceedings of the Institute of Hydrobiology Academy of Sciences of the USSR, 35, 10-18. (In Russian) Anistratenko, V.V., Anistratenko, O.Yu., Khaliman, I.A. (2007). Composition of the molluscs fauna of the Sea of Azov as a function of its salinity regime. Dopovidi NANU, 4, 161-166. (In Russian) Anistratenko, V.V., Khaliman, I.A., Anistratenko, O.Yu. (2011). The Molluscs of the Sea of Azov. Kiev: Naukova dumka. (In Russian) Antonovskiy, O.G., Degtyarenko, O.V. (2009). Comparative description of fresh and saline water mollusks of North Azov region. Recent questions biology, ecology and chemistry: electric. science. profession. kind., 2, 33-45. Available at: http://sites.znu.edu.ua/bio-eco-chem-sci. (In Ukrainian) Antonovskiy, O.G., Gaponova, V.V. (2008). Sivash macrozoobenthos on the present state of ecosystem development. Science and Practice: Procedd. Int. Sc. Conf. (Poltava, March 3-7, 2008). Poltava: Poltava National Agrarian University (In Ukrainian) Antonovskiy, O.G., Krutikova, O.O. (2012). Dynamics of macrozoobenthos of Eastern Sivash in conditions of hydroecological changes. Bulletin of the Zaporizhzhya National University. Series Biological sciences, 3, 96-103. (In Ukrainian) Grintsov, V., Sezgin, M. (2011). Manual for the identification of Amphipoda from the Black Sea. Sevastopol. Khaliman, I.A., Anistratenko, V.V., Degtyarenko, E.V. (2015). Regional peculiarities of malacofauna in waterbodies of different types of the North-West Azov Sea Coast. Dopovidi NANU, 11, 98-105. doi.org/10.15407/dopovidi2015.11. (In Russian) Kiseleva, M.I. (2004). Polychaete worms (Polychaeta) of the Black and Azov seas. Apatity: A publication of the Kolskiy Scientific Center of the Russian Academy of Sciences. (In Russian) Marushkina, O.O. (2013). Features of distribution and ecology of macrozoobenthos of Eastern Sivash. Proceedings of the Zoological Museum, 44, 10-41. (In Ukrainian) Methods of hydroecological researches of surface waters. (2006). Romanenko, V.D. (Ed.). Kyiv: Logos. (In Ukrainian) North-western part of the Black Sea: biology and ecology: monograph. (2006). Zaitsev, Yu.P., Aleksandrov, B.G., Minichev, G.G. (Eds.). Kyiv: Naukova Dumka. (In Russian) Pauli, V.L. (1936). To the biology of Sivash. Proceedings of Kharkiv A. M. Gorky State University. 6-7, 273-276. (In Ukrainian) Stocker, G., Bergmann, A. (1977). Ein Modell der Dominanzstruktur und seine Anwendung. 1 Modelbildung. Modellrealisierung. Dominanzklassen . Arch. Naturchutz. und Landschaftsforschung, 17 (1), 1-26 (in German). Stolyarov, A.P. (2013). Features of the structural organization of the macrobenthos community in estuarine ecosystems (Kandalaksha Bay, the White Sea). Succeeding in modern biology, 133 (2), 191-208. (In Russian) Tarasov, N.I. (1927). To Syvash hydrobiology. News of State Hydrobiological Institut., 19, 59-68. (In Russian) Vinogradova, Z.A., Vinogradov, K.O. (1960). Zoobentos of the Eastern Sivash. Proceedings of the Institute of Hydrobiology, Academy of Sciences of the USSR., 35, 50-71. (In Ukrainian) Vorobiev, V.P. (1940). Hydrobiological essay of Eastern Sivash and the possibility of its fishery use. Proceedings of Azov-Black Sea Research Institute of Marine Fisheries and Oceanography, 12, 69-164. (In Russian) Vorovka, V.P. (2013). Features of the hydrological connection of Sivash with the Sea of Azov. Hydrology, hydrochemistry and hydroecology, 2 (29), 84-89. (In Ukrainian) Zhadin, V.I. (1960). The Methods of hydrobiological study. Moscow: Vysshaya shkola. (In Russian)

Preliminary results of the Transarktika-2019 winter expedition in the Arctic Ocean on the R/V “Akademik Tryoshnikov” are presented. The expedition program included studies on meteorology, hydrology, hydrochemistry, hydrobiology, geology, geophysics and an extensive complex of ice measurements in the Northern Barents Sea from the drifting ice and from the ship. During the expedition, it was possible to complete a wide range of tasks. The data obtained comprise a unique material for a comprehensive study of the current state of the environmental conditions in the Barents Sea. This paper highlights the most significant preliminary results of multidisciplinary observations in various environments, which will be further comprehensively analyzed and published in separate thematic articles.

In the study of hydrobiology of water basins, a separate study of higher plants is required. Higher plants growing in water for aquatic organisms remain not only a habitat, a nutrient, a source of oxygen, but they are also important in the course of many biological processes in this environment. The vegetation of aquatic and coastal aquatic plants weakens the rate of flow of water, impedes the movement of silt and mineral particles, has anti-erosion significance and is used to strengthen the banks of water bodies. Among the higher aquatic and coastal aquatic plants, many species have diverse uses as a raw material for the pulp and paper, medical, perfume industries, building materials, fertilizers for the fields, food for people and pet food.

Vitamin B1 is an essential exogenous micronutrient for animals. Mass death and reproductive failure in top aquatic consumers caused by vitamin B1 deficiency is an emerging conservation issue in Northern hemisphere aquatic ecosystems. We present for the first time a model that identifies conditions responsible for the constrained flow of vitamin B1 from unicellular organisms to planktivorous fishes. The flow of vitamin B1 through the food web is constrained under anthropogenic pressures of increased nutrient input and, driven by climatic change, increased light attenuation by dissolved substances transported to marine coastal systems. Fishing pressure on piscivorous fish, through increased abundance of planktivorous fish that overexploit mesozooplankton, may further constrain vitamin B1 flow from producers to consumers. We also found that key ecological contributors to the constrained flow of vitamin B1 are a low mesozooplankton biomass, picoalgae prevailing among primary producers and low fluctuations of population numbers of planktonic organisms.

Information on the first findings of Gaillona rosea (Roth) Athanasiadis 2016:814 (Aglaothamnion roseum (Roth) Maggs & L’Hardy-Halos 1933:522) in the Russian part of the South-Eastern Baltic is given. Samples of algae in the Russian part of the South-Eastern Baltic along the coast of the Kaliningrad region at depths of 1–15 m were collected by diving method on the north coast of the Sambian Peninsula near Cape Taran and Cape Gvardeysky at the stations confined to hard ground. First samples of G. rosea collected from drifting mats of perennial algae Furcellaria lumbricalis and Polysiphonia fucoides were first registered along the west and north coast of the Sambian Peninsula (Cape Taran) at depths of 1.5–7 m in autumn 2015. The finding of the species in 2015 on the west coast of the Sambian Peninsula is the first registration for the coast of the Gdansk Bay. In July 2016, the species was found in samples at Cape Taran at a depth of 0.5 m. The length of the thalli does not exceed 3 cm. The species was registered with F. lumbricalis and P. fucoides, both in attached communities and in drifting mats. G. rosea is quite common in the Baltic Sea, with the exception of the Gdansk Bay and the northernmost part of the Baltic Sea, where the salinity is low. There is no data available on the abundance of the species in the adjacent Lithuanian waters. The species is rarely registered in the Russian part of the South-Eastern Baltic, and therefore G. rosea is rare in the entire South-Eastern Baltic Sea.

The rate of linear and weight growth of triploid spat of oyster Crassostrea gigas in Donuzlav Liman (Black Sea, Crimea) was investigated. A quantitative relationship between the mass (W, g) of the whole oyster and the height of the shell (H, mm) is given (it is described by the equation W = 7 · 10-5 · Н3.1, R² = 0.78), as well as a quantitative relationship between the mass (W, g) of the whole oyster and the length of the shell (L, mm) (W = 3 · 10-4 · L3.12, R² = 0.65). The maximum rates of linear growth of triploid oysters T20 were registered in April (1.15 mm per day), of weight growth – in June (0.50 g per day) and August (0.61 g per day). It was shown that 27 % of triploid oysters T20 can reach commercial size after 6 months. It is recommended to use Pacific oysters of T20 size as a planting material on the shellfish farms in the Black Sea region.

Environmental DNA (eDNA) is an emerging biological monitoring tool that can aid in assessing the effects of forestry and forest manufacturing activities on biota. Monitoring taxa across broad spatial and temporal scales is necessary to ensure forest management and forest manufacturing activities meet their environmental goals of maintaining biodiversity. Our objectives are to describe potential applications of eDNA across the wood products supply chain extending from regenerating forests, harvesting, and wood transport, to manufacturing facilities, and to review the current state of the science in this context. To meet our second objective, we summarize the taxa examined with targeted (PCR, qPCR or ddPCR) or metagenomic eDNA methods (eDNA metabarcoding), evaluate how estimated species richness compares between traditional field sampling and eDNA metabarcoding approaches, and compare the geographical representation of prior eDNA studies in freshwater ecosystems to global wood baskets. Potential applications of eDNA include evaluating the effects of forestry and forest manufacturing activities on aquatic biota, delineating fish-bearing versus non fish-bearing reaches, evaluating effectiveness of constructed road crossings for freshwater organism passage, and determining the presence of at-risk species. Studies using targeted eDNA approaches focused on fish, amphibians, and invertebrates, while metagenomic studies focused on fish, invertebrates, and microorganisms. Rare, threatened, or endangered species received the least attention in targeted eDNA research, but are arguably of greatest interest to sustainable forestry and forest manufacturing that seek to preserve freshwater biodiversity. Ultimately, using eDNA methods will enable forestry and forest manufacturing managers to have data-driven prioritization for conservation actions for all freshwater species.

Aims This study was conducted to assess the presence and extent of differences in the gut microbiota of common bottlenose dolphins depending on rearing facilities. Methods and Results Faecal samples were collected from 16 common bottlenose dolphins at three aquaria in Japan. After extracting DNA from the faeces, the V3–V4 region of bacterial 16S rRNA was amplified and sequenced using Illumina MiSeq platform. The constituent phyla of the gut microbiota were similar among aquaria; however, the most dominant phylum differed depending on the facility, and the compositions of microbiota were remarkably varied at the family level among aquaria. The alpha diversity indices tended to differ among aquaria. Some bacterial families observed in terrestrial mammalian carnivores or carnivorous fish were detected, as well as several bacterial species suspected of being pathogenic in dolphins. Conclusion Our findings indicate that captive environmental conditions including prey and housing types may contribute to differences in the gut microbiota of the dolphins. Significance and Impact of the Study This is the first study revealing the differences in gut microbiota of captive dolphins among facilities. Our findings will provide valuable information for improving the health management of dolphins.