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Study of the sedimentation and erosion rates of the la Barra sector of the San Andrés de Tumaco navible channel, Nariño
No full textEl seguimiento de la evolución del fondo marino en canales navegables permite garantizar la navegación segura. En esta investigación se estimó la tasa de sedimentación y erosión a partir de datos batimétricos multihaz en el canal navegable de San Andrés de Tumaco (Nariño), específicamente en el sector denominado La Barra, para diferentes períodos entre 2019 y 2021. Además, se realizó el trazado de las líneas de costa para los años 2019, 2020 y 2021 con el objetivo de identificar la dinámica costera en la desembocadura de los esteros más cercanos al área de estudio y su relación como fuente de aportes de sedimentos. Por último, se analizaron datos de precipitación con el fin de relacionarlos como una variable forzante de transporte y aporte de sedimentos continentales en la bahía de Tumaco. Producto de estos análisis, en el sector La Barra se obtuvo el mayor volumen acumulado de sedimentación, con 188 881 m3 y de erosión con 150 245 m3, debido a que es el período más amplio observado. Adicionalmente, se calculó la tasa promedio de sedimentación de 24409 m3/mes, sin considerar el período más amplio. En el análisis espacio temporal de la línea de costa se evidenciaron sectores con cambios de acreción, retroceso y nulos o constantes; sin embargo, predominaron los procesos de acreción, asociados a acumulación de sedimentos continentales. Por otra parte, la relación entre la precipitación y el volumen cumulado de sedimentación en el sector La Barra se representó con la ecuación S = 56.591p + 15529, y con el volumen acumulado de erosión E = 48.749p - 5263.6. Basados en la estimación de la tasa de sedimentación/erosión, la dinámica costera y su correlación con la precipitación, como variable influyente en el transporte de sedimentos generadora de cambios morfológicos del fondo marino, las autoridades tomadoras de decisiones pueden proponer un ajuste en los procesos de remoción sobre el sector La Barra, que contribuya a una navegación segura en el canal de acceso al segundo puerto más importante del Pacífico colombiano.Monitoring the evolution of the seafloor in navigable channels ensures safe navigation. In this research, the sedimentation and erosion rates were estimated using multibeam bathymetric data in the navigable channel of San Andrés de Tumaco - Nariño, specifically in the sector known as "La Barra," for different periods between 2019 and 2021. Additionally, the coastline was traced for the years 2019, 2020, and 2021 to identify coastal dynamics at the estuary mouths closest to the study a rea and their relationship as sediment sources. Lastly, precipitation data were analyzed to establish its correlation as a forcing variable for sediment transport and continental sediment input into Tu maco Bay. As a result of these analyses, the sector of La Barra exhibited the highest accumulated sedimentation volume of 188 881 m3 and erosion volume of 150 245 m3, attributed to the longest observed period. Additionally, the average sedimentation rate was calculated as 24409 m3/month, exc/uding the longest period. The spatiotemporal analysis of the coastline revealed sectors with accretion, retreat, or which are stable or constant, with accretion processes predominating due to continental sediment accumulation. Furthermore, the relationship between precipitation and the accumulated sedimentation volume in La Barra sector is represented by the equation S = 56.591p + 15529, and for the accumulated erosion volume, E = 48.749p - 5263.6. Based on the estimation of sedimentation/erosion rates, coastal dynamics, and their correlation with precipitation as an influential variable in sediment transport, which generates morphological changes in the seafloor, decision-making authorities can propose adjustments in removal processes in the La Barra sector to ensure safe navigation in the access channel to Colombia's second most important Pacific port.PublishedNot Know
Размножение и условия, определяющие урожайность поколений азовской тюльки в период 1993–2022 гг.
No full textVariability in the yield of the Azov Sea tyulka (Azov Sea stocks of the Black Sea–Caspian sprat) generations affected by the environmental changes in 1993–2022 has been estimated. Stock assessments of the ichthyoplankton have been conducted in the Azov Sea in June for more than 50 years. Evaluation of the fingerling abundance is carried out in the course of the surveys with lampara nets in August. During the survey period, considerable environmental changes attributable to natural and anthropogenic factors have been identified; they heavily influence the yield of the Azov Sea tyulka generations.Дана оценка колебаний урожайности поколений тюльки в связи с изменениями условий обитания в период 1993–2022 гг. Исследования по оценке численности ихтиопланктона проводятся в Азовском море в июне более 50 лет. Учет численности сеголеток осуществляется в учетной лампарной съемке в августе. В течение анализируемого периода выявлено, что произошли значительные изменения условий, вызванные природными и антропогенными факторами, которые определяют урожайность поколений тюльки.PublishedNon Referee
Энергетический метаболизм Mytilus galloprovincialis в условиях низких pH морской воды
No full textThe problem of acidification of the World Ocean and predicting the consequences for its inhabitants is becoming more and more relevant every year. The effect of short-term pH fluctuations in coastal ecosystems on the physiology of calcifying organisms—bivalves—remains poorly understood. The energy metabolism of the Black Sea mussel Mytilus galloprovincialis was investigated for the marine environment in a wide pH range, from 8.2 to 6.65. Lowering the pH to 7.0–7.5 led to a 20–25 % reduction in oxygen consumption by molluscs. At lower pH (6.54–6.7), aerobic respiration sharply decreased by 85– 90 %, down to the minimum values (2.12–2.62 μgO2/g dry/h), and the organisms transitioned to anaerobic metabolism. The metabolic response of the mussels subjected to short-term pH changes (8.2→6.65→7.2) has been investigated. The oxygen consumption of molluscs exposed at the same pH of 7.2 depended on the direction of the change in pH. Thus, in the case of pH 6.65→7.2, the respiration intensity was 30 % higher compared to the values obtained under the acidification pH 8.2→7.2. The Black Sea mussel M. galloprovincialis is shown to have the capacity for survival in the marine environment characterized by the rapid fluctuations in pH that occur during the upwelling events in the coastal areas of the Black Sea.Проблема закисления Мирового океана и прогнозирования последствий для его обитателей с каждым годом становится все более актуальной. Остается малоизученным влияние краткосрочных колебаний pH в прибрежных экосистемах на физиологию кальцифицирующих организмов — двустворчатых моллюсков. Исследовали уровень энергетического метаболизма черноморской мидии Mytilus galloprovincialis в широком диапазоне рН морской среды, от 8,2 до 6,65. Понижение рН до 7,0–7,5 единиц привело к сокращению потребления кислорода моллюсками на 20–25 %. При более низких рН (6,54–6,7 ед.) аэробное дыхание резко уменьшалось на 85–90 % вплоть до минимальных значений (2,12–2,62 мкгО2/г сух/ч), и организмы переходили на анаэробный тип обмена. Исследовали метаболический отклик мидий в условиях краткосрочно меняющегося рН (8,2→6,65→7,2). Потребление кислорода моллюсками при одном и том же рН 7,2 зависело от направленности изменения рН морской среды. Так, при смене рН 6,65→7,2 интенсивность дыхания была на 30 % больше по сравнению со значениями, полученными при закислении рН 8,2→7,2. Показан потенциал выживаемости черноморских мидий M. galloprovincialis при быстрых колебаниях рН морской среды, возникающих при явлениях апвеллинга в прибрежных районах Черного моря.PublishedReferee
Exchange of Pb from Indian to Atlantic Ocean is driven by Agulhas current and atmospheric Pb input from South Africa.
No full textUsing a spatiotemporal dataset of dissolved lead (dPb) from the subtropical oceans surrounding South Africa, this study quantifies the exchange of dPb between the Indian and Atlantic Oceans. Despite the absence of a major Pb source within the South Atlantic sector and the complete phase-out of leaded petroleum in Southern Africa, the ecologically important southeast Cape Basin shows an elevated surface dPb concentration (21–30 pmol kg− 1). We estimated up to 90% of the measured dPb in surface waters of the Cape Basin was delivered from the Indian Ocean via the Agulhas Current (AC). Eddy dynamics and leakage at Agulhas retroflection result in an increased Pb flux from winter to summer, while a long-term (2008–2019) temporal change in dPb in the AC-derived water of Cape Basin was contemporaneous to a change in atmospheric Pb emissions from South Africa. The South Africanorigin atmospheric Pb, however, contributes first to the Agulhas waters in the West Indian Ocean, which is then transported to the South Atlantic, thereby regulating the dPb inventory of the Cape Basin. This indirect mechanism of Pb transfer emphasizes the importance of regulating Pb emissions from Southern Africa to protect rich fishing grounds associated with the Benguela marine ecosystem.Challenge 4, 9PublishedReferee
Нейронные сети как инструмент совершенствования математической модели движения судна
No full textUsing neural networks opens up great opportunities for studying mathematical models of ship motion. Correction by a network of identified parameters of the selected model should be as adequate as possible to the results of standard full-scale tests defined by the IMO Resolution N 137 of 2002. A mathematical model in displacements is considered, containing 16 parameters that determine the hydrodynamic forces acting on the ship's hull and steering gear, and is the source of a data set for training the network by randomly varying the parameters and subsequent computer testing. The standard maneuver is a steady-state circulation with fixation of the maneuvering elements: diameter, linear velocity, drift angle and angular velocity of rotation. Improving the quality of the model has consisted of changing its parameters and minimizing the mean square errors of the values of the maneuvering elements obtained during testing. For these purposes, a neural network with 16 inputs (model parameters) and four outputs (maneuvering elements for steady-state circulation) has been built. The data set for training the network was obtained using a program developed by the authors and intended for calculating parameters and conducting maneuver tests. A tanker with a displacement of 30,000 tons was chosen as a test object. Various options for network architecture and tools for working with it have been considered; the Statistica Neural Nets (SNN) software environment and the ANN package in the SciLab environment have been used. Comparative assessments of the results of working with these tools have been given.Использование аппарата нейронных сетей открывает большие возможности для исследования математических моделей движения судна. Коррекция с помощью сети идентифицированных параметров выбранной модели должна быть максимально адекватной результатам стандартных натурных испытаний, определенных резолюцией ИМО. Рассмотрена математическая модель в перемещениях, содержащая 16 параметров, определяющих гидродинамические усилия, действующие на корпус судна и рулевой орган, и являющаяся источником набора данных для обучения сети путем случайного варьирования параметров и последующего компьютерного испытания. Стандартным маневром выбрана установившаяся циркуляция с фиксацией маневренных элементов: диаметра, линейной скорости, угла дрейфа и угловой скорости поворота. Улучшение качества модели состояло в изменении ее параметров и минимизации средних квадратических погрешностей значений маневренных элементов, полученных при испытаниях. Для этих целей выстроена нейронная сеть с 16 входами (параметры модели) и четырьмя выходами (маневренные элементы для установившейся циркуляции). Массив данных для обучения сети получен с помощью программы, разработанной авторами и предназначенной для расчета параметров и проведения маневренных испытаний. В качестве объекта испытаний выбран танкер водоизмещением 30 000 т. Рассмотрены различные варианты архитектуры сети и инструменты работы с нею; использованы программная среда Statistica Neural Nets (SNN) и пакет ANN в среде SciLab; даны сравнительные оценки результатов работы с этими инструментами.PublishedReferee
The new BBNJ Agreement.
No full textIn the second video (2/6) of the series, Prof. Dr. Andree Kirchner (ISRIM) explains the historical background of the initiative and the negotiation processes, which lead to the adoption of the Agreement under the United Nations Convention on the Law of the Sea on the conservation and sustainable use of marine biological diversity of areas beyond national jurisdiction (BBNJ Agreement) on 19 June 2023 in New York. The presentation is part of the workshop "Conservation and sustainable use of marine biological diversity of areas beyond national jurisdiction (BBNJ)", which took place in the framework of the 9th Summer School on the European Union and the Law of the Sea (EULoS). It was organized by the Institute for the Law of the Sea and International Marine Environmental Law (ISRIM) and the University of Genoa on 1 September 2023. The workshop is a UN Ocean Decade Activity.Challenge 2: Protect and restore ecosystems and biodiversity;
Challenge 10: Change humanity’s relationship with the ocean.Publishe
Возможные сценарии формирования материкового стока и солености вод Азовского моря с учетом современных и перспективных тенденций изменения климата
No full textThe ongoing climate changes have a significant impact on the formation of the habitat conditions for the aquatic biological resources of the Azov Sea. Salinity of the Azov Sea waters and continental runoff, which role in maintaining the ecological well-being of the habitat of aquatic biological resources is paramount, has underwent particularly noticeable transformations. Relevance. Assessment of the degree of influence of ongoing and expected climate changes on the formation of abiotic parameters of the marine ecosystem is a prerequisite for planning the successful development of the fisheries industry of the Azov Sea Basin. The aim of this work is to assess the current and expected changes in the hydrometeorological parameters of the Azov Sea ecosystem, as well as to identify the most probable scenarios of changes in the Azov Sea salinity depending on the annual volume of continental runoff. Methods. The study is based on the data from AzNIIRKH database for the time range 1960–2020 collected over the course of the expedition surveys examining the Azov Sea hydrological regime and the data of the reference observation network of the Russian Federal Service for Hydrometeorology and Environmental Monitoring (Roshydromet). Methods of mathematical statistics, graphoanalytical construction, mapping and analogy have been used for the data analysis. Results. This paper assesses the changes in the hydrological regime of the Azov Sea based on the annual monitoring of the habitat of aquatic biological resources. Preliminary calculations have been performed, and new data on the changes in the parameters of the sea water balance equation not covered by monitoring over the past forty-five years have been presented. The most probable formation scenarios for the continental runoff and the Azov Sea water salinity for the future up to 2030 are considered, with the observed trend of climate warming taken into account. Conclusions. Both the climatic and anthropogenic factors have contributed to considerable changes in the current hydrometeorological regime of the Azov Sea. These changes have mainly been manifested in an increase in air and water temperatures, a decrease in wind activity, and in a reduced continental runoff, in the formation of which, since 2006, a prolonged low water content cycle has been observed. The shortage of river runoff and increased water evaporation rate, along with other factors, have induced an unprecedented increase in the Azov Sea salinity, the average annual value of which in 2021 reached a record high (14.97 %). In the most probable scenario (60 %) with the continuation of the low water content period and the continental runoff into the Azov Sea of about 22 km3 in volume, the average annual salinity of the Azov Sea, including Taganrog Bay, can reach 15±0.40 ‰ with a variation range from 14.5 to 16.5 ‰ in the sea itself (excluding Taganrog Bay). 2021 can serve as an analogous year in terms of salinity formation and its spatial distribution.Происходящие изменения климата оказывают существенное влияние на формирование условий среды обитания водных биологических ресурсов Азовского моря. Особенно ощутимые преобразования коснулись солености азовоморских вод и материкового стока, роль которых в поддержании экологического благополучия среды обитания водных биологических ресурсов первостепенна. Оценка степени влияния происходящих и ожидаемых изменений климата на формирование абиотических параметров экосистемы моря является необходимым условием для планирования успешного развития рыбохозяйственного комплекса бассейна Азовского моря. Цель данной работы — оценить современные и ожидаемые изменения гидрометеорологических параметров экосистемы Азовского моря, а также определить наиболее вероятные сценарии изменения солености Азовского моря в зависимости от годовых объемов материкового стока. Использованы материалы экспедиционных исследований гидрологического режима Азовского моря за период 1960–2020 гг. из базы данных АзНИИРХ и данные опорной сети Росгидромета. Для анализа данных применены методы математической статистики, графоаналитического построения, картирования и методы аналогии. Результаты. В работе дана оценка происшедших изменений гидрологического режима Азовского моря по данным ежегодного мониторинга среды обитания водных биологических ресурсов. Выполнены предварительные расчеты и представлены новые данные по изменению не охваченных мониторингом параметров уравнения водного баланса моря за последние сорок пять лет. Рассмотрены наиболее вероятные сценарии формирования материкового стока и солености вод Азовского моря на перспективу до 2030 г. с учетом наблюдаемой тенденции потепления климата. Влияние климатических и антропогенных факторов способствовало существенным изменениям современного гидрометеорологического режима Азовского моря. Эти изменения в наибольшей степени проявились в повышении температуры воздуха и водной среды, снижении ветровой активности и уменьшении материкового стока, в формировании которого начиная с 2006 г. отмечается затянувшийся маловодный цикл. Дефицит речного стока и возросшие расходы воды на испарение, наряду с прочими факторами, спровоцировали беспрецедентный рост солености вод Азовского моря, среднегодовое значение которой в 2021 г. достигло рекордно высокого уровня (14,97 ‰). При наиболее вероятном сценарии (60 %) с сохранением маловодного периода и материковым стоком в Азовское море объемом около 22 км3 среднегодовая соленость Азовского моря, включая Таганрогский залив, может достичь значений 15±0,40 ‰ с диапазоном колебаний в собственно море в интервале от 14,5 до 16,5 ‰. Годом-аналогом формирования такой солености и ее пространственного распределения может служить 2021 г.PublishedReferee
Biodiversidade de Ostracoda (Crustacea): uma abordagem taxonômica e funcional.
No full textThe impacts of human actions, as deforeations, pollution and introduction of species have been causing negative effects on the environment. The extinction of species, and change of distribution range, are some of them, especially in the aquatic environment were it is observed a hogh richness compared to its extension. Thus, the knowledge about biodiversity is of extreme importance conservation of ecosystems. Ostracods are one example of a group constantly affected but ill studied. It was performed a revision of Cyprettinae s.l. from circumtropical regions, using morphological taxonomy. The first step in the revision of Cyprettinae s.l. was redescribe the type species of Cypretta Vavra, 1895 from the original type material, discuss the morphology and diagnosis of the genus. After that it was described two new species from Pseudocypretta Klie, 1932 genus from South Africa and Brazil; and described a new genus and four new species from Brazil. With the redescription of the type species of the Cyprettathe diagnosis characters for the species and genus were delimited. Analyzing the features of the new species of Pseudocypretta this genus was moved from the Cyprettinae subfamily to the Cypridopsinae subfamily, and expanded the distribution of this genus to the Afrotropical and Neotropical regions. The new genus and new species were recorded from the four main floodplain of Brazil and were designated to the Cyprettinae subfamily. Both Cypretta, Pseudoypretta and new genus are characterized by presence of septas in its valves, however they vary in level of development (complete or incomplete) and disposition along the margins of the valves. Using a database of ostracods distribution and ecological niche modelling (ENMs) the effects of climate change were evaluated to the functional diversity of ostracods in the South Cone of South America, in the moderate-optimistic and pessimistic scenarios of 2050 and 2080. It is projected that the ostracod functional diversity will suffer a gradual reduction in 2050 and 2080on bothscenarios of carbon emission, but especially in the pessimistic scenario of 2080. The results highlight the importance of evaluate the functional diversity for ostracod conservation, since several areas marked to have low taxonomic richness supported intermediate and high levels of functional diversity.O impacto de ações humanas, tais como desflorestamento, poluição e introdução de espécies vem causando efeitos negativos no meio ambiente. A extinção de espécies e mudanças nas áreas de distribuição das espécies, são alguns desses problemas, principalmente no meio aquático onde e observada uma elevada riqueza de espécies comparada a sua extensão. Portanto, o conhecimento acerca da biodiversidade é de extrema importância para a conservação dos ecossistemas. Os ostracodes são um exemplo de grupo que está sendo afetado por mudanças climáticas e, no entanto, são pouco estudados. Realizou-se uma revisão de Cyprettinae s.l. de regiões circumtropicais, usando a taxonomia morfológica. A primeira etapa na revisão de Cyprettinae s.l. foi redescrever a espécie tipo de Cypretta Vavra, 1985 a partir do material tipo original, e discutir a morfologia e diagnóstico do gênero. Após, descreveu-se duas novas espécies de Pseudocypretta Klie, 1932 da África do Sul e do Brasil; e um novo gênero e quatro novas espécies do Brasil. Com a redescrição da espécie tipo de Cypretta nos determinamos os caracteres diagnósticos da espécie e do gênero. Analisando as características das novas espécies de Pseudocypretta moveu-se esse gênero da subfamília Cyprettinae para a subfamília Cypridopsinae, e expandiu-se a distribuição desse gênero para as regiões Afrotropical e Neotropical. O novo gênero e novas espécies foram registradas nas quatro principais planícies de inundação brasileiras, e foram classificados na subfamilia Cyprettinae. Ambos Cypretta e Pseudocypretta e novo gênero são caracterizados pela presença de septas em suas valvas, no entanto variam em nível de desenvolvimento (completas ou incompletas) e disposição ao longo das margens das valvas. Usando um banco de dados de ostracoda e modelos de nicho ecológico, avaliaram-se os efeitos das mudanças climáticas na diversidade funcional de ostracoda no Cone Sul da América do Sul, em cenários moderados-otimista e pessimista dos anos de 2050 e 2080. E projetado que a diversidade funcional de ostracoda sofrerá uma gradual redução em 2050 e 2080 em ambos os cenários de emissão de carbono, mas principalmente no cenário pessimista de 2080. Os resultados destacam a importância de avaliar a diversidade funcional para a conservação de ostracodes, desde que algumas áreas reportadas e possuírem baixa riqueza taxonômica suportam intermediários a elevados valores de diversidade funcional.Ph
Frequent occurrence of tetrodotoxin in the marine gastropod Nassarius glans causing a food poisoning in Khanh Hoa province, Vietnam in 2020
No full textA fatal neurotoxic poisoning case happened in Khanh Hoa province in 2020 after eating a certain number of marine gastropods, later identified as Nassarius glans, one of the common marine gastropods in Vietnam. As the remaining causative food in the incident, 62 specimens were collected to examine tetrodotoxin toxicity individual variation and frequency of toxic specimens by using HILIC/MS-MS analysis. 100% of studied specimens exhibited toxicity (556 ± 821 MU/g) beyond the regulatory level of consumption (10 MU/g) for puffer(fish) recommended in Japan and extensive variation (18–4,046 MU/g). The result pointed out that only 5 g of soft tissue from N. glans (equivalent to 2–3 specimens) containing maximum toxicity detected in the present study may cause human death if consumed. Fhe first time, this study identified TTXs in the gastropods as a causative toxin in the poisoning in Vietnam. Moreover, 65.5% of studied specimens with high toxicity higher than 100 MU/g, including 16.1%, showing extremely high toxicity (> 1,000 MU/g). The results suggested that this gastropod is quite dangerous for human consumption and should be alerted to public awareness.PublishedReferee