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Оценка пороговой устойчивости бентосной диатомовой водоросли Pleurosigma aestuarii (Bréb. in Kütz.) W. Smith, 1853 (Bacillariophyta) к воздействию ионов меди (ii)
No full textCopper compounds accumulate in marine bottom sediments as the result of human activity and, being highly toxic, affect microphytobenthos. Evaluation of the tolerance ranges of benthic diatoms to copper pollution is important for biotesting and assessment of coastal marine environment. This work is aimed to reveal the dynamics of growth and cell death of marine benthic diatom Pleurosigma aestuarii (Bréb. in Kütz.) W. Smith, 1853 under the impact of a wide range of copper (II) ions concentrations over the course of a 10-day experiment in clonal culture, as well as to identify a tolerance threshold for this species, critical for its survival when exposed to the toxicant. The study has focused on assessment of the changes in the proportion (%) of alive cells, absolute cell number and specific growth rate of the culture at different exposure durations and concentrations of Cu2+ ions (32–1024 μg/L) and was meant to evaluate the applicability of this species as a new test object for ecotoxicology. In the control culture and in the cultures exposed to Cu2+ in the range of concentrations 32–256 μg/L, the proportion of alive cells did not change over the course of the experiment (95–99 %). At Cu2+ concentration 320 μg/L, the proportion of alive cells decreased to 23 % on the 3rd day and to 10 % on the 5th day, which provided a basis to consider this value as a threshold one for P. aestuarii survival. At Cu2+ concentrations 384 μg/L and higher, up to the maximum one (1024 μg/L), drastic inhibition of the culture was recorded as early as on the 1st day, and on the days 3–5, all the cells died. The increase in the absolute cell number in the concentration range 32–256 μg/L was consistent with the dose–response sigmoid model. Over the timespan of days 1–7, the cell number increased by 3–5 times, reaching its maximum, and then it decreased by 10–12 % by the 10th day. At Cu2+ concentrations 320 μg/L and higher, the increase in the cell number was strongly suppressed since the 1st day. Within the 32–256 μg/L range, the test culture is characterized by positive specific cell growth rate for the period up to 7 days; at the threshold concentration 320 µg/L and higher, this test parameter becomes negative. Thus, P. aestuarii should be recommended as a new appropriate test object both for toxicological experiments and for monitoring of coastal marine environment affected by technogenic pollution.Соединения меди, будучи высокотоксичными и аккумулируясь в донных отложениях вследствие антропогенной деятельности, оказывают негативное влияние на микрофитобентос. Выявление границ устойчивости бентосных диатомовых к загрязнениям медью — актуальная задача для биотестирования и оценки состояния морской среды. Исследовано воздействие ионов меди (II) в различных концентрациях на новый для токсикологии вид морской диатомовой водоросли Pleurosigma aestuarii (Bréb. in Kütz.) W. Smith, 1853 в условиях 10-суточных экспериментов на клоновой культуре. Цель работы состояла в оценке динамики доли живых клеток (%), абсолютной численности и удельной скорости прироста числа клеток при разных сроках экспозиции и различных концентрациях Cu2+ (от 32 до 1024 мкг/л), а также установлении критической для выживания вида концентрации токсиканта. В контроле и при концентрациях ионов меди 32–256 мкг/л доля живых клеток P. aestuarii на протяжении эксперимента не менялась (95–99 %). При содержании Cu2+ 320 мкг/л доля живых клеток в культуре уже на 3-и сутки резко снижалась до 23 %, на 5-е сутки — до 10 %, что определяет данную концентрацию как пороговую для выживания P. aestuarii. При повышении концентрации Cu2+ до 384 мкг/л и вплоть до максимальной (1024 мкг/л), отмечено резкое угнетение культуры уже в первые сутки, а на 3–5-е сутки доля живых клеток падала до 0 %. Прирост абсолютной численности клеток P. aestuarii при концентрациях Cu2+ 32–256 мкг/л описывается сигмоидной кривой отклика. В период 1–7-х суток численность возрастала в 3–5 раз, достигая максимума и снижаясь к 10-м суткам на 10–12 %. При концентрации 32–256 мкг/л культура характеризовалась положительным удельным приростом; при концентрации токсиканта 320 мкг/л и выше удельный прирост клеток становился отрицательным. P. aestuarii рекомендована как тест-объект для токсикологических экспериментов и мониторинга техногенного загрязнения акваторий.PublishedReferee
2023 International Quality-Controlled Ocean Database (IQuOD) – 7th IQuOD Annual Workshop 8th IODE SG-IQuOD 4th SCOR WG 148 10-11 July, 2023 Potsdam Institute for Climate Impact Research, Potsdam, Germany
No full textThe historical archive of global ocean subsurface temperature contains a large proportion of poorly quality-controlled as well as biased data. As a result, efforts to analyze past ocean change and variability are confounded, as is the use of ocean data assimilation systems. Currently many data centers perform automated ‘quick and dirty QC’ – redoing the same job poorly many times around the world. There have been no previous efforts to form a clean and definitive and very much needed historical archive. No single group has the manpower and resources to do the job properly – thus international cooperation is needed. The IQuOD 7th Workshop goals are to: 1. Ratify new co-Chairs. 2. Review work achieved so far. 3. Review IQuOD structure. 4. Plan for tasks for the coming 12-24 months.PublishedNon Referee
Depredación por perforación en ensambles de conchas de bivalvos de Playa Guardalavaca, Cuba
No full textDrilling predation plays an important role in the evolution and diversification of organisms, and is one of the most studied biotic interactions in fossil and modern records. Marks of drilling predation on mollusc shells are proof of food activity and the selective pressure of one taxon on another. In this study, we explore drilling predation on preserved bivalve death assemblages (thanatocoenosis) at Playa Guardalavaca, Cuba. We characterize the taxonomic composition, relative abundance and incidence of drilling. Furthermore, geometric morphometric tools were used to test whether there was a preference for any particular form of shell. Forty-eight species were identified, and a little less than half (21) showed drilling predation marks. The families with the highest species richness were Lucinidae and Tellinidae, with 11 species each. A total of 1,726 valves were quantified, estimating an abundance of 863 specimens. 190 valves showed drilling marks (22% of the abundance). The most abundant species were Lucina sp. (464 shells), Divalinga quadrisulcata (328), Americardia media (242), Ctena imbricatula (156), and Chione spp. (117). However, the most predated species were Epicodakia sp. (100%), Acorylus gouldii (56%), and Eurytellina sp. (44%). The highest predation rate occurs on small and medium-sized valves (≤ 7 mm); however, according to the Kolmogorov-Smirnov test, this result is only statistically significative in Lucina sp. (p < 0.001). The morphometric analysis showed predation preferences for species with semi-circular rather than elliptical shells. These results elucidate that drilling predation on bivalves is not only determined by the abundance of prey, but also by their external morphology and size, suggesting highly specialised feeding behaviour by predators.La depredación por perforación juega un importante papel en la evolución y diversificación de los organismos y es una de las interacciones bióticas más estudiadas en el registro fósil y actual. Las marcas de depredación por perforación en las conchas de los moluscos son evidencias y pruebas de la actividad alimentaria y la presión selectiva de un taxón sobre el otro. En este estudio, se explora la depredación por perforación en ensamblajes preservados de bivalvos muertos (tanatocenosis) en Playa Guardalavaca, Cuba. Se caracteriza la composición taxonómica, su abundancia relativa y la incidencia de perforaciones. Además, técnicas de morfometría geométrica fueron utilizadas para evaluar si existe preferencia por alguna forma particular de las conchas. Cuarenta y ocho especies fueron identificadas, y poco menos de la mitad (21) presentaron marcas de depredación por perforación. Las familias con mayor riqueza de especies fueron Lucinidae y Tellinidae con 11 cada una. Un total de 1 726 valvas fueron cuantificadas, estimando una abundancia de 863 ejemplares. De estas 190 valvas presentaron marcas de perforación (22% de la abundancia). Las especies más abundantes fueron Lucina sp. (464 conchas), Divalinga quadrisulcata (328), Americardia media (242), Ctena imbricatula (156) y Chione spp. (117). No obstante, las especies más depredadas fueron Epicodakia sp. (100%), Acorylus gouldii (56%) y Eurytellina sp. (44%). La mayor tasa de depredación se encontró en conchas pequeñas y medianas (≤ 7 mm); no obstante, acorde a la prueba de Kolmogorov-Smirnov, este resultado es estadísticamente significativo solo para Lucina sp. (p < 0.001). El análisis morfométrico mostró preferencias de depredación por especies con conchas semicirculares en lugar de las elípticas. Estos resultados evidencian que la depredación por perforación en bivalvos no está solo determinada por la abundancia de presas, sino también por su morfología externa y tamaño, sugiriendo comportamientos de alimentación altamente especializados de los depredadores.PublishedReferee
Overview of Bottlenose dolphin depredation in Teboulba region (East of Tunisia).
No full textThis work was carried out in response to the numerous fishermen claims following to the interaction between dolphins and fishing gears along the coast of Teboulba. The aims of this work were: to establish an inventory of dolphins present in the study area and interacting with fisheries, to define the most affected fisheries by the depredation and to attempt to assess it economic consequences. For this purpose, field surveys as well as weekly monitoring of a sample of the fleet and sea trips were carried out in order to respond to the previously mentioned objectives. The findings of this study led to the conclusion that there are two dolphin’s species: the Bottlenose dolphin and the Striped dolphin. These two species have a different demographic and ecological distribution. They also interact in two different ways with the fishing boats and their nets. According to the surveys, the most depredated fisheries is the small scall fisheries. Set gillnet and trammel nets were the types of the fishing gear most vulnerable to dolphin depredation. The depredation rate and economical loss due to depredation vary slightly between gillnets and trammel nets. The depredation induces many holes with different size requiring mending operations that can be onerous. Likewise for landing, the resulting bites on the catch leave it unsaleable. It is necessary to continue this study in order to identify the factors that can cause the depredation and propose mitigation measures to avoid any ecological and economic blunder.PublishedReferee
Региональные особенности ветрового режима Черного моря (район Туапсе)
No full textSpecific features of the development of the wind regime in the coastal waters near Tuapse, Black Sea, have been investigated. The average and extreme characteristics of the wind regime (speed, direction, repeatability, strong winds, windless situations, local winds) are given.Рассмотрены особенности формирования ветрового режима Черного моря в прибрежном районе г. Туапсе. Приведены средние и экстремальные характеристики ветрового режима (скорость, направление, повторяемость, сильные ветры, штилевые ситуации, местные ветры).PublishedNon Referee
New analytical system for monitoring ocean conditions especially the sea surface temperature, with the aid of the remote sensing products of Himawari.
No full textWe have used the remote sensing products for sea surface temperature （SST） provided by the artificial satellites to monitor SST and to perceive ocean currents around Japan, as well as to publish the Quick Bulletin of Ocean Conditions. In September 2022, we changed the method from using the SST observed by NOAA and MetOp to using the SST observed by Himawari-8. We had directly received the signals of SST data observed by NOAA and MetOp using an analytical system with parabolic antenna. We replaced that with the new system witch receives SST data observed by Himawari-8 provided by the Japan Aerospace Exploration Agency （JAXA） via an internet site. The replacement could reduce cost and workload for maintenance. In this report, we describe the outline of our new system for monitoring SST and the characteristic of the new SST images. The new system receives the SST products observed by Himawari-8 from JAXA. The observation interval of Himawari-8 is every 10 minutes. The high frequency observation could reduce data blanks in a one-day composite image caused by cloud coverages in comparison with the previous products. The daily average value was selected for composite SST images in order to avoid improbable SST patterns resulting from the comparison with the daily maximum and minimum values. To assure the accuracy of the new SST images, we compared the new product against SST datasets based on the result of direct observation in several cases. The anomaly between new images and the CTD dataset of the Chiba light beacon in the Tokyo bay is approximately ±0.6℃ among the 10－28℃ in SST. In other case, the anomaly compared with the SST datasets of Kuroshio-Bokujo buoys off the coast of Shikoku is approximately －1.1℃ and mostly accorded at 17℃ and 29℃ of buoy-observed temperature, respectively. When comparing the water temperature data of NOAA and Metop with the water temperature data of Himawari-8, it was found that Himawari-8 was approximately 0.7 ℃ lower at water temperature 28℃, and approximately 0.4℃ at water temperature 5℃.PublishedReferee
Seasonal variation of the ectoparasite infestation levels of Trachurus picturatusin Bizerte (Tunisia).
No full textThe blue jack mackerel, Trachuruspicturatus, is a commercially important resource in the Mediterranean Sea and the North-East Atlantic. The main aim of this work was to assess the infection levels and diversity of the ectoparasites of the blue jack mackerel.Over a one-year period, between March 2017 and February 2018, 126 specimens of T. picturatuswere collected seasonally from the Bizerte coast (Tunisia). The ectoparasite fauna of the examined host was composed ofthe two monogenean species, Pseudaxinetrachuriand Gastrocotyletrachuriand a copepod species,Peniculusfistula fistula. This is the first record of thiscopepod parasite inTunisia. The analysis revealed that the infection levels fluctuated throughout the year. Both monogeneans (P. trachuriand G. trachuri) had high prevalences during the warm season (P%=87.1, P%= 32.3, respectively). Additionally, P. trachurishowed some seasonal variations in mean abundance and mean intensity between summer and the other seasons. Furthermore, there was a highly significant variation in the mean abundance of G. trachuribetween the summer and autumn-winter seasons. The resultsof the current study may be explained by the seasonal variations in environmental conditions, the life cycles of the hosts and parasites, the feeding and migratory patterns of the hosts, the chemicals released by the hosts, and the interspecific competition between the two monogenean species.PublishedReferee
Dinâmica trófica de peixes na planície de inundação do alto rio Paraná por meio de isótopos estáveis : cenário de vinte anos de barramentos em série, invasões biológicas e áreas protegidas.
No full textThe Paraná River basin is affected by a series of impoundments that alter the natural river flow, with significant impacts on the water's chemical and physical characteristics with serious consequences for the aquatic biota. The Upper Paraná River Floodplain (UPRF) suffered biological invasions directly influenced by two damming events and, due to its importance for the conservation of biodiversity, it also received mitigation measures with the installation of protected areas in its surroundings. Considering the potential consequences of impacts caused by extensive flow regulation and biological invasions, but also mitigation measures, this study aimed to investigate long-term changes in the trophic dynamics of UPRF fish through the analysis of stable isotopes. Analyzes were carried out in three periods (the early 2000s, 2010s, and 2020s) regarding food chain energy sources, trophic niche, and trophic position of fish from different guilds in the floodplain associated with the Paraná River and the floodplain associated with the Ivinhema River that make up the UPRF, in the years following the installation of a dam directly upstream of the floodplain and the creation of protected areas around the plain. The results show that in the plain associated with the Paraná River, an invasive fish is inserting carbon from an invasive macrophyte into the green food chain, and a native detritivore fish is probably moving to lagoons to utilize the abundant detritus from native emersed macrophytes. In the floodplain associated with Ivinhema, despite the more restrictive protection area in its surroundings, the riparian vegetation did not become an important carbon source, only the emersed macrophytes increased their contribution to the fish. Still, fish from both systems showed an increase in the trophic niche in the second studied period, potentially due to the occurrence of El Niño, which caused the largest and longest flood in the analyzed period. Thus, our study reveals that invasive species can replace native food sources, alter local food chains, and amplify the negative consequences of impoundments. Furthermore, we reveal that the trophic dynamics of fish species from different guilds continue to suffer from anthropic impacts, despite the protected areas surrounding the floodplain. Therefore, measures that mimic the natural flow and water fluctuations would make the positive effects of protected areas tangible for the functioning of aquatic communities.A bacia do rio Paraná é impactada por uma série de represamentos que alteram o fluxo natural do rio, causando distúrbios significativos nas características químicas e físicas da água com graves consequências para a biota aquática. A planície de inundação do alto rio Paraná (PIAP) sofreu invasões biológicas diretamente influenciadas por dois eventos de represamento e, devido à sua importância para a conservação da biodiversidade, também recebeu a medidas de mitigação com a instalação de áreas protegidas nos seus entornos. Considerando as potenciais consequências dos impactos causados pela ampla regulação de fluxo e invasões biológicas, mas também das medidas mitigatórias, investigou-se as alterações de longo prazo na dinâmica trófica de peixes da PIAP por meio da análise de isótopos estáveis. Para tanto, analisou-se períodos subsequentes à instalação de uma barragem diretamente a montante da planície e à criação de áreas protegidas nos entornos da planície. Foram realizadas análises em três períodos (início das décadas de 2000, 2010 e 2020) quanto às fontes de energia da cadeia trófica, nicho trófico e posição trófica de peixes de diferentes guildas da planície associada ao rio Paraná e da planície associada ao rio Ivinhema. Os resultados indicam que, na planície associada ao rio Paraná, um peixe invasor está disseminando o carbono de uma macrófita invasora na cadeia trófica verde, e um peixe detritívoro nativo está provavelmente se deslocando para lagoas a fim de utilizar os detritos abundantes provindos de macrófitas emersas nativas. Na planície associada ao Ivinhema, apesar da área de proteção mais restritiva em seus entornos, a vegetação ripária não se tornou uma importante fonte de carbono, apenas as macrófitas emersas ampliaram sua contribuição para os peixes. Ainda, os peixes de ambos os sistemas apresentaram uma ampliação no nicho trófico no segundo período estudado, potencialmente devido à ocorrência do El Niño que causou a maior e mais longa cheia do período analisado. Assim, o estudo revela que espécies invasoras podem substituir as fontes de alimento nativas, alterar cadeias tróficas locais, e ampliar as consequências negativas dos represamentos. Outro destaque é que a dinâmica trófica de espécies de peixes de diferentes guildas continua sofrendo com impactos antrópicos, apesar das áreas protegidas nos entornos da planície de inundação. Portanto, devem ser implantadas medidas que viabilizem um mimetismo de fluxo e flutuações hídricas naturais tornariam os efeitos positivos das áreas protegidas tangíveis para o funcionamento das comunidade aquática.Ph
О влиянии логарифмирования данных на оценку длины, при которой наступает половая зрелость у рыб
No full textTo characterize fish sexual maturity, such parameter as the length at which 50 % of individuals are sexually mature is widely applied. The conventional practice is to use the fish length values directly, without their preliminary logarithmic transformation. However, based on theoretical considerations, such logarithmic transformation should be expected to improve the quality of approximation of the relationship between the percentage of mature individuals and their length. This study is aimed at the testing of the hypothesis that logarithmic transformation improves the quality of approximation of the data on fish maturity, as well as at the assessment of practicability and expedience of the logarithmic transformation when estimating the length at which 50 % of the individuals are sexually mature. This research is conducted based on the published data. Approximation was carried out using two methods: by the probability integral of a normal distribution and by the logistic function. Following the data analysis involving an original two-level approach, it has been found out that the preliminary logarithmic transformation of the length values statistically significantly improves the quality of approximation. However, this pattern manifests only in the case of analyzing a certain volume of data sets. The difference between the results obtained using transformed and non-transformed length values is not big and, oftentimes, unsubstantial. Nevertheless, in some cases, such a difference is noticeable, which provides a reason to recommend the logarithmic transformation of the fish length values when conducting the analysis. It is also demonstrated that, during the estimation of the length at which 50 % of the individuals are sexually mature, both tested functions are equally suitable for approximation.Для характеристики полового созревания рыб широко используется значение длины, при которой 50 % особей являются половозрелыми. При расчетах обычно применяются непосредственно значения длины рыб без их предварительного логарифмирования. Однако, исходя из теоретических соображений, следует ожидать, что логарифмирование значений длины должно приводить к улучшению качества аппроксимации зависимости доли половозрелых рыб от их длины. Целью данного исследования является проверка гипотезы о том, что логарифмирование способствует улучшению качества аппроксимации данных по созреванию рыб, а также определение практической целесообразности логарифмирования при оценке длины, при которой 50 % особей являются половозрелыми. Исследование проведено по опубликованным данным. Аппроксимация осуществлялась двумя способами: интегралом вероятностей нормального распределения и логистической функцией. При анализе данных с использованием оригинального двухуровневого подхода установлено, что предварительное логарифмирование значений длины статистически значимо улучшает качество аппроксимации. Однако указанная закономерность проявляется лишь при анализе некоторого множества наборов данных. Разница между результатами, полученными при использовании преобразованных и непреобразованных значений длины, невелика и зачастую несущественна. Тем не менее, в некоторых случаях такое различие заметно, что и дает основание рекомендовать логарифмирование значений длины рыб при анализе. Кроме того, показано, что при расчете длины, при которой 50 % особей являются половозрелыми, обе использованные функции подходят для аппроксимации в одинаковой степени.PublishedReferee
Net rates of calcium carbonate accretion in the marinecoastal ecosystem complex of Ensenada Rancho Luna, Cienfuegos, Cuba
No full textDebido a las emisiones cada vez mayores de dióxido de carbono a la atmósfera, la absorción de este gas por el océano se realiza a gran velocidad, provocando un aumento en la acidez del agua de mar. Este proceso, conocido como acidificación oceánica, conlleva a que en muchos organismos calcificadores se reduzca la capacidad de formar sus estructuras de carbonato de calcio. El objetivo de esta investigación fue determinar las tasas netas de acreción de carbonato de calcio (g CaCO3 cm-2 año-1) de taxones de sucesión temprana, en el complejo de ecosistemas marinos-costeros de la Ensenada Rancho Luna, Cienfuegos. Para la cuantificación de la tasas netas de acreción de carbonato de calcio se construyeron 12 dispositivos de muestreo basados en la metodología Vargas-Ángel et al. en el 2015, posicionándose seis de ellos en cada ecosistema estudiado (manglar y arrecife). Los valores medios de netas de acreción de carbonato de calcio fueron de 0.87 ± 0.19 g CaCO3 cm-2 año-1 en el arrecife y 0.59 ± 0.05 g CaCO3 cm-2 año-1 en el manglar. Se identificaron siete taxones, correspondientes a cuatro grupos funcionales de sucesión temprana, el césped (turf), el CaCO3/sedimento, el grupo funcional Sin Calcio y las algas coralinas costrosas. Estas últimas fueron las principales aportadoras de CaCO3, encontrándose principalmente en el arrecife. Se determinó a la magnesita como forma cristalina de CaCO3 dominante, y las algas coralinas costrosas, el grupo de mayor vulnerabilidad ante el efecto de la acidificación oceánica.Due to the increasing emissions of carbon dioxide into the atmosphere, the absorption of this gas by the ocean is carried out at great speed, causing an increase in the acidity of seawater. This process, known as ocean acidification, leads to a reduction in the ability of many calcifying organisms to form their calcium carbonate structures. The objective of this research was to determine the net rates of calcium carbonate accretion (g CaCO3 cm-2 yr-1) of early successional taxa, in the marine-coastal ecosystem complex of Ensenada Rancho Luna, Cienfuegos. To quantify the net calcium carbonate accretion rates, 12 sampling devices were built based on the Vargas-Ángel et al. in 2015, positioning six of them in each ecosystem studied (mangrove and reef). The mean values of net calcium carbonate accretion rates were 0.87 ± 0.19 g CaCO3 cm-2 yr-1 in the reef and 0.59 ± 0.05 g CaCO3 cm-2 yr-1 in the mangrove swamp. Seven taxa were identified, corresponding to four early successional functional groups, grass (turf), CaCO3/sediment, Calcium-free functional group, and crusted coralline algae. The latter were the main contributors of CaCO3, being found mainly in the reef. Magnesite was determined as the dominant crystalline form of CaCO3, and crusty coralline algae, the group with the greatest vulnerability to the effect of ocean acidification.PublishedReferee