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The culture of marine sponges (Spongiidae) in Cuba: Description and comparison of two methods of sponge culture.
No full textLas esponjas de la familia Spongiidae constituyen un rubro exportable en Cuba desde el siglo xix. Las denominadas “esponjas de baño” tienen un alto precio en el mercado y su oferta ha disminuido por el impacto de diferentes factores naturales, y de una máxima explotación de las poblaciones silvestres. El cultivo de esponjas, además de una alternativa de producción sostenible, constituye una solución para alcanzar tallas de mercado sin afectar la biomasa silvestre, y garantiza la protección de las poblaciones naturales. Acciones de esponjicultura desarrolladas en el archipiélago de Sabana-Camagüey (ASC), centro norte de Cuba, fueron evaluadas y se describen y comparan dos variantes de cultivo: cultivo de esponjas ensartadas en líneas de monofilamento (tendales) y cultivo de esponjas libres en parcelas cercadas (corrales). Los resultados demuestran la viabilidad de ambos cultivos a partir de la regeneración de fragmentos de esponjas, con tasas máximas de crecimiento mensual de entre 1-2 cm de diámetro, y alcanzan en 12 meses un tamaño acorde con la demanda del mercado. Pasados los primeros seis meses de cultivo ocurre una disminución de la tasa de crecimiento. La calidad del sitio, la selección del método de cultivo según características del sitio, las especies en cultivo, el tamaño de los fragmentos (semillas) para siembra, y el manejo del cultivo, son factores a tener en cuenta para obtener resultados satisfactorios.The sponges of the Spongiidae family have been an exportable item in Cuba since the 19th century. The so-called "bath sponges" have a high price in the market and their supply has decreased due to the impact of different natural factors, and the maximum exploitation of wild populations. Sponge farming, in addition to a sustainable production alternative, constitutes a solution to reach market sizes without affecting wild biomass, and guarantees the protection of natural populations. Sponge culture actions carried out in Sabana Camagüey archipelago (ASC), north-central Cuba, were evaluated and two culture variants are described and compared: the culture of sponges strung on monofilament threads (clothesline) and the culture of sponges free in fenced plots (corrals). The results demonstrate the viability of both cultures from the regeneration of sponge fragments, with maximum monthly growth rates of between 1-2 cm in diameter, and reaching a size in 12 months according to market demand. After the first six months of cultivation, a decrease in the growth rate occurs. The quality of the site, the selection of the cultivation method according to the characteristics of the site, the species under cultivation, the size of the fragments ("seeds") and the cultivation management, these are factors that must be taken into account to obtain satisfactory results.PublishedReferee
Особенности обеспечения качественной работы современных электротехнических комплексов беспилотных судов
No full textUnmanned seagoing vessels are increasingly being used. In the paper the dump scow Rabochaya is considered as an example of an unmanned vessel. An extended marine control system, a video surveillance subsystem, a surveillance and search engine are additionally installed on the scow to carry out industrial tasks in unmanned mode. The correct operation of these systems and the whole vessel depends on the high-quality operation of the ship's electrical power system. The aim of the study is to identify abnormal modes of parallel operation of marine diesel generator sets and to develop methods and means for their elimination. The results of the experimental research and mathematical modeling have revealed the existence of power exchange oscillations when the ship generators operating in parallel. Power exchange oscillations can be detected with the help of generator current oscillations. It has been proposed to introduce a unit for eliminating power exchange oscillations (EPEO) into the automatic control system of ship electrical power systems for eliminating such oscillations. An algorithm for the operation of the EPEO unit has been developed, it controls the settings of the rotational speed regulators of diesel-generator sets. The proposed methods and tools reduce the amplitude of power exchange oscillations to an acceptable value, and therefore contribute to the high-quality operation of the ship's electrical power system and control systems in unmanned mode. The results obtained make it possible to ensure reliable and trouble-free operation of any autonomous electrical power system during the operation mode without maintenance personnel.Беспилотные морские суда находят все более широкое применение. В статье в качестве примера беспилотного судна рассматривается грунтоотвозная шаланда "Рабочая". Для выполнения производственных задач в беспилотном режиме на шаланде дополнительно установлены расширенная судовая система управления техническими средствами, обзорно-поисковая система и подсистема видеонаблюдения. Корректная работа этих систем и всего судна зависит от качественной работы судового электротехнического комплекса. Целью исследования является выявление нештатных режимов параллельной работы судовых дизель-генераторных агрегатов и разработка методов и средств для их устранения. Результаты проведенного экспериментального исследования и математического моделирования выявили существование обменных колебаний мощности при параллельной работе судовых генераторов. Обменные колебания мощности могут быть определены по колебаниям токов генераторов. Для устранения таких колебаний предложено ввести в состав системы автоматического управления судовыми электротехническими комплексами блок устранения обменных колебаний мощности (УОКМ). Разработан алгоритм работы блока УОКМ, который управляет настройками регуляторов частоты вращения дизель-генераторных агрегатов. Предложенные методы и средства уменьшают амплитуду обменных колебаний мощности до допустимого значения, т. е. способствуют качественной работе судового электротехнического комплекса и систем управления в беспилотном режиме. Полученные результаты позволяют обеспечить надежную и безаварийную работу любого автономного электротехнического комплекса в режиме эксплуатации без обслуживающего персонала.PublishedReferee
Some biological aspects of bogue Boops boops (Linnaeus, 1758) from Saros Bay (Northern Aegean Sea, Turkey).
No full textThis study was conducted to determine the growth parameters, mortality and length at first maturity of bogue Boops boops (Linneaus, 1758) in Saros Bay (Northern Aegean Sea). A total of 363 specimens were obtained, monthly, from commercial fishermen between February 2016 and January 2017. The total length and weight of sampled fish ranged from 11.3 to 24.1 cm and from 16.61 to 165.32 g, with a mean of 16.9 cm and 60.40 g, respectively. The length-weight relationship was calculated as W = 0.0080TL3.13. The von Bertalanffy growth equations were computed to be �∞ = 27.9 cm, k = 0.21 year-1, �0 = -1.57 year. The growth performance index (�′) was found as 2.21. The length at first maturity was estimated as 16.6 cm. Total mortality rate (Z), natural mortality rate (M), fishing mortality rate (F) and exploitation rate (E) of the bouge were 0.44 year-1, 0.38 year-1, 0.06 year-1 and 0.13 year-1, respectively. The present study provides preliminary information on the growth parameters, mortality and length at first maturity of B. boops for the Saros Bay (Northern Aegean Sea, Turkey).PublishedReferee
Presentation of parallels and meridians in the Maritime-domain-awareness (MDA) Situational Indication Linkages, UMISHIRU
No full textThe Maritime-domain-awareness （MDA） Situational Indication Linkages, UMISHIRU, operated by the Japan Coast Guard, is a Web-GIS （Geographic Information System） featuring more than 200 items of marine information. Since being upgraded from the former Japan Marine Cadastre in 2019, UMISHIRU has covered global-scale information items, but it can overlay the parallels and meridians to a limited extent on the map. This paper describes a method for beginners to draw parallels and meridians beyond the limited range, and likewise to draw other geographic lines.PublishedReferee
Анализ комплексных изменений при посоле лососевых инъектированием с использованием пищевой добавки PRE-LACKS
No full textThe paper presents the results of a comprehensive assessment of the quality of delicacy fish products – salmon fillets of weak salt made using the food additive PRE-LACKS (LLC "Vash technologist", St. Petersburg, Russia) and curing by injection. For the first time, the influence of technological factors has been studied (the concentration of a food additive (in the range recommended by the manufacturer from 3 to 5 % with a step of 1 %), as well as the value of the hydromodulus (in the range from 5 to 20 % with a step of 5 %) characterizing the ratio of masses of the fillet introduced into the thickness when injecting brine and a salted fillet piece) on the formation of a complex indicator of the finished product quality. The developed scale for a comprehensive assessment of the quality (K) of lightly salted salmon fillet of injection salting is presented, including the main groups of indicators – organoleptic and rheological, nutritional value and physico-chemical. The scale includes weighting coefficients based on the results of experimental and sensory studies – both group and for each quality indicator taken into account. It has been shown that using the fuzzy logic method made it possible to obtain the values of the selected influencing factors optimized according to the criterion of achieving the maximum value of K (in the range from 0.9 to 1.0 conventional units, corresponding to the category "delicacy product") – the concentration of the food additive and the value of the hydromodulus – 4 and 15 %, respectively. The results of assessing the influence of selected technological factors on the yield of a semi-finished product immediately after salting by injection, on the yield of finished low-salted products (after ripening), on indicators characterizing the completeness of its maturation (buffering, the ratio of the mass fraction of non-protein nitrogen to the mass fraction of total nitrogen, total acidity, mass fraction of amine nitrogen) have been presented. Based on the results of the research, technological recommendations are formulated for salting salmon by injection using the PRE-LACKS food additive to increase the yield of finished products and improve its consumer properties.В статье представлены результаты комплексной оценки качества деликатесной рыбной продукции – филе семги слабой соли, изготовленного с использованием пищевой добавки PRE-LACKS (ООО "Ваш технолог", г. Санкт-Петербург, Россия) и посола инъектированием. Впервые изучено влияние технологических факторов – концентрации пищевой добавки (в рекомендуемом производителем диапазоне от 3 до 5 % с шагом 1 %), а также величины гидромодуля (в диапазоне от 5 до 20 % с шагом 5 %), характеризующего соотношение масс вводимого в толщу филе при инъектировании рассола и просаливаемого филе-куска, – на формирование комплексного показателя качества готовой продукции. Приведена разработанная шкала комплексной оценки качества К слабосоленого филе семги инъекторного посола, включающая основные группы показателей – органолептические и реологические, пищевой ценности и физико-химические. Шкала включает в себя обоснованные по результатам экспериментальных и сенсорных исследований коэффициенты весомости – как групповые, так и для каждого учтенного показателя качества. Показано, что применение метода нечеткой логики позволило получить оптимизированные по критерию достижения максимальной величины К (в диапазоне от 0,9 до 1,0 усл. ед., соответствующем категории "деликатесный продукт") значения выбранных влияющих факторов – концентрации пищевой добавки и величины гидромодуля – 4 и 15 % соответственно. Представлены результаты оценки влияния выбранных технологических факторов на выход полуфабриката сразу после посола инъектированием, на выход готовой слабосоленой продукции (после созревания), на показатели, характеризующие полноту ее созревания (буферность, показатель отношения массовой доли небелкового азота к массовой доли общего азота, общую кислотность, массовую долю аминного азота). По результатам исследований сформулированы технологические рекомендации по посолу семги инъектированием с использованием пищевой добавки PRE-LACKS для повышения выхода готовой продукции и улучшения ее потребительских свойств.PublishedReferee
Niche overlap analysis in fish assemblages in an eutrophic lagoon from Cayo Coco, Cuba
No full textUn problema en la ecología es identificar y relacionar los factores que determinan la coexistencia deespecies.Este estudio se centró en analizar si la competencia prevalece como un factor deter- minante en la estructura de la asociación de peces deLaguna Larga,Cayo Coco,apesardeestar sometida a un filtro ambiental. Se realizaron muestreos desde junio de 2016 hasta marzo de 2017, utilizando el chinchorro playero para la recolecta de los individuos. Para caracteri- zar los rasgos funcionales, se hicieron mediciones morfométricas de cada individuo. Se analizó el balance entre los procesos de competencia y filtro ambiental en las asociaciones de peces y se determinaron las similitudes interespecíficas de los peces. En la laguna, las fami- lias dominantes fueron Gerreidae y Scaridae. En relación con la dieta, el predominio fue de individuos bentófagos. La riqueza de especies y los valores de heterogeneidad registrados fue- ron similares tanto en el este como en el oeste. Los rasgos funcionales tipo de alimentación y tolerancia a la salinidad indicaron agrupamiento, mientras los ocho restantes mostraron un espaciamiento; por ello, la coexistencia de especies estuvo mediada por la competencia interespecífica en general. En cuanto a similitudes interespecíficas, se evidenciaron cuatro grupos con mayor similitud, unas agrupaciones con especies taxonómicas relacionadas (1: Sparisoma rubripinne, Scarus taeniopterus y Sparisoma atomarium y 2: conformado por Eucinostomus gula, Eucinostomus havana, Eugerres brasilianus y Gerres cinereus), mientras otras se agruparon por afinidades ecológicas (3: Lutjanus griseus, Centropomus undecimalis, Sphyraena barracuda, y 4: Haemulon plumierii y Lachnolaimus maximus).Currently a fundamental problem in the ecology is to identify and relate what factors deter- mine species coexistence. This study focused on analyzing whether competition prevailsasa determining factor in the structure of the fish assemblage of Laguna Larga, Cayo Coco despite being subjected to an environmental filter. Samples were taken from June 2016 to March 2017, using a beach seine for the collection of indi- viduals. To characterize the functional traits, a morphomet- ric analysis of each individual was carried out. The balance between competition and environmental filter processes in the fish assemblages was analyzed, and the interspecific similarities of the fishes were determined. The dominant families were Gerreidae and Scaridae. In relation to feeding habits, benthos feeder fishes were more abundant. These species richness and the heterogeneity values were similar in both the Eastern and Western sites. The functional traits feed- ing type and salinity tolerance indicated clustering. While the remaining eight showed spacing, therefore in general, the coexistence of the species was mediated by interspecific competition. Regarding interspecific similarities between species, there were four main groups with greater similarities, some grouped by taxonomically related species (1: Sparisoma rubripinne, Scarus taeniopterus and Sparisoma atomarium and 2: formed by Eucinostomus gula, Eucinostomus havana, Eugerres brasilianus and Gerres cinereus), while others were grouped by ecological affinities (Lutjanus griseus, Centropomus undecimalis, Sphyraena barracuda and Haemulon plumerii and Lachnolaimus maximus).PublishedReferee
OceanTeacher Global Academy brochure.
No full textDelivering IOC capacity development for the ocean we need for the future we wantGovernment of FlandersPublishedReferee
Galeón San José, I Campaña de verificación no intrusiva para la seguridad del bien de interés cultural del ámbito nacional
No full textA lo largo de los últimos tres siglos, el Galeón San José ha suscitado el interés de marinos, historiadores, arqueólogos, académicos, científicos y ciudadanos alrededor del mundo. Su significancia como embarcación Capitana de la Armada de la Guarda, de la Carrera de Indias, dedicada a custodiar y transportar el fisco real de la Corona Española en América le ha merecido una enorme curiosidad asociada a los personajes que estuvieron a bordo, su arquitectura y diseño naval, los impresionantes vestigios de la cultura que se pueden entender a través de su cargamento y los detalles de su última batalla librada contra la flota inglesa cerca de la bahía de Cartagena de Indias en 1708. Tal ha sido el grado de interés que despierta este naufragio, que en su búsqueda se han suscitado profundas discusiones del derecho internacional asociadas a la delimitación marítima del país y las capacidades para el ejercicio de la soberanía sobre las aguas nacionales, remontadas incluso a los años ochenta del siglo pasado. La imagen de la mítica embarcación hundida en el Caribe ha producido también profundas y variadas manifestaciones artísticas y literarias, engalanadas algunas de ellas por la magistral prosa de nuestro premio Nobel de Literatura, Gabriel García Márquez. La existencia de un naufragio de tal importancia en nuestro territorio marítimo nos recuerda que Colombia es un país con alto potencial de Patrimonio Cultural Sumergido (PCS), presente en los litorales y aguas profundas que conectan al archipiélago de San Andrés y Providencia, la península de La Guajira, los puertos de Cartagena de Indias o Santa Marta y en el Pacífico, los puertos de Buenaventura o Tumaco, entre otros territorios, que permiten reencontrarnos con ese pasado común que subyace en las profundidades del mar. El océano ha sido parte fundamental de nuestra formación histórica como nación y, sin duda alguna, ha impregnado nuestra cultura y desarrollo como país bioceánico. La fascinación por investigar y descubrir los secretos de los fondos marinos, recreados permanentemente en figuras como el Galeón San José, posibilita hoy una amplia oportunidad para el estudio científico del territorio marítimo y como una ruta para el reconocimiento de la historia, la posición estratégica, la tradición y los vínculos que desde antaño nos conectan con el mundo. Ante el imponente desafío para la investigación y protección de sus activos marítimos, Colombia ha asumido el desarrollo de la I Campaña de verificación no intrusiva para la seguridad del Bien de Interés Cultural (BIC) Galeón San José disponiendo del recurso humano, los medios tecnológicos propios y la voluntad institucional para alcanzar este hito de la investigación científica marina nacional. Estamos seguros de que el desarrollo de esta campaña posiciona a Colombia como un referente internacional en las discusiones sobre la investigación científica y la protección del patrimonio cultural sumergido, bajo el liderazgo de las mujeres y los hombres que protegen el azul de la bandera.Over the past three centuries, the Galleon San José has aroused the interest of sailors, historians, archaeologists, academics, scientists and citizens around the world. Its significance, as the flagship of the Armada de la Guarda within Carrera de Indias maritime route, dedicated to protect and transport the treasury of the Spanish Royal Crown in the Americas, has made it the object of a Deep interest regarding matters such as the people who boarded the ship, its structure and naval design, the impressive vestiges of civilizations’ past that can be discovered through its cargo and the amazing details of the last naval battle it held against the english fleet near the bay o Cartagena de Indias, in 1708. The curiosity developed around the shipwreck has sparked Deep discussions over international rights, related to the country’s maritime limits and about to exert the sovereignty over national waters, that even date back to the 1980s. The image mythical image of this vessel at the bottom of the Caribbean Sea has also brought with it diverse artistic and literary manifestations, some of them embellished by the masterful prose of our Nobel Prize in Literature, Gabriel García Márquez. The existence of such an important shipwreck located in our maritime territory reminds us that Colombia is a country with a high number of Underwater Cultural Heritage, to be found along the coastlines and deep waters that connect the San Andrés and Providencia archipelago and La Guajira peninsula; Cartagena de Indias’ or Santa Marta’s harbor; and, in the Pacific Ocean, Buenaventura or Tumaco’s ports, amongst other territories, that allow us to engage with that common past, resting at the bottom of the sea. The ocean itself has been a bedrock of our history as a nation, and, without a shadow of a doubt, has seeped into our culture as a Bioceanic country. The fascination that comes from researching and discovering the secrets of the sea’s depths, exemplified perfectly in cultural contexts such as the Galleon San José, provides opportunities for the scientific study of the maritime territory and also a route for engaging with history, our own strategic position, and both traditions or connections that, for a long time, have made us part of the world. Given the challenge entailed by researching and protecting its maritime resources, Colombia has taken unto itself the carrying out of the first non-intrusive verification campaign for the Security of Underwater Cultural Heritage Galleon San José, making the most of the human resources, technological developments and the government’s goodwill to achieve this milestone for the nation’s scientific maritime research. We are confident that the conduct of this campaign places Colombia am international benchmark in discussions on scientific research and protection of Underwater Cultural Heritage, under the guidance of both women and men with a duty to protect what’s symbolized by the blue banner of the national flag.PublishedNot Know
Morphometric relationships and meristic characteristics of Megalaspis cordyla (Linnaeus, 1758) from the Bay of Bengal.
No full textMegalaspis cordyla is one of the Carangid fish species commonly found in marine areas of the Sundarbans and the Bay of Bengal in Bangladesh. This study described the morphometric relationships including length-weight and length-length relations (LWRs and LLRs) and meristic characteristics of M. cordyla. A total of 100 individuals were collected from commercial fishers’ catch in the Bay of Bengal, Bangladesh during January-December 2021. For each individual, a total of fourteen various lengths were measured by measuring board with 0.01 cm and body weight (BW) was taken by digital balance with 0.01 g accuracy. Fin-ray numbers from all fins as well as scutes were counted by a magnifying glass. Total length (TL) varied from 17.0-36.5 cm and the total body weight (BW) ranged from 75.0-416.6 g. All LWRs were significantly related (p < 0.001), with r2 values ≥ 0.910. Based on r2 value (0.979), LWR by BW vs. TL (W= a × Lb) was the best fitted model among 14 equations. Besides, the LLRs were also significant with r2 values ≥ 0.908. According to r2 value (0.995), LLR by TL vs. FL (TL = a + b× FL) was the best fitted model among 14 equations. The fin formula of M. cordyla is: first dorsal, D1 I+VII; second dorsal, D2 I/14-18+6-8 finlets; pectoral, P1 20-26; pelvic, P2 I/5; anal, A II+I/12-16 +5-7 finlets. This study provided knowledge on morphometric and meristic features that would be very useful for species identification and stock assessment of M. cordyla in the Bay of Bengal and other marine ecosystems.PublishedReferee
Dynamics of quantitative development of spring and summer zooplankton in the Krasnodar Reservoir
No full textThis paper presents information on the quantitative development and species composition of the spring and summer zooplankton of the Krasnodar Reservoir in 2019, as well as long-term changes in the abundance and biomass of zooplankton for two seasons (spring and summer). The data on the changes in species diversity and quantitative development of zooplankton during the reservoir filling period and 25 and 45 years onward are presented. The dominant groups of zooplankters and dominant species among them have been identified. A comparison of the dynamics of qualitative and quantitative development of zooplankton in the Krasnodar Reservoir has shown that for the past 25 and 45 years (from 1974 to 2019), changes in species composition were insignificant. The number of species of planktonic organisms in each period under review is almost the same: 42 species during the reservoir filling period and 45 species in 1999–2001 and 2019. In terms of their abundance, rotifers and copepods prevailed in the present plankton composition, accounting for 57.3 and 40.7 %, respectively. Copepods accounted for 80.1 % of the total biomass. The average abundance of zooplankton organisms in the spring and summer seasons of 2019 exceeded the count for the period after flooding by 1.4 times, and for 1999–2001 it was by 2 times. However, the biomass of zooplankton in previous years was, on average, 3.5 and 8 times higher, respectively, due to the development of larger forms of cladocerans and copepods. The biomass of spring and summer zooplankton in the Krasnodar Reservoir in 2019 was 0.21−0.34 g/m3, which is compliant with the values characteristic for mesotrophic reservoirs. It is concluded that the Krasnodar Reservoir is a water body that has preserved its fishery potential for growing fish on natural feed resources.В работе представлены сведения по количественному развитию и видовому составу весенне-летнего зоопланктона Краснодарского водохранилища в 2019 г., а также многолетним изменениям численности и биомассы зоопланктона по двум сезонам (весна и лето). Приведены данные изменения видового разнообразия и количественного развития зоопланктона в период заполнения водохранилища, через 25 и 45 лет. Выделены доминирующие группы зоопланктеров и виды-доминанты среди них. Сравнение динамики качественного и количественного развития зоопланктона Краснодарского водохранилища показало, что за прошедшие 25 и 45 лет (с 1974 по 2019 г.) изменения видового состава незначительны. Число видов планктонных организмов в каждый рассматриваемый период практически одинаково: 42 вида в период заполнения водохранилища и 45 видов в 1999−2001 гг. и 2019 г. Численно в планктоне в современный период доминировали коловратки и веслоногие раки, составляя, соответственно, 57,3 и 40,7 %. На долю веслоногих приходилось 80,1 % всей биомассы. Средние показатели численности зоопланктонных организмов в весенне-летний период 2019 г. превышают значения за период после залития в 1,4 раза, за 1999−2001 гг. — в 2 раза. Но биомасса зоопланктона в прежние годы была выше за счет развития более крупных форм ветвистоусых и веслоногих ракообразных — в среднем в 3,5 и 8 раз, соответственно. Показатели биомассы весенне-летнего зоопланктона в Краснодарском водохранилище в 2019 г. равны 0,21−0,34 г/м3, что соответствует показателям мезотрофных водоемов. Сделан вывод о том, что Краснодарское водохранилище является водоемом, сохранившим рыбохозяйственный потенциал для выращивания рыбы на естественных кормовых ресурсах.PublishedReferee