16,976 research outputs found

    Satellite Images Show the Movement of Floating _Sargassum_ in the Gulf of Mexico and Atlantic Ocean

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    The question of the origin, distribution and fate of the floating seaweed _Sargassum_ has fascinated sailors and scientists from the time of Columbus. Observations from ships are hampered by the large and variable area over which _Sargassum_ is dispersed. Here we use satellite imagery to present the first mapping of the full distribution and movement of the population of _Sargassum_ in the Gulf of Mexico and western Atlantic in the years 2002 to 2008. For the first time, we show a seasonal pattern in which _Sargassum_ originates in the northwest Gulf of Mexico in spring of each year, is advected into the Atlantic in about July, appearing east of Cape Hatteras as a "Sargassum jet", and ending northeast of the Bahamas in February of the following year. This pattern appears consistent with historical surveys. Future satellite observations will show whether this pattern repeats in all or most years

    The Protection and Management of the Sargasso Sea

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    The Sargasso Sea is a fundamentally important part of the world's ocean, located within the North Atlantic sub-tropical gyre with its boundaries defined by the surrounding currents. It is the only sea without land boundaries with water depths ranging from the surface coral reefs of Bermuda to abyssal plains at 4500 m. The Sargasso Sea's importance derives from the interdependent mix of its physical structure and properties, its ecosystems, its role in global scale ocean and earth system processes, its socio-economic and cultural values, and its role in global scientific research. Despite this, the Sargasso Sea is threatened by a range of human activities that either directly adversely impact it or have the potential to do so. Being Open Ocean, the Sargasso Sea is part of the High Seas, the area of ocean that covers nearly 50%of the earth's surface but which is beyond the jurisdiction and responsibility of any national government, and as such it enjoys little protection. To promote the importance of the Sargasso Sea, the Sargasso Sea Alliance was created under the leadership of the Government of Bermudian 2010. This report provides a summary of the scientific and other supporting evidence for the importance of the Sargasso Sea and is intended to develop international recognition of this; to start the process of establishing appropriate management and precautionary regimes within existing agreements; and to stimulate a wider debate on appropriate management and protection for the High Seas. Nine reasons why the Sargasso Sea is important are described and discussed. It is a place of legend with a rich history of great importance to Bermuda; it has an iconic ecosystem based upon floating Sargassum, the world's only holopelagic seaweed, hosting a rich and diverse community including ten endemic species; it provides essential habitat for nurturing a wide diversity of species many of which are endangered or threatened; it is the only breeding location for the threatened European and American eels; it lies within a large ocean gyre which concentrates pollutants and which has a variety of oceanographic processes that impact its productivity and species diversity; it plays a disproportionately large role in global ocean processes of carbon sequestration; it is of major importance for global scientific research and monitoring and is home to the world's longest ocean time series of measurements; it has significant values to local and world-wide economies; and it is threatened by activities including over-fishing, pollution, shipping, and Sargassum harvesting. Apart from over-fishing many of the threats are potential, with few direct causal relationships between specific activities and adverse impacts. But there is accumulative evidence that the Sargasso Sea is being adversely impacted by human activities, and with the possibility of new uses for Sargassum in the future, the lack of direct scientific evidence does not preclude international action through the established precautionary approach. The opportunity to recognize the importance of the Sargasso Sea and to develop and implement procedures to protect this iconic region and the wider High Seas should be taken before it is too late

    Ethnobotany Study of Seaweed Diversity and Its Utilization in Warambadi, Panguhalodo Areas of East Sumba District

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    This paper reports the ethnobotany study of seaweed diversity in Warambadi –Panguhalodo areas of East Sumba District, the island of Sumba. The study recorded19 genera of 54 species of seaweed, which were utilized as food or edible seaweed.The group consisted of 17 species of green algae, 17 species of red algae, and 20species of brown algae. The study also reported that 18 genera of 38 species weretraditionally utilized for medicinal purposes as herbal medicine. The herbal speciesconsisted of 7 species of green algae, 13 species of red algae, and 18 species ofbrown algae.Seaweed is traditionally consumed as food in various forms: raw as salad and vegetable,as pickle with sauce of allspice or with vinegar, as relish or sweetened jellies and alsocooked for vegetable soup. As herbal medicine seaweed is usually used for traditionalcosmetics, as antipyretic and antiseptic, as vermifuges, and treatments for cough andasthma, hemorrhoid, nosebleed and boils, goiter and scrofula, stomach ailments andurinary diseases.Indigenous knowledge on seaweed still exist and are continually employed bypeople living in particular areas such as the Sumba and Sabu ethnic groups. Yet,the knowledge is gradually decreasing due to localities, socio-economic change andcultural development

    Bermuda's Legacy

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    The Sargasso Sea is one of the great ecological wonders of the world; on its surface floats a "golden rainforest" as teeming with colorful life as a coral reef. It remains much as it was when first described by Christopher Columbus in 1492. Plants, fish, turtles, and crabs thrive in this exceptionally clear, warm body of water, miles above the ocean floor. Among its wonders are birds that roost on the mats of golden Sargassum seaweed; a fish that has evolved pectoral fins, like five-fingered hands, that enable it to grasp and climb the seaweed; and eels that travel vast distances from the rivers of Europe and North America to reproduce somewhere in its depths before they die. This is the only sea in the world surrounded by currents, rather than land, and Bermuda is the only island within it. In addition to providing a nursery for fish and other sea life, the seaweed benefits Bermuda directly when it washes ashore and sinks into the sand, fertilizing the soil and strengthening the island against storms and erosion

    Utilization of seaweed resources

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    A brief discussion is presented on the commercial importance of seaweeds in the Philippines, which is mainly concerned with their use as sources of industrial gums such as agar, carrageenan, and alginic acid. Carrageenan as a substitute for microbiological agar and the use of seaweeds as a binder of heavy metal pollutants are examined

    A genome-wide investigation of the worldwide invader Sargassum muticum shows high success albeit (almost) no genetic diversity

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    Twenty years of genetic studies of marine invaders have shown that successful invaders are often characterized by native and introduced populations displaying similar levels of genetic diversity. This pattern is presumably due to high propagule pressure and repeated introductions. The opposite pattern is reported in this study of the brown seaweed, Sargassum muticum, an emblematic species for circumglobal invasions. Albeit demonstrating polymorphism in the native range, microsatellites failed to detect any genetic variation over 1,269 individuals sampled from 46 locations over the Pacific-Atlantic introduction range. Single-nucleotide polymorphisms (SNPs) obtained from ddRAD sequencing revealed some genetic variation, but confirmed severe founder events in both the Pacific and Atlantic introduction ranges. Our study thus exemplifies the need for extreme caution in interpreting neutral genetic diversity as a proxy for invasive potential. Our results confirm a previously hypothesized transoceanic secondary introduction from NE Pacific to Europe. However, the SNP panel unexpectedly revealed two additional distinct genetic origins of introductions. Also, conversely to scenarios based on historical records, southern rather than northern NE Pacific populations could have seeded most of the European populations. Finally, the most recently introduced populations showed the lowest selfing rates, suggesting higher levels of recombination might be beneficial at the early stage of the introduction process (i.e., facilitating evolutionary novelties), whereas uniparental reproduction might be favored later in sustainably established populations (i.e., sustaining local adaptation).Agence Nationale de la Recherche - ANR-10-BTBR-04; European Regional Development Fund; Fundacao para a Ciencia e a Tecnologia - SFRH/BPD/107878/2015, UID/Multi/04326/2016, UID/Multi/04326/2019; Brittany Region;info:eu-repo/semantics/publishedVersio
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