NGUỒN LỢI, SỬ DỤNG VÀ NUÔI TRỒNG RONG Ở VIỆT NAM

Trong bài này, dựa trên dữ liệu của riêng các tác giả và tài liệu đã công bố, mô tả nguồn tài nguyên tự nhiên, sự sử dụng và trồng rong biển ở Việt Nam. Cho thấy rằng nguồn lợi của thực vật biển (đặc biệt là rong nâu) giảm đáng kể do việc khai thác rong tự nhiên bừa bãi. Ở Việt Nam, rong được sử dụng rộng rãi trong thực phẩm, trong y học dân gian, thu nhận các chất hữu ích như agar, alginat và Fucoidan, nhưng một lượng lớn thu được từ các nguồn tài nguyên tự nhiên và rong biển trồng đem xuất khẩu, chủ yếu là sang Trung Quốc. Công nghiệp trồng rong biển chủ yếu là việc trồng rong chứa agar giống Gracilaria và giống Kappaphycus chứa carrageenan. Bài viết cung cấp các khuyến nghị và thảo luận về cách trồng trọt các loài Sargassum phổ biến  nhất. Summary: Base on data of individual authors and documents published, the natural resources, use and seaweed cultivation in Vietnam aredescribed. It shows that the resources of marine plants (especially brown algae) significantly reduced due to the indiscriminate exploitation of natyral seaweed. In Vietnam, the seaweed is widely used in food and in folk medicine, obtain usedful substances such as agar, alginates and fucoidan, but a large amount of revenue from natural resources and seaweed mainly contains agar seaweed breeds Gracilaria and carrageenan seaweed breeds kappaphycus. Th review makers recommendation and disuss how to cultivate the most common species of Sargassum

Climate-induced range shifts shaped the present and threaten the future genetic variability of a marine brown alga in the Northwest Pacific

Glaciation-induced environmental changes during the last glacial maximum (LGM) have strongly influenced species' distributions and genetic diversity patterns in the northern high latitudes. However, these effects have seldom been assessed on sessile species in the Northwest Pacific. Herein, we chose the brown alga Sargassum thunbergii to test this hypothesis, by comparing present population genetic variability with inferred geographical range shifts from the LGM to the present, estimated with species distribution modelling (SDM). Projections for contrasting scenarios of future climate change were also developed to anticipate genetic diversity losses at regional scales. Results showed that S. thunbergii harbours strikingly rich genetic diversity and multiple divergent lineages in the centre-northern range of its distribution, in contrast with a poorer genetically distinct lineage in the southern range. SDM hindcasted refugial persistence in the southern range during the LGM as well as post-LGM expansion of 18 degrees of latitude northward. Approximate Bayesian computation (ABC) analysis further suggested that the multiple divergent lineages in the centre-northern range limit stem from post-LGM colonization from the southern survived lineage. This suggests divergence due to demographic bottlenecks during range expansion and massive genetic diversity loss during post-LGM contraction in the south. The projected future range of S. thunbergii highlights the threat to unique gene pools that might be lost under global changes.UIDB/04326/2020 - PTDC/BIA-CBI/6515/2020 - DL57/2016/CP1361/CT0035info:eu-repo/semantics/publishedVersio

Inventory and Historical Changes in the Marine Flora of Tomioka Peninsula (Amakusa Island), Japan

Intensive algal sampling was conducted from 2012 to 2017 in the Tomioka Peninsula, Amakusa-Shimoshima Island (the East China Sea, Japan), yielding a total of 293 benthic macroalgal taxa, of which 63% were red algae, 16% were brown algae, and 19% were green algae. The majority (69%) of species were previously recorded only for the tropics and/or subtropics, whereas 31% of species were recorded for temperate latitudes. Among all species of algae found from 2012 to 2017 in the Tomioka Peninsula, 163 species (56%) were newly identified species for Amakusa-Shimoshima Island, including six taxa, which were recorded in Japan for the first time. Comparison of the current data from the Amakusa-Shimoshima Island with those of nearby tropical regions suggested that the recent marine flora of the Amakusa-Shimoshima Island was more closely affiliated with the flora of a warm-temperate region. Moreover, we found that the benthic flora of the Tomioka Peninsula was significantly changed between the 1950s (Segawa & Yoshida 1961) and 2012–2017. For example, the species diversity was increased by two times, mainly at the expense of red and green algae, and the biogeographic status of the benthic flora was changed from the flora of a cold-temperate region to the flora of a warm-temperate region, which could be attributed to an introduction of red algae from the tropics of South East Asia and widespread opportunistic green algae, as well as the disappearance of cold-water brown algae. Collectively, our data suggested that these changes were driven by the global warming effect on the ocean

New records of benthic marine green algae (Chlorophyta) for the island of Hainan (China)

The island of Hainan (China) is located on the northern periphery of the subtropical Pacific Ocean in the South China Sea and possesses one of the most prominent fringing coral reefs of China. The marine algal flora of the island was described for the first time after several early expeditions in the 1930’s (and around 1960) mentioning 68 species of marine green algae (Chlorophyta) in total. Sixty years later, the island was revisited in autumn 1990 and spring 1992 within in the framework of two extensive expeditions in order to scrutinise the algal biodiversity of the coral reef habitats. Again 20 years later, three more surveys were performed in 2008, 2009 and 2010 focusing only on the southern shores of Hainan Island near Sanya city. The analysis of this material revealed the existence of 31 new records of marine green algae for Hainan Island, including 17 species which also constitute new records for China. The new records are described and characteristic details are depicted. Collection sites around Hainan Island and world-wide distributions are given. Thirteen newly recorded species were only sampled once and therefore seem to be rare. Thirteen other species are pre-dominantly epiphytic or endophytic. The new records for China are fairly typical for tropical to subtropical locations of south-western to south-eastern Asia, except Chlorochytrium cohnii (distribution hitherto restricted to Europe), Chaetomorpha minima (distribution hitherto restricted to North and Central America, Africa, Indian Ocean islands) and Cladophora perpusilla (distribution hitherto restricted to Central and South America, Australia, New Zealand, Pacific islands). None of the new records are considered to represent an invasive species

New records of benthic brown algae (Ochrophyta) from Hainan Island (1990-2016)

This study reports on the intertidal and shallow subtidal brown algal flora from Hainan Island in the South China Sea, based on extensive sample collection conducted in 1990, 1992, and 2008-2016. The analyiss revealed 27 new records of brown algae for Hainan Island including 5 species which also constitute new records for China. 21 of these species are described with photographs and an annotated list of all species with information on life forms, habitat (localities and tidal zones) and their geographical distribution is provided