23 resultados para SARGASSUM-MUTICUM


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Thirty-six species of Sargassum collected on the sea shore of Vietnam are studied. Four taxa are new: S. Feldmannii, S. Congkinhii, S. piluliferum var. nhatrangensis and S. hemiphyllum forma serrata.

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The Pennekamp Coral Reef State Park was established in 1960 and the Key Largo National Marine Sanctuary in 1975. Field studies, funded by NOAA, were conducted in 1980 - 1981 to determine the state of the coral reefs and surrounding areas in relation to changing environmental conditions and resource management that had occurred over the intervening years. Ten reef sites within the Sanctuary and seven shallow grass and hardbottom sites within the Park were chosen for qualitative and quantitative studies. At each site, three parallel transects not less than 400 m long were run perpendicular to the reef or shore, each 300 m apart. Observations, data collecting and sampling were done by two teams of divers. Approximately 75 percent of the bottom within the 18-m isobath was covered by marine grasses, predominantly turtle grass. The general health of the seagrasses appeared good but a few areas showed signs of stress. The inner hardbottom of the Park was studied at the two entrances to Largo Sound. Though at the time of the study the North Channel hardbottom was subjected to only moderate boat traffic, marked changes had taken place over the past years, the most obvious of which was the loss of the extensive beds of Sargassum weed, one of the most extensive beds of this alga in the Keys. Only at this site was the green alga Enteromorpha encountered. This alga, often considered a pollution indicator, may denote the effects of shore run off. The hardbottom at South Channel and the surrounding grass beds showed signs of stress. This area bears the heaviest boat traffic within the Park waters causing continuous turbidity from boat wakes with resulting siltation. The offshore hardbottom and rubble areas in the Sanctuary appeared to be in good health and showed no visible indications of deterioration. Damage by boat groundings and anchors was negligible in the areas surveyed. The outer reefs in general appear to be healthy. Corals have a surprising resiliency to detrimental factors and, when conditions again become favorable, recover quickly from even severe damage. It is, therefore, a cause for concern that Grecian Rocks, which sits somewhat inshore of the outer reef line, has yet to recover from die-off in 1978. The slow recovery, if occurring, may be due to the lower quality of the inshore waters. The patch reefs, more adapted to inshore waters, do not show obvious stress signs, at least those surveyed in this study. It is apparent that water quality was changing in the keys. Water clarity over much of the reef tract was observed to be much reduced from former years and undoubtedly plays an important part in the stresses seen today over the Sanctuary and Park. (PDF contains 119 pages)

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The seaweed industry in India is mainly a cottage industry and is based only on the natural stock of agar yielding red seaweeds, such as Gelidiella acerosa and Gracilaria eduli and algin yielding brown seaweed species such as Sargassum and Turbinaria. India produces 110-132 t of dry agar annually utilizing about 880-1100 t of dry agarophytes, and 360-540 t of algin from 3600-5400 t of dry alginophytes.

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Fourteen commonly occurring species of marine benthic algae, i.e., Colpomenia sinuosa (Mertens ex Roth) Derbes et Solier, Dictyopteris australis (Sonder) Askenasy, Dictyota dichotoma (Hudson) Lamouroux D. dumosa Børgesen, D. hauckiana Nizamuddin, D. indica Sonder, D. maxima Zanardini, Hincksia mitchelliae (Harvey) Silva, Jolyna laminarioides Guimardes in Guimarâes et al., Padina tetrastromatica Hauck, Sargassum tenerrinum J. Agardh, Spatoglossum variabille Figari et De Notaris, Stoechospermum marginatum (C. Agardh) Kültzing and Stokeyia indica Thivy et Doshi, belonging to all three classes of Phaeophyta, were collected from coastal areas near Karachi, Pakistan and their taxonomy determined. Although all are taxonomically known species, Dictyota dichotoma, D. dumosa, D. hauckiana, D. indica, D. maxima, Jolyna laminarioides, Padina tetrastromatica, Sargassum tenerritnum and Stokeyia indica are described for the first time from the coast of Pakistan.

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The authors report on the antibacterial activity of 11 algae, green, brown and red. Prepared extracts were tested, and varying degrees of activity were exhibited. Most activity was shown by Ulva fasciata, Sargassum cervicone and Halimeda macroloba.

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The configuration for the eastern side of the Gulf of Suez was studied over 241 km from Ras Mohammed to Ras Sudr including 35 station. Litters, tar balls and aged oil patches aggregated in considerable amounts on the beach and shore line of the middle part due to the oil spills from off-shore oil wells. A large reef flat in the shallow intertidal waters exists at stations 1 and 2 (Ras Mohammed, Protected area) and spars coral patches are less frequent at the Stations from 7 to 13. Density and diversity of marine benthos were higher on hard and cobble bottoms compared to muddy sand and sandy substrates. The assemblages of the benthic fauna are dominated by the gastropod Courmya (Thericium) vulgata; the bivalve Brachiodontes variabilis, and the barnacles Chthamalus stellatus, Balanus amphitrite and Tetraclita rubescens. The distribution of the algal cover in the intertidal region shows high abundance of the brown algae, Sargassum latifolium; padina pavonica and Cystoseira trinodis rather than the green and red algae. These species are found in both polluted and unpolluted areas. The changes in benthic structures in the study area depend not only on the state of pollution but also on the type of substrates.

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In this part 1, after a brief description of the habitat, the author describes in details (in descending order) the supralittoral, littoral and infralittoral zones. The author describes many permanent groups of Cyanophyceae in the higher horizon of intertidal zone, the cosmopolitan group of Navicula Grevillei, Hildenbrandtia prototypus, the pantropical group of Calothrix pilosa, Chaetomorpha antennina, indopacific group of Dermonema Frappieri, Sargassum, Padina, Thatassia Hemprichii, Halophila. The group of cold or temperate habitat with Bangiophycideae are present in winter. Some are described, formed by the oysters, Vermetus or Cirripeds, or by the algae (Calothrix, Brachytrichia, Gelidium, Dermonema, Chaetomorpha).

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The sohal surgeonfish or sohal tang, Acanthurus sohal, is a Red Sea endemic which grows to 16 in (40 cm) in the wild. Its striking blue and white horizontal stripes have made it what many consider the 'poster fish' for the Red Sea reef environment. It is a valued aquarium fish. A common species found in seaward edges of reefs exposed to surge. Aggressive and territorial. Feeds on various kinds of algae, mainly Sargassum, and fine filamentous green algae. Caught with nets; traps and occasionally by trawls.