Marine bioinvasion: concern for ecology and shipping

Marine bioinvasion - introduction of marine organisms alien to local ecosystem through ship hulls and ballast water - has serious consequences to native biota, fishery and general coastal ecosystem. Over 80% of the world cargo is mobilized transoceanically and over 12 billion tones of ballast water is filled at one part of the ocean and discharged at the other. These ballast waters offer conducive situation for bacteria, viruses, algae, dinoflagellates and a variety of macro-faunal larval/cyst stages to translocate to alien regions, usually along the coasts of the continents. As an example, there are over 18 species of animals and plants documented along the Indian coasts as those that might have got invaded and established. They can cause deleterious effects to local flora and fauna through their toxigenic, proliferative and over-competitive characteristics. This article points out the threats arising out of marine bioinvasion and various technological developments needed to deal with this unavoidable scourge in global shipping transport

Marine Tar Residues: a Review

Abstract Marine tar residues originate from natural and anthropogenic oil releases into the ocean environment and are formed after liquid petroleum is transformed by weathering, sedimentation, and other processes. Tar balls, tar mats, and tar patties are common examples of marine tar residues and can range in size from millimeters in diameter (tar balls) to several meters in length and width (tar mats). These residues can remain in the ocean envi-ronment indefinitely, decomposing or becoming buried in the sea floor. However, in many cases, they are transported ashore via currents and waves where they pose a concern to coastal recreation activities, the seafood industry and may have negative effects on wildlife. This review summarizes the current state of knowledge on marine tar residue formation, transport, degradation, and distribution. Methods of detection and removal of marine tar residues and their possible ecological effects are discussed, in addition to topics of marine tar research that warrant further investigation. Emphasis is placed on ben-thic tar residues, with a focus on the remnants of the Deepwater Horizon oil spill in particular, which are still affecting the northern Gulf of Mexico shores years after the leaking submarine well was capped

Benthic marine algae of the inshore water at Vestfold Hills, Antarctica

110-114Distribution and composition of benthic marine algae were studied at 4 stations in the Ellis Fjord (Iat. 68° 35' and 68° 38' E; long. 77° 50' and 78° 15' S) Vestfold Hills, Antarctica. Algae were collected through drilled hole in sea ice from May to December 1983 and during summer in the intertidal zone. Of the 14 algal species recorded from Ellis Fjord and Vestfold Hills, Antarctica brown algae Himantothallus grandifolius and Desmarestia menziesii were abundant near the mouth of the Fjord, but apparently absent inside the Fjord. Red algae Palmaria decipiens and Phyllophora antarctica were the dominant species of the region. Porphyra endiviifolium occurred in the upper littoral zone while Urospora penicilliformis and Enteromorpha bulbosa occurred in the intertidal rock crevices and furrows. Monostroma hariotii was present both in the intertidal pool and in infralittoral zone. Decrease in nitrate concentration was related with the luxuriant growth of U. penicilliformis during December, which was evident from the increase in photosynthetic activity resulting into high dissolved oxygen and pH of the water

Effect of treated sewage on growth of marine algae

33-36Eight algal species belonging to Chlorophyta, Rhodophyta and Phaeophyta were used to assess the effect of different concentrations of secondary treated sewage on their growth. Chlorophyta and Rhodophyta members. Ulva fasciata and Gracilaria verrucosa respectively, showed good growth as compared to the control in 5% sewage-seawater medium. Phaeophyta members did not show satisfactory growth. However, in 5 and 10% sewage-seawater media growth was observed in Padina tetrastromatica, stoechospermum marginatum and Spatoglossum asperum, while Sargassum sp. was found to be least tolerant to sewage pollution. Correlation coefficients between algal growth (weight) and nutrients showed that U. fasciata and G. verrucosa can be cultivated in diluted sewage effluent as tertiary sewage treatment species to remove nutrients in high concentrations and toxic substances from the sewage polluted areas

Subtidal marine algae of the Dwaraka coast (Gujarat)

297-301A total of 35 marine algal species were recorded during a survey of the subtidal flora of Dwaraka. Maximum number of species were found at 5-8 m. depth. Red algal species were dominant (20), followed by green (8) and brown (7). The biomass at 5 m depth was 2.044 kg/m(2) and comprised of species of Caulerpa, Dictyota and Spatoglossum. The similarity index calculated between intertidal and subtidal species of Dwaraka was 43.40, indicating that the subtidal floral composition is as diversified as that of the intertidal region

Primary productivity and nutrients in the Indian sector of the Southern Ocean

6-12Hydrography, nutrient and biological productivity data collected from 1981 to 1986 in the Indian sector of the Southern Ocean between 11-degrees to 53-degrees-E longitude are reported. The physical processes are most active in this region, with nutrient rich water upwelling at the Antarctic divergence (AD) at 65-degrees-S and water downwelling at the Antarctic convergence (AC) or subtropical convergence (STC) to the north. Chlorophyll a, primary producitivity and zooplankton estimations suggest that the regions south of AC are more productive than others. Higher productivity at the continental ice-edge than in oceanic waters is accounted for by the stability of the water column brought about by low salinity due to ice melting. Sharp depletion of Si near the AC where NO3 and PO4 maintain high values, as in the higher latitudes, reflects a unique behaviour of this element (Si) as regards to its biological uptake and regenerative mechanisms. Nutrient anomaly studies indicate that N regeneration is sufficiently fast in surface waters while most of the Si incorporated in diatoms and silicoflagellates tend to escape to deeper waters or to bottom sediment. The importance of microbial population is stressed to understand the food chain dynamics of Antarctic ecosystem

Properties of phycocolloid extracts from seaweeds of Goa (India)

181-182Phycocolloid extracts from 3 algal species (Hypnea musciformis, Gracilaria corticata and Gelidiella sp.) and their mixtures were studied for gel strength, gelling temperature and melting point. Total yield varied from 20 to 30% dry weight of the seaweed. Addition of an electrolyte such as KCl (0.5%) increased the yield and improved gel strength

Biochemical Constituents of Seaweeds along the Maharashtra Coast

297-299Protein, carbohydrate and organic carbon were estimated in 43 marine algal species from different stations along the Maharashtra Coast in India. These species showed variation in their biochemical contents. Protein varied from 10 to 33%. Chlorophyceae and rhodophyceae members were rich in protein and carbohydrate compared to phaeophyceae. Organic carbon showed maximum average value (33%) in chlorophyceae. C:N ratio varied from 5.2 to 29.8 and showed inverse relationship with protein

Ecology of clam beds in Mandovi, Cumbarjua canal and Zuari estuarine system of Goa

122-126Observations on environmental parameters clearly indicate two independent ecosystem at Ribandar and Banastrim clam beds in Mandovi-Cumbarjua canal-Zuari estuarine system of Goa. Maximum size attained by Meretrix casta in this estuarine system is 55 mm. Recruitment to the clam population at Banastrim is earlier and more prolonged than at Ribandar. Length-frequency studies indicate that M. casta at Banastrim breeds throughout the year, whereas at Ribandar, breeding is suspended during peak summer. Low salinity adversely affects the growth. Year-class composition at Ribandar is dominated by 1-yr class and at Banastarim by 0-yr class. Possibility of migration of adult clams at Banastrim is postulated. Dimensional relationship marks out the existence of different stocks of M. casta in this estuarine system of Goa. An overall appraisal of the results reveal the possibilities of culture of clams in the estuaries of Goa

<smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="place" downloadurl="http://www.5iantlavalamp.com/"> Marine macroalgal diversity along the Maharashtra coast: Past and present status </smarttagtype>

18-24 A comparative study on distribution and abundance of marine macroalgae was carried out at six sites along the Maharashtra coast with the available data from 1935 onwards. The analyses and interpretation of this data revealed very interesting trends in marine macroalgal diversity. A typical cyclic change in their distribution, abundance and the reproductive features were observed in these algal forms. Although, northern part of Maharashtra is subjected to increasing industrial pollution and habitat destruction, there are some pockets wherein high macroalgal diversity occurs. This may be because of the increased tolerance to the environmental changes. </smarttagtype