Rhodolith beds are important marine benthic ecosystems, representing oases of high biodiversity among sedimentary seabed environments. They are found frequently and abundantly, acting as major carbonate ’factories’ and playing a key role in the biogeochemical cycling of carbonates in the South Atlantic. Rhodoliths are under threat due to global change (mainly related to ocean acidification and global warming) and local stressors, such as fishing and coastal run-off. Here, we review different aspects of the biology of these organisms, highlighting the predicted effects of global change, considering the additional impact of local stressors. Ocean acidification (OA) represents a particular threat that can reduce calcification or even promote the decalcification of these bioengineers, thus increasing the ecophysiological imbalance between calcareous and fleshy algae. OA should be considered, but this together with extreme events such as heat waves and storms, as main stressors of these ecosystems at the present time, will worsen in the future, especially if possible interactions with local stressors like coastal pollution are taken into consideration. Thus, in Brazil there is a serious need for starting monitoring programs and promote innovative experimental infrastructure in order to improve our knowledge of these rich environments, optimize management efforts and enhance the needed conservation initiatives.
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Aquaculture, the farming of aquatic animals and plants, is a well-established industry in many parts of the world. Aquaculture has, in fact, replaced inland capture fisheries as the most important source of freshwater fish (Revenga et al. 2000). According to FAO statistics, aquaculture's contribution to global supplies of freshwater and marine species has grown from 3.9 percent of total production by weight in 1970 to 27.3 percent in 2000. Overall, aquaculture has increased at an average compounded rate of 9.2% per year since 1970, compared with only 1.4% for capture fisheries and 2.8% for terrestrial animal production (FAO 2002). In 2000, total aquaculture production reported to FAO was 45.7 million metric tons with a value of $56.5 billion US dollars. Almost half of the total, some 20.2 million metric tons was produced in freshwater (Figure 1).
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Sea cucumber harvesting has been carried out in the Northern Territory (NT) since 1700 when Macassans regularly visited the area. Tasmanian Seafoods Pty Ltd currently holds all licences for sea cucumber in the NT, with the main target species being sandfish (Holothuria scabra). Tasmanian Seafoods has successfully trialled propagation and juvenile production for wild fishery stock enhancement and land-based grow-out in ponds. Lease of an ex-prawn farm and hatchery facilities at Darwin Aquaculture Centre has progressed its efforts. Tasmanians Seafoods has established working relationships with remote Indigenous communities situated nearby on recognised fishing grounds on Groote Eylandt, to develop the sea-ranching component of the project and establish joint ventures for the harvesting of the ‘released’ sea cucumbers. Appropriate policies and management arrangements are also being negotiated with the NT Government Department of Resources Fisheries Group.
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Just in case you needed more reasons to be concerned about the stability of the Middle East, new research using data from NASA’s gravity-sensing Grace satellites shows a substantial decline in the volume of groundwater reserves in the Tigris and Euphrates river basins. Data gathered between 2003 and 2009 show the seasonal recharge of the region’s aquifers (the blue pulses in the illuminating animation above) but then the onset of a potent drought in 2007 followed by a persistent big drop in water amounts, 60 percent of which is ascribed to unsustainable rates of pumping in a study to be published on Friday in the journal Water Resources Research.
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Fifty five seaweed extracts belonging to 11 species of seaweeds were tested against post operative infectious drug resistant bacteria viz., E. coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Streptococcus pyogens, Staphylococcus aureus. Among the seaweed extracts, the acetone extracts of Caulerpa cupressoides shows maximum inhibtory activity against E. coli and propanol extracts of Gracilaria edulis shows maximum inhibitory effect against K. pneumoniae. Acetone extracts of Padina tetrastromatica and Laurencia cruciata show maximum inhibitory activity against P. aeruginosa, butanol extracts of Hypnea musciformis, Caulerpa cupressoides and Chaetomorpha linoides show maximum inhibitory effect against S. aureus.
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During the survey carried out for inventorying the marine and estuarine biodiversity of coastal Karnataka for the Karnataka Biodiversity Board in December 2005, considerable populations of thin bladed grass species were collected from Kundapur (13.64306 ºN & 74.6586 ºE) and Mavinahole (13.9833 ºN & 74.5616 ºE) estuaries as well as from the intertidal areas of Devgad Island (14.8225 ºN & 74.0644 ºE) and these were later identified as Ruppia maritima L popularly known as beaked tassel-weed.
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Young plants of S. ilicifolium and S. myricosystum appear in April and May and reach the maximum size in September or October. Alginic acid yield varies with the seasonal growth behaviour of these alginophytes. with maximum yield in July or August. Alginic acid content varies from 22.3 to 30.8% in S. ilieifolium and from 15.9 to 34.5% in S. myriocyslum. Mannitol content ranges from 2 to 5 and 1.3 to 5% in S. jlicifolium and S. myriocysmm respectively. The suitable harv.esting period for getting the maximum yidd of algin ic acid appears to be between July and September.
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Some might be put off by its texture, aroma, or murky origins, but the fact of the matter is seaweed is one of the oldest human foods on earth. And prepared the right way, it can be absolutely delicious. Long a staple in Asian cuisines, seaweed has emerged on the global market as one of our new superfoods, a natural product that is highly sustainable and extraordinarily nutritious. Illuminating seaweed’s many benefits through a fascinating history of its culinary past, Kaori O’Connor tells a unique story that stretches along coastlines the world over.
O’Connor introduces readers to some of the 10,000 kinds of seaweed that grow on our planet, demonstrating how seaweed is both one of the world’s last great renewable resources and a culinary treasure ready for discovery. Many of us think of seaweed as a forage food for the poor, but various kinds were often highly prized in ancient times as a delicacy reserved for kings and princes. And they ought to be prized: there are seaweeds that are twice as nutritious as kale and taste just like bacon—superfood, indeed. Offering recipes that range from the traditional to the contemporary—taking us from Asia to Europe to the Americas—O’Connor shows that sushi is just the beginning of the possibilities for this unique plant. -
Stepping Stones to Commercialization : Food, feed, fuel
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Using Nature's Filters to help curb pollution and fish farm waste.
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Marine Agronomy Group, CAFNRM, UH-Hilo
200 W. Kawili st., HI 96720, USA
Contact: Marine.Agronomy.Group@gmail.com
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