The Northern Territory is in a unique position to support sandfish (Holothuria scabra) ranching as it has an intact wild fishery and low poaching pressure. Indigenous people own 85% of the coastline, and are keen to develop economic opportunities through their natural resources. The commercial wild-caught sector has well-established markets, and has expressed a willingness to partner with Indigenous coastal communities. Research currently underway is focused on the biological and economic feasibility of sea cucumber ranching as well as developing effective facilitation and evaluation approaches to ensure that Indigenous people drive enterprise development themselves.
Digital library
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In south-western Madagascar, anthropogenic and environmental factors are adversely affecting marine resources, and alternatives to fishing for the local Vezo community are limited. In an effort to overcome this problem, a non-government organisation (NGO), Blue Ventures, has been pioneering farming of sandfish (Holothuria scabra) in pens as a livelihood strategy for communities. Successful preliminary trials resulted in Blue Ventures and the NGO Trans’Mad-Développement obtaining funding to expand the project to include 40 families in seven villages. The pens, measuring between 625 and 900 m2, were constructed in nearshore seagrass beds and stocked with batches of 300–450 hatchery-reared juveniles (15 g) at 3–4-month intervals. Sea cucumbers reaching a minimum size of 300 g between 4 and 12 months later were harvested and sold to the commercial partner, Madagascar Holothurie S.A., for processing and export. During the period of the study, a total of 51,500 juveniles were released at seven sites during 21 release events spread over 45 months. Although preliminary trials yielded high survival rates (80%), on scaling up the project a number of factors led to increased mortality rates; these included suboptimal transportation and stocking conditions, and predation. To meet these problems, methodologies were improved and a number of strategies were adopted to improve survival of juveniles following release. Socioeconomic issues remained a challenge throughout the project, as theft of market-size sea cucumbers was prevalent.
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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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Mosquito-borne diseases are a big global concern, being responsible for 300 million of annual cases of infection, according to World Health Organization (WHO), and being one of the main causes of deaths worldwide. Some of these diseases were reduced in the last centuries, particularly in the XX century, but many are remerging and also appearing in places that they were not used to. The genera of mosquitos with more medical importance are Anopheles, Aedes and Culex, but this work focus on Aedes aegypti (Ae. Aegypti). Most of these diseases do not have a vaccine or treatment, so the best way to fight against them is controlling the vectors – in this case Ae. aegypti, and some authors defend that this control is easier when applied in larvae stage. Four main strategies have been used: physical, genetic, chemical and biological control. Chemical control, namely the use of phytochemicals such as seaweed extracts, is receiving more attention lately, once the other methods pose problems like the environmental persistence, hazard in non-target organisms, and resistance by the insects. Seaweed are a big source of compounds that have a wide range of bioactivities serving several applications, as antibacterials, antifungals, antivirals, antitumorals, among others. In this work, the mosquito larvicidal potential of five organic extracts from two macroalgae species - Fucus vesiculosus (F. vesiculosus) and Ulva lactuca (U. lactuca) – were accessed in Ae. aegypti. The extracts were obtained with the solvents ethanol, methanol, chloroform, hexane and dichloromethane. Mortality assays, according WHO guidelines, were performed counting the dead larvae after 24 and 48 hours of exposure. Body length and the weight of surviving larvae were also measured to investigate potential gross impacts of the extracts on larval growth/development. From these assays, dichloromethane extract from F. vesiculosus was the only one that showed significant differences compared with the control, reaching 58% mortality after 48 hours of exposure. Body size measurements and weighings showed no differences between treatments. Assays with Artemia salina (A. salina) were also carried out with 24 hours of exposure, to access possible effects of these extracts in non-target aquatic organisms. In the same concentration used in mosquito larvae, no significant differences were observed between the extracts and the control. However, in a higher concentration, three extracts from F. vesiculosus showed toxicity, namely ethanol, chloroform and dichloromethane. The results showed that dichloromethane extract from F. vesiculosus could be a useful source of larvicidal compounds to fight mosquitos, the most important disease vectors for transmitting diseases to Humans. The A. salina data support that lethality in non-target species is only attained at higher concentrations of extract when compared with those for the mosquito. Anyway, a wider range of non-target organisms should be assayed. Having the present work as basis, further studies could try to elucidate the mode of action of the extracts effects when inducing lethality, in addition to isolate and characterize the compounds present in the most promising extracts. By other hand, screening tests using combinations of extracts could be useful to pinpoint yet unknown synergy or potentiation effects. At last, our data support that more studies should be done on a wider range of seaweeds, as extracts from different species do present quite different bioactivities.
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Microsoft Excel file on Preliminary " back of envelope" numbers as of March 22, 2012.
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Biofuels from Opihi Algae. 10 to 15 years of technology development. Current business exists in high quality, fresh algae. Research needed on strains, biomass production, enviornmental manipulation, harvest, processing. Cost must be competitive with petroleum.
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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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When waves of sargassum - a type of seaweed - washed up on Eastern Caribbean shores seven years ago, people hoped it was a one-off. Matted piles swamped coastlines from Tobago to Anguilla.
"In 2011 it was the first time we'd seen it," says Professor Hazel Oxenford, an expert in fisheries biology and management at the University of the West Indies.
"It came as a complete shock and no-one had a clue what to do with it."
Three years later the seaweed returned, in larger quantities. Over several months, it made its way through the Caribbean to southern Mexico, where its impact on Cancun's beaches made international headlines.
Now it is happening again and everything suggests 2018 could be the worst year yet.
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The invasive marine macroalga Sargassum muticum was recorded from Kilmore Quay, Co. Waterford, for the first time in the Republic of Ireland in 2001. It was found at several other places in that year and in subsequent years. An intensive survey was carried out from April 2003 to November 2003 to map the geographical distribution and spread of this invasive brown macroalga, and data on distribution were collected in subsequent years through 2006. This study indicated that S. muticum most probably arrived in the early or mid 1990s and has spread all around the Irish coastline colonising Co. Donegal for the first time in 2006. The results indicate that spreading is facilitated by boating and perhaps via shellfish transport. A rough rate of spread of 2–3 km year−1 has been calculated within one bay and for the Irish coastline of about 54 km year−1 . Observations showed that S. muticum has been found growing in seagrass beds and in rock pools, which might have serious consequences for the biodiversity in rock pools and for the protective status of seagrass habitats. It is recommended that monitoring of S. muticum should continue, especially in areas of high amenity value and economic importance in order to observe possible effects on local flora and fauna, aquaculture, the seaweed industry and tourism.
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The world’s population has been predicted to rise to over nine billion by 2050 (e.g. FAO, 2009a; Lutz and Samir, 2010), with most of this increase predicted to occur in low and middle income (developing) countries (Alexandratos and Bruinsma, 2012; Government Office for Science, 2011; Lutz and Samir, 2010). The proportion of the population living in urban areas and income levels are also expected to rise (with at least 3 billion people entering the global middle classes) which is likely to increase demand for more nutritious and higher quality foods (i.e. more resource-intensive foods such as meat and vegetable oils; Searchinger et al., 2013 and references therein).
The question of how to achieve such increases in food production to feed this larger, increasingly affluent population, whilst ensuring sufficient food calories to adequately feed the entire global population, in a sustainable manner (i.e. that ensures food production that contributes to inclusive social and economic development whilst reducing environmental impacts and pressures on limited resources), is the subject of current discussion and research (e.g. Searchinger et al., 2013; Alexandratos and Bruinsma, 2012; The Government Office for Science, 2011). An increased global population will also necessarily have greater energy requirements.
The Scottish Aquaculture Research Forum (SARF) and WWF-UK commissioned this study to investigate whether the pressure on land and freshwater for future food and energy resources, and impacts on the climate, related to greenhouse gas (GHG) emissions, may be reduced through expansion of global mariculture. The study has undertaken a high level assessment of the ‘environmental footprint’ of global mariculture and terrestrial-based food and energy production systems through the collation and assessment of available Life Cycle Assessments (LCA) for key food products (beef, pork, chicken, freshwater finfish, marine finfish, shellfish and crustacean species) and biomass (terrestrial and algal) for energy production. The outputs of the footprint comparison were then used to assess the risks and benefits of increasing global mariculture, through the development of projected future scenarios in which mariculture contributes differing proportions of projected future food requirements. The analysis also qualitatively considered the socio-economic and wider environmental risks and benefits (e.g. in relation to ecosystem services) of global mariculture expansion, where expansion may occur geographically and whether future technological developments may help mitigate against identified impacts.
The study identifies the key uncertainties and limitations of the risk/benefit analysis and makes prioritised recommendations on how these limitations can be addressed and the analysis developed for more regional or site-specific assessments.
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Marine Agronomy Group, CAFNRM, UH-Hilo
200 W. Kawili st., HI 96720, USA
Contact: Marine.Agronomy.Group@gmail.com
Funding for this web portal is provided by the World Wildlife Fund and the University of Hawaii-Hilo.