Aquaculture

Marine net-pen fish farms aren’t popular with environmentalists for a number of reasons, one of the main ones being the amount of fish feces and uneaten food that they release into the surrounding ocean. In the UK, help for that problem may be coming in the form of the sea cucumber. Despite its name, the sea cucumber is an animal, that resembles a big slug and is about the same size as ... well, as a cucumber, or sometimes larger. Given that sea cukes subsist on organic matter that they scavenge from the sea floor, scientists at Newcastle University have proposed that they be introduced to fish farms where they could process waste. After eating all that fish poop, some of the cucumbers could then be served up as gourmet cuisine for humans. Read More

Oh, choices, choices... do you grow vegetables, raise worms or raise fish? Well, the just-released Fishy Farm is designed to do all three in one hit. The small-scale aquaponic set-up is based around an ecosystem in which fish-waste-infused water fertilizes the veggies and feeds the worms, which in turn filter the water before it returns to the fish. All that users need to do is feed the fish, top up the water, and gobble up the bounty... except for the worms. Read More

Researchers have developed transgenic rainbow trout with enhanced muscle growth that results in fish with what have been described as six-pack abs and muscular shoulders. Aside from ensuring the muscular trout don’t get bullied by other fish, the development could provide a boost to the commercial aquaculture industry. Read More

March 5, 2008 Hydroelectric dams produce little-to-no emissions and draw energy from a renewable resource, but they are still plagued with the inherent problems of all large-scale power plants: they’re costly to build and maintain, land intensive, and have negative environmental consequences. That’s why Bourne Energy believes the future of hydropower, and the solution to global energy demand, is in small generators that harness power from river currents. The company's RiverStar power modules collect kinetic energy by passing the water through low RPM turbines that don’t harm aquaculture. The units can be cheaply mass-produced, and require no construction on river bottoms, allowing them to be installed quickly and inexpensively even in areas inhospitable to development. Read More

January 29, 2008 Ocean Thermal Energy Conversion uses the temperature difference between surface and deep-sea water to generate electricity – and though it has an efficiency of just 1-3% - researchers believe an OTEC power plant could deliver up to 250MW of clean power, equivalent to one eighth of a large nuclear power plant, or one quarter of an average fossil fuel power plant. Architect and engineer Dominic Michaelis and his son Alex, along with Trevor Cooper-Chadwick of Southampton University are developing the concept with plans of putting the theory to the test on an unprecedented scale by building a floating, hexagonal Energy Island that will harness energy from OTEC, as well as from winds, sea currents, waves, and the sun. Read More

February 28, 2007 Biofouling of marine organisms on ship hulls has been a global problem since man crafted the first boat. These days, many marine enterprises suffer the problem and the cost of reducing it, in aquaculture, offshore industries and harbours. In shipping alone, marine biofouling and its most significant organism, the barnacle, increase drag, adversely affect fuel consumption, increase pollution (via the workload on the machinery and downtime due to dry-docking. The annual global cost of cleaning alone is in the billions of dollars. Toxic paints are the most prevalent current anti-fouling strategy but they cause severe environmental disturbances due to the emission of toxic substances into the marine environment. Currently used toxic paints based on Tributyl tin oxide (TBT) are the first target as they generate unwanted effects at non-target organisms and will be banned by 2010, but this ban may be followed by the prohibition of other substances in marine paints. Now a new type of paint has been developed which uses an extract from the microscopic fungus Streptomyces avermitilis to poison barnacles. The fungus lives in the ocean and is extremely poisonous to acorn barnacles and other crustaceans, a feature based on the environmentally friendly defense of the fungus against being eaten. A new study from Goteborg University in Sweden has found that when this fungus is added to paint for ship hulls, the surface remains entirely free from barnacles. As little as a 0.1-percent mixture of pure fungal extract in paint is sufficient to affect the nervous system of barnacles and prevent any growth and the fungal extract is toxic only as long as the paint is on a painted surface. When the paint is dissolved in sea water, the activation of the poison appears not to take place, making the paint apparently harmless to organisms in the open sea. Read More

March 30, 2005 A landmark study released today reveals that approximately 60 percent of the ecosystem services that support life on Earth -- such as fresh water, capture fisheries, air and water regulation, and the regulation of regional climate, natural hazards and pests -- are being degraded or used unsustainably. Scientists warn that the harmful consequences of this degradation could grow significantly worse in the next 50 years. The Powerpoint presentation of this report makes compelling reading - it should be downloaded by every school, every office and every human being with an interest in seeking positive change. Show it to all those who will listen. It can be downloaded here. Read More