Fish Facts

Fish Facts: Offshore power – Win win for anglers?

RENEWABLE energy has to be part of the future, as by definition, non-renewable forms of energy are not sustainable and will eventually run out. While “peak oil” is a reality that is close or may have already been reached, existing coal and gas reserves are projected to last several hundred years. But if all that is available is burned, what will be left after that?

Burning fossil fuels (coal, oil and gas) gives off carbon dioxide that will acidify the oceans. This is as certain as a chemical reaction, when CO2 meets water, it forms carbonic acid and the pH of the water drops, as it already has in open oceans over the past century following recent increases in atmospheric CO2 concentrations. While some uncertainty remains regarding the extent of effects of increasing CO2 on climate, there is no uncertainty about ocean acidification. It will happen on a significant scale if large amounts of fossil fuels continue to be burnt in the next 100 years or so.

The phenomenon of ocean acidification could cause significant, but as yet not fully understood, damage to ocean ecosystems. The fallout almost certainly would include damage to coral reefs, as many hard corals can’t calcify their skeletons properly when water pH drops below certain levels. Calcification processes for other planktonic organisms that are food for juvenile fishes may also be disrupted, as can some of the calcification processes inside fish larvae (which are also plankton). Even fertilisation success for the eggs of fish and other marine organisms can be reduced by water that is too acidic. While natural selection will ensure there will be winners and losers with ocean acidification, the end result may not be pretty.

The Gulf of Mexico disaster demonstrated the risks involved with scraping the bottom of the oil barrel, and scientific consensus is that we should be transitioning to renewable energy sources ASAP, to allow us to leave as much oil, gas and coal in the ground as possible. Because of the impending detrimental effects on ocean ecosystems from  continuing to burn fossil fuels, and potential issues with terrestrial ground water contamination from processes such as natural gas fracking, anglers interested in clean aquatic environments, and more fish, should be very interested in renewable energy projects that broaden our energy mix. Which is why Australia’s first wave-energy projects, situated off Portland and Port Fairy, in Victoria, off Port MacDonnell in South Australia and off Garden Island near Perth, should be celebrated by anglers around Australia. But is there a catch that could make these developments unpopular with the recreational fishing community ?

Each of the wave energy projects uses different technology. The Victorian Wave Project will use “Powerbuoy technology” – large floating buoys that move up and down as waves rise and fall, converting mechanical energy into electricity that is then sent to shore through underwater cables – see more here: http://www.oceanpowertechnologies.com/PDF/OPT_Mark 3_Sept2013.pdf. The first pilot stage is planned to produce around 2.5-megawatt peak power, but once all three stages are completed, the project is expected to produce enough energy to meet the needs of 10,000 homes.

The wave power project at Port Fairy uses a 30 metre high steel bioWAVE unit that sits on the ocean floor and sways back and forth, like a big seaweed frond, driving hydraulic fluid that spins a generator, producing electricity which is transported to the grid via an undersea cable. In contrast the Greenwave project at Port MacDonnell in South Australia run by Oceanlinx uses a large hollow concrete “cave” that sits on the ocean floor. The rise and fall of the waves inside the concrete acts like a piston, pushing air past turbines mounted on top of the concrete structure, thus generating electricity, which is then transported to the grid via an undersea cable.

Finally, in Western Australia the Perth Wave Energy Project, run by Carnegie Wave Energy, uses large subsurface buoys that move up, down and sideways with water movement, driving a hydraulic pump that is attached to the sea floor. The pump in turn delivers high pressure water through a pipe back onshore where it’s used to drive a hydro electric turbine. The pressurised water can also be used to power reverse osmosis desalination plants, making the Carnegie technology capable of producing both clean power and clean water. The fact that there is no high voltage out on the water must also be reassuring to water users nearby!

When you look at the mind boggling potential for wave energy, which essentially uses the ocean as a storage facility for wind energy (itself a form of solar energy from the sun), it’s clearly more reliable than both solar energy (which is only available for half of each day, and is weather dependent) and wind energy (ocean swells still occur on zero wind days). Because of this, wave energy must form a significant component of the renewable energy mix in the future. But what struck me most when reviewing all of these different engineering designs, is how much they resemble traditional ways of improving fish habitat. For example, the Powerbuoys and the Carnegie subsurface buoys are basically identical to floating Fish Attraction Devices, while the Oceanlinx “artificial sea cave” and the Biopower structures look just like artifical reefs.

It’s clear not only from looking at them, but also from the various environmental impact assessments that these projects have had to endure, that not only are wave power developments environmentally benign, they actually enhance habitat for aquatic animals, including fishes, resulting in increases in marine biodiversity. This is in stark contrast to traditional oil and gas developments, which can have huge detrimental impacts on aquatic environments (such as mercury and CO2 from coal fired power stations, oil spills like in the Gulf of Mexico, contamination of ground water due to coal seam gas fracking, and even the botched gas developments in Gladstone Harbour).

Considering the relative pittance (tens of millions) of Government financial support given to these pioneer wave energy projects to date, compared to the big dollars thrown at gas and coal in Australia, due to their combination of clean energy and fish habitat improvements, recreational fishing groups around the country should be amongst the most ardent supporters of the scale up of wave energy projects. However, there’s a potential drawback that needs to be addressed – that is access. Nearly all of the current pilot wave energy projects in Australia will lock anglers out of the areas where the power generation arrays are located. While this may be only a small portion of coastline at the moment, the problem would escalate exponentially if the industry expands, as it needs to do if we are to have a sustainable clean energy future.

When researching this article, I took the time to contact all four wave power proponents in Australia to ask about their policies regarding fishing around their projects. Only one of them, the Oceanlinx project at Port McDonnell in South Australia, publically acknowledged fishing access issues by stating on their website that access of rock lobster fishers would not be affected by their project. “The Greenwave design ensures there is no conflict with fishing activities in the area, such as the imposition of exclusion zones, which would further reduce the available fishing area”.

Of the remaining three projects, only the people from the Biowave project at Port Fairy saw fit to respond to inquiries, stating that “Transport Safety Victoria has imposed a 150m safety distance zone around the unit. Therefore, anglers are advised not to get closer than 150m.” When I pointed out that anglers might be able to live with a 50 metre exclusion zone (i.e. being able to get within casting distance of the structure), but they would see a 150 m exclusion zone as a lockout, Biowave project CEO Tim Finnigan stated “As we learn more, if we find that it is safe for anglers to approach within closer proximity of the unit, then we can consider revised zoning for the next project.” Promising stuff, unfortunately after waiting several weeks for replies from the other two proponents, it seems they don’t see fishing access as enough of an issue to warrant a reply. This must be worrisome for recreational anglers in the vicinity of these developments.

So at this early stage there are encouraging signs that wave power could be a good thing for the recreational fishing community, but again access issues have raised their ugly head – kudos to the Oceanlinx designers for ruling out fishing lockouts, and let’s hope other wave power projects follow suit with sensible rules so these developments don’t become the next marine parks debate. Indeed, if wave power projects are considered to be incompatible with marine parks (lets face it, a whale could be snagged……), anglers could benefit by having wave power projects providing more fish habitat in areas open to fishing.

Who knows, if the fishing access issues are sorted out, in the future we could even see fishing licence fees used to purchase more wave power infrastructure, feeding clean energy back into the grid at the same time as providing more fish habitat and fishing opportunities… The future for fishing can indeed look rosy sometimes…

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