Globe and Mail
They have been talking about getting power from the tides in Nova Scotia's Bay of Fundy forever; once they even thought of damming the whole thing. More than 100 billion tonnes of water, more than all the world's rivers combined, rush in and out every day; that is a lot of potential power.
Now the provincial government is dipping its toe in the water, with three test turbines. Three different companies are dropping turbines into the bay to see what happens to the ecosystem and if they survive the winter.
There is a lot of concern for herring, the foodstock for porpoises. According to the National Post,
Herring are easy prey because they travel in massive schools. [marine biologist] Dadswell said that while porpoises are probably smart enough to avoid the spinning blades of a tidal turbine, herring, which are often directed by the current of the tides, might not be so lucky.
"In the Minas Channel, every six hours they're going to be going through the turbines. So if it misses them the first or second time, they could hit them on the sixth."
Cleancurrent claims their turbine is fish friendly;
The novel duct design of the unit ensures that there are no exposed blade tips and provides a large hole in the middle of the unit (about 5 metres diameter in commercial scale unit) through which fish and sea mammals can pass in the highly unlikely event that they are to enter the inlet duct area.
Seagen makes similar claims:
The risk of harming marine wild-life is thought to be extremely small bearing in mind that virtually all marine creatures that choose to swim in areas with strong currents have excellent perceptive powers and agility, giving them the ability to successfully avoid collisions with static or slow-moving underwater obstructions. Marine growth is also severely inhibited by the strength of the currents, so there is little feeding to be done in the vicinity.
Open Hydro has other fish to fry; they point out the dangers of NOT using greenhouse gas free sources of power.
Increasingly, governments are introducing progressive legislation to curb and replace the use of fossil fuels. With global energy demand set to increase, there is an undeniable and urgent need to develop new renewable energy technologies. OpenHydro is leading the way in developing technologies that harness the power of the world's largest natural resource - the world's oceans.
It is such a huge resource, with such massive tides; surely they can figure out how to do this without shredding the fish.