There and Back Again: A Tidal Tale
by Nicole Carlozo -- October 29th, 2011
France Part III. As our journey neared its end, we found ourselves marveling at the tides. Whether harnessed by La Rance tidal power facility, or left to create and take away islands at will, the tides left us awestruck.
Day 5: October 13th
From Brittany to Normandy and Back Again
It was early when we arrived at the Ifremere office in Dinard. Our hosts greeted us with espresso, croissants, and a presentation on La Rance tidal power station, which is the very first tidal station in the world and the second largest after Sihwa Lake station in South Korea. La Rance has a maximum tidal range of 13.5 meters, and now the facility produces about 70% of Brittany’s energy.
Construction occurred between 1960 and 1966, during which time two walls were built to dry out sections of the basin. Consequently, the marine life there suffered. But now, after over 40 years, the benthic communities have bounced back. We visited the site, both at La Rance facility and further up-river where the marine and estuarine waters meet.
From La Rance, we traveled to a mussel culture site at Vivier Sur Le Mer. We watched as the mussel boats traveled down the mud flats, through the mist and towards the bouchots. Mussel larvae are produced and grown on ropes in Southern France, and then transported to Northern France where they’re attached to wooden poles, or bouchots, and grown until harvest. It was quite a sight to see the fishermen hurrying towards their harvest, always working on a tidally-driven schedule. Every boat was equipped with wheels – perfect for low-tide travel!
- A poster depicting mussel culture in Brittany, with bouchots (pilings) in the foreground and Mont Saint-Michel looming behind.
Soon we were in the van again, heading for Normandy to see the Champeaux honeycomb worm reef in the Mont Saint-Michel Bay. As the tide receded, we walked along the packed-sand beach, stepping over slipper shells and seaweed, and searching for the polychaetes that create these massive structures. While no worms were in plain sight, we did happen upon some other wildlife, including anemones, green crabs, and tunicates.
The day ended with a trip to Mont Saint-Michel – an old Benedictine abbey that once sat on an island during high tide. Now, the mud and sand flats span wide in all directions from the abbey, even during high tide. France is currently spending money to make the structure an island once again, but the tide is only high enough three times a year to actually cover the surrounding flats. As we approached the abbey, I wondered at its height and design.
Throughout this trip, I definitely embraced my nerdy side, and Mont Saint-Michel brought out the fantasy nerd in me. Did you know that the city of Minas Tirith in the Lord of the Rings films was based off Mont Saint-Michel? As we walked up the large staircases, through alleys, and under stone archways, I looked on in awe. Many hobbit jokes ensued.