July 12th, 2006
Actually, we never get bored — but we did hang around waiting for the tidal bore to sweep by the Maccan Tidal Wetlands Park on Day Four of our maritimes odyssey. This morning, we arrived at the park about an hour before the tidal bore was due to make its appearance. We put the time to good use looking for insects, but more about that below.
I’m not sure of how common tidal bores are in other parts of the world, but they occur on many rivers throughout the Bay of Fundy region in Nova Scotia. For those who are unfamiliar with the Bay of Fundy, it’s the long body of water that separates most of Nova Scotia from New Brunswick. It’s roughly 250 km. long and about 70 km. across at one of its wider points. However, at its uppermost end, it narrows down considerably and terminates in two smaller bays – Chignecto Bay, and Cobequid Bay. As the Atlantic tide comes up the Bay of Fundy, the tidewaters enter the narrowing upper end and are increasingly restricted and forced higher. The result is that the tides along Fundy are among the highest in the world – having been recorded at above 50 feet in certain places. There’s a good explanation of the high tides on this page about the Hopewell Rocks. By the way, the extremely high and often quickly rising tides are something that one should always keep in mind while exploring the coastline or tidal rivers of this region. But back to the tidal bore.
The force of the incoming tide sends a rush of water up most of the tidal rivers that flow into Fundy. Known as the tidal bore, this wall of water comes upriver as the tide turns and waters of the Bay of Fundy begin to flow inland. The height of the bore varies from river to river and tide to tide depending on the lunar cycle, the weather, the shape of the riverbed and banks, and the flow of water coming downriver. Today, I shot a .mov clip of the incoming bore on the Maccan River. You can watch it by clicking on the above image (note: it’s about 1 MB, and requires Quicktime to play – and there’s no sound). The bore at Maccan is quite good — not as high as other sites, but there’s a good viewing point where you can see the bore coming around a bend in the river.
I also shot some before-and-after photos of the Maccan River (see above – click on pair of photos for a larger view). The photo on the left was taken at 10:54 hours, and the one on the right at 12:21 hours — so they were taken just a little under one and a half hours apart. As you can see in the image on the left, the riverbed and banks are almost entirely visible. You won’t be able to see this from the photo, but the water is flowing downstream. In the second photo, the water has risen quite far up the shoreline and the water is flowing backwards against the downstream flow of the river. At peak, the waters can rise well up the river banks depending on the tide cycle. It can be quite rough when it’s flowing upstream, often developing huge undulating waves in a part of the river for a minute or so. They will disappear as quickly as they begin, but start up in another location. The river seems very much alive when these waves are undulating… almost as though there are great sea serpents beneath the water’s surface. The shape of the river is also in a state of constant flux, with the riverbed and shoreline being shaped by the force of the incoming tide. On our three visits to this site, we’ve had the pleasure of speaking with a local resident who lives nearby and has been watching the incoming tidal bore at this site for around 40 or 50 years if I remember correctly. He posts the tide schedule on a notice board at the park and is often present to speak to visitors. Much of the above information has been gleaned from our conversations with this most interesting gentleman.
Now, a word about the insects. We had hoped to see many dragon and damselflies at the Maccan site this morning. Last year, we found many, but they seemed to be scarce on this day – perhaps because the winds were quite brisk. However, it seems that not a day goes by that we don’t see at least one interesting insect. This time, it was an interesting “spider mimic” fly. I’ve seen similar before, but this one was particularly convincing (see above photo – click for larger view). In fact, I noticed it after watching a snooping damselfly back off from the fly when it raised and wiggled its black-marked wings. We also saw a very convincing bumble-bee mimic fly which was almost identical to one that I wrote about finding several weeks ago at the farm.
Well, that’s all for this post. I’ll save writing about Wards Falls and the Joggins Fossil Cliffs until tonight or tomorrow. Hopefully the info on the tidal bore was of interest and not…ahem…too boring (just couldn’t resist).