Friday, July 18, 2008

Part II, Day 4: 080630

Today was not a ferociously busy day, but much was accomplished nonetheless. My bottle trap in the outflow of Halfway Lake contained only three beetles, but one was quite large and of a species I am sure I have never collected before. The others were quite small, and probably of one of the small-bodied species I’ve met in Halfway Lake already. So, I swept my net through the local supply of rotting aquatic vegetation, gaining a few snails, and I grabbed a few gyrinids (whirligig beetles) and gerrids (waterstriders).

I also went for a bit of a walk around the rocky parts of the shore of Lake Superior, turning right on the first beach rather than following the hiking trail to the left. This beach extends perhaps 500 metres to the West, with a few large rock outcrops scattered along. The far end of the beach is a series of rocky bluffs dropping almost straight down into the lake, with their tops perhaps 5 metres above normal water level. On these bluffs are some splash pools that look remarkably like tide pools on the rocky shores of Vancouver Island. The lack of barnacles, kelp, and echinoderms is the only obvious clue (to me) that we’re not beside an ocean.

The bluffs with the splash pools, viewed from a rocky outcrop in the middle of the first beach.

Each splash pool appears unique, and fall into several categories on first glance. Some are barren, with no sand or anything else on the bottom. Others are similar, but have a few pieces of driftwood and are stained red with tannins leached from uphill soils. I found some pools with thick layers of sand on the bottom, and one or two that appear to be in imminent danger of filling completely. The only pools with beetles had dense mats of gooey algae on the bottom, and lacked water colour. I found one or two beetles in each of several splash pools, and each pool, even those without algae, had its complement of waterstriders; the smallest pools had only one waterstrider.

One of the pools I collected beetles from, not really visible in this picture, just under the large stump.

Tomorrow I expect to get more good stuff from my trap, and the park has some Canada Day activities scheduled that I’ll probably check out, including a bar-b-que and a presentation about flying squirrels.

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