Saturday, June 7, 2014

Tidepool at the Southern End

"HOLY COW!" Drew and Emily yelled.  Loud.  Except they didn't yell cow.  They yelled something inappropriate for a family blog like this, and followed it up with nervous laughter and "Oh my god"s.

Considering the things we've found on the shoreline here -- intact staircases, appliances, computers, clothing, dead whales, and once a dead person (yes, that's right, unfortunately), I hurried their way, scrabbling over seaweed-covered rocks in my boots and rain pants.  Hurrying is a relative term in the rocky intertidal.  "What is it?" I called to them, hoping it wasn't dangerous.

"A seal!  Maybe a baby!"  they called back.

Right after that, the thing started bellowing, his own equivalent of "holy cow!", probably with seal-words equally inappropriate for publication.

Climbing over the ridge to escape our prying eyes.
Sliding down the knotted wrack beds.
The students were on a ridge of rock, looking down into a crevice, where our new friend had been sunning itself in peace.  A surprised seal, with no way to get back to the water, isn't happy.  This one was small.  Not a baby, although moms often leave their pups ashore while they go off to feed.  Perhaps a "weaner" -- one year old, sent on its way by mom, who by now has a new pup she's busy taking care of.  At first I thought it was a harbor seal, because it was so small, but looking at the photos, I'm thinking this was a young gray seal, and had a couple hundred pounds to gain before it was done growing.  It could already make some loud noises though, so we backed off, snapped a few photos, and left it on its own.  Once we had moved on, it humped itself over the ridge and slid away on the seaweed, eager to get away from us.  Hopefully we didn't disturb it too much.

We'd been down at the southern end of the island, where there is a large and complex rocky intertidal zone. If you're willing to climb over walls of bedrock, covered with ascophyllum, you're rewarded with a very deep tidepool with sheer walls (like a swimming pool).  Kelp is thick on the sides of the pool -- horsetail kelp, my favorite, is found in abundance.  In amongst the kelp is a rich tidepool community -- sponges, nudibranchs, urchins, and pink coralline algae.  Drew was checking out the pool as a possible site to deploy some settling plates, in order to study invasive species.  Settling plates are just ceramic or nylon plates that you put out for plankton to settle on.  Many of the invertebrate species common in the intertidal have a planktonic stage, during which they float with the currents, before they grow larger (usually going through several stages of growth) and start to look for an appropriate spot to settle down.  Common periwinkles; mussels; barnacles -- all have planktonic stages.  Drew is particularly interested in an invasive bryozoan, Membranipora membranacea, which settles on kelp (particularly Laminaria saccharina, AKA  Saccharina latissima AKA sugar kelp.  It's all over Maine, but interestingly, after days of searching our intertidal, Drew hadn't found any yet.  Hence the settling plates -- maybe he could detect it as it settled onto the plates.

Creating his settling plates
The next day  Damon and I accompanied Drew down to the tidepool at low tide and helped him deploy his plate.  To get it positioned in the middle of the pool, he brought his snorkeling gear and jumped in.  (People do swim here on the island, but not for long, given the temperature, and with great care.  Snorkeling only happens for research purposes, and only under strict supervision.  Safety truly does come first out here.)

Damon just standing around while his student does all the work.  Typical.
Deploying the plate.
The pool was filled with urchins (no surprise there).
Our little friend.
Hopefully this plate survived the big storm we just had.

Warming up after time in the Bay of Fundy.
As the summer progresses, Drew will be checking the plates and photographing them to document the settlement patterns.  At the end of the season, he'll collect his many plates and look carefully at them. Drew's one of several students blogging this summer, so you can learn more, and get his point of view on the island, here.

1 comment :

  1. Thanks for taking these great pictures Janet!

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