Wednesday, June 25, 2014

The Lobster Nursery, In Which We Are Pinched

The mysteries of the ocean never cease to amaze me.

A small, probably year-old lobster, plucked from his hidey-hole.  Don't worry, he went back after this pic.
Last week while I was home, I tagged along with some colleagues who were out collecting Crepidula fornicata and Crepidula plana -- slipper shells.  These mollusks have a very interesting life history -- they live in piles.  The one on the bottom -- the biggest one -- is a female.  The ones on the top -- the littlest ones -- are males.  The ones in the middle could go either way.  They can change sex from male to female, being protandrous hermaphrodites; not an uncommon thing in the animal world (nor is going the other way, from female to male).  The females release pheromones that prohibit the males above from changing sex; maintaining a neat little reproductive stack.

We had a good idea of where we could find Crepidula that weren't attached to big boulders; that would make collecting them difficult since they suck down to rocks and are hard to remove without killing them.  So we needed them on small cobbles; easy to collect and transport.  We hit the jackpot; easily collecting the number we needed in only about a half hour.  (Note; we have a special collecting permit from the State of Maine, and can only collect specimens for research or teaching purposes.  Don't collect organisms from the ocean without one; you can get into serious trouble with the law, and populations can be severely impacted if we all just take things for fun.)

Collecting under a perfect summer sky.
Sorting through the organisms.
Crepidula fornicata.  Notice the smaller one (the male) stacked on the larger one (the female).
Our job was done, but the tide was still going out, the sun shining.  A perfect opportunity to do some poking around in the many tidepools nearby.  We had some suspicions there would be a lot of interesting things in them.  Our first hint?  This very intriguing rock, with plenty of sand newly pushed out from under it:

What lurks under the rock?
What could be under there?  One way to find out!
Do you see what I see?  Look carefully!
Just as I suspected!  A small lobster!
The tidepools at this spot were chock full of juvenile lobsters.  Almost every rock we turned over had a small lobster hiding under it -- which would grouchily raise its claws at us, or walk away in disgust.  Some of the pools held lobsters simply walking around, seemingly unconcerned by our presence.

Lobsters have a fascinating reproductive cycle.  It starts when the female molts.  She finds a dominant male, then molts in his presence.  Given their reputation for ravenous cannibalism, this might seem surprising.  But the male can only give her his sperm packet while she's soft, so he has to be a tender lover, not a ferocious fighter, in this situation.  After she molts, he protects her for a few days, then she wanders off to live her own life (often being replaced by another female who's ready to grow a new shell).  She holds onto that sperm packet until the time is right, then fertilizes her eggs, which she holds on her "swimmerets" -- under what we call the tail of the lobster -- until they mature and are released as plankton during the warm months.

Planktonic lobsters go through three stages, which can last from a month to three months in total. During this time they hunt (being ravenous just like their parents), molt and grow, and are swept along by currents. When they reach the third stage, they start to look like tiny lobsters, can swim very well, and begin to look for a place to settle.  They start to avoid light, therefore swim away from the surface.  They make frequent forays to the bottom, to see if currents have carried them to a suitable nursery.  What does a baby lobster look for in a home?  The absolute best habitat for a tiny lobster, who's vulnerable to predation by fish, crabs, and what have you, is a shallow cobble-strewn area.  One with lots of nooks and crannies to burrow into. They'll settle for a salt marsh bank, or eel grass bed where they can dig a hole, but these aren't the best homes. Once they find a good spot, they settle, molt, and with that, aren't plankton anymore.  Tiny benthic lobsters can actually filter feed in a way -- they create a current and eat plankton that get carried into their burrows.  Eventually they grow large enough to be safe(r), and emerge from their hiding places to forage.

This juvenile stage might last a year, after which they move away from shore and act more like adult lobsters. So it's not unusual to find baby lobsters near shore, under cobbles.  Often, the east side of islands and peninsulas are great nurseries, because the prevailing currents carry lobsters to these areas, where they run into land and it's the end of the line.  For example, the east side of Damariscove Island is known to house many baby lobsters, but the west side is a desert.  There are over 100 hot spots known, and monitored, in the state of Maine.  The settlement of lobsters is a big deal up here:  big lobsters come from little lobsters, so knowing how they reproduce and grow is important.  There are plenty of interesting questions being worked on about lobster reproduction right now -- like does a hot spot for babies mean the area is a hot-spot for adults?

Just out for a little stroll.
Barnacles in a tidepool.  I love how they settle in the cracks of the rock!
Maine, the way life should be.
Now you might be saying "where is this magical place where baby lobsters are a dime a dozen?"  Well, for now, I think I'll keep it to myself.  Baby lobsters don't need a ton of people turning over their rocks every nice day.  But I'll let you in on a spot where you're likely to find them, if you promise to be very careful about turning over rocks, to put the rocks back without crushing anything, and if you don't take any lobsters home (you can't do it; it's illegal):  drive down to Land's End in Harpswell (all the way down Bailey Island).  You might just get lucky.

But if you do see a baby lobster, a word of caution.  They pinch.  They really, really pinch hard.  How might I know?  Well, I'm not above embarrassing myself.  For your entertainment, Janet catches a baby lobster (don't laugh too hard):

video

And he just kept holding on and pinching . . . .  He won.  He was small but potent.

Want to know more about lobsters?  I recommend The Secret Life of Lobsters by Trevor Corson. Check it out of your library, or find it at your local bookstore.  It's a great read.  Just watch those pinchy parts.

Monday, June 23, 2014

Spring Point, South Portland

Willard Beach.  Only dog friendly in the early morning and evening, but a great spot nonetheless.
A few years ago, I attended a workshop at Southern Maine Community College.  It was a good workshop, but what I really liked was the campus.  It was hard to concentrate on the subject matter (RNA and gene annotation) surrounded by such beauty.  Plus it was foggy, so every minute or so we'd hear the boom of a fog horn -- like a siren's call to me.  SMCC's campus rivals any college's, anywhere, for beauty.  It's right on Portland Harbor, has a friendly neighborhood beach next door, and looks out on Spring Point Lighthouse. Can it get much better?

The Spring Point Shoreway, preserved by the South Portland Land Trust, borders the SMCC campus, and is a great way to enjoy the sights.  You can walk from Willard Beach, with its gentle surf and family-friendly vibe, to Bug Light, all the while enjoying wonderful views of Portland Harbor, lighthouses, and the lovely SMCC grounds.  A nice long walk out the breakwater to Spring Point Light (over very rough rocks, be careful!) puts you right out in the harbor.   This is a popular walk in fine weather, with families, couples strolling hand in hand, and plenty of dogs (including this one).

For a quick escape from the city, this is a good bet!  See you on the Shoreway!

The old fort at Spring Point, the lighthouse, and a sailboat race in the background.
Spring Point Light.
So beautiful!
Providian, one of the countless boats Spring Point Light has guided in over the years.
Downwind leg of the sailboat race.  Spinnakers flying.
GETTING THERE:  From US1 in Portland, take Rt 77 south, across the Casco Bay Bridge.  Once you cross the bridge, go straight on Broadway (77 will turn right; do not follow it) 1 1/3 miles, until you can't go straight any further without going into the parking lot for Joe's Boathouse restaurant.  Turn right onto Benjamin Pickett St, then left onto Fort Rd; park in one of the many student lots.

Wednesday, June 18, 2014

Hikes in Harpswell -- Potts Point

I'm home for a few days, voted off the island.  Okay, I'm actually home to pay bills and work on the house.  Being away for all the warm summer months isn't conducive to home maintenance.  Some porch renovation; some painting; some gardening are all on the schedule.

But woman cannot live by construction projects alone.  I mean, the sun is out, the temperature is perfect, and the dog is ready for fun!  How can I resist a quick trip out to Harpswell?

Potts Point is conserved by the Harpswell Heritage Land Trust, and it's an amazing spot.  The preserve is only an acre or two -- just an island connected to the mainland by a spit of sand, but where else could you get all this:

Wildflowers to enjoy:

Wild roses

Rosa rugosa

Orach -- you can eat it!

Beach peas

Raspberries

Honeysuckle
Tiny pocket marshes all through the upper intertidal:



And gulls, eiders, and terns raising a ruckus:

Eiders, with babies.  Right after I took this a black back gull carried a baby away!

Common terns feeding.
And some interesting sights:

This is where you park.  Well, up on the road, not on the beach.

Who doesn't love a mailbox that looks like its owner?
Driftwood in the evening sun
And to top things off:

Sunset over Casco Bay
GETTING THERE:  From US 1 in Brunswick, take Rt 24 south to Rt 123 (at the corner of Bowdoin College).  Turn right on Rt 123 and follow it 13.5 miles -- until you literally can't go any further.  You'll be at Dick's Lobster and Crab; park out of the way of traffic and the wharf.  Walk along Potts Point Road -- all the way to the end, where you will find a little path to follow.  This will take you to the preserve!


Tuesday, June 10, 2014

Three eggs and a prayer

Your run of the mill three egg nest.  One of them is unlikely to make it far in life!
Kent Island is an offshore seabird colony.  When people hear about our summer home, they say "oh, that must be so peaceful".  No.  Not at all.

Everywhere you go; there they are.
We are surrounded by gulls, eiders, guillemots, petrels, and eagles; all in their breeding season, all desperately trying to survive and raise a chick or two to pass their DNA on to.  Gulls are the most obvious of our residents (though not the most numerous; those are Leach's storm petrels).  We have quite a lot of herring gulls (as in thousands), plus a few black-backed gulls thrown in for good measure.  Herring gulls can be annoying; especially when they poop on you or dive bomb you or scream in your ear (my personal favorite) to keep you away from their nests.  But they're also very funny, and easy to observe.  They often visit camp at night, when the june bugs are out, and watching them catch these big bugs is amusing.  Later in the season, they also visit the blueberry bushes surrounding camp, to gobble down the berries.  There's nothing funnier than watching a big gull swimming through the blueberry bushes plucking tiny lowbush blueberries off the branches.

Right now the gulls are all sitting on nests; which you can find all over the island.  Some are right above the high tide line on the beaches; some are in the tall grass; some are up in the ferns on South Hill.  Herring gulls lay three eggs each year; each one on a consecutive day.  In the old days, islanders would collect gull eggs every summer, and to make sure they were getting eggs that hadn't developed into chicks yet, they would choose eggs from nests with only one or two eggs in them -- so the eggs were less than two days old.

A modern dinosaur sitting on her nest. She looks like one mean momma!
Hiding behind Priscilla's gravestone -- the perfect place for a nest.

The third egg in the nest is the "insurance policy".  It's smaller and lighter than the other eggs, and the chick hatches later, grows slower, and is more likely to die than its siblings.  Unless there is an abundance of food, the third chick is pretty much doomed.  We see those third chicks die quite a lot -- death is a big part of life on a small island.

So why have three chicks if only two are likely to survive?  In really good years, all three can survive.  Other years, that third chick is a back up -- if the first two (hardier) chicks die, all the resources can go towards the little guy.  Chicks die a lot -- preyed on by eagles, blackback gulls, and ravens, or killed by other herring gulls if they wander to far from their own nest.  So the third one sometimes comes in handy.  But if the first two aren't killed before fledging, it's a good bet the runt won't make it.  And if the first two do make it?  The mom didn't lose too many resources on that third egg anyways.

Pretty soon chicks will be hatching out all over the island.  When that happens, the gulls will get even more aggressive and irritating (ever tried to walk through a patch of divebombing gulls that use poop as a weapon?).  But the babies are pretty cute for their first few weeks.  I'll post some shots of those when they come along.  In the meantime, if you're interested in another Kent Island blog, check out Emily's.

Even though gulls are a pain in the butt, they're rather amazing.

Sunday, June 8, 2014

Sea cucumber feeding: finger lickin' good

Just before leaving for this island last month, I moved all our teaching organisms out of Bowdoin's Marine Lab and into my tanks on campus.  That meant I spent some quality time out there, moving animals and cleaning tanks.  I get easily distracted from this work, and spent quite a lot of time observing our collection of sea cucumbers (Cucumaria frondosa).  They were busily feeding away.  Cucumaria, an echinoderm like seastars and sea urchins, is a suspension feeder; with sticky tentacles (frond-like; hence the name) that it holds out in the water column.  Plankton sticks to these tentacles, then the cucumbers curl up the fronds and roll them into their mouth, where the plankton is transferred to their digestive tract.  It looks like they"re licking their fingers.

I was able to get some great video of one feeding:


Pretty amazing, huh?  Sometimes I find the diversity of life, and many strategies for making a living amazing. What a wonderful world.

All is well on the island, and since it's Sunday, most of us are taking it easy, although many projects can't have a whole day off.  The sun is out though, and the fog has cleared -- for now.

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.

Monday, June 2, 2014

Island Bound

Summer is here, and for Damon and I, that means we're island bound.  The Bowdoin Scientific Station is located on Kent Island, smack-dab in the middle of the mouth of the Bay of Fundy.  That means fog sometimes, but brilliant blue skies and sparkling waters other times.

We've been here for a week now, and the first one is always the hardest.  Getting everyone here, unpacking weeks worth of food, falling into a routine, and getting students started on their projects is a monumental task.  And on a small island with no public utilities, everything is exponentially harder than it is in civilization. We make all our electricity with a small array of solar panels, pump water up from the well, carry all our food and supplies from the mainland (given our 24 foot tides, sometimes we literally carry it over the marsh and through the mudflats), and create what we need out of the supplies we have.  This can be hard work, but it makes small rewards very satisfying.

Summer will fly by, although right now it might not seem that way.  Research will happen, problems will be solved, and friendships will blossom.  Sometimes a romance or two develops.  Birds will be banded, snails counted, and meals will turn out brilliant or terrible.  I'll post some photos as the summer progresses, but our internet connection is slow and bandwidth small, so posts probably won't be extensive (we have a radio antenna delivering internet from the next island over; an inefficient but cost-effective way to stay connected).

Here are some photos from our first week:

Our house on the island.  It's our waterfront cottage built by Rockefeller.

An eider nest.  Looks cozy.

A student working on his bird blind.

One of our artists.

Lunch in the dorm.

The bird blind comes together.