July 2009 Archives

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This greater shearwater (Puffinus gravis) was rather curious about our work off the back of the boat. While the CTD was making it's roundtrip voyage to the bottom, I got down on the deck and shot this with my lense sticking out through the scupper (on a boat a scupper is a hole in the hull at deck level for water to drain).
Shearwaters are pelagic seabirds that are seen regularly offshore, but only seen on land when they're nesting. Even then, since they nest on remote islands, they are rarely seen from (any populated) shore.

Cruise fauna: a whale's breakfast

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Much of our sampling was directed toward characterizing the abundance and distribution of whale food.  This image shows a sample containing a few of the delicacies enjoyed by whales in the Gulf of Maine.  The large shrimp-looking animals are krill, enjoyed by minke, fin, and humpback whales, all of which we observed during our cruise (stay tuned for photos).  Among the smaller animals in the sample are copepods: the breakfast cereal of right whales.  If you've swum in Maine waters, you've probably swallowed many mouthfuls of them.

The favorite variety, Calanus finmarchicus (Finnmark copepods) occur in very high abundance in the deeper waters of the gulf.  We generally find them in waters deeper than 100 m.  This year, there seemed to be strangely low numbers of them in the waters south of the Penobscot, where we also saw a lot of bioluminescence.  Of course, we'll have to do the full analysis before we can be sure about these results.

Keep checking back for more wildlife photos from the cruise.

Copepods and krill from a net sample.

Cruise Day 7: VOLT

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Day 7.  Wrapping up the "VOLT" cruise.  We've been calling it the Volt cruise, because the track roughly spells out the word "volt".  (See image.)  We didn't hit every station, due to some weather limitations, but we crammed in as many as possible when the weather allowed.

Some notes ... an extraordinary amount of bioluminescence on the "O" transects, south of Penobscot Bay.  Also, it appears that there are fewer copepods (right whale food) here than one might expect, based on the patterns we see elsewhere and in the past.  This is preliminary at this point, until we count the samples.

Stay tuned for some of our analysis of the cruise, as well as some whale photos and other highlights that Pete has saved up.

Cruise plan, marking the stations we have hit so far.

Cruise Day 6: Nick gets deployed

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These photos came without comment.  I'm guessing that they decided that Nick was better at sampling plankton than the LOPC.

"Safety first."

Cruise Day 5: Nick's view

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From Nick:
Day 5. We're going through stations like they're chocolate-covered espresso beans.  With the ideal weather and the almost gratuitous wildlife, it sometimes feels more like a Gulf of Maine vacation cruise.  I'm telling you, it's non-stop action.  Alas, I fear our poor young grad students may be getting spoiled.  Yet there are likely many more Maine cruises in their futures to set them straight...

I'd like to take a quick interlude to make a mention of our vessel, the R/V Stellwagen.  She's a 70ft converted shrimp trawler, 20ft wide, 50 tons.  The engine is a truck engine, manufactured to move tractor trailers.  This is uncommon, but works well and is really neat.  I've included a picture, so you aren't forced to imagine a tractor in a hamster-wheel powering the boat.


Cruise Day 5: Night sampling

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Pete again:
It's 12:40 AM. We just finished our last station of the day. Pictured is us geting the LOPC ready. We also put the Tucker in. During which a minke whale came to play. Literally. Phoebe and I got distracted putting the net in as a minke whale surfaced not 5 feet off the starboard stern. It was glowing as it agitated the bioluminescence. Alex, the captain, quickly got us back on task with a quick shout. It's important to stay focused when putting things over the stern when you're miles from shore. Way too easy to get pulled in. The whale hung around while we were towing the Tucker and as we put it away. Wicked cool. Quite a day. Up at 6 for the next station. Night.


Cruise Day 5: Pete eats krill

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From Pete:
Today was great. Sunny, calm, and beautiful. Right now we're steaming to our last station of the day, the moon is rising (pic below) and the bioluminescence is awesome. Our bow wave is glowing brilliant green and you can see schools of fish swimming by like shooting stars under the wAter. Too low light for good pictures, sorry. Today we saw (to name a few):  several fin whales, a minke, a basking shark right off the stern, lots of shearwaters, blackbacks, and storm petrels, a few gannetts and a northern fulmar.

Becoming one with my thesis project I covered my head with water at Platts bank and ate a euphausiid alive. I swear, I can still feel it squirming in my belly.

Northern krill Meganyctiphanes norvegica
from wikipedia.org

Cruise Day 4: Finally! Sun!

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From Pete
Today is our first day on the boat with sun! We've got a 4 or 5 hr steam out to Platts Bank. Last night, we stayed in the Isles of Shoals harbor to wait out the weather. If the wind comes around like we're expecting the swell should lay down and we can start plugging away at our stations.

Cruise Day 2: LOPC test

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From Nick:
Here's our first LOPC cast, by the side of the dock.  Splice held.  Phoebe is here safely, after rowing this morning from Witch Island.  Plan is to test the weather tomorrow at 6 am, and hopefully begin sampling, though it could be rough.  If things go as planned, I won't be in internet contact after tomorrow morning.  Maybe next time we dock, I can get a signal and do another post.

The figure is the output from the LOPC test cast.  Each bar on the left indicates the number of particles passing through the unit that had a particular "equivalent spherical diameter".  As you can see, not a lot of big stuff. 

"I'm on a boat, and..."

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Day 2.  Still tied up at the UNH dock.  Easterly winds and chilly rain persist, despite the tantalizing glimpse of sun yesterday.  Hark!  Yon thunder booms!  Conditions are disagreeable, but not altogether prohibitive.  At this point, we are delayed only by some technical glitches.

As I write this correspondence from aboard the Stellwagen, I can think only of this piece of advice to relay to those green thumbs thinking of following in my wake: learn to splice cable.  Due to some malfunctions, our LOPC system has become handicapped.  Our only hope is to provide life-support through a live sea cable, fed over the side by hand (by an intern).  

To get this rigged up, Rebecca and I are MacGyvering a cable splice with nothing but a sandwich bag, a hair drier, and two pieces of regurgitated licorice.  So far so good.. but stay tuned.  We may wind up short-circuiting the Gulf of Maine.

Splice in coccoon phase.

Maine Cruise: Day 2 AM

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From Peter:
After a nice sleep on the boat we woke up to clouds and drizzel, ate a nice breakfast and got to work setting things up. Here's a picture of me setting up the Tucker trawl. We got it together much faster this year since our winch, big Bertha, is working. Also Nick says "things look promising for the LOPC",  (laser optical plankton counter) but our intern missed the bus in Portland and will be late.
Time for a quick trip to town to get sunscreen, butt connectors (electrical supplies, thank you), and some diesel for Bertha. This afternoon we'll head out and test the gear, perhaps get the first station in.

Note: the Tucker trawl is a net system that allows nets to be opened at specific depths.  This gives us some information about whether the copepods are more abundant at the surface, bottom, or in between.  The LOPC is an entirely electronic system that measures the size of plankton-sized particles that pass through it.  It gives us even more information on how deep the plankton are, but we can't tell one species from another, only the size of the particles.  Unlike the nets that have to be counted by hand on shore, the LOPC data is available in real time and can help guide the sampling.

Maine Cruise Blogging

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The Ecosystem Modeling Lab has teamed up with the UM/GMRI modeling lab and the UM bio-oceanography lab to conduct a zooplankton survey of the Maine Coast.  The cruise is funded by the Maine Department of Marine Resources, and its goal is to map potential right whale feeding areas.  Pete and Nick will be sending regular updates, which I'll be posting here.  Here's the first post:

And so begins the voyage. We're here working on the winch at the unh dock.  The gear has been unloaded from the Gmri truck. And we have some time to kill before the R/V Stellwagen arrives.

Pete is taking the photo.  Nick & I are standing in the foreground.  Rebecca is in the background trying to figure out why the winch won't start.

Airplane photo update

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Couldn't help playing a bit with one of the airplane photos from the previous entry.  Thepicture below (left) shows a series of vortices trailing off of the upper edge of the island.  The vortices were hard to see when the plane was just above them, but they really jumped out when the moved into the sun glint.  While you can see them in the raw photo, a little work in Matlab highlights the vortices (image on the right).  To get this image, I made a black & white version of the image.  I then created a smoothed version (median smoother with a radius of 5 pixels).  The smoothed version removes the fine scale features we're interested in, leaving only large-scale continuous features like the island and the sun.  I then subtracted the smoothed version from the raw, to create an anomaly.  I then squared the anomaly (to make the large differences pop) and multiplied by the sign of the anomaly (so that +/- were retained).  Finally, I replaced values close to zero (absolute value <5) with nans and then overlayed on to the photo.  So, the vortices highlighted in red are reflecting more light than expected (sea surface angled towards the camera or smoother water), and those in blue are reflecting less light than expected (rougher water?). 


Oceanographer on an airplane

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One of the perks of my job is getting to visit cool places.  Of course, Hawaii is my all time favorite (three Ocean Sciences conferences), with Copenhagen (ASLO Meeting) and Aquafredda (Italy, NATO summer institute) also meriting consideration.  Worst business travel experience: Orlando (Ocean Science conference).  My guess is that hell looks a lot like International Dr. in Orlando, with the Orlando-Orange County Civic Center containing the 8th and 9th circles. 

Most of the time, I'm pretty busy at these conferences and don't have a lot of time to sightsee.  Still, travel always presents something new and different.  For example, last week, I attended the GLOBEC Open Sciences Meeting in Victoria, BC Canada.  Beautiful town, nice hotel, nice conference center, and interesting meeting.  The only disappointment was not getting a chance to go diving or hiking.  However, just flying in the Northwest is fun, and scientifically interesting. On my flight to Seattle, we flew over the San Juan Islands (I think).  There was a bit of wind, enough to give the ocean's surface some texture, but not enough to make white caps.  Ideal conditions for observing physical oceanography from space.  While taking off from Vancouver, I could see thin (few meters wide) bands of smooth water--almost certainly Langmuir cells. The smooth water indicates a convergence zone, with oils on the surface of the water (mostly from algae) damping out the waves at the convergence.  Unfortunately, airline safety rules didn't allow for photos during takeoff.  As we leveled off, I could see larger areas of smooth waters trailing off of the islands.  My guess is that these are ribbons of algal-oils being swept off the shore.  One thing I was fascinated by was how the surface features changed if you looked into the sun glint.  For example, the picture below shows a series of vortices trailing off of the upper edge of the island at the center of the photo (the one that looks suspiciously like a sideways "X" chromosome).


Another non-oceanographic example is the propeller in the photo below.  While taking a photo of the Olympic Mountains peaking above the clouds, I noticed that the iPhone screen was doing weird things to the planes propeller.  When I took the picture, it looks like the propeller is falling to pieces, with the bits lining up in a regular way.  Still haven't worked out the details exactly, but it is an aliasing between the scan rate the iPhone's CCD camera (exposes pixel by pixel, not all at once) and the rate at which the propeller is spinning.  


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