Saturday, June 6, 2015

Hello, Alaska!

After finishing fieldwork in California, I loaded up my kayak and headed north to Corvalis, Oregon to meet up with my friend Michelle, a PhD student in the ORCAA Lab at Oregon State University.  Michelle and I are part of a cooperative project with OSU, Syracuse, and the National Park Service to investigate the effects of vessel noise on the vocal behavior of harbor seals (that’s my job) and humpback whales (that part is Michelle’s) in Glacier Bay National Park, Alaska.  During the initial phase of planning for this project, a topnotch team of bright minded acousticians and marine mammal biologists came up with a plan to address this noise issue using a four-element underwater autonomous hydrophone array and shore-based visual observations.  This project has been in the works for quite a while (i.e., years), and last week it was finally time to put our hydrophone array in the ocean!

Glacier Bay National Park is a beautifully pristine wilderness area in Southeast Alaska that’s home to drastic mountain ranges, calm blue waters, and otherworldly glaciers.  The Park is not accessible by car, but despite this, over 400,000 people visit Glacier Bay each year.  Visitors arrive mostly by cruise ship or other private vessels – these boats make all sorts of noise, which is what prompted the research questions behind this project.

Cruise ship in Glacier Bay (Photo: L. Matthews)

The other option to get to Glacier Bay is to fly into Juneau, and then take a flight from Juneau to the small town of Gustavus (population: 500).  Gustavus is connected to the Park via one ten-mile stretch of road.  The flight from Juneau to Gustavus takes about 25 minutes, and it is by far the most beautiful flight I’ve ever taken in my entire life.

Flying into Gustavus (Photo: L. Matthews)

Michelle and I, along with our friend Samara (another member of the ORCAA lab), arrived in Gustavus on Monday morning, picked up our rental car from a man named Uncle Bud, and drove about a half mile down the road to our temporary Park housing.  The rental car was a 1999 gold Ford Minivan with approximately 199,872 miles on the odometer and a random assortment of misbehaving dashboard lights…and it ended up being the most perfect vehicle for our trip.  We then made our way over to Park headquarters to inspect the equipment that Michelle had shipped from Oregon.  This included the hydrophones and all the other pieces necessary to sink hydrophones to the bottom of the ocean.  You can read more about the shipping container here in Michelle’s blog.

Pallets full of anchors (left) and Michelle hanging out in the landers for the hydrophones (right).
(Photo: L. Matthews)

We also needed to assemble the acoustic releases.  Acoustic releases are how we’re able to retrieve the instruments off the seafloor when they’re done recording.   They’re attached to the landers via a 500ft line.  When we’re ready to retrieve the hydrophones in a few months, we’ll send an acoustic signal to the releases, and they’ll pop up to the surface.  Then, we can reel in all of our equipment and download the data.

Samara and Michelle assembling the acoustic releases (Photo: L. Matthews)

We checked everything off of our Monday to-do list and headed back to the house for a well-deserved night’s sleep.  The next day, our ragtag grad student team met up with Chris Gabriele, a Park biologist who spearheaded this project, to prep the hydrophones and landers for deployment.  We carried anchors (so many anchors), tightened bolts (so many bolts), electrical taped hydrophones (so much electrical tape), and zip-tied shackles (so many zip ties).  The electrical tape is to deal with biofouling – the accumulation of microorganisms, plants, algae, and animals – on the hydrophones.  And each hydrophone is color-coded so we know which one is recording in each location.

Loading and unloading hundreds of pounds of lead and concrete, but still smiling.
(Photo: C. Gabriele)
Securing anchors to landers.  (Photo: C. Gabriele)

All four hydrophones prepped and ready for deployment!  (Photo: L. Matthews)

Chris, me, and Michelle proudly posing with our lovely acoustic equipment.  (Photo: S. Haver)

Then it was finally Wednesday!  Deployment day!  It was an early morning and a long day – though not as long as we had anticipated – but I’ll keep this story short and just sum it up to say that all four hydrophones and their associated acoustic releases made it safely to the bottom of the ocean.  We couldn’t have done it without the help of the M/V Liteweight, Captain Paul Weltzin, and Deckhand John Michael.

Loaded up and en route to the drop site!  (Photo: L. Matthews)

It takes a village...  (Photo: L. Matthews)

Bye bye hydrophone!  See you in a few months...  (Photo: L. Matthews)

The next day we focused on preparing the base camp for our shore-based visual observations.  Samara, Michelle, and I spent most of our energies building a hunting blind.  Clearly it won’t be used for hunting anything, but it’s the perfect height for a panoramic view of the array area.  From this vantage point, the field team will be able to conduct scan surveys of whales and seals and focal follows of whales – the perfect behavioral complement to our acoustic data.

Map of hydrophone locations (yellow pins) and camp for shore-based observations (orange star).

That afternoon was spent cruising around with Chris dropping a dip hydrophone in various locations and looking/listening for whales and seals.  We spotted tons of animals in the array area, including harbor seals, humpback whales, stellar sea lions, harbor porpoises, and sea otters.  We heard a faint humpback vocalization, lots of boat noise, but no seal calls.  Not surprising though, since it’s still a little early in the season.

Harbor seal in Glacier Bay (Photo: L. Matthews)

Friday morning we talked sampling protocols over coffee and discussed Michelle’s return trip to Glacier Bay in a few weeks.  This summer, Michelle and a team of four undergraduate students will be living on the island in Glacier Bay to conduct the shore-based observations.  Unfortunately, I won’t be able to join them for the field season, but *fingers crossed* I’ll probably be able to swing a trip next summer to help out with data collection.

The view from the island.  Not a bad view.  (Photo: L. Matthews)

Another clear-skied flight back to Juneau on Friday and a lovely weekend with friends was the perfect ending to a successful deployment trip.  And now we wait!  Come October, Michelle and I will return in Glacier Bay to recover our hydrophones and download our data.  Until then, I will relish in Alaska’s overwhelming beauty and prepare for the onslaught of data that will be arriving in just a few short months.

Flying back to Juneau...  (Photo: L. Matthews)

FUN SCIENCE FACT #41:  Alaska is home to 616 officially named glaciers, but the Alaskan Almanac estimates that there are about 100,000 in the state.  Glaciers form when there is more snow fall than snow melt in an area.  This snow accumulates and transforms into ice.  The compression of new layers of snow causes the ice to re-crystallize, forming larger and larger crystals. In very old glacial ice, crystals can be up to several inches long.  And, when the glacier becomes extremely dense (large crystals, few air pockets), it results in a blue-ish tint to the ice.  (Source: NPS & NSIDC)

The blue-ish ice of the Mendenhall Glacier in Juneau (Photo: L. Matthews)

Thursday, June 4, 2015

Goodbye, California...

I recently wrapped up my first field season in California.  It definitely didn’t go as planned; but then again, fieldwork never really does go the way you think it will.

The original plan was to make recordings of individual male harbor seal calls, take pictures of the males that were surfacing near the underwater vocalizations, and then match these individuals to pictures of males on land.  The pictures on land (described in a previous blog post) allow me to estimate the size and weight of an individual seal.  Basically I was going to create a catalog of males in Elkhorn Slough that contained information on their vocal behavior, any distinguishing physical characteristics, and various body measurements.  There were lots research questions to answer with this catalog, but step number one was obtaining the data to populate said catalog.

Harbor seals in Elkhorn Slough. (Photo: L. Matthews)

After a rough start to the season – various delays, both weather and animal related – I managed to get out in my kayak and make recordings.  I didn’t know where exactly the males would be, so I decided to stop at about four or five different locations along the slough to listen.  And sure enough, I found one!  He was calling near the haulout on the south side, close to Seal Bend.  Woooooo data!

This is a map of Elkhorn Slough.  The red boxes show seal haulouts.
The red marker represents where I heard seal vocalizations

I did this for a few days.  I paddled around and around and made recordings in lots of different locations, but I could only ever find that one caller.  The same male vocalized in the same spot for all of my recording days.  Consistency was nice, but it wasn’t really what I needed to answer my research questions or construct that catalog.  I had planned for multiple recordings of multiple individuals over a two-month period, but ended the season with a one or two good recordings of one seal that I made in the last couple days of my field season.

There are a few explanations as to why I didn't get what I was expecting.  First of all, I might have started recording a little late in the season.  By the time I got out there, it was the middle to end of May, which is towards the end of the breeding season in that area.  It could be that the other males had already stopped vocalizing.  Second, maybe there was only one male calling this year.  In the past, there have been three, four, or five males vocalizing in Elkhorn Slough, but maybe this year was different.  No one has gone out to listen to them in a few years, so it's possible that things have shifted and there's only one man seal patrolling in the slough.

This is not the seal that I recorded.  This is just a random seal.
(Photo: L. Matthews)
But everything is going to be okay!!  I’ve got multiple projects going on at the moment and with the combination of this year and next year, I will easily have enough data to write up a dissertation.  More on these other projects in a future blog…still focusing on harbor seals, just harbor seals that live a little further north…

FUN SCIENCE FACT #40:  Walruses have a pretty impressive vocal repertoire.  Males make vocalizations that sound like knocks, pulses, and even bell-like sounds.  The bell sounds are my favorite.  Here's a video of a captive male walrus showing off his sweet skills.