The logical place to start is where we left off nearly a week ago, at
which point we were on the Fish and Wildlife Service vessel Tiglax getting hammered by bad
weather, and NOT the happiest collection of people. Despite poor seas, we
managed to complete Line 209 and 213, without losing anything significant.
After more than a week at sea, operations had become very efficient and
each 6-station line was completed in just less than 1 day. Timelines had
become tight and we had little margin left for weather shutting down our
sampling again.
On Friday May 3rd, we jumped onto the outer end of the Seward Line where
we have been studying the Gulf of Alaska for the past 15 years. The Seward
Line differs from the rest of the cruise is that there are different
operations conducted during day and night. Day shift does the CTD casts,
water chemistry, phyto/microplankton sampling, and the smaller vertical
plankton nets, while night shift only tows our electronically controlled
multiple net system (the Multinet). The multinet allows us to carve the
water column into 5 separate layers by opening and closing plankton nets
at specific depths, and targets the plankton that migrates toward the
surface to feed under the protection of darkness. The challenge to the
night work is that during the month of May, when skies are clear, it does
not get completely dark until nearly 11pm and dawn is beginning by 4am!
The first 24 hours on the Seward Line went well, with an iron profile
completed at the outer end of the line (GAK-13). Though still working in
large swells, the Multinet was deployed at a record 5 stations the first
night, aided by overcast skies extending the dark hours. Weather
deteriorated the second night, preventing work (and sleeping), but had
subsided by the next morning allowing us to the complete the day-work on
schedule. After finishing off the day work on the nearshore end of the
line, we made at side trip to the AOOS/UAF Ocean Acidification buoy near
GAK-1 to pick up a calibration water sample. There we were treated to a
humpback whale and her calf lounging around the buoy. The calf was
splashing, spy-hopping and even breaching while mother was pretty subdued,
and indifferent to both us and her child’s behavior. We wanted to stay
longer, but only one night remained available for completing the line, and
we needed pushed through all the remaining stations – regardless of
daylight – in order to get them done. We started multinetting at 9 pm and
finished the line at 8am more than half way out the line. With luck, we
hoped to repeat the two inshore-most stations under darkness the last
night of the cruise – but given the weather so far, we were not relying on
that possibility. From there we headed over to Prince William Sound,
reaching it mid-afternoon on Monday the 6th.
Reaching the Sound brought new life to the science team and crew alike.
After a week and a half of poor weather and gear problems, we were
enjoying the calm waters of the Sound, AND the ability to sleep without
being tossed around in your bed. To add to this practical perspective,
Prince William Sounds has to be one of the most scenic coastal regions in
Alaska, with a multitude of islands of all sizes and snow covered
mountains descending down rapidly in the numerous bays, passages and
fjords. Everything went smoothly as expected, with the Sound proving to
be a predictable wild-life extravaganza. Black bears were spotted on the
mountain-side at the end of our first transects in Montague Strait, soon
to be followed by views of more humpback whales, Stellar sea lions, and
sea-otters. Dall’s porpoises came by to check out the ship and circled us
for nearly 20 minutes. The second day, we awoke to sample in pieces of
ice near Columbia Glacier, and the small boat was launched to collect
smaller floating icebergs as souvenirs. Given the pleasant working
conditions, we were even unphased when the communications cable to the CTD
failed on the second station, and the end of the sea-cable had to be
rewired. Later that night we were surrounded once again by Dall’s
porpoises for more than an hour as we waited for darkness to fall so the
night sampling could begin. That night went smoothly; we are now wrapping
up last 5 stations over the course of today, and then heading out to
resample the inshore Seward Line stations tonight.
With the cruise nearly completed, people are starting to pack up what they
no longer need. By the time we reach Seward early tomorrow morning, the
labs will be nothing more then piles of boxes waiting to be offloaded by
our fearless crew. We start finalizing our notes, form preliminary
impressions of the state of the ecosystem, and where possible, make actual
calculations of what we collected. While most analyses will takes many
months to complete back at the lab, the CTD data can be processed to near
final-results immediately, and the quantity of chlorophyll (algal biomass)
present has already been determined. The ocean is cooler than normal for
this time of year by 0.70C (1.250F). We appear to have hit the spring
bloom of algal production, over both the grid and the Seward Line –
large-celled phytoplankton dominated at most stations and frequently
clogged out nets. Zooplankton biomass was still low, perhaps simply
delayed by the colder waters. Some rarer species of seabirds were
observed in some of the most offshore waters. And in the end, our junior
scientists ARE NOT still reassessing their career choices, and we have
accomplished most of what we set out to do!
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