Update from Tiglax: Never give up, never surrender…. May 1
We are now 5 days into the Western Gulf’s spring cruise on the Tiglax. Although we often concentrate on the science, I am going to focus mostly on the logistical challenges of mobilizing such complex research, particularly from a relatively small platform by oceanographic standards. On top of this, we deal constantly with the wildcard of weather conditions and sampling gear problems.
The purpose of our cruise is basically to describe the state of the physical, chemical and biological condition in the western Gulf of Alaska. Our sampling plan involves sampling 53 stations along a fixed grid of 10 “lines” stretching across the shelf at 20 nautical mile spacing, plus the long-term observations along the Seward Line. Our general approach involves 4 main sampling tools: 1) the CTD (Conductivity/salinity, temperature, Depth sensor) plus its various accessory sensors, along with the “rosette” of 12 bottles attached to it that are triggered at defined depths to provide samples for nutrients (fertilizers), chlorophyll (plant pigments) and micro-plankton (single-celled plants and animals), 2) Plankton nets – “butterfly” nets attached to strong paired frames resembling a pair of spectacles or Bongo drums used to catch the small animals in the water (we will be deploying 2 sets of Bongo nets of different sizes), 3) a neuston net used to capture small animals that “float” on the ocean’s surface 4) a special “metal-free” vane with motorized water sampler used to collect water for analysis of the important micronutrient “dissolved iron”. Additional measurements of temperature, salinity, plant pigments, and ocean acidification are being made continuously on water pumped through the ship. Finally, during daytime hours, a dedicated observer records the seabirds and marine mammals encountered.
Setup by our 13 member science team was to begin early on the morning of the 25th. The Tiglax was on time, but high winds prevented loading of equipment until late morning. The additional complexities of adding an 8’x10′ shipping container this cruise – to create a lab for iron work – further slowed mobilization. Few sat idle as everyone scrambled to setup and store things securely. Ultimately, we did not leave the dock until late evening, and Captain Billy Pepper had us to our first “test” station, GAK1, at ~3 am. Weather was poor, and the transit across Stevenson Entrance of Cook Inlet humbled the less seasoned members of the science team with seasickness. Those still functional continued preparing their equipment and labs for sampling. I focused primarily on configuring the new primary CTD system purchased over the winter, and became familiar with the smaller CTD system supplied by NOAA to be used to monitor our plankton nets.
We reached our first station at on the outer end of Line-181 at 4 am on the 27th. Seas had improved sufficiently that we could work. As expected, the first few stations went slowly as people made final adjustments to gear, then worked out the best ways to launch, recover and store it between deployments. A mini-Bongo net was lost almost immediately during the first deployment, apparently it was not adequately tightened to the Bongo frame. Both shifts were initially short-handed by those still too sick to work, but by the inshore end of the line, Kodiak Island proved enough shelter for an easy deployment of even the iron-sampling vanes. By start of the second line of stations, we were hitting our pace, then disaster stuck – the cable deploying the tandem set of Bongo nets came back onboard with a frayed rope beneath the CTD where the nets had been. Our best guess is that the mini bongo latching clamp had cut through the rope. At least $10,000 of gear lost. While we had backups for the net systems, the depressing fin used to pull the nets down had no backup, and was a key component of the Multi-net sampler to be used on the Seward Line.
We scrambled to assemble the backup Bongo systems, finding some short lengths of steel cable to replace the rope sections, but we lacked enough steel cable (and enough flow-meters) to deploy the mini-bongo. After 2 hrs, we were ready to re-deploy the large bongo nets using 100 lbs of cannon-ball lead weights to pull them down. We substituted a separate vertical net deployment to compensate for the lost mini-Bongo. We were back on track. Two stations later the unimaginable happened; once again the cable deploying the Bongo net came back with no gear below the CTD. Inspection of the short steel cable below the CTD revealed that the metal sleeve crimped to hold the attachment loop had failed. Typically these crimps are made from brass or stainless steel for marine use, but someone had crimped this cable with an aluminum sleeve (as would typically be used for land-based applications). Over time, the aluminum crimp had corroded, cracked and finally broken.
With our backups now gone, I resisted the temptations to scream and swear, or throw myself off the ship (thoughts that were not mutually exclusive). I had to come up with a plan to replace the lost gear or the cruise goals would be severely compromised. We were too far away from the city of Kodiak to reach it during business hours, plus nothing could be there today shipped since it was now Sunday. While my mind raced through possibilities, sampling continued at the station with a full set of 6 iron vanes deployed. Consistent with events to dates, 3 of the vanes lost their samplers during deployment. We joked that there must be a contest underway to see who could loose the greatest value of equipment during the cruise!
By next station, we had dug through our supplies, cannibalized a few things, and assembled a single ring net of provide partial replacement for the lost Bongo net. Calls were out to UAF, plus Billy had calls out to FWS in Kodiak and Homer to locate possible Bongo net systems and depressor replacements. Nets and flow-meters were located in Fairbanks and we knew a Bongo net frame was in Seward, but both would take too long to reach. A fishing vessel stabilizer that might function like the lost depressor, and large lead weights were located at Kodiak merchants, and a plan was in place to make a detour into Kodiak, IF we could also determine Monday morning that a Bongo net could be borrowed from there. Simultaneously, a backup plan was forming to go into Homer where a Bongo net had also been located, and a backup depressor was being sought that could be shipped there too. We sampled through the night with out make-shift nets, anxious to see what we would learn the next morning.
Seas were nearly flat Monday morning. Once the business day began, we were able to locate an identical set of Bongo nets belonging to Bob Foy at NOAA in Kodiak. We finished off our station and headed to town. As my sister says, “When the going gets tough, the tough go shopping”. We hit the dock at ~1:30 pm, and with the aid of FWS in Kodiak, we picked up 250 lbs of lead weights, the stabilizer, various hardware, and had new steel cables custom made in several lengths. The Bongo frame and nets were delivered to the ship along with 4 flow-meters. A Multinet depressor was in route from Juneau to Anchorage in the event it was needed. By 4:00 pm we were castoff, and heading back out to sample. Equipment was assembled and the addition of the extra flow meters even allowed us to complete construction of the backup mini-bongos.
The remainder of Monday went smoothly. We sampled dissolved iron on our way to the next station. We deployed the Multinet with the stabilizer, and after a few adjustments determine it flew correctly. Another port call would not be necessary! We redeployed the iron-vanes successfully. Sampling during Tuesday was going smoothly, until during an iron-vane deployment, the ship roled and sloshed water onto the computer programming the vanes, frying it instantly. We spent the afternoon disassembling the laptop, washing out the salt, drying and reassembling it to no avail – luckily they had a backup too. The rest of day went smoothly as we wrapped up our 5th sampling line. Nonetheless, it was apparent we had lost time and some sampling lines would need to be dropped: Line-201 was the first to go.
Shortly after completing our fifth line, the weather has come up, and sampling is no longer possible today. Line-205 is now no longer possible. Weather is predicted to lay down this evening, and there is still the hope we can complete the next 2 lines before shifting over to the Seward Line Wednesday night. Stay tuned
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