The Kona IEA survey is underway!
The Kona IEA survey is underway! After a rough transit to our survey grid, we were able to begin our operations comfortably in the lee of Hawaii. As we’ve moved offshore, the seas have picked up a bit, but they’re much calmer than what we saw crossing the Alenuihaha Channel.
During this first week of the cruise we’re conducting sunrise and sunset conductivity-temperature-depth (CTD) casts, collecting active acoustic data, trawling, and conducting DIDSON imaging sonar casts. Now that we’re a few days into the cruise, everyone is up to speed on their various operations. And the Sette’s crew has been excellent in helping us figure out how to do new operations like the DIDSON cast. For this, they devised a way to connect a CTD, an ecological acoustic recorder (EAR), DIDSON imaging sonar, back-up acoustic release, and concrete block in series and deploy it with the port-side winch. And, after the first DIDSON cast when data collection was limited by the batteries being too cold, Lead Fisherman Mills Dunlap found us some thermal “space blanket” insulation to keep the batteries warm enough to allow for continuous data collection for the entire DIDSON unit cast.
Our mid-water trawls have been going well. So far, we’ve collected replicate trawls at one near-shore and two offshore sites. Our near-shore trawls collected a high proportion of crustaceans compared to our offshore trawls. In addition to the expected catch of animals like myctophids, dragonfish, and gelatinous zooplankton, we’ve also caught two remoras and a cookie cutter shark (which thankfully did not bite holes in our trawl net cod end).
In addition to collecting transect data and determining our target depth for trawls, the active acoustics team has been hard at work finding ways to improve the data collected by the EK60. So far, they’ve grounded some components and cleaned them of dust and debris that’s accumulated on them over the years.
It’s a bit early in the cruise to discern much from our CTD data, but near-real-time altimetry data indicate that we may be near the northeast corner of an anticyclonic eddy.
All in all, the cruise is off to a great start. Keep following our blog for updates on our progress. You can also check out our Teacher at Sea, Adam Renick’s, blog at http://teacheratsea.wordpress.com/2013/06/14/adam-renick-heading-out-and-the-science-begins-june-13-2013/.
Map of this year’s Kona IEA survey grid, with progress as of 0600 16 June.
Combined CTD, EAR, DIDSON, acoustic release, and concrete block (just under the water’s surface) being recovered after a cast.
DIDSON batteries wrapped in thermal insulation.
Clockwise from top left: high volume of crustaceans caught at Station C, shore fish caught at station C, cephalopods caught at station D, and two remoras and other fish caught at station D.
Sea level altimetry anomaly during SE-13-04.