NOAA Ship Fairweather begins multi-mission projects in Alaska

In a unique deployment of resources, last week NOAA Ship Fairweather split its scientific team and vessels to tackle two distinct projects in Alaska. Coast Survey physical scientist Katrina Wyllie and Lt.j.g. Bart Buesseler report on the multi-mission projects.

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On August 9, NOAA Ship Fairweather departed Dutch Harbor, Alaska, for a FISHPAC project, led by Dr. Bob McConnaughey from NOAA’s Alaska Fisheries Science Center. This project’s primary mission is to statistically associate acoustic backscatter returns with the abundances of fish and crabs that frequent the Bering Sea seafloor. The science team accomplishes this with acoustic data from multibeam, single beam, and side scan sonars. Understanding the value of acoustic backscatter as a habitat-defining character will help scientists understand where fish live and the importance of different habitats. The acoustic data will also be used to correct for differences in the performance of research bottom trawls on different seafloor types, so that stock assessments and fishery management can be improved. To make sure the scientists understand what the acoustic data are showing, each day the ship will stop and collect physical bottom samples of the seafloor to see, touch, and interpret their findings. Further increasing the effectiveness of this mission, all of the multibeam bathymetry data acquired will directly support NOAA’s Office of Coast Survey as the data will be used to update soundings on the nautical charts for the eastern Bering Sea where the ship will be operating.

NOAA Ship Fairweather will survey the red tracklines for the FISHPAC project this year. The green lines will be surveyed at a later date.
NOAA Ship Fairweather will survey the red tracklines for the FISHPAC project this year. The green lines will be surveyed at a later date.
Fig2
FISHPAC mission equipment on deck of NOAA Ship Fairweather

With Fairweather actively conducting 24-hour ship survey operations in Bristol Bay, there wouldn’t be any chance to deploy her four survey launches for additional acquisition. Sensing an opportunity, the Office of Coast Survey, the command of the Fairweather, and Marine Operations Center-Pacific collaboratively came up with a multi-mission plan to maximize the capabilities of Fairweather during the FISHPAC project. Before departing Dutch Harbor, Fairweather deployed a shore team with the four survey launches to stay in Dutch Harbor and address some critical navigation needs identified by the port.

Two of the NOAA Ship Fairweather launches depart for a day of hydrographic surveying
Two of the NOAA Ship Fairweather launches depart for a day of hydrographic surveying.

 

Although its location is remote, the port of Dutch Harbor is a vibrant and bustling port serving full-size container ships. It is the country’s top fishing port in terms of landings for the past 18 years. Deep draft and ice-free year-round, Dutch Harbor provides a critical link in America’s transportation infrastructure. Trivia buffs may also know that Dutch Harbor is the only other American soil, in addition to Pearl Harbor, to be bombed during World War II. (For more on Alaska in World War II, see USC&GS Ship Hydrographer contributes to significant Allied victory.)

With the increase in commerce flowing into and out of the harbor, local maritime pilots asked Coast Survey navigation manager Lt. Timothy Smith for updated nautical charts to improve the safety of maritime traffic. This need was underscored in July 2015, when a polar ice class vessel ran aground in an area of the chart which hadn’t been surveyed since before World War II. Shortly after this grounding, Fairweather was able to alter their schedule to conduct a response survey in the area of the grounding (green area in project sheet layout, below). Additionally, Fairweather had previously surveyed small high priority areas in 2011 (orange areas).

Project area of the north coast of Unalaska Island hydrographic survey project being conducted by NOAA Ship Fairweather launches.
Project area of the north coast of Unalaska Island hydrographic survey project being conducted by NOAA Ship Fairweather launches.

 

This month’s collaborative project, performed in conjunction with FISHPAC, provided the perfect opportunity to address these navigational needs. With the survey launches remaining in Dutch Harbor, with a team of scientists, coxswains, and engineers to support them, Fairweather’s shore team will acquire complete coverage multibeam data in the entire project area, totaling approximately 38 square nautical miles, as outlined by the blue shapes in the project sheet layout.

The City of Unalaska has graciously facilitated this unique mission by providing pier space for all four launches for the project’s duration. The team itself has established a base of operations at the Grand Aleutian Hotel, where they have converted a conference room into a command center to process the day’s freshly collected data, while preparing the mission for the subsequent day.

The shore team has plenty of work to keep them busy until August 27, when Fairweather returns to Dutch Harbor after completing the more than 4,000 line-mile  FISHPAC mission and recovers the survey team and launches. Fairweather then transits back to Kodiak, Alaska, for a scheduled inport and well deserved break before hydrographic survey operations resume in the vicinity of Sitkalidak Strait.

Lt.j.g. Bart Buesseler review multibeam bathymetry data in the shore team base of operations room.
Lt.j.g. Bart Buesseler review multibeam bathymetry data in the shore team base of operations room.
Launch crews hold morning safety meeting at the pier.
Launch crews hold morning safety meeting at the pier.
The four launches tie up alongside at the Robert Storrs International Small Boat Harbor facility.
The four launches tie up alongside at the Robert Storrs International Small Boat Harbor facility.

 

Additional resource:Combining expertise makes for better nautical charts and better understanding of fish habitats in Alaska, Oct. 9, 2012

Combining expertise makes for better nautical charts and better understanding of fish habitats in Alaska

Today’s post is written by a guest blogger, Dr. Bob McConnaughey. Bob is the FISHPAC project chief scientist, with NOAA’s Alaska Fisheries Science Center.

Fishery biologists and hydrographers in NOAA are working together to solve two very important problems in the eastern Bering Sea. This area is one of the richest and most productive fishing grounds in the world. Careful management of harvest levels is one part of the effort to sustain these populations into the future. However, it is also important to understand the habitat requirements of the managed species so we can protect the foundation for these high levels of production.

To this end, a team of scientists at the Alaska Fisheries Science Center (AFSC) is developing mathematical models to explain the distribution and abundance of groundfish, such as pollock and cod, and benthic invertebrates, such as red king crab, in order to determine their essential habitats. The research team gathers new environmental data at locations where other AFSC scientists sample fish populations during annual bottom-trawl surveys. In many cases, existing habitat information is very limited, but studies will identify useful variables and the best tools for measuring them over large areas of the continental shelf.

NOAA hydrographers working in Alaska are likewise challenged by the sheer size of the offshore areas and the dearth of recent depth measurements. This region includes over 47,000 miles of coastline and roughly 70% of the nation’s continental shelf. Soundings data for nautical charts are usually quite old and coverage is incomplete. Similar to the habitat studies, there is a great need to gather new data, efficiently and cost-effectively.

A diverse team of NOAA personnel and external partners are collaborating to address the critical need for new habitat data and new hydrographic data from the eastern Bering Sea. Beginning in 2006, NOAA Ship Fairweather has conducted multi-mission cruises to simultaneously achieve these two objectives. The so-called FISHPAC project has developed procedures to collect acoustic backscatter data to characterize seafloor habitats while also collecting high-quality bathymetric data for updating nautical charts.

This joint effort has been a great challenge for two groups that have typically worked alone, generally focusing on a single specialized activity. The successful integration of these activities makes efficient use of valuable ship time and will ultimately increase the amount of data collected for both purposes in a single survey season.

The prototype long-range side scan sonar is prepared for deployment. An emergency locator beacon is activated to help locate the towfish if it becomes detached from the double armored tow cable.

The AFSC scientists have introduced new types of equipment on Fairweather for this work, including a prototype side scan sonar capable of very broad coverage (up to 1 km) at a fast tow speed (up to 12 kts), an acoustic underwater tracking system that provides accurate positions for towed instruments, and several “groundtruthing” instruments to help interpret the backscatter data for habitat purposes. The partners have worked out safety and deployment details, and now the ship can simultaneously acquire acoustic data from the ship’s two multibeam echosounders and a towed side scan sonar, while underway and collecting sound velocity profiles and geotechnical data from the seafloor with a free-fall cone penetrometer! Operating this way, the ship does not need to stop; they can conduct survey operations around the clock during the entire time at sea.

Fairweather hosted a major FISHPAC cruise during July-August 2012. A team of 12 scientists joined the Fairweather’s standard crew of officers, physical scientists and seamen to conduct a combined fish-habitat and hydrographic-survey effort in the eastern Bering Sea. The group worked together ‒ night and day ‒ to acquire the multi-purpose data. They tested five different sonar systems in an experiment designed to identify the most cost-effective system for characterizing the seafloor and improving the existing fish-habitat models. At the same time, the ship collected over 1,000 nautical miles of hydrographic data in an area with outdated or non-existent information.

Technicians from the Naval Undersea Warfare Center (Keyport, Washington) and a retired NOAA engineer and hydrographer provided valuable assistance.

Neither high seas, nor fatigue, nor equipment problems stopped the intrepid group. The project was fully successful in the end and Fairweather safely returned to port in Dutch Harbor, Alaska to discharge some scientists and then head back out on her Arctic Reconnaissance voyage.

The towed auto-compensating optical system (TACOS) is a two-part towed video system consisting of a weight sled connected to the ship’s fiber optic winch, with a camera sled trailing approximately 20 meters behind the weight sled. The camera sled includes an analog video camera, a digital video camera, six high intensity discharge lights as well as an acoustic release/buoy for emergency recovery. TACOS creates high-quality downward-looking video mosaics.