Archive for the ‘Fisheries management’ Category
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.
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.
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.
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.
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.
Launch crews hold morning safety meeting at the pier.
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
Coastal planners, fishery managers, and oceanographic researchers will soon reap important seafloor and water column data from the coast of Washington, when NOAA Ship Rainier undertakes a special project in the waters within and near the Olympic Coast National Marine Sanctuary in May.
The blue lines indicate NOAA Ship Rainier’s survey project areas. From north to south, the project encompasses Juan De Fuca Canyon (65 square nautical miles), Quinault Canyon (378 square nautical miles), and Willapa Canyon (189 square nautical miles). The teal dots in Quinault and Willapa canyons are the locations of deep underwater natural methane gas seeps being investigated in a University of Washington research project. The green shaded area is the extent of the Olympic Coast National Marine Sanctuary.
The project, which is being managed by NOAA’s Integrated Ocean and Coast Mapping program, grew from NOAA’s National Centers for Coastal Ocean Science seafloor mapping prioritization exercise among coastal stakeholders from federal and state (Oregon and Washington) agencies, tribes, and academia. The group determined that one of the biggest needs by most of the organizations was a better understanding of canyon depths, seafloor, and habitat.
A scientific team of experts from the College of Charleston, University of Washington, and Oregon State University will contribute to the NOAA-led multi-disciplinary survey project, gathering data for a host of research projects and ocean management activities. In general, the data will collect swath bathymetry, acoustic backscatter, and water column data to:
- inform regulatory decisions on coastal development;
- provide benthic habitat mapping and seafloor characterization for sustainable fisheries initiatives, and to help assess fishery stocks and critical spawning aggregation locations;
- better understand and manage shelf and canyon resources;
- aid in resolving multiple-use conflicts;
- advance research in determining chemical and biological contamination levels; and
- provide a data repository for the development of ocean tourism and recreational fishing.
Some specific research projects are also planned.
- A University of Washington scientist will analyze the water column plumes over natural methane gas seeps in the planned survey areas. The university is a leader in the study of methane hydrates.
- Because Rainier heads to Alaska after the survey in the sanctuary, the ship will also conduct an exploratory survey to obtain seafloor imagery and data over a newly discovered mud volcano in the upper continental slope offshore of Dixon Entrance, just off the Inside Passage near Ketchikan, Alaska. California State researchers will use the data from this 40 square nautical mile survey to analyze the seafloor shape, assess the area for effects on potential tsunamis, and identify unique biological communities.
As part of her regular mission, Rainier will acquire depth measurements and other hydrographic data throughout the entire project to update NOAA nautical charts 18480 and 18500 off the coast of Washington, and chart 17400 in Alaskan waters. The corresponding electronic navigational charts (NOAA ENC®) are US3WA03M, US3AK40M, and US3AK40M.
Chris Stubbs, from the College of Charleston, will serve as the project’s chief scientist. Cmdr. Edward J. Van Den Ameele is Rainier’s commanding officer.
NOAA ship Rainier, a 48-year-old survey vessel, is part of the NOAA fleet of ships operated, managed and maintained by NOAA’s Office of Marine and Aviation Operations, which includes commissioned officers of the NOAA Corps, one of the seven uniformed services of the United States, and civilian wage mariners.
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.
Before we get to the Fairweather logs, we need to update the last post, NOAA Ship Fairweather zigzags her way to accurate and precised depth soundings. Cmdr. Crocker reports that the “normal” zigzagging won’t start until they head further north, starting near Point Hope. It was not planned for the trip to Kotzebue, and he would have run a straight course if he could have. This log by Ensign Hadley Owen explains why they zigzagged earlier than planned, as well as what they are doing for their first scientific project. We apologize for the error in the last post. -DF
Fairweather Log Entries, August 2 and August 5
by Ensign Hadley Owen, NOAA, Junior Officer, NOAA Ship Fairweather (S-220)
2400 hours, Thursday, August 02, 2012: 57°04.9’N 167°05.5’W, underway, Dutch Harbor to Kotzebue Sound
We left Dutch Harbor on the NOAA Ship Fairweather on August 1, to begin our 30-day reconnaissance trip bound for the Arctic. Our departure had been delayed until 1800 on Wednesday in order to let pass a 988 MB low-pressure system moving northeast through the Aleutians. Our initial plan was a straight line running generally west by north, on which we would acquire seafloor data using the ship’s hull-mounted multibeam echo sounder and a towed Klein 7180 long-range side scan sonar (a one-of-a-kind device designed to maximize the effectiveness of broad-scale fish habitat studies using acoustic “backscatter”). However, a persistent 8’ swell on the ship’s beam resulted in a more than 20-degree roll that kept many crewmembers in their beds and made useful data acquisition nearly impossible. Cmdr. James Crocker, commanding officer of the Fairweather, made the call to alter course in order to pass over the acquisition stations in a tacking motion – zigzagging our way north in order to minimize the effects of the swell on our ship’s data collection activities.
The first leg of our Arctic cruise is focusing on work conducted for NOAA’s National Marine Fisheries Service, and led on the Fairweather by Dr. Bob McConnaughey. He and his team of NOAA scientists and Navy technicians have been studying and mapping benthic regions in the eastern Bering Sea since 1996, addressing a congressional mandate to understand the habitat requirements of the nation’s managed fish and crab populations. Their recent work has focused on using a variety of sonars to identify seafloor properties that affect the distribution and abundance of fish, including the Fairweather’s multibeam echosounders (traditionally used for hydrographic surveying) and side scan sonars that can continuously survey a swath of seafloor up to a kilometer-wide, at a maximum speed of 12 knots. The project goal is to measure backscatter from the ocean’s bottom, rather than to simply produce images of it, and to use this information in combination with other environmental data and estimates of fish abundance from annual bottom trawl surveys to improve the team’s mathematical models that identify the habitat requirements of individual species. At the same time, we are taking care to produce hydrographic-quality bathymetric data for updating nautical charts in areas with outdated or non-existent information – a great example of NOAA’s integrated ocean and coastal mapping strategy.
The NOAA team onboard Fairweather during the NMFS fish research project
The NMFS team’s broader interest in the Fairweather’s reconnaissance mission is to be at the forefront of activity documenting the areas that are opening up as the region’s ice-cover retreats. By this work, NOAA’s intention is to be well prepared to support fishery management decisions related to emerging uses: commercial fishing, large-scale shipping and navigation, and oil exploration interests. The team aims to document similarities and differences in the seafloor habitats found along the more than 1,000 km reconnaissance line extending from Dutch Harbor in the Aleutian Islands to the Kotzebue Sound area above the Arctic Circle. The data collected from the eastern Bering Sea, the northern Bering Sea and the Chukchi Sea will provide insights about possible outcomes if fish populations redistribute northward due to environmental change. It will also help us to understand the susceptibility of these areas to new forms of human disturbances.
Fairweather deploys the Klein side scan sonar
As of the end of Thursday, August 2, the seas have settled down and allowed the Fairweather to deploy the long-range side scan sonar and begin acquiring data. Depending on conditions, the sonar’s towfish will remain in the water until the northern end of the survey line near Kotzebue. In addition to backscatter data, the side scan sonar is also acquiring data about water column properties such as chlorophyll.
We are keeping a close eye on ice conditions for the latter part of our route. The current ice edge runs to Barrow, and will at present prevent us from completing the last leg of our track in the Beaufort Sea – along the north coast of Alaska and east to the Canadian border. However, any data obtained during this reconnaissance mission will initiate a new large-scale systematic study of the region’s benthic habitats, will provide new bathymetric data for nautical charts, and will ultimately create a foundation for appropriate management and safe navigation in the region’s future.
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1800 hours, Sunday, August 5, 2012: 67°00.8’N 165°35.5’W, heading east, Kotzebue Sound, north of the Arctic Circle
We have been transiting increasingly shallow water since we passed Nunivak Island. As the Klein 7180 operates best in depths greater than 20 fathoms, we were able to take advantage of improved weather and relatively calmer seas to bring the towfish on board yesterday morning. However, data acquisition continues with the ship’s multibeam echo sounder.
At 1400 hours we crossed the Arctic Circle (66°33’N), heading northeast towards the town of Kotzebue. Dr. Bob and his crew will disembark the Fairweather early Monday morning and we will shift focus with a new team of scientists as we continue north. As we transit to our anchorage near the head of the Sound this evening, we will navigate using the newest chart (16161) of the area. NOAA produced Chart #16161 in May, using survey work conducted on the Fairweather last summer; it will be an inspiration for the work to come.