Auke Bay Laboratory  (cont.)

NMFS Alaska Coded Wire Tag  Responsibilities

Since the late 1960s, coded-wire tags (CWTs) have been a primary means for marking Pacific salmon (Oncorhynchus spp.) for stock assessment, harvest management, and enhancement evaluations. Because anadromous salmonid stocks range the length of the Pacific coast from California to Alaska in their migrations from natal stream to the ocean and back to spawn, they typically traverse many different fisheries in many different political jurisdictions. Recovery of salmon tagged as juveniles with CWTs has been one of the principal procedures used by fisheries agencies to assess stock abundance, manage fisheries, and protect stocks which are depressed, threatened, or endangered. Since 1968, 82 Federal, State, Native American, and private agencies in Alaska, Washington, Oregon, Idaho, California, and British Columbia have released over 600 million salmon with CWTs. Currently, over 45 million young salmon are marked with CWTs and are released to migrate into the Pacific Ocean each year.

Information on the release, sampling, and recovery of all CWT salmonids throughout the Pacific region is available in an online coastwide database, the Regional Mark Information System (RMIS). This database is maintained by the Regional Mark Processing Center (RMPC) of the Pacific States Marine Fisheries Commission (PSMFC) to facilitate exchange of CWT data between managers, release agencies, sampling/recovery agencies, and other data users.

The Marine Salmon Interactions (MSI) program at ABL has been responsible for many years in maintaining several different components of this coastwide CWT database, including:

1. Releases of CWT salmonids from research programs conducted at Federal facilities in Alaska such as Little Port Walter (LPW) and Auke Creek.
   
   
2. Recovery of CWT salmonids from Federal research programs in Alaska such as the Southeast Coastal Monitoring Program and the Ocean Carrying Capacity Program, as well as adults returning from experiments at LPW and Auke Creek.
   
   
3. Recovery and catch samples of CWT salmonids caught incidentally in three commercial high-seas groundfish fisheries:

1. Pacific whiting (hake) fishery off Washington, Oregon, and California
2. Gulf of Alaska (GOA) groundfish fishery
3. Bering Sea-Aleutian Islands (BSAI) groundfish fishery

Salmon bycatch in the three groundfish fisheries are sampled by onboard observers that have been managed, through calendar year 2001, by the AFSC.  Beginning in 2002, placement of observers in the Pacific whiting fishery, the responsibility for managing salmon bycatch sampling, and maintaining and reporting CWT databases to PSMFC will be transferred to the Northwest Fisheries Science Center and the NMFS Northwest Region.  Responsibilities for observers in the GOA and BSAI groundfish fisheries will remain at the AFSC.  Since 1980, over 4,400 CWT salmonids have been recovered on the high seas from releases by 48 agencies.

By Adrian Celewycz.

 
Little Port Walter Field Station Headquarters Building Exterior Renovation

The headquarters building at LPW field station is getting a complete facelift.  The LPW field station is the oldest biological research laboratory in Alaska. Built in 1940 with a $5,000 congressional appropriation, the headquarters building was initially constructed by the Civilian Conservation Corps using old bricks from a nearby abandoned cannery.  The present renovation is being done by the Paug Vik Construction Company and managed as a Capital Improvement Project by WASC engineer Bud Sawisch.  The project calls for removal of the entire brick facade along with all the windows, doors, and roof, installation of insulation, and refinishing of the exterior.  Work has progressed on schedule, even though 7 feet of snow fell in one 3-day period in December.  All the old brick has been removed and the building has been insulated and house wrapped.  The expected completion date is 1 March and a rededication ceremony will probably occur in June.

By Frank Thrower.

 
SCUBA Diving Study of Sponges

Previous studies by the ABL on the effects of mobile fishing gear on the benthos of the continental shelf in the eastern Gulf of Alaska (GOA) have shown that several species of large erect sponge are important components of structural habitat on the seafloor and are particularly susceptible to removal or damage by commercial trawling activity.  A follow-up study conducted by ABL staff 1 year after trawling indicated no sign of recovery from trawl damage.  In contrast, experimental trawling carried out in warm, shallow water on the southeastern continental shelf of the coterminous United States has shown that sponge communities are quick to recover to pretrawl abundances and that individual damaged sponges undergo rapid regeneration.

Because the ability of benthic epifauna to recover from trawl damage may be a consideration in future fishery management plans, ABL biologists initiated a study of several species of sponge in 2001.  A small community of sponges was discovered at scuba-diving depths in Seymour Canal, Admiralty Island, Southeast Alaska.  Several of the species resembled those found in deeper waters on the continental shelf in the GOA and presented the opportunity to conduct manipulative experiments.  A second nearshore shallow-water sponge community was later discovered with a remotely operated vehicle (ROV) in the vicinity of Benjamin Island, Lynn Canal, Southeast Alaska.

The purpose of the study is to determine basic life history parameters (particularly growth and regeneration) of shallow cold-water sponges.  During April 2001, ABL biologists visited Seymour Canal site during a cruise of the NOAA ship John N. Cobb to 1) chart the distribution of the sponge community; 2) tag individual sponges; 3) take manual measurements of individual sponges; 4) videotape individual sponges for growth measurements; and 5) collect specimens for species identifications through spicule analysis.  On 11-12  December 2001, the second community of sponges near Benjamin Island was investigated using the chartered fishing vessel Solstice and objectives 1-5 (above) were carried out again.  ABL biologists located the sponge community which consisted of an isolated reef approximately 30 m by 30 m in areal extent and approximately 95-130 feet in depth.  Two species of sponge, yet to be identified, were abundant and covered 100% of the reef.  Thirty specimens were tagged, and two circular cores 2.24 cm in diameter were removed from each specimen.  The site will be revisited at regular intervals to determine tissue regeneration rates of the sponges and to collect additional information regarding large-scale distribution of the sponges, habitat associations, and recruitment.

By Linc Freese.

Next >>>

AFSC Quarterly
Research Reports
Oct-Dec 2001