Environmental Projects: Kotzebue Sound 2004-2006 Young Bearded Seal Satellite Tagging Project:

Fall 2005

Methods

(A) Seals were captured by using large-mesh nets in open water in fall. Kotzebue hunters participated in or conducted all seal capture activities. The nets used to catch seals have a solid foam-core float line (no corks) and a thin light lead line. They are 100’ x l2’ and have zippers on the ends so they can be joined into larger nets if needed. The nets have 12” stretch mesh and are made of dyed twine. The nets are designed light enough that the seals are able to easily float and breathe after they are caught. In addition some net sites are shallow enough that a seal can be touching the bottom while its head is above water. The water where most of the nets were set is less than 5 feet deep.

In 2005, nets were set in York’s Bay during the last half of September and near Sisualik in early October. During two weeks in late September, scientists worked with tribal member John Goodwin to set nets and tag seals. During that time information was shared about how to set nets more efficiently, where nets should be set, and methods for disentangling, tagging and measuring seals. John Goodwin received the training necessary to become an official co-investigator on the project, which allowed him to tag seals when scientists were not present. Seals were tagged under Alaska Department of Fish and Game Scientific Permit No. 358-1585 (Amendments 07 and 08).

The scientists left on September 29 th and after that all nets were set near Sisualik. Tribal member John Goodwin and Cyrus Harris both set nets along the beach at Sisualik and near Nuvugraq. They continued until October 11 th when ice conditions prevented further netting. In total, 15 bearded seal pups were tagged in 2005. Three were caught in York’s Bay and the other 12 were caught off of Sisualik. All seals captured in 2005 were found alive and in good health, except for one large pup or yearling that was captured off of Wolf Creek and drowned. Another smaller bearded seal was caught alive and healthy in the other end of the same net. The seal that was drowned was tangled in a single mesh and the anchor line was free. It is unknown why it drowned. A tribal member cooperating on the project salvaged the seal for food.

When a bearded seal was captured it was transferred from the catch net to a smaller hoop net so it could be safely restrained and transported to the tagging site. Some seals were tagged in the boat and others were taken to the beach for tagging. Each seal was measured and checked to determine whether it was a male or a female. When scientists were present each seal was sampled for blood, blubber and DNA. Satellite depth recorders (SDRs) were glued to the hair on the back of the seal using quick-setting epoxy. The tags will be shed when the animals molt in the spring. The tags used are the newest, smallest, lightest and most streamlined of tags used for seal work to date. They not only tell where the seal is located, but also how deep it dives, how long it dives, and how long it spends at the surface and at certain depths. The tags are about 4” long, an inch wide, and an inch and a half high. They are powered by a single C cell lithium battery, which is activated by being submersed in water and should last for 50,000 signals to the satellite (about one year, or until the seal molts in the spring when the tag will fall off). The tags have a 7” flexible whip antennae that is located on top of the tag and rides above the water when the seal is at the surface. The antennae are easily seen from a distance, allowing hunters to visually identify tagged seals and hopefully avoid premature removal from the project.

SDRs transmit to receivers operated by Service Argos on board National Oceanic and Atmospheric Administration polar orbiting satellites. The Argos data collection and location system records the date and time of each signal received by the satellite and calculates a location for the tag whenever sufficient uplinks are received during a satellite pass. A multi-stage process will be used to screen out erroneous location records. SDRs will include a conductivity sensor that indicates whether the tag is dry or submerged and a pressure sensor to determine dive depths. Location records and associated data will be put into an ArcInfo geographic information system (GIS) and plotted using ArcView. Maps will be distributed to interested parties weekly and posted on the Tribal website.

(B) In addition, small samples of skin were obtained for genetics analysis from subsistence-caught seals and preserved in a solution of DMSO and salt. These samples will be used to examine genetic variation in mitochondrial DNA (mtDNA) and will be contributed to an ongoing study by ADF&G and NMFS to examine stock structure of bearded seals in Alaska. Greg O’Corry Crowe and Aquatic Farms at the Southwest Fisheries Science Center will analyze samples. Greg has worked with the Alaska Beluga Whale Committee to analyze beluga DNA and to understand stock structure of belugas harvested by Alaska hunters.

Highlights

Fifteen bearded seal pups (ugrutchiaq) were tagged during the fall 2005 field season for a total of 17 seals in two years. This is five more than our goal of 12 in the original proposal for the project. Eight were males and seven were females, which will allow us to compare the movements and diving of males and females. One month after tagging, all 15 tags were still transmitting data.

Tribal members John Goodwin and Cyrus Harris, plus friends and families, successfully netted 12 of the 15 seals that were tagged in 2005. John Goodwin received training in handling and tagging live seals and was named an official Co-Investigator under the ADF&G Scientific Permit to tag seals. He tagged 11 of the seals caught after the scientific party left. Alex Whiting tagged the last seal of the season on October 11th.

As an add-on to this project, the National Marine Mammal Lab tagged five spotted seals (3 pups and 2 adult males). These were caught during bearded seal tagging activities. Spotted seals were last tagged in 1994 in Kasegaluk Lagoon near point Lay. Winter movement's information from the Kotzebue spotted seals will be compared to movements of spotted seals 10 years ago.

Movement's data for both bearded seals and spotted seals is being distributed weekly by email to more than 50 individuals throughout Alaska and elsewhere. In addition, information is posted weekly on the Kotzebue IRA web page. It will be presented at the 16th Biennial Conference on the Biology of Marine Mammals in December 2005. Project participants John Goodwin and Michael Cameron will give a project update to the Alaska Ice Seal Committee in early 2006.

Project Activities

John and Pearl Goodwin conducted reconnaissance field work in northeastern Kobuk Lake (Hotham Inlet) on 12-13 September. This area is locally referred to as York’s Bay. The Goodwins set several nets but did not catch anything nor did they see any young bearded seals (ugurachaqs). Kathy Frost, Rob DeLong and Michael Cameron arrived on September 16 th. Three nets were set near Sisualik on September 17 th. The weather was excellent with light winds, high water and temperatures in the low to mid-50s. No seals were caught or seen in the area.
On September 18 th, all nets were moved to York’s Bay. From September 18 th-28 th seal catching activities were conducted in York’s Bay. Water depth in this area is generally < 6 ft, with many creeks and sloughs entering the bay. Young bearded seals are present in these areas during fall just before and during freeze-up. Temperatures throughout this period were in the high 40s or low 50s F. It was an unseasonably warm September with no freezing temperatures or any signs of ice or snow.

After initial exploratory sets, seal nets were set in two areas. The first was near Wolf Creek and the second in or near Ugrivik Creek. These are areas where local residents hunt bearded seal pups in the fall, and near where two were caught and tagged by this project in 2004. The water is very shallow (3-6 ft) and muddy without much current. Creeks are surrounded by low willow and birch tundra where young bearded seals sometimes haul out in the grass. Up to six nets were set each night. Nets were checked daily unless high winds and storm conditions prevented boating activities. There was only one period when nets were not checked daily, and that was during September 21-23 when wind speeds were 35-60 mph throughout Kotzebue Sound and precluded all boating activity.

Two live bearded seal pups and one spotted seal pup were caught on September 24 th after the days of stormy weather when the nets could not be checked. One bearded seal pup was caught at the mouth of Wolf Creek and the other at the mouth of Ugrivik Creek. A second dead bearded seal pup/yearling was caught at the mouth of Wolf Creek in the same net (opposite end) as the live one. The spotted seal pup was caught well up Ugrivik Creek in a side branch near the entrance to a small lake. All three seals were loaded into the boat and taken back to Kotzebue for tagging. Tagging was done by Frost, Cameron and Delong with assistance from Goodwins. Seals were released several miles offshore from Kotzebue in hopes that they would move offshore where they would not be subject to hunting.

On September 25 th, after project nets were set, Michael Cameron set and attended a net at the entrance to York Bay near Theodore Creek (66.94º N, 161.52º W). This was a monofilament net especially designed to catch seals during daylight hours. This net was set under a NMML permit to catch and tag seals as part of a different project. Two spotted seal pups of the year were caught within 30 minutes of net deployment. Both were taken back to Kotzebue where they were instrumented with SDRs and released. These seals were released on the beach west of Kotzebue. Information for these seals will be reported by NMML under their scientific research permit 782-1676.

On September 26 th, a very large male bearded seal pup (mass estimated >350 pounds) was caught at the mouth of Wolf Creek. This seal was sampled, measured and tagged in the boat, then released in the channel west of Kotzebue.

On September 27 th, no seals were caught in York’s Bay. A high wind warning was in effect for the next day or two, so all nets were pulled out of York’s Bay. Nets were reset near a sand bar/island by the navigational channel off Kotzebue and also near Sisualik. On September 28 th, one large male spotted seal was caught in the offshore channel net. This seal was tagged in the boat and released near where it was caught. Another medium-sized male spotted seal was caught on September 29 th in the same area. Nothing was caught in the nets near Sisualik, although at least one bearded seal pup was seen.

Frost, Delong and Cameron left Kotzebue on September 29 th. John Goodwin and/or Cyrus Harris set nets near Sisualik from September 30 th-October 15 th. September 28 th was the first day of near-freezing weather in Kotzebue Sound. Ice began running out of Kobuk Lake on October 1 st and young bearded seals were commonly seen near Sisualik from then until freeze-up. Seals were caught and tagged on September 30 th, October 1 st-4 th, October 7 th and October 11 th. They were caught in nets set very close to shore, and pulled to the beach for tagging. All but two were released at the tagging location. Those two were released at Kotzebue. Catch activities ceased on October 15 th when freezing conditions and snow prevented further netting and tagging activities.


2005 Female Bearded Seals Project

2005 Male Bearded Seals Project

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