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Alaska
Science Center - Biological Science Office Fisheries Projects Testing Satellite Pop-up Tags |
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Testing Satellite Pop-up
Tags Objectives 2000:
Accomplishments for Objectives 2000: 1. Collect halibut from Resurrection Bay and bring them into captivity at the Alaska Sea Life Center.
All halibut were in good health after transfer to the caddies and survived until we docked at the Resurrection Bay Seafood dock where they were transferred by the dock lift to a flatbed for the brief transport (10 min.) to the Sea Life Center. There was a delay at the Center getting the fish from the caddies into the tanks because of the lack of a forklift or ramp to move the heavy caddies onto the loading deck. During the time we waited for a forklift the caddie water was refreshed from the Center’s sea water supply, however, this addition of ASLC water represented a temperature shift of about 4-7oC that further stressed the halibut. By the time the halibut were downloaded and lifted into the tanks at the Center several fish appeared in poor condition.
On the 8th of August we charted the same vessel for another long line set off Bear Glacier. This time we set the line at dawn and left it for 5 hours in approximately the same place we had set the line previously. This haul brought up a similar assemblage of fishes with the addition of two sleeper sharks and one giant wrymouth that was about 3 feet long. The wrymouth was collected and returned to the Sea Life Center for display. Four more large halibut (50-70 lbs) were collected and returned to the Sea Life center alive from this trip. Stress-limiting chemical treatments were made to the caddie waters during our trip back to ASLC. We docked at the public pier at the north end of the boat harbor.
2. Tag halibut with satellite pop-up tags while in captivity. Fourteen satellite pop-up tags were purchased from
Wildlife Computers to be shipped in two installments. These tags were
programmed to release on June 15, 2001 at 00:1:41:00. The tags have
three sensors. Depth will be measure at a range 140 to 1000m, with 0.5m
resolution. Temperature is measured over the range –40 to 60oC,
with 0.05oC resolution. Light will be measured over the
range: 0 to 255 LLU, with resolution – 1 LLU. All three variables will
be measured at one-minute intervals. Twelve-hour
histograms are allocated 86 Kbytes of memory in the tag and the
remaining 874 Kbytes are used to store sample data. Status message will
be We were scheduled to deploy six tags on the captive halibut (with one control) in the Center tanks on September 14-15, 2000. An injury suffered while tagging walrus by the USGS – BRD veterinarian, Dr. Dan Mulchay, prevented his participation at the last moment. Dr. Mulchay was scheduled to administer anesthetics during the tagging operation and I felt his participation was critical to the success of this part of the study, so we have rescheduled the tagging for mid-October. A decision was made to tag all seven captive halibut, three halibut were tagged on October 19th and four on the 20th at the ASLC, after which behavior and tag retention were monitored for approximately four weeks before release.
The halibut will be tagged using a dart applicator designed by Dr. Barbara Block, Stanford University, for her work on tuna. The tag anchors were assembled with instructions from the Block laboratory at Stanford. A titanium dart is attached to the satellite tag by a secure tether of monofilament fishing line encased in a black shrink-wrap sleeve. The dart is attached to the halibut by insertion into the muscle about ½ inch below the caudal fin where the body starts to taper towards the tail, making sure the nose of the tag does not rub against the skin of the fish and the antenna does not touch the tail when laying flat against the fish. We have concerns about incidental predation of the tags by other fish after attachment and release since the tags resemble fishing lures. To help the tags blend in with the halibut and the sea floor, they were painted black before attachment. After tagging, the halibut appeared to pay little attention to each other's tags. However, predation by sharks or other halibut in sea floor habitats may be a problem we face in recovery of the tag data. 3. Release halibut with satellite pop-up tags back into Resurrection Bay after tag effects are monitored at the Alaska Sea Life Center.
4. Tag live halibut from the boat at the time of release. A new set of 8 tags arrived at ASC-BSO on October 28, 2000. Four tags were allocated for the buoy study put into place at the mouth of Resurrection Bay in November 2000. One tag was used to tag a halibut from the ASLC on-board at the time of release of halibut from the ASLC. The remaining three tags were used during an on-board tagging trip made in conjunction with the start of the commercial halibut fishery in March 2001. These halibut were returned to the sea immediately after tagging to test the durability and efficiency of tags placed on halibut at sea. The halibut were captured off Granite Island in Harris Bay southwest of Resurrection Bay. Tags on these fish are scheduled to pop-up in November 2001. Additionally, three warranty tags granted from Wildlife Computers because of a programming error found to effect the release date of the November 2001 release batch, plus one refurbished tag returned by a commercial fisherman, were used to tag and release four halibut in Resurrection Bay, July 2001, with a release scheduled for November 2001.
5. Develop a bathymetric database for Resurrection Bay from existing sources. USGS – BRD has 2x2 minute resolution global bathymetric database on line in GIS format <http://topex.ucsd.edu/marine_topo.html>. We also have the NGDC CD-ROMs containing point-measures (bathymetric soundings) for both marine trackline surveys and the NOS hydrographic survey data. USGS Mapping Division has a partial benthic side scan imagery database from Alaska coastal fjords including most of Resurrection Bay. The Resurrection Bay database has not been formally worked up. I plan to work with Dr. Monty Hampton, USGS, Menlo Park in using this database to further our analysis of critical habitat developed from the satellite tags. 6. Literature review on halibut physiology, husbandry, movements and behavior. This literature review is well under way with over 300 articles, books, and presentation abstracts. Our collection will continue throughout the course of the study and a bibliography will be made available on line later in the study. 7. Install satellite pop-up tags on an oceanographic buoy at the mouth of Resurrection Bay. Design and implementation of the buoy array of tags will be done in collaboration with Dr. Tom Weingartner, University of Alaska, Fairbanks, and Dr. David Welch, DFO, Vancouver, Canada. The UAF oceanographic buoy (supported by EVOS) is located at the mouth of Resurrection Bay in 260m of water. This buoy if a fixed position buoy with no surface float. Pressure is recorded at 25m below the surface to document wave action.
Tags for the satellite pop-up array destined for the buoy will be calibrated in unison for 4 days under natural light conditions to test for differences among the sensors on each tag. Initially six tags were designated for the buoy array, but from closer examination of light penetration into the sea in the area, four tags was determined to be sufficient in covering and collecting physical data of the entire photic zone.
Dr. Weingartner’s staff will be servicing this buoy in December 2000 to clean and calibrate on board oceanographic equipment. We will deploy the satellite tag array at that time. Tags will be placed on disks at four set depth intervals (27, 57, 96, 146 m). These tags will be left in place through both the spring and fall equinox light patterns and will either pop-up to the surface or be collected during the subsequent March 2002 service of the buoy. (continued with Objectives 2001) Anchorage Daily News Featured Article 3/24/02 Alaska Public Radio Network Article from the Alaska Economic Report 5/29/01 Fish Information and Services Web Article 5/24/01 |
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Permits
from the North Pacific Halibut Commission allowed collection of up to 10
live halibut for this study. On Aug 6, 2000 we chartered the F/V
Rocinante, a vessel owned by Harold Kalve, to place a long line set with
baited circle hooks for halibut off Bear Glacier. Early on the morning
of the 7th we pulled in the set line and collected seven
51-97 lb halibut on the boat. Halibut were lifted onto the boat with
ropes and net and were transferred to a platform on the deck for length
measurements and fin samples (for genetic analysis). These fish were
then placed in 5’x7’ plastic fish caddies placed on the deck of the
boat with continuous circulating seawater flow. Other fish caught in the
long line set included Pacific cod (Gadus macrocephalus),
blackcod (Anoplopoma fimbria), smaller halibut (Hippoglossus
stenolepis), arrowtooth flounder (Atheresthes stomias),
Pacific sleeper shark (Somniosus pacificus), Alaska skate (Bathyraja
parmifera), giant wrymouth (Cryptacanthodidae Delolepis gihantea)
and yelloweye rockfish (Sebastes ruberrimus). 
Unfortunately,
overnight four of the initial seven halibut died in the tanks at the
Center. These carcasses were measured, sexed, and dissected at the ASLC,
vertebra stored for aging, and the meat frozen for distribution to other
animals housed at the Center. One halibut was left frozen whole for
future use in the tagging study during tests of tag anchor placement.
Staff
from the Sea Life Center were at the dock waiting and immediately began
circulation of the water in the caddies with buckets of water brought
from the Center. The temperature change was monitored and shifted
gradually to the Center’s water temperature and the caddies were
trucked to ASLC by the boat captain and immediately transferred via
hoist to the loading dock. Fish were placed in the tanks quickly and we
had no additional mortality for halibut at the Center. Fish were
distributed as follows: four fish in the large 20’ tank, two fish in
one smaller tank, and one fish solo in the second smaller tank.
All
fish remained healthy and well at the Center for the duration of
captivity during which the halibut quickly became accustomed to swimming
to the surface for feeding in the tanks - a sign of rapid domestication
common in this species. This behavior has made halibut feeding one of
the most popular public events at the ASLC. The ASLC has decided to keep
two of the halibut on display at the Center after tagging for the
duration of the study.
sent
every 20 transmissions. All 14 tags have been assigned Argos PTT IDs for
use in this study. Both Argos satellite telemetry and NOAA have been
contracted for 14 PTTYears (365 PttDays each) for this study. A PttDay
is defined as 1 ptt transmitting any amount of data to the satellite
during one day (based on the GMT clock).
On
the 20th and 21st of December 2000, five of the seven tagged halibut
were transported and released near the mouth of Resurrection Bay.
We used the same transportation procedures which were successful
bringing the halibut in to the Center to get them back to their original
habitats. Two halibut were retained at the Sea Life Center for public
display and educational presentations.
