REU Student Abstracts

AT-SEA SURVEYS OF MARBLED MURRELETS: METHODOLOGICAL CONSIDERATIONS

Jennifer L. Carroll, UAS REU Summer 2004 Student
REU Mentor: Matt Kirchoff, Alaska Department of Fish and Game

ABSTRACT
Marbled murrelets (Brachyramphus marmoratus) are solitary nesters, and nest in the tops of old-growth trees. As a result, surveys are necessarily conducted on populations at sea. We evaluated the accuracy of alternative line transect methods, and described the spatial distribution and density of marbled murrelets in Stephen’s Passage, Southeast Alaska. We used these results to develop an optimal survey design. We found that the perpendicular distance from the object to the transect centerline could be more accurately calculated by estimating radial distance and angle, than by estimating the perpendicular distance directly. Repeated boat surveys along 23 transects (range 5.4 – 12 km) were conducted in the study area using GPS to record all bird locations spatially. The information gathered from the survey produced density estimates of 41.3 murrelets/sq. km (95% CI =25.73 to 50.268) for June and 47.1 murrelets/sq. km (95% CI = 30.546 to 55.707) for July. Half of all murrelets occurred within 2.0 km of the shore, and peak density occurred 1.7 km from shore. Bird density varies greatly with distance from shore, therefore, the optimal survey design would orient transects perpendicular to shore and calculate density from line transects using radial distance estimates and measured angles.

SPECTROGRAPHIC ANALYSIS OF RECORDED BAT ECHOLOCATION CALLS FOR THE DEVELOPMENT OF A ROBUST BAT MONITORING SYSTEM IN SOUTHEAST ALASKA

Michael Glista, UAS REU Summer 2004 Student
REU Mentor: Dr. Matt Heavner, University of Alaska Southeast

ABSTRACT
The most recent and extensive effort to document the occurrence of bats in Alaska confirms that five species inhabit certain parts of the state for at least a portion of the year. However, much remains uncertain about the geographic range, seasonal distribution, and population size and dynamics of these northern bats. This project aims to clarify these uncertainties by building upon that which is already known about bats in Southeast Alaska. Within the next two years, the investigators will develop a robust, sophisticated bat sensor system capable of monitoring bat activity for extended periods of time. This bat detector array will employ a software program capable of automatically identifying bat calls. For this component of the study, in addition to the development of the bat detector system, bat calls recorded in Southeast Alaska by D. Parker et al. (1997) have been analyzed in order to determine what sounds are likely to be recorded during the bioacoustical monitoring of the region. In particular, the sounds on the tapes were investigated and classified, the different types of identified signals were processed and described, and a preliminary investigation of the parameters that can be used to identify different species of bats in Southeast Alaska by their echolocation calls was conducted. Two factors, duration and frequency of maximum power, were found to be useful in discriminating between sound types. Although measurement and consideration of these factors alone theoretically make automated call identification possible, further statistical analysis may be necessary to ensure more accurate sorting.

NEAR SHORE FORAGING BEHAVIOR OF MARBLED MURRELETS IN STEPHEN’S PASSAGE

Kira Pontius, UAS REU Summer 2004 Student
REU Mentor: Matt Kirchoff, Alaska Department of Fish and Game

ABSTRACT
The marbled murrelet is an alcid that nests in old growth forests and lives and forages at sea. I studied near shore diving behavior of marbled murrelets (Brachyramphus Marmoratus) in mid July, at Pont Bishop near Juneau Alaska. Birds were observed from land during all stages of tide and over all daylight hours on 3 days in mid July. I recorded 1964 behavioral observations on 177 birds, including 887 diving bouts. The mean dive time was 27.1s, sd=10.1s, and the mean surface time was 10.5s, sd= 8.4s. I found as tidal stage increased from low to high tide both surface and underwater time increased significantly (P < 0.05). Birds foraging in pairs spent more time under water (mean 31.1 s) compared with singles (mean = 26.1 s). Pairs also spent more time recovering on the surface in between dives than singles (14.4 s versus 9.7 s). All differences in up times and dive times were significant (P< 0.05). Average group size increased with increasing tides p=0.000. I also found birds that performed a pre-dive head dip spent significantly more time underwater (30.8 s) than birds that dove without a head dip (26.0s) (P= 0.00).

DECAPOD LARVAE HITCHHIKING ON CNIDARIANS IN GLACIER BAY

Cirse Gonzalez, UAS, REU Summer 2004 Student
REU Mentor: Dr. Ginny Eckert, University of Alaska Southeast

ABSTRACT
Interactions between planktonic crustacea and gelatinous zooplankton have long been noted by scientists. This study examined the association between the cnidarians Aurelia aurita and Cyanea capillata and decapod larvae in Glacier Bay National Park, Alaska. At eight, random locations in the east arm and lower bay, decapod larval abundance was surveyed both from jellyfish collected in horizontal trawls and vertical zooplankton tows. Decapod larvae from both samples were identified to species and stage. Both Chinoecetes tanneri and Cancer magister were found in greater numbers on the jellyfish than in the water column. Implications of this interaction could affect distribution of these commercially fished species. Consideration of this interaction is recommended for any future study surveying decapod larvae.

INFLUENCE OF PREDATION RISK ON THE MOVEMENT OF THE SUBTIDAL WHELK, NEPTUNIA LYRATA

Alison Gould, UAS REU Summer 2004 Student
REU Mentor: Dr. Chris Siddon

ABSTRACT
Movement is ecologically important in maintaining an organism’s population, although often difficult to measure, especially for far ranging species. In such cases, model systems become a useful means for simplifying these larger, more complicated systems. We examined the Lyre Whelk (Neptunea lyrata) as a potential model system for studying movement. We first quantified the density, and the size frequency distribution (measured in shell length) of a subtidal population of N. lyrata along the northeastern coast of Admiralty Island in southeast Alaska. Whelk density at depths of 7, 10, 13, 15, and 20 meters were 0.3 + 0.5, 4.4 + 4.4, 3.2 + 3.1, 5.3 + 5.1, and 3.2 + 3.0 N. lyrata respectively (#/40 m2 + SD), and the average shell length was 99 mm, ranging between 60 and 140 mm. The effects of shell length and predation by the sea star, Pycnopodia helianthiodes on the movement of N. lyrata were studied in a series of individual mark and recapture (IMR) experiments in which tagged snails representing a range in shell length were placed into circular plots (20 meters in radius) both with and without the presence of predators. Individual moves were measured as a random walk over 6 hours (at 2 hour intervals) and the net squared displacement (D) was calculated for each N. lyrata. Trial one showed a significant relationship between the size of the snail and their displacement, in which smaller snails moved less than larger ones. In both trails two and three however, the size of the snails had no significant effect on their displacement; therefore, in combining the data from these trials there was a significant effect of the presence of predators, in which snails in the predator and non-predator treatments had average net squared displacements of 0.55 + 0.05 and 0.27 + 0.06, respectively (D + SE). These results support the hypothesis that both size and predation will effect the movement of N. lyrata.

KELP BEDS AS HABITAT AND NUTRIENTS FOR INVERTEBRATES IN SOUTHEAST ALASKA

Douglas Rasher1, Elizabeth Calvert2, and Michael Stekoll3

1 UAS, REU Summer 2004 Student, Lyman Briggs School, Michigan State University
2 Juneau Center School of Fisheries and Ocean Sciences, University of Alaska Fairbanks,
3 REU Mentor: Department of Natural Sciences, University of Alaska Southeast.

ABSTRACT
Kelp beds act as an important source of habitat for a variety of invertebrate species. In addition, certain algal species may be an essential source of food for invertebrates. To test the hypothesis that the presence of understory kelp species (Laminariales) alters invertebrate species abundances, a large scale manipulation study was conducted near Auke Bay, Alaska. In June 2004, study areas were selected and manipulations were performed in order to create two replicate kelp (600 m2) and control (600 m2) plots. In July and August 2004, visual quadrat surveys were performed to quantify, as well as algal composition and density at each site. Microinvertebrates were quantified using light traps deployed one meter from the surface and one meter from the substratum (surface and bottom locations), in both kelp and cleared sites, to test for the effects of location in the water column and presence of algal structure on microinvertebrate abundance. Visual quadrat data revealed that there were significantly greater abundances of combined shrimp species and Pycnopodia helianthoides in plots where understory kelps were present. In contrast, the abundance of combined snail species were greater in cleared plots. Light trap results indicated that species abundance of shrimps, cumaceans, amphipods, and snails were significantly greater in light traps located at the bottom of plots where understory kelps were present. These results indicate that the presence of understory kelps does alter invertebrate species abundance. The removal of these kelps may have profound effects on the ecological interactions present in kelp beds.

DETERMINING GROWTH POTENTIAL UTILIZING HORMONE LEVELS IN THE DEEP SEA CRAB, MACROREGONIA MACROCHIRA

Matt Richards1, Sherry Tamone2 and Thomas Shirley3

1 Department of Biology, Western Washington University, Bellingham, WA,
2 REU Mentor: Department of Biology, University of Alaska Southeast, Juneau, AK
3 School of Fisheries & Ocean Sciences University of Alaska Fairbanks

ABSTRACT
Macroregonia macrochira is a deep sea spider crab, which ranges from 900 to 3000 meters in depth. M. macrochira is a majid crab related to the commercially important Tanner and snow crabs. To gain a better understanding of the biology of deep-sea spider crab, morphometric measurements and hemolymph samples were required. The crabs were collected from depths of 900 to 3000 meters using crab traps. The traps were sent down in the Gulf of Alaska located over several seamounts. Measurements included shell length, width and chelae height. These measurements showed morphometrically mature males did not share the allometric growth changes associated with functional maturity as do the Tanner and snow crab. Functionally mature males had a longer chelae length compared to the immature male. The chelae length in mature males equaled the length of their first pair of walking appendages. 3ml of hemolymph was withdrawn from each crab. The hemolymph was analyzed by an enzyme-linked immunosorbent assay (ELISA). The ELISA specifically measured ecdysone (molting hormone) levels in order to determine growth potential. Elevated levels of ecdysteroid are good indicators of growth whereas low ecdyteroid levels can indicate a terminal molt. Ecdysone levels showed similar patterns compared to Tanner and snow crab. M. macrochira ecdysteroid levels were ten times higher in when compared to other majid crabs.

DETERMINING DIET AND FORAGING BEHAVIORS OF RINGED SEALS IN THE BEAUFORT SEA

Stephanie Sell, UAS REU Program Summer 2004
REU Mentor: Dr. Brendan Kelly, University of Alaska Southeast

ABSTRACT
We analyzed the feasibility of using an underwater camera system along with scat samples to determine the diet and foraging behavior of ringed seals under the shore-fast ice of the Beaufort Sea. In a pilot study, we attached an underwater digital video recorder (CRITTERCAM) to an adult female ringed seal. Scat samples were collected from that seal and two others. The camera recorded continuously for 2h directly after deployment. Underwater behaviors recorded by video were categorized and quantified. Distinguishable prey items in scat samples were identified to the lowest taxonomic level. Most (61%) of the seal’s time was spent resting in one of approximately 9 breathing holes she used during the 2h recording period. The video record also included prey capture and other non-foraging behaviors. Prey identified in the scat samples mainly consisted of isopods (Saduria entomon, S.sabini), gammariid amphipods, and Arctic cod (Arctogadus glacialis). Underwater camera systems and scat analysis can extend our knowledge of ringed seal diet and foraging behaviors. We recommend programming the video recorder to sample for 12 minutes per hour (3min every 15min) and only when submerged below the ice to extend the record of foraging behavior.

HEAT SHOCK PROTEIN EXPRESSION IN ADULT ZEBRAFISH AFTER EXPOSURE TO OIL

Matthew Siegle, UAS REU Program Summer 2004
REU Mentor: Dr. Sherry Tamone, University of Alaska Southeast

ABSTRACT
Oil contains many different polycyclic aromatic hydrocarbons (PAHs), which are known to cause detrimental developmental abnormalities including cardiac dysfunction, edema, spinal curvature and reductions in craniofacial structures. In addition, PAHs have been shown to persist in near-shore sediment for a decade after an oil spill. This long-term exposure to sub-lethal PAH concentration influences population recruitment and multigenerational fitness, thus representing an important yet ambiguous part of the total impact of oil spills on biota. In environmental monitoring, the use of a biomarker is a very powerful tool. By using a physical, quantifiable characteristic of an organism, which is representative of physiological stress, one could look to that characteristic and, if physiological stress is observed, infer the existence of a harmful environmental “stressor”. This study is aimed at characterizing hsp 70 (a heat shock protein known to be up regulated in vertebrate cells upon physiological perturbation) in zebrafish after they have been exposed to sub-lethal concentrations of crude oil. Hsp 70 concentration will be quantified in zebrafish gill and viscera tissues over a 32 h sampling period. Sampling will be done after 0, 1, 2, 4, 8, 16, and 32 h of exposure to the sub-lethal oil concentration. To date, I have been trouble shooting the western blot analysis (protein analysis technique). KODAK image analysis will be used to quantify hsp 70 concentrations in the respective tissues.

CIRCULATING ECDYSTEROIDS IN MATURE AND
IMMATURE SNOW CRABS (CHIONOECETES OPILIO)

Timothy Baldwin, UAS, REU Summer Program 2003
North Carolina State University

ABSTRACT
Immature and mature male snow crabs were studied to compare the difference in circulating ecdysteroid concentrations (molting hormone). Crabs were collected from the Bering Sea and maintained at University of Alaska Southeast. Each crab’s carapace width and cheliped height were measured and recorded. The crab was tagged and a hemolymph sample withdrawn then returned to its tank. Molt stage for juvenile male snow crabs were determined by setogenesis. The exopodite of the second maxilliped was removed and examined for cuticular changes. Ecdysteroid concentrations were measured using an established ELISA (Enzyme Linked Immunosorbent Assay. The sample was first extracted in 75% methanol, and then assayed using an Elisa to determine the molting hormone concentration. Molt stages were related to ecdysteroid concentration. It was found that the ecdysteroid concentration of immature males was significantly higher than that of mature snow crabs (p= 0.004). Ecdysteroid concentration in immature crabs was 5.74 ng/ml while the concentration in mature crabs was 1.85 ng/ml. All the juvenile crabs were found either to be in the premolt or intermolt stage. Ecdysteroid concentrations of premolt crab were not significantly different from ecdysteroid concentrations in the intermolt stage. Immature crabs were in the early part of the premolt molt stage, so that there is not a considerable difference in hormone levels between the two molt stages.

Predicting Lair Abandonment by Ringed Seals
Based on Physical Properties of the Snowpack

J.E. Conway
Davidson College and UAS, REU Summer Program 2003

ABSTRACT
Poster Presented at the Institute of Arctic and Alpine Research (INSTAAR), 34th Annual International Arctic Workshop, Boulder Colorado, 11-13 March

Ringed seal (Phoca hispida) populations may be responding to habitat changes associated with industrial activity and climate change in the arctic. Population assessment, however, has relied on visual surveys of the extensive sea ice habitat, and interpretation of those surveys has proven difficult. Throughout most of the year, ringed seals are not visible because they are feeding underwater or resting in lairs excavated in the snow covering the ice. They are visible on the surface only in the window between the onset of snowmelt, when lairs are abandoned, in late spring and ice breakup in summer. Surveys are meant to take place during that window, but the relationship between the onset of snowmelt and the timing of lair abandonment is not well understood. We used radio-telemetry to determine when 16 seals abandoned their lairs and compared the timing of lair abandonment with changes in cold content of the local snowpack. Snowpack cold content is the amount of energy required to raise the average temperature of a snowpack to its melting point (0º C). Thus, cold content integrates average density, average temperature, and depth of the snowpack—all of which are directly related to the structural integrity of the snowpack. Our findings suggest that cold content is an accurate gauge of the structural integrity of ringed seal lairs. Cold content also was strongly correlated with snow temperature at the ice surface and that parameter may prove to be a more convenient predictor of lair abandonment. Predicting the timing of lair abandonment will allow for more accurate aerial surveys of ringed seal populations.

INFLUENCE OF PREDATION ON
HABITAT SELECTION BY RINGED SEALS

Kyndall B.P. Hildebrandt and Brendan P. Kelly

ABSTRACT
Ringed seals create breathing holes each fall, when the ice begins to solidify, and maintain those holes through the winter by scratching at the ice with their claws. Where enough snow accumulates over a breathing hole, seals often excavate a snow cave above the hole. In the winter, seals rest and give birth on the ice, protected from the cold and predators by the snow cover. In the spring and early summer, seals resting on the ice are no longer under the protective snow cover. Basking in the sun allows seals to elevate their skin temperature and regenerate epidermal cells. Not being concealed under snow, however, makes them vulnerable to surface predators. Basking ringed seals alternate between lying flat and raising their heads to scan for predators. We hypothesized that ringed seals would select basking sites where snow depth does not inhibit their ability to see predators. We further hypothesized that breathing holes that had lairs associated with them would be surrounded by deeper snow and be less suitable for basking seals. From 1998 - 2003, dogs were used to locate lairs, breathing holes, and basking sites off the shore of Prudhoe Bay, Alaska. Snow depths at the seal holes were recorded using a snow probe. Snow depth remained constant over six years, and snow depth was deeper at lairs than at breathing holes. Seals basked at areas of lower snow depth and more often at breathing holes than at lairs. Thus, ringed seals selected basking sites that enhanced vigilance.

ARE DECLINES IN HARBOR SEAL NUMBERS NEAR SPIDER ISLAND IN GLACIER BAY RELATED TO HUMAN DISTURBANCE?

Kate Kanouse and Elizabeth A. Mathews

ABSTRACT
The number of harbor seals (Phoca vitulina) in Glacier Bay National Park have declined by 64-75% since 1992. Counts indicate that the population was relatively stable from 1992 to 1996 with declines most evident after 1996. In 11 of the summers from 1991 to 2003, counts and behavioral observations, including disturbances by potential marine mammal predators (killer whales and Steller sea lions) of harbor seals and by vessels (primarily kayakers) have been made near Spider Island, the largest terrestrial haulout in Glacier Bay. Two of several hypothesized causes of the declines are increased human disturbances and increased predation. We conducted an initial test of these hypotheses by comparing disturbance rates (number/observation hour) during the period of time before the decline (1991-1996) to those from after the decline became pronounced (1997-2003). We used Fisher’s Exact tests to compare human-caused and predator-caused disturbances from the two time periods. Human disturbances were significantly lower in the 1997-2003 period compared to the earlier, non-decline period (16/83 hrs vs. 23/234 hrs; p = 0.3), suggesting that disturbances by humans are not a key factor in the declines at this site. In contrast, we found a non-significant increase (0/83 hrs vs. 7/234 hrs; p = 0.11) in disturbances by predators. Although the predator disturbance rate was not statistically significant, the increase may be biologically meaningful. We conclude that predation is a more likely factor than human disturbance in the decline in harbor seals, but further studies are needed to verify if predation may have increased mortality.

EFFECTS OF DENSITY ON MOVEMENT OF THE GIANT RED SEA CUCUMBER

Steve McMurray, UAS, REU Summer Program 2003
Hiram College

ABSTRACT
The Alaskan sea cucumber fishery was established in 1987 to meet an increased demand by Asian markets for the dried product beche-de-mer after the collapse of traditional Indo-Pacific fisheries. The target of this fishery, the giant red sea cucumber, Parastichopus californicus, is found off the west coast of North America from Baja California to the Gulf of Alaska. This fishery is currently managed via a surplus production model developed by the Alaskan Department of Fish and Game in 1990. However, managers have little information on the biology of P. californicus for making sound fishery decisions. Even basic knowledge about the movement patterns of this holothurian is lacking. This study determined how population density affects the rate of movement of P. californicus. In 10 x 10 m plots at two sites in Southeast Alaska, densities of P. californicus were manipulated by divers using SCUBA. Movement rates of P. californicus within these plots were then measured every twenty-four hours over the course of three, five day trials. We found no significant effect of density on movement rate. The limited results of this study indicate that cucumbers are not likely to migrate from more dense areas to less dense or cleared areas after fishing has occurred. Further studies are needed to provide information necessary to ensure a sustainable P. californicus fishery.

Bull Kelp, Nereocystis leutkeana, as recruitment habitat
for juvenile fishes and invertebrates in southeast Alaska,
determined by use of light traps

Erin Meyer, UAS, REU Summer Program 2003
Cook College, Rutgers

ABSTRACT
Canopy forming kelp, such as Macrocystis pyrifera and Nereocystis leutkeana, are becoming increasingly recognized as important habitat for both fishes and invertebrates. Off the coast of Juneau, Alaska, N. leutkeana is the dominating canopy forming kelp, and few studies have been conducted exploring its role as a habitat. This study used light traps to capture juvenile fishes and invertebrates from four sites within the Saginaw Channel. Two sites were cleared of N. leutkeana in order to isolate the role of canopy kelp from other biological factors, and two sites were unaltered. Two mooring lines were set up at each of the four sites, and two traps were attached to each of the mooring lines, one meter above the substrate and one meter below the surface. The light traps were deployed for 24 hours. A total of five trials were completed between July 8 and August 18, 2003. The mean invertebrate counts for the bottom light traps for the canopy present and canopy cleared sites are significantly different to one standard deviation. The mean invertebrate counts for the surface light traps for the canopy present and canopy cleared sites are not significantly different. The mean invertebrate counts for the bottom light traps were 100 times greater than for the surface light traps. No significant differences between the fish counts were found. Since only five trials were completed in this study, more trials and sampling methods need to be used in order to determine the importance of N. leutkeana as habitat for fishes and invertebrates.

PHYSICAL DISINTEGRATION OF FECAL PELLETS
OF THE RED SEA CUCUMBER
(PARASTICHOPUS CALIFORNICUS)
AT DIFFERENT CURRENT VELOCITIES

Kevin Turner, UAS, REU Summer Program 2003

ABSTRACT
Fecal pellets of the giant red sea cucumber disintegrate rapidly under field conditions, but deteriorate more slowly when exposed to minimal or no current in laboratory conditions. Fecal pellets were monitored in the field at Amalga Harbor, and in lab in two different flow tanks set at a control speed of no current and at a “maximum” speed of 11.8 ± 0.7 (x ± s.d.) cm/sec, separately. Pellets in the control treatment first showed complete disintegration after 9 days, and several were still intact when the trial ended after 13 days. The max speed treatment had some pellets reaching complete disintegration beginning at 4 days, but the majority were still intact when the trial ended after 5 days. Pellets in the field completely disappeared after 2.4 ± 0.5 days (x ± s.d., n=7). Under the current forces experienced at Amalga Harbor, sea cucumber pellets are no longer visible after more than just a few days. However, at the presumably lower currents experienced in lab in the max and control treatments, disintegration is far slower.

The Effect of Tag Weight on Tanner Crab (Chionoecetes bairdi) Movement: Implications for Sonic Tagging Procedures

Lia Herron, Dr. S. James Taggart, Jennifer Mondragon

ABSTRACT
The USGS Glacier Bay Field Station is tracking sonic tagged Tanner crabs and red king crabs in the East Arm of Glacier Bay National Park. The goal of this research is to estimate the length of time breeding adults spend inside and outside of a marine reserve (transfer rate). Sonic tag weight is assumed to have an insignificant effect on crab movement, but this assumption has not been verified. If sonic tags reduce crab movement, transfer rate could be underestimated. Therefore, it is important to determine the effect of tag weight on crab movement. For this study, two G-Force loggers were used to record three-dimensional acceleration, due to gravity and movement, of adult male Tanner crabs. Lead weights were added to the loggers to simulate sonic tags of varying weights. Changes in crab movement between seven different tag weights (treatments zero through six) were then compared. The crab’s movement in treatment one was similar to its movement in treatment zero—a neutrally buoyant logger used as the control—suggesting that treatment one had little effect on the crab. In contrast, when compared to treatment zero, treatment three and six reduced the crab’s movement. These results demonstrated that heavy tags can affect Tanner crab movement. However, to determine the maximum weight a crab can carry without affecting its movement, treatments will need to be conducted on a finer scale.