Graduate Research

Students earn the Master of Science in Environmental Sciences degree and may work on Marine Biology projects that are part of the Alaska Octopus Project.

 
 
 







 
Neal Smith, MS Environmental Sciences, Alaska Pacific University. c D Scheel
Smith, N. 2012 expected.  The effects of seabed slope and other environmental variables on the movement patterns of giant Pacific octopuses (Enteroctopus dofleini).  Thesis for Masters of Science in Environmental Sciences, Alaska Pacific University, Anchorage.
[Finished thesis, pdf]








R Toussaint MS Environmental Sciences, Alaska Pacific University. c D Scheel
Toussaint, R.  2012 expected.  Genetic anlaysis of Giant Pacific Octopuses in south-central and Dutch Harbor AK .  Thesis for Masters of Science in Environmental Sciences, Alaska Pacific University, Anchorage.

R.K. Toussaint, G.K. Sage, S.L. Talbot, and D. Scheel.  2012.  Microsatellite Marker Isolation and Development for the Giant Pacific Octopus (Enteroctopus dofleini). Conservation Genetics Resources 4(3): 545-548.  DOI 10.1007/s12686-011-9588-z
Abstract We isolated and developed 18 novel microsatellite markers for the giant Pacific octopus (Enteroctopus dofleini) and examined them for 31 individuals from Prince William Sound (PWS), Alaska. These loci displayed moderate levels of allelic diversity (averaging 11 alleles per locus) and heterozygosity (averaging 65%). Seven loci deviated from Hardy Weinberg Equilibrium (HWE) due to heterozygote deficiency for the PWS population, although deviations were not observed for all these loci in other populations, suggesting the PWS population is not in mutation-drift equilibrium. These novel microsatellite loci yielded sufficient genetic diversity for potential use in population genetics, individual identification, and parentage  studies.

Toussaint, R K, D Scheel, G K Sage, S L Talbot.  2012 in press.  Nuclear and mitochondrial markers reveal evidence for genetically segregated cryptic speciation in giant Pacific octopuses from Prince William Sound, Alaska.  Conservation Genetics.



L Bisson MS Environmental Sciences Alaska Pacific University. c D Scheel
Bisson, L.  2011.  The effects of environmental variables on Giant Pacific Octopuses.  Thesis for Masters of Science in Environmental Sciences, Alaska Pacific University, Anchorage.
Scheel, D., Bisson, L. 2012. Movement patterns of giant Pacific octopuses, Enteroctopus dofleini (Wülker, 1910) Journal of Experimental Marine Biology and Ecology 416–417:21–31. DOI 10.1016/j.jembe.2012.02.004. (Abstract) | (Request pdf) | (Author accepted ms) | (BBC Nature: In pictures) |
Abstract  We attached sonic transmitters to, and tracked, 40 giant Pacific octopuses (Enteroctopus dofleini) ranging from <1 kg to 21 kg in size in south-central Alaska using near-continuous tracking by fixed-array receivers and intermittent tracking with a mobile receiver. We documented area use, daily activity patterns, spatial scale of movements and whether these differ by octopus size, and whether octopuses actively select habitats. Near-continuous fixed tracking provided positions about every 4 minutes over a limited area; while intermittent mobile tracking provided positions every 1-6 h but over open and larger areas. Mantle-mounted transmitters on modified Peterson disks had >83% retention to the end of a tracking period (range <1 d [before animal left the study area] to at least 88 days post-release), an improvement over published studies. Octopuses were found to be stationary or hiding 94% of the time.  Otherwise, octopuses were active throughout the day but more so from midnight to 0500. During low tides, movements were restricted for animals in intertidal habitats but not for those deeper.  Maximum movement distance from release was 4.8 km (by a 16.5 kg female).  Minimum convex polygon area use averaged 4,300 m2 for the smallest animals to an average over 50,000 m2 for the largest during 2 to 20 d tracking, substantially larger than previously reported. Larger octopuses moved further and used greater area than smaller animals, but differences between sexes were not significant.  Stationary behavior and periods without detection (rest) by fixed near-continuous tracking were bi-modally distributed, with peaks <3 h duration and >18 to 48 h. Direct movements (indicating relocation or den-switching) were common at night, central-tendency movements (indicating localized area use and return to den) were common at dawn, and stationary behavior was common in daylight, although each pattern occurred at all periods. Central-tendency movements recorded by intermittent tracking were oriented parallel to contours, while movements without central tendency crossed contours, suggesting that animals navigate by contour-following to return to a known den. During a relocation experiment, octopuses released at shallow depths moved deeper and those released deeper moved shallower; both into habitats with greater kelp cover. Although >90% of their time was spent stationary and hiding, Enteroctopus dofleini utilizes information about its environment (contour following), selects habitats (preference for more kelp cover), and occupies large use areas (minimum convex polygons) by making substantial direct movements from previous use areas.


D Pulgretova, MSc Environmental Sciences, Alaska Pacific University. c D Scheel
Pulgretova, D. 2011.  Lower Intertidal Community Structure in Relation to Diet Composition of Enteroctopus Dofleini, on Busby Island in Prince William Sound, Alaska. Thesis for Masters of Science in Environmental Sciences, Alaska Pacific University, Anchorage.













D. LoBaugh. 2008. Octopus suckers as flexible and versatile mechanical actuators. Thesis for Masters of Science in Environmental Sciences, Alaska Pacific University, Anchorage.
 [Unpublished manuscript version.  With D. Scheel, C. Plautz, R. T. Hanlon.  2008.  Octopus suckers as flexible and versatile mechanical actuators.]
Abstract  Octopus arms typically have ca. 200 suckers each, and these suckers are the primary organs that interact with the environment for touch and taste perception as well as mechanical adhesion and manipulation. Each sucker is a complex, self-contained muscular hydrostat, yet little is known about the mechanical capabilities of individual suckers. To begin to understand the flexibility and capabilities of individual suckers, we filmed Octopus bimaculoides (Pickford and McConnaughey 1949) and measured sucker disk deformation during each attachment / detachment sequence. We used a simple metric (i.e., proportional change in sucker face area) to evaluate the idea that suckers act as undifferentiated units at a variety of anatomical positions in the execution of octopus behavior. Proportional increases in sucker disk area during attachment/detachment sequences ranged from single digits to over 60% upon attachment, with an average proportional increase of 37%. In most anatomical positions on the octopus arm (i.e., along the arm, right vs. left arms, etc.) and during various mechanical actions, suckers appeared undifferentiated. There were three exceptions possibly related to the adhesive force needed to retain attachment: (i) individual octopuses were characterized by significantly different degrees of proportional change in sucker face area; (ii) suckers on rear arm pairs 3 and 4 had greater proportional change than those on front arms by a factor of 1.24; and (iii) there was a nonsignificant trend for proportional change in sucker area to negatively correlate with movement. Overall, the suckers of O. bimaculoides appear to exhibit flexible mechanical capabilities; i.e. all suckers appear to have an enormous number of degrees of freedom in performing multiple behaviors, providing evidence for the sophistication and versatile utility of sucker design in octopuses.
Key Words: Octopus bimaculoides, coordination, biomechanics, muscular hydrostat, infundibular disc


C. Lyons, M.Sc. Environmental Sciences, Alaska Pacific University. c D Scheel
Lyons, C. 2006. Community Structuring Impacts of Enteroctopus dofleini in Pince William Sound, Alaska, USA. Thesis for Masters of Science in Environmental Sciences, Alaska Pacific University, Anchorage.
Subpages (2): Danielle Verna Neal Smith
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