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Carolyn Bergstrom

How does natural selection maintain phenotypic variation within marine species?  What role do ecological interactions like predation and competition play?  My research interests are broadly concerned with these questions.  More specifically, I investigate (1) how ecological interactions in the ocean orchestrate relationships between form, function, and fitness, (2) the ecofunctional implications of bilateral asymmetries, and (3) the interaction between phenotypic plasticity and heritable variation.   I explore these topics with a variety of techniques, including morphometrics and behavioral observations, field experiments, multivariate statistics, stable isotope analyses, and experimental assessment of fitness.  I currently have two main research projects underway. The first of these is the evolution of body asymmetry in flatfish. Flatfish exhibit remarkably derived body morphology.  They undergo metamorphosis as pelagic larvae, where one eye migrates over the dorsal midline so that both eyes are on the same side of the head.  The fish then lie on the ocean floor, eyed-side facing up.  While the vast majority of the 715 flatfish species contain all left-eyed or all right-eyed individuals, 7 species contain both morphs. To date, we don't have a good understanding of the evolutionary trajectory flatfish took to become asymmetric, or the significance of asymmetry direction.  One polymorphic species, the starry flounder, exhibits a cline in the north Pacific in the relative frequency of left- vs. right-eyed individuals, and the two morphs show evidence of ecological segregation. It is one of the first demonstrations of the ecological significance of polymorphism in a marine species, and contributes to our understanding how asymmetry evolved across the flatfish order.

 My second current research project involves how selective predation maintains variation in body color and color plasticity of sculpins.  Sculpins exhibit tremendous variation in their body coloration and their ability to change color both among and within populations.  Collaborators (David Tallmon, Andrew Whiteley, Tyler Linderoth) and I are currently investigating the role selective predation plays in molding the expression of color and color plasticity in these fish. This could have important implications to our understanding of color variation and ecological selection in other cryptic marine fish species such as juvenile flatfishes and gunnels.

Michael Stekoll

The biological communities along most of the rocky shores of Alaska are defined by the marine plant associations. A major portion of the primary production throughout the year is provided by the benthic plants in the nearshore. These communities are often disturbed not only by natural phenomena, such as winter storms and ice, but also by anthropogenic disturbances such as harvesting and pollution. My research has concentrated in both basic and applied aspects of the biology and ecology of marine benthic plants and on the effects of disturbances on this community. My associates and I have investigated the effects of harvest and pollution on the intertidal and subtidal seaweeds.  We have also developed techniques fore using remote sensing to map floating kelp beds in SE Alaska. We have conducted applied research on the commercial exploitation of seaweeds. In addition to performing seaweed resource assessments for potential commercial harvest, we have investigated the potential of mariculture as a means to enhance exploited algal resources. There are many organisms that can be cultured which have potential to be developed as a high value product. Among these are seaweeds such as Macrocystis (giant kelp), Nereocystis (bull kelp) and Porphyra (nori).  My lab has worked out the procedures for the successful mariculture of Macrocystis.  We have researched the physiological ecology of Porphyra as it relates to its culture. This plant can be marketed both as nori for the sushi and health food market and as black seaweed for the Native community.  Our latest project is investigating nitrogen partitioning in the red alga Palmaria, a potential feed for abalone culture, throughout its growing season. I am also involved in kelp ecology and mariculture studies in South Africa in cooperation with colleagues at the University of Cape Town and Marine and Coastal Management. Other "non seaweed" projects have involved the effects of pollution on salmon and herring. We completed research on the potential impacts of mining activities on the nearshore benthos, and have investigated the effects of common ions (hard water) from mine wastewater on the growth and development of coho salmon. Another project has been research on delayed effects of oil exposure on zebra fish as a model for salmonid exposure. 

Dave Tallmon

My general interests are in evolution, ecology, and conservation biology.  My focus is on understanding the evolutionary and ecological dynamics of natural populations using demographic and genetic models, molecular genetic data, and field data.  I have long-standing interest in combining population genomics and demographic information to infer important evolutionary and demographic parameters for wild populations.  More recently, my post-docs and I have focused upon the role of phenotypic plasticity in adaptation. I have used models based on likelihood and approximate Bayesian computation to infer demographic vital rates or effective population size with the goal of providing useful results and tools for conservation and evolutionary biology.  As an example, some collaborators and I have recently developed an approach to infer effective size of a population using a single sample of microsatellite data and approximate Bayesian computation.  To use this application, visit http://genomics.jun.alaska.edu/We focus on a number of different taxa in my lab, with current work on a handful of terrestrial and marine vertebrates and invertebrates, including: coastrange sculpins, giant Pacific octopus, red king crab, spruce grouse, file dogwinkles, ringed seals and boreal toads.  I enjoy working with students who are highly-motivated, broadly interested in evolution and conservation, and focused on understanding population-level process using descriptive and manipulative approaches.  Prospective grad students should read more here.

Sherry Tamone

My studies are concerned with the role of hormones in regulating physiological processes in decapod Crustacea (crabs and lobsters). Hormones are chemical mediators that regulate physiological processes such as growth, reproduction, and osmoregulation. I am interested in the mechanism by which hormones such as ecdysteroids, methyl farnesoate, and molt-inhibiting hormone regulate growth and reproduction in decapod crustaceans. The majority of crustaceans that I study are commercially important crabs. These include Dungeness crab, Cancer magister, snow crab, Chionoecetes opilio, and king crab, Paralithodes camtschaticus.Ecdysteroids are crustacean hormones that function to regulate the molt cycle and therefore the growth of these animals. Methyl farnesoate is a sesquiterpenoid hormone derived from the mandibular organ that functions in both reproduction and growth. Methyl farnesoate also may be critical during crustacean larval development and morphogenesis. Methyl farnesoate is structurally similar to the insect juvenile hormones, which regulate insect development.Other studies related to crustacean physiology involve the effect of endogenous crustacean hormones on ectoparasites. Specifically, I have an interest in how hormones (ecdysteroids, methyl farnesoate) can be exploited by certain parasites. The model for these studies is the infection of the Dungeness crab, Cancer magister by the nemertean worm, Carcinonemertes errans.

 
 

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