EEB Seminar: December 5th 2013

Fish research at Husky Lakes, NWT

Nikolaus Gantner will talk on

CSI Husky Lakes: Fractionation of mercury isotopes in water, sediments, and fish from the Husky Lakes, Northwest Territories, Canada

at 12:30 in the EEB lounge (BioSciences 4338)

Mercury can accumulate in apex-predator fish muscle to concentrations exceeding those considered safe for subsistence consumption by humans. Fish species such as Lake trout are typical apex-predators of Arctic lakes and can be a significant source of food for local indigenous peoples. The influence of abiotic factors and biological parameters on Hg accumulation in apex-predators are not well understood. Further, a good understanding of sources of Hg to and processes within water column and food webs is still lacking. Our study aims to investigate the interactions of water column, food webs and Hg transfer in aquatic systems in the Inuvialuit Settlement Region (Canada). The selected Husky Lakes, Yaya, and Noell Lake ecosystems represent a range of water column and ecological characteristics, as well as Hg delivery (marine-, riverine- or freshwater-derived). We investigate how those characteristics affect Hg transfer and fractionation. All lakes are frequented by the Inuvialuit communities Inuvik and Tuktoyaktuk for subsistence fishing. Sampling includes surface water, benthic and pelagic invertebrates, tissues from harvested fishes, and non-target fishes. Biological parameters of fishes (age, length, weight, diet) are recorded and invertebrates separated by species. Sample analysis includes total Hg (THg), monomethylHg (MeHg), and stable isotopes of carbon (δ13C), nitrogen (δ15N), and Hg (δxHg) and otolith microchemistry. Hg IRs are analyzed by multi-collector inductively coupled plasma mass spectrometry (MC-ICP/MS). Hg mass independent fractionation (MIF; Δ199Hg) and mass dependent fractionation (MDF; δ202Hg) was calculated and evaluated against conditions in the water column, food web transfer and the potentially difference in Hg delivery. We demonstrate that MIF varies in Lake Trout from different lakes up to ~2‰; We will present new results from this multidisciplinary study and discuss our preliminary findings with particular focus on implications for future research efforts in a changing Arctic environment.

Nikolaus and pike

Nikolaus is the founder/owner of Gantner Consulting Services and is affiliated with the Dept of Chemistry at Trent University. He holds an MSc in Zoology from the University of Innsbruck (Austria), a PhD in Environmental Biology and Toxicology from the University of Guelph, and then completed an NSERC Visiting Fellowship in Government Laboratories with Environment Canada at the Water and Climate Impacts Research Centre (Victoria, BC).

Everyone is welcome to attend
Coffee and cookies right after the seminar

EEB Seminar: November 28th 2013

Dianthus carthusianorum (sheep food)

Yessica Rico will give a talk entitled

Does traditional management by rotational shepherding supports landscape connectivity in fragmented calcareous grassland plants?

at 12:30 in the EEB Lounge

Understanding the mechanisms and patterns of dispersal and gene flow in human-modified landscapes is crucial for effective conservation. In plants, seed dispersal is fundamental for recolonization and recruitment, whereas pollen flow and seed dispersal support gene flow. Calcareous grasslands are one of the most species-rich habitats in Central Europe, but abandonment of traditional management since the 20th Century has caused a dramatic decline of calcareous grassland species. In the Southern Franconian Alb in Germany, the establishment of a landscape management project since 1989 by reintroduction of rotational shepherding in previously abandoned calcareous grasslands showed numerous plant recolonizations, and it has been suggested that sheep acts as the main dispersal vector. To test the effect of rotational shepherding on landscape connectivity, I tested competing models of different assumptions on source patch effects, seed dispersal, and accounting for postdispersal effects. I found that patch colonization rates at the community level (aggregate data for 48 plants) was explained by patch connectivity by rotational shepherding and the diversity of microsite in focal patches related to plant establishment. Landscape connectivity models of individual species showed that even plants without dispersal adaptations to animals responded mainly to connectivity by shepherding. In addition, I investigated the potential effect of shepherding on landscape genetic structure in the calcareous grassland plant Dianthus carthusianorum, whose seeds lack morphological adaptations to dispersal to animals or wind. The genetic data showed a significant pattern of landscape genetic connectivity among grazed patches associated to shepherding routes, while ungrazed patches strongly responded to isolation by geographic distance. Also within individual patches, I found that grazing significantly decreases kinship structure and increases genetic diversity. The ecological and genetic data thus show the potential effect of traditional management by rotational shepherding on landscape connectivity in fragmented calcareous grassland plants.

Yessica Rico

Yessica Rico is currently a Postdoctoral Researcher  at the Natural Resources DNA Profiling and Forensics Centre at Trent University. She did her PhD with Helene Wagner in Ecology and Evolutionary Biology, University of Toronto at Mississauga

Everyone is Welcome to Attend the seminar

Coffee and Cookies right after the talk

EEB Seminar: November 21st 2013

Mesocosm City

James Sinclair will speak on

Ecological surprises’ in a bottom-up/top-down stressor interaction

at 12:30 in the EEB lounge (BioSciences, 4th floor)

Interactions between multiple anthropogenic stressors can have unexpected synergistic or antagonistic effects, making it difficult to predict their combined effect using single stressor studies. The bottom-up/top-down interaction between invasive consumers and nutrient enrichment is particularly important as both of these stressors frequently co-occur, and their multi-trophic impacts can be severely damaging to affected communities.

We conducted a field mesocosm experiment that crossed an increasing nutrient addition gradient against an increasing zebra mussel invasion gradient. Native zooplankton communities were added to the mesocosms, and after three months we examined how the single stressor effects on available resources and the zooplankton community were altered by their multiple stressor interaction. Added nutrients had no effect on primary producer abundance, but increased the abundance and dominance of the top consumer, which likely increased predation pressure on the producers and so prevented their response to increased nutrients.

Zebra mussels reduced large phytoplankton abundance by ~75%, rotifer abundance by ~80%, and shifted community composition towards larger consumer species. When combined, the top-down control exerted by the mussels interacted antagonistically to prevent any bottom-up influence of nutrient enrichment on the zooplankton community. These results provide insight into the potential outcomes of bottom-up/top-down stressor interactions, and illustrate the need for researchers to consider single stressor problems in a multiple stressor context.

James showing off his mussels

James is just finishing up his MSc in Shelley Arnott’s lab. Immediately following the seminar he will be defending his thesis and then, he hopes, will begin a PhD in Shelley’s lab, committing himself to endless servitude in the pursuit of more mussels. Unfortunately James goes immediately into his defence at 1:30 on Thursday so will not be able to hang around and receive your questions and accolades but don’t let that stop you from enjoying coffee and cookies after the seminar.

 

Everyone is welcome to attend

Coffee and cookies right after the seminar

 

Departmental Seminar: November 15th 2013

Ehab and ant

Dr. Aheb Abouheif will speak on

The Evo Devo of Cooperation and Conflict in Ant Societies

at 10:30 AM in BioSciences Room 3110

This week, Dr. Ehab Abouheif visits from McGill University where he is an Associate Professor and Canada Research Chair in Evolutionary Developmental Biology (Evo Devo). Dr. Abouheif’s research mission has been to understand how genes and environment interact to guide development, and in turn how these interactions have evolved to generate diversity both between and within species. Polyphenism – the capacity of the same genotype to generate discrete phenotypes – in the ants is dramatic, with comprehensive differences in behaviour, life history and morphology between castes. The Abouheif lab works on gene networks associated with development and caste-differentiation in ants, and on the evolution of eusocial behaviour in the ants more broadly. His research is part of the new wave in Biology, breaking down traditional boundaries between disciplines — development, molecular biology, evolution and ecology — with modern tools.

Note: This is the second talk in Dr. Abouheif’s visit.  See post below for more details.

EEB Seminar: November 14th 2013

The different morphologies of queen and worker ants are the result of environmentally induced differences in gene expression during their development.

Ehab Abouheif will talk on

What have Evo Devo and supersoldier ants taught us about how evolution works?

at 12:30 in Medical School Atrium room 132  [note venue as we needed space for the BIOL-440 class as well]

Abouheif is Associate Professor and Canada Research Chair in Evolutionary Developmental Biology at McGill where he studies the eco-evo-devo biology of ants.

Ehab’s research mission has been to understand how genes and environment  interact to guide development, and in turn how these interactions have evolved to generate diversity both between and within species. Polyphenism – the capacity of the same genotype to generate discrete phenotypes – in the ants is especially dramatic, with comprehensive differences in behaviour, life history and morphology between castes. The Abouheif lab has not only been at the fore in mapping out the gene networks associated with development and caste-differentiation in ants, but does incredibly cool manipulative experiments with environmental induction. In the first of two lectures this week (Thursday’s EEB and Friday’s Departmental), Ehab will explain how his lab has developmentally resurrected super soldiers in species that normally don’t have these sumo-sized fighting machines for colony defence, among other things.

Ehab’s second talk “The Evo Devo of Conflict and Cooperation in Ant Societies” will be on Friday at 10:30AM in BioSci 3110. He would also love to tell anyone interested about his ventures into understanding the Evo Devo of sexual conflict in water striders.

Abouheif and some ants

His lab website is here and some of his recent papers are:

  • Shbailat SJ, Abouheif E. 2013. The wing-patterning network in the wingless castes of Myrmicine and Formicine ant species is a mix of evolutionarily labile and non- labile genes. J. Exp. Zool. (Mol. Dev. Evol.) 320B:74-83.
  • Abouheif E. 2013. Evolution: oskar reveals missing link in co-optive evolution. Current Biology 23 (1): R24-R25.
  • Khila A, Abouheif E, and Rowe L. 2012. Function, developmental genetics, and fitness consequences of a sexually antagonistic trait. Science 336: 585-589
  • Rajendhran Rajakumar, Diego San Mauro, Michiel B. Dijkstra, Ming H. Huang, Diana E. Wheeler, Francois Hiou-Tim, Abderrahman Khila, Michael Cournoyea, Ehab Abouheif. 2012. Ancestral Developmental Potential Facilitates Parallel Evolution in Ants. Science 335 (6064): 79-82.

Please contact Adam Chippindale if you are interested in talking with Dr Abouheif during his visit.

Everyone is welcome to attend the seminar

EEB Seminar: November 7th 2013

King of Holland Bird of Paradise, first described in 1875 and painted here by John Gould in the late 1800. This ‘species’ is a hybrid between the Magnificent Bird of Paradise and the King Bird of Paradise.

Paul Martin will talk on

The Paradox of the Birds-of-Paradise: persistent hybridization as a signature of historical reinforcement

12:30 in the EEB Lounge

Paul is an Associate Professor in the Dept of Biology at Queen’s.

Birds of Paradise are way cool. And Paul’s going to tell us why. These birds are native to Australia and New Guinea. There are about 40 species in the family and they are among the most colourful and ornamented birds on the planet. Bright colours and bizarre plumage are often thought to be the signatures of speciation that help to keep closely related species from hybridising but the Birds of Paradise appear to hybridise much more than most birds.

Paul’s lab website is here and some of his recent papers are:

  • Eikenaar, C., F. Bonier, P.R. Martin and I.T. Moore. 2013 High rates of extra-pair paternity in two equatorial populations of Rufous-collared Sparrow, Zonotrichia capensis. Journal of Avian Biology DOI: 10.1111/j.1600-048X.2013.00212.x.
  • Paul in the field (though he does wear the hat indoors, too)

    Rohwer, V.G., F. Bonier, and P.R. Martin. 2012. Juvenal plumage polymorphism in Yellow Warblers is not associated with sex. Condor 114:407-411. PDF

  • Moore, S.D. and V.G. Rohwer. 2012. The function of adult female begging during incubation in sub-arctic breeding Yellow Warblers. Animal Behaviour 84:1213-1219. PDF  [Drew Moore‘s honours thesis project in our lab]
  • Danner, J.E., R.M. Danner, F. Bonier, P.R. Martin, T.W. Small and I.T. Moore. 2011. Female, but not male, tropical sparrows respond more strongly to the local song dialect: implications for population divergence. American Naturalist 178:53-63. PDF  Featured in The New York Times, online and print (July 5, 2011, pg D3).
  • Crossman, C.A., V.G. Rohwer and P.R. Martin. 2011. Variation in the structure of bird nests between northern Manitoba and southeastern Ontario. PLoS ONE 6(4): e19086. doi:10.1371/journal.pone.0019086. LINK  [Carla Crossman‘s honours thesis project in our lab]

Everyone is welcome to attend the seminar

Coffee and cookies right after the seminar

EEB seminars

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