Pamela Moriarty

Food webs are pervasive throughout ecological research. Quantifying interactions in food webs has become increasingly important, as we seek a stronger understanding of many ecological processes. However, we often lack the quality information we need to quantify interactions within food webs.

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I'm broadly interested in improving existing and developing new methodology to quantify predator-prey interactions. By increasing how much information we can extract from data sources and improving the accuracy of that information we can improve our ability to quantify interactions.

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Statistical Approaches

I developed a mixture model to quantitatively estimate prey contributions to a predators diet using stomach content data. Stomach content data is common in aquatic and terrestrial ecology, but is challenging to analyze.My model accounts for covariance between consumption amount and prey type and extreme consumption by a few predators. It also provides a likelihood framework for the diet estimates, which allows for model selection and further analyses.

 

Analytical Approaches

As the use of stable isotope analysis (SIA) has grown, it has increasingly been applied for taxonomic groups outside of those it was developed in. In these cases, the necessary taxon-specific knowledge to accurately apply SIA is often unknown. I'm working to determine the effect of alternative methodological assumptions on the results and conclusions from SIA data. Due to the quickly increasing numbers of studies applying SIA to jellyfish (Cnidaria), I'm focused on this taxnomic group. This information will allow me to provide a framework for the analysis and interpretation of SIA when applied to jellyfish.

 

Ecological Applications

As part of a larger, collaborative project, I'm investigating the effect of hypoxia on energy flow from zooplankton to planktivorous fish. This is a critical link in many pelagic food webs and by using Hood Canal, WA as a model system, I'm aiming to quantify ecological changes that occur with the development of hypoxia that lead to a change in energy flow by combining information from fish trawls, zooplankton tows and acoustic surveys.

 

Post-smolt Atlantic salmon Migration Mechanisms

At the Gulf of Maine Research Institute, I modeled Atlantic salmon migration pathways through the Gulf of Maine.  The time they spend in the Gulf of Maine as post-smolt is thought to involve high mortality rates, creating a bottleneck for population recovery efforts.  However, little is known about the paths they take through this region.  My research investigated possible migration mechanisms that the salmon may use and the effects of environmental variability.

 

Jellyfish Movements Using Acoustic Telemetry

I worked with NOAA researchers to tag and track lion’s mane and fried-egg jellyfish in Hood Canal, Washington using acoustic telemetry.  We found high individual variation in vertical movements, with three different types of behavior apparent.  Estimated horizontal movement rates indicated that jellyfish actively swim, rather than simply passively drifting.

 

Other Research

Other prior research includes investigating the tropical conservatism hypothesis as an explanation for the latitudinal gradient in species richness, modeling the impacts of climate change on the bioenergetics of bald eagles, and studying the ecosystem function of restored wetlands.  Take a look at my CV for more information or send me an email!