Our next guest is Matt Vaughan, a third year PhD student in Integrative Biology working with Prof. Sarah Henkel in the Benthic Ecology Lab. Matt originally hails from Melbourne, Australia and recently joined the ID team as a host. A major theme of his research interest is biological “disturbance and change”, meaning the impact of stressors on organisms and ecosystems.

Matt’s PhD research centers around invertebrate life found on the ocean floor, known to researchers as the “Benthic zone”. He focuses especially on ghost shrimp, a type of crustacean that builds burrows on the ocean floor. In the Pacific Northwest, ghost shrimp have historically inhabited estuaries, the areas where rivers flow into the sea. Within the last decade however, a significant population of ghost shrimp has arisen much farther than expected for the species, more than seven miles off the coast of Oregon and southern Washington. This mysterious colonization could have been spurred by environmental disruptions such as climate change, and the shrimp also represent a significant change in the local ecology of the ocean floor. Firstly, ghost shrimp burrows alter the habitat for preexisting invertebrate species, reducing stability on the seafloor. The large and intricate burrows are often in high densities, and the sand they kick up through their bioturbation can affect the survival and behavior of invertebrates like bivalves. Ghost shrimp burrows also oxygenate the sediment and host vibrant microbial communities, together altering the biogeochemistry of the ocean floor.

Matt studies these ecological dynamics by surveying the ocean floor during boat trips out of Newport. His team samples the bed using box cores to collect, identify and count the invertebrates. Matt then uses computational and statistical analysis to characterize the population structure of these areas, particularly seeking to tease out the differences in species distribution between areas with and without ghost shrimp burrows. Ghost shrimp are also relatively large compared to other invertebrates in the area, so their arrival provides a significant potential food source for larger marine life like sturgeon and even gray whales. In the rest of his PhD, Matt hopes to model this trophic impact in the long term.

To hear more about Matt’s research and how his travels to the Great Barrier Reef and Southeast Asia helped him discover his love for science, tune into KBVR 88.7 tonight at 7pm or listen soon after wherever you get your podcasts.

Trophic ecology studies how energy flows through food webs; basically who is eating whom in an ecosystem. Understanding the structure of feeding relationships among species in a system helps us to understand why populations may fluctuate in terms of abundance or distribution at different times. These dynamics are particularly important to consider in the face of a changing climate as conditions like increasing temperatures make resources less predictable. Our guest this week is Luke Bobay, who is trying to do exactly this for anchovy in the Pacific Ocean off the US West Coast.

Luke, a 3^rd year PhD student in Integrative Biology, is researching the potential influences of climate change on anchovy abundance by studying its ecological effects on their early life stages. Anchovy are forage fish, which means they are eaten (aka foraged upon) by a lot of larger animals such as birds, marine mammals, other predatory fish, and humans. They are also short-lived and therefore we expect their population dynamics to respond pretty quickly to things that are happening in the environment.

For his research, Luke is looking at the larval stage of anchovy. He uses samples and plankton imagery data collected on weeks-long research cruises that Plankton Ecology Lab has conducted during the past six years, as well as samples collected by the National Oceanic and Atmospheric Administration (NOAA) since 1996. The samples that Luke uses are collected using large nets with a very fine mesh that enables the collection of tiny plankton. The imagery data are collected using a sampling technology unique to Luke’s lab called the In Situ Ichthyoplankton Imaging System (ISIIS). ISIIS uses a high-resolution camera to take images of the water column at a very high spatial and temporal scale, allowing the lab to basically take one long continuous image of what’s happening in the top 100 m of the ocean. These images are then run through an AI image classification model that automatically identifies and measures each individual plankter that is recorded. Both the net and the ISIIS also record data about the environment, such as temperature, salinity, and depth. By examining relationships between environmental conditions, the abundance of other plankton, and the abundance and other characteristics of anchovy larvae, Luke explores the factors that may contribute to variability in anchovy abundance.

In Situ Ichthyoplankton Imaging System (ISIIS)

To hear more about the day in the life of an anchovy, as well as Luke’s journey from OSU to another OSU, tune in this Sunday, November 5^th live on 88.7 FM or on the live stream . Missed the show? You can listen to the recorded episode on your preferred podcast platform!

Northern anchovy (credit: Monterey Bay Aquarium)