Invasivore Interview: Dr. David Costello

Recently, we had the opportunity to sit down with Dr. David Costello to talk earthworms, research, and invasivory. 

Can you start by giving us a quick overview of your dissertation research?

My dissertation research focused on how the impact of invasive species can extend outside the typical boundaries of an ecosystem.  For example, invasive earthworms are typically thought of as a terrestrial problem, but my research showed that the way earthworms change nutrient cycling can cause excess nitrogen to enter adjacent streams.  In general, I found that if you are trying to manage invasive species in an ecosystem, you need to be aware of what is going on in the surrounding areas, even if they are completely different ecosystems.

When did you first become interested in invasive species research?

As an undergraduate at Hobart College, I got my first exposure to invasive species during a summer research internship after my sophomore year.  We conducted a survey of Seneca Lake trying to correlate zebra and quagga mussel densities to lake characteristics.  I spent the following semester studying biology abroad in Australia where the imprint of invasive species, like European rabbits, is really severe.  Both of these experiences sparked my interest in invasive species issues and research in general.

Returning to your dissertation research- have you eaten earthworms?  How did you cook them?  Can you describe your first bite?

I have eaten earthworms a couple times.  In my experience, I’ve had some success blanching them before battering in flour and deep-frying.  It is tough to get earthworms completely clean so I would describe my first bite as “gritty”.  If you can get all the dirt out of them, I think earthworms wouldn’t taste too bad.  For now, I’ll stick to gummy worms!  (Editor’s note: check out some tips on preparing earthworms here)

Dr. Costello samples a deep-fried earthworm

Do you have any other eating invasive species experiences you’d like to share?

I really enjoyed eating rusty crayfish while doing my graduate work at the University of Notre Dame Environmental Research Center in the upper peninsula of Michigan.  My favorite cooking technique involved simply throwing them on the grill and letting them steam in their own shell (technically, an exoskeleton).  It gave them a nice smoky flavor and the meat was still pretty juicy.

What have you been working on since you graduated?

I am currently a postdoctoral research fellow at the Cooperative Institute for Limnology and Ecosystem Research (CILER) at the University of Michigan.  For now I am taking a break from invasive species and working almost exclusively on chemical pollution.  I am working on a number of projects that focus on metal contamination in sediments, which is often the last thing to be cleaned up after a mine or industrial plant closes.  We are exploring the chemical and physical process that cause metal buried just below the surface to be released and how this can potentially affect organisms living on the bottom of aquatic ecosystems.  Invasive earthworms are not far from my mind and I am looking forward to resuming that research.

Any plans to eat any of your study organisms in the future?

I think it is a fun idea as long as your study organism isn’t endangered or poisonous.  I don’t have any specific study organisms right now but for any new projects in the future that will definitely be a consideration!

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