AFS: Some other days


I saw a number of contributed talks on Tuesday, including one on an endangered snail, Assiminea pecos, given by Beth Roesler at Texas Tech. A. pecos is a small, ~2 mm, freshwater snail found in a handful of counties in Southwester United States.   Its status and major threats are unclear, so Beth set out to characterize preferred habitat for the snail and consider methods in quantifying snail densities. One characteristic important to snail presence-absence was related to moisture. The snails seemed to occur in a fairly narrow band of soil saturation/moisture levels, and in arid environments, like the South West, these bands can be pretty sparse and easily impacted. She also suggested that common reed Phragmitis australalis invasion may add to the threats facing A. pecos.

One interesting thing I noticed in her talk, and a number of other talks here, is that regression tree analyses seems to be increasing in popularity.  I recall my first experience with it in a paper by Usio et al. on native and invasive crayfish presence in Japan. It seemed like an unusual and powerful analysis at the time.

Some food, beer and ska

In the evening, I enjoyed my first gastropod meal at Le Moine Enchanson, and a beer at Barbarie.  The beer was a coffee stout, and, while not quite as caffeinated as the Southbound Brewery + Perc coffee stout sold in Savannah, it was creamy and delicious. On my way back to the hotel, I saw a few posters for an upcoming ska show with the Planet Smashers in the line up – would love to see them again.



I started today with a 5k run – the Spawning Run – which is held during each AFS meeting. The course took us through Battlefields Park, and it was quite hilly. I finished in 26:01, which is, to the best of my knowledge, nearly a two minute PR. Certainly a good start to the day.


From the run, I began sitting in on the Larval Fish conference and saw a talk by Michael Miller. Miller discussed some hypotheses regarding movement of pelagic leptocephali from off-shore to near-shore habitats. Leptocephali are slimy, snot-like, larval forms of some marine fish, including Angullid eels. There’s not much to these little fish, so it’s expected that after adults spawn off shore (often hundreds of miles), the leptocephali larvae are at the mercy of the ocean currents, with little active movement on their own. Miller, however, proposed that the “leptos” may actively swim back to their near-shore habitats. While he didn’t really present any data to support this directly, surveys of adult and larval locations suggest that the larvae are crossing large ocean currents – something that is unlikely if they are riding the currents. The lack of support was actually the most interesting thing to me. It says that we don’t know what some large, ecologically and sometimes economically, groups of fishes are doing as larvae. Most importantly, with dramatic changes in ocean currents predicted under climate change, leptocephali fishes have some big challenges ahead.

Tonight ends with the big networking event. Traditionally, this event has been open bar… I guess I’ll go ahead an post this one a little early.

AFS: Day One

The 144th annual American Fisheries Society meeting (AFS) is currently running in Québec City, and I’ve had a blast so far. While I arrived yesterday afternoon and met up with David Ushakow, one of the NAPIRE students I mentor last summer, at the welcoming social, today started the meeting’s oral and poster presentations.

Plenary Sessions

I saw a few of the talks in the plenary session this morning, which were quite eclectic.

Louis Bernatchez of Université Laval gave an excellent talk about the importance of basic science as “fuel” for technological innovation, social and economic growth, and as a feedback for more basic science. This talk appealed to the skeptic in me. As a listener of podcasts like Skeptics Guide to the Universe, a reader of skeptic blogs, and a former member of Kent State’s Freethought club, I’m often thinking about science and society. It was great to see a plenary speaker advocating for basic science research with clear examples, such as the discovery of Thermus aquaticus and subsequent advent of Taq polymerase chain reaction.  This would certainly be a good talk for non-science majors to discuss, and AFS was filming the plenary sessions. If I get a hold of the video, I’ll link it here.

A couple of other talks, like that of Theirry Oberdoff of the Muséum National d’Histoire Naturelle who summarized some patterns of fish diversity at several spatial scales, were more fisheries-based and data driven, but the last speaker, David Bella of Oregon State University, discussed what he called “Systematic Distortion.” He described a conceptual model for understanding the occurance of confirmation bias in large organizational systems, such as regulatory organizations, corporations, or even AFS… He was certainly interesting and passionate, but I wondered at the novelty of his presentation and ideas. It seems that psychological and sociological fields have likely developed such ideas extensively. Further, his message, which was advocating being a ‘trouble-maker’ and challenging status quo within such large organizations, seems to be explicitly addressed in many organizations. Internal and external auditing agencies comes to mind.

Contributed Presentations

In the afternoon, I attended a handful of oral presentations, all on the development and use of a relatively new technique called eDNA (environmental DNA). eDNA methodology is being developed to perform many conservation applications, and David Lodge of the University of Notre Dame (and my advisor’s [Mark Kershner] master’s advisor) introduced the audience to some of the uses and challenges eDNA presents. For instance, Lodge’s group is using eDNA to indicate the presence of Asian carp in the Great Lakes, but the particle size distribution and degradation rate of eDNA are little known.  The power of this technique currently resides in its sensitivity. Briefly, cells, tissue, and/or fragments of DNA are constently being sloughed off by organisms into their environment. With eDNA techniques, we can sample a tiny bit of the physical environment (e.g., a cup of water from Lake Michigan), and estimate whose living there by sequencing DNA within the water. This may allow assessment of who communities through metagenetics, or probing for specific species, like carp.  As Lodge pointed out, we often struggle with controlling invasive species because they are well established in an environment before we take notice. eDNA may indicate presence of an invasive while it has low enough abundance that we can eradicate it.

Towards the end of his talk, Lodge mentioned an initiative to monitor coastal systems impacted by shipping yards for invasive species using eDNA. I would hope Savannah is part of this, as it’s the 3rd or 4th busiest port in the US.

The City and Some Coffee

In the late afternoon, I took a stroll though Battlefields Park, and the Old City.  I then visited an excellent coffee roaster’s shop. Upon my arrival, a Canadian customs agent searched my bag and, when she found some coffee that I had brought, she recommended that I visit LES BRÛLERIES DE CAFÉ. Excellent stuff.

David’s Presentation

To finish the day off, my student presented his poster during the evening’s poster session, and we celebrated with couple of beers on Grande Allee.

Red Mangrove Expansion

The Red Mangrove, Rhizophora mangle, reaches the ends of its ranged near Cape Coral, Florida, as did the black mangrove. However, climate change has allowed for mangrove range expansion, likely due to a decrease in the frequency of extreme cold events per year (Cavanaugh 2013 PNAS).

Having seen Costa Rican red mangrove, and those at 4-mile Cove pictured here, the lack of cold tolerance in the trees is clear: the Costa Rican mangroves stand much taller and have a lower stem density (# of trees per area) than those in Florida, because of periodic (on the order of decades) frosts or cold events that wipe most of the trees out in Florida.