Last weekend I attended the 26th Annual Meeting of the Tidewater Chapter of the American Fisheries Society, better known as AFS Tidewater or just plain Tidewater. To recap, this conference encompasses fisheries academics, students, and managers from the so-called “tidewater region,” which is made up of the states of Delaware, Maryland, Virginia, and North Carolina. This chapter emphasizes marine and estuarine topics, which can be a welcome change from the larger, more freshwater-dominated meetings. This year the conference was in Beaufort, NC, which is well-covered by marine and fisheries research, with the NC State, UNC, and Duke marine labs, the main office of the NC Division of Marine Fisheries, and a good-sized NOAA lab all nearby. Beaufort is also rich in ocean-related history, and the venue (The NC Maritime Museum) reflected this well. As it turned out, the spring weather (mostly) broke out the day before the conference, making it a perfect time to be in Beaufort. So how’d it go this year?
The ECU contingent typically rolls deep at Tidewater, and this year was no different, with ten students from the various fisheries biology labs presenting either posters or talks. The whole shebang was also run by a recent ECU alumni, Jacob Boyd. Other schools that regularly bring a crowd include NC State, VIMS, and the Maryland Chesapeake Bay Laboratory (CBL). The local DMF and NOAA labs usually present some pretty interesting stuff as well. Here’s a rundown of the stuff that I personally found interesting, and if I missed something worth mentioning feel free to recap it in the comments.
ECU had a few posters up. Christina Booth recapped the findings of the Fisheries Techniques class in their assessment of whether some small ponds at one of ECU’s rec centers could support fishing. Turns out they’d need a lot more shelter to keep the fish safe long enough to reach catchable size. Coley Hughes and Jeff Dobbs showed their progress in different aspects of a large project using otolith microchemistry to figure out where striped bass were born and have been migrating. Joey Powers identified habitat preferences in juvenile red drum and spotted seatrout, finding that detritus bottoms make better nurseries for red drum while submerged aquatic vegetation (think seagrass) is preferable for seatrout.
Other cool posters: Sam Binion (ECU alum, now at NC State) worked some stats magic to try and develop a method for predicting fish communities based on environmental factors. Travis Richards (Florida State) looked at stable isotopes in spotted seatrout from different areas of an estuary, and found that the underlying water can influence isotope values enough to throw off the diet signature. He stressed the importance of getting baseline values from the study area, which is something that some of the more isotope-crazy researchers working on highly migratory species (isotopes have really blown up in the shark world) should be worried about.
Talks – Day 1
The first day of talks included all of the student presentations. Again, I’m just going to briefly describe the main points of those that I paid special attention to.
Andre Buchheister (VIMS) kicked things off with an overview of the fish community within Chesapeake Bay over time. It looks like there’s been a major shift since 2007, with less croaker (formerly the highest biomass of any species in the bay) and more biomass of various elasmobranchs (particularly cownose rays, but the mighty spiny dogfish were in there too).
Andrea Dell’Apa (ECU) showed evidence for a shift in male-female ratio of spiny dogfish schools off of Cape Cod that seems to be based on time of day. He suggested that fishermen can selectively target the less at-risk males by fishing early in the morning.
Dan Zapf (ECU, whose blog The Endolymph came back from the dead this week – check it out for all your herring, otolith, and hockey needs) identified the Chowan River as the potential best nursery habitat for blueback herring, and showed through otolith chemistry that the fish will move between rivers to find optimum habitat. Mike O’Brien (CBL) continued the nursery habitat theme by showing that juvenile fish in Maryland coastal bays are more affected by seasonal differences than their position in the bay with respect to the inlet.
River herring took the place of striped bass as the dominant species for the ECU talks. Matt Butler found that three creeks in the Chowan River seem to produce the most herring larvae, and are characterized by high Chlorophyll a (a sign of primary production from algae), alkalinity, and relatively little human influence. Annie Dowling compared these trends in juvenile abundance and found evidence for the first stages of a possible recovery of river herring populations in the Chowan River.
Molly Taylor (Florida State) looked at patterns of spot feeding habits within a Florida estuary. She found that seasonality and river flow are important, and that freshwater insects make up a decent amount of the diet for spot in the upper regions of the bay. Chelsie Wagner (Florida State) also looked at trophic dynamics, this time for large predators (sharks, dolphins, rays) in relation to the Gulf of Mexico hypoxic zone using aerial surveys (pretty badass study if you ask me). None of the predators or fish schools showed any predictable patterns in relation to the hypoxic zone, but this may have had to do with the fact that it’s largely confined to bottom water. Cownose rays did hang out at the margins, and it was theorized that they may be dive-bombing benthic critters trying to escape from the zone.
I should give a specie mention to Danielle Zaveta (CBL) for being a good sport as I embarrassed myself spectacularly before her talk. The fire alarm had gone off during Annie’s presentation, throwing the timing of the talks off and leading me to think it was my turn when actually it was hers. This played out in front of the entire audience as I went to take the podium while everyone in the ECU crowd screamed that it wasn’t my turn. Fortunately she was cool about it and gave a great talk on finding the appropriate models for blue crab stock assessments.
The next couple talks (separated by lunch break, appropriately enough) involved fish eating other fish. For my talk, I focused on the interactions between spiny dogfish and striped bass off of North Carolina, where they chase the same prey and occasionally stripers end up in dogfish stomachs. This allowed me to quote Mitch Hedberg during my talk. In conclusion: stripers likely don’t have much to fear from dogfish unless both predators run out of other prey. Nicole Mehaffie (CBL) followed up her quality talk from Seattle by expanding on the role of anadromous species (fish that run up rivers to spawn) in the diets of ocean-going predators. For dogfish, cod, and monkfish, anadromous prey are relatively unimportant on a large scale but become very important near the actual river mouths. Delicious.
Garry Wright (ECU) attempted to develop a model for just how many dogfish are actually present based on the catch in a gillnet. Using an enclosed net containing a known number of dogfish (that I tried to help him set up last winter with nearly disastrous results), he found that a gillnet set will account for about 7.7 % of the dogfish in the general area. He also used vertical gillnets to show that dogfish can be present anywhere in the water column, so bottom trawl surveys may not be getting the whole picture.
Friday concluded with a dinner social and afterparty at the awesome Backstreet Pub (a favorite haunt of ocean bloggers, salty fishermen, and wayward boaters) featuring the alt-country (good music, not the garbage you heard on country stations) musical stylings of Tobacco Roses.
Talks – Day 2
The second and final day of talks was made up entirely by professionals in fisheries fields, mainly from state and federal agencies.
James Morris (ECU alum, currently at NOAA) has become the invasive species guru in the Carolinas, and talked about a new (potentially tasty) invader, the Asian tiger shrimp. These critters can grow up to a foot long, eat smaller fish and shrimp, and have been showing up in large numbers in shrimp trawls since last year. They’re popular in aquaculture, and the invasive population growing off the southeast U.S. likely originates from shrimp farm escapees. If you get one, do your part and eat it, then tell me what it tastes like.
Todd Kellison (NOAA) showed disturbing evidence that degradation of coral reef habitat is causing fish to show less site fidelity towards specific reefs. This is true across all trophic guilds, from the top predators to the little herbivores, suggesting that it affects the entire reef fish community.
Julianne Harris (NC State) tagged striped bass with acoustic transmitters at spawning grounds in the Roanoke River and used receivers in the river and ocean to determine not only where the fish went, but how long they were resident in the river and even how they behaved after catch and release. At least once a tag stopped moving from a site entirely and turned out to have been eaten by a turtle. I’m looking at using acoustic telemetry in some way and this talk really illustrated the diversity of things you can find out from it.
And that wraps up my epic recap of Tidewater 2012. Hope to see everyone next year in Maryland.