ICP-OES

If you have been reading this blog since the summer/fall you already know that I collected a lot of water samples.  Well today was the day I moved away from analyzing otolith data and started analysis of water samples.  I am analyzing the water samples, which were collected from five rivers around the Albemarle Sound, for elemental composition, which I will then compare to elemental concentrations in otoliths. 

I am analyzing the samples using inductively coupled optical emission spectrometry.  The video above shows the machine in action with a few of my samples being analyzed, it's a pretty cool machine but kind of complicated to start up.  Today (and yesterday) were filled with a lot of trouble shooting, familiarizing ourselves with procedures, mixing, checking, and then re-mixing standards (I spent a lot of time trying to figure out standards). 

The process has been frustrating but I'm starting to feel more confident with the analysis and it feels good to have data from a few samples.  Currently, I don't know enough about the inner workings of the ICP-OES to give a solid description, but when I do I will certainly write about it here.

The Recap

About a week ago I posted I was en route to the 2011 American Fisheries Society Southern Division Meeting in Tampa FL.  The meeting has come and gone, so I decided to share my two cents and give a recap of interesting happenings at the conference.   

We arrived in Florida on January 12, and found the weather to be unseasonably chilly.  Granted it was around 40 or 50 degrees, which to some seems downright warm for this time of year, so I guess temperature really is relative.  The next two days are a blur to me, and I don't specifically remember doing anything memorable.  As best I can recall, I volunteered at the registration table really early in the morning but even that's a bit fuzzy.  You may notice a common theme while reading this that during the conference I had to wake up really early, which I'm normally not opposed to, but for some reason it took it's toll on me during these four days.  I guess the conference really started with the poster social on Friday night, so that's where I'll pick things up. 

East Carolina University was well represented at the poster session with five fellow students presenting their work.  Among these were Annie Dowling who presented work she had conducted in Hawaii on Ciguatera, and Joey Powers who presented his work on juvenile spotted sea trout habitat.  From my lab Jacob Boyd, Jeff Dobbs and Coley Hughes presented posters detailing their work on striped bass.  Jacob Boyd is looking at maturation and fecundity of striped bass in the Albemarle Sound, but also using otolith microchemistry to investigate skipped spawning.  Coley Hughes and Jeff Dobbs are using otolith microchemistry to identify striped bass natal origins in the Albemarle Sound and Neuse River respectively.  All of these posters were very well put together and it seemed there was a lot of interest particularly in the striped bass projects. 

The poster by B.K. Barnett, and W. F. Patterson titled "Interspecific and regional variation in otolith chemical signatures between juvenile red and lane snappers in the northern Gulf of Mexico" was interesting in that they found significant differences in otolith elemental signatures between two species found in the same location.  These results caught my attention because I am working with two closely related species (alewife and blueback herring) and as I have mentioned in previous posts the two species are typically lumped together as river herring.  However, if there are differences in  elemental signatures in the otoliths of these species it would be necessary to do individual analysis for each species.  Unfortunately, I only have information for adult blueback herring and juvenile alewife at this point so I haven't been able to make any comparison yet...but at least I have something to look forward to.  As a whole the poster social was great, I even had some interesting conversations about pipefish genetics and the potential of elemental markers being present in the otoliths of fish exposed to the Deep Water Horizon oil spill. 

Oral presentations started the next day and I was scheduled to run the A/V equipment for the freshwater mussel symposium that morning.  Freshwater mussels are one subject that I know absolutely nothing about (despite having some experience with brackish water varieties), and I would not have attended this symposium had I not volunteered to work on the A/V stuff, so I was a little curious.  The talks I saw dealt with status and distribution of species in the southeast and using genetics as a conservation tool.  I was impressed, the mussel community seems to be a pretty tight knit group and the research seems to be on the cutting edge of conservation genetics techniques.  I was astonished at how many freshwater mussel species there are, I guess it's one of those things where if you haven't seen them you never think of them.

Unfortunately, being in the mussel symposium caused me to miss the only other talk (besides my own, which I was in fact present for) about otolith chemistry.  The talk "Defining fish nursery habitats of Centropomus undecimalis using otolith elemental fingerprinting" by H. Rolls, was about developing elemental fingerprints for snook from tributaries to Tampa Bay and then using those fingerprints to identify natal origins of adult snook.  I was pretty bummed out I didn't get to hear this talk as I would have been interested in seeing how distinct the elemental signature could be for tributaries in a relatively small geographic range, but I guess I can just listen to the podcast later (more about that in a bit).

The rest of my time at the conference, I kind of bounced around between different rooms wandering in on whatever talk happened to be going on.  For whatever reason I just couldn't seem to grasp the schedule and could never seem to link an abstract to a presentation time.  Either way I still heard about some interesting research.  Mike Bednarski and Doug Peterson, from the University of Georgia, gave extremely informative, thorough talks about recruitment and population estimation of shortnose and Atlantic sturgeon in the Altamaha River Georgia.  These talks were interesting in that their population estimates seem to be very accurate with relatively small confidence intervals.  They also raised interesting points about the increased accuracy mark-recapture abundance estimates have compared to catch per unit effort data.  Lab mate Chuck Bangley gave an amazing talk about the feeding habits of spiny dogfish off the coast of North Carolina.  The diet information he collected was well presented and he even managed to work in the line "their bite is much worse than their bark' which is EPIC!       

I spent a decent chunk of time in the snook symposium mostly because I feel there are many questions relating to snook ecology that could be addressed using otolith chemistry.   Also, because there has been so much work done on snook habitat use and movements I think there could be a decent baseline to compare otolith chemistry data.

Now for the moment you have all been waiting for...my talk


My talk was on Sunday morning at 8:20 ish.  I give the starting time loosely because the talk didn't exactly start at 8:20 am.  Just prior the start of my talk it seemed that the projector wasn't working which pushed back my start time by about 5-7 minutes or so, which is fine but it did make me a bit antsy.  I hate trying to judge my own presentation skills because I am probably way more harsh on myself than necessary (as I'm sure most people are), and I tend to take the opinions of friends with a grain of salt because well their friends.  The one area I absolutely must improve on (and I have heard this many times) is slowing down, and breathing.  I tend to rush through talks and while I can sometimes hold it together,  I do occasionally leave things out.  Because, this presentation was a bit more data intensive than other talks I have given, it definitely would have been beneficial for me to slow down and make sure I was hitting all of my points.  One thing that threw me off a bit, was the format on a few of my slides was screwed up, however I don't think this really messed up the overall presentation.  Most of the feedback I get typically concerns the vanity of the presentation, which is appreciated but I feel like I could used some criticism/advice on the content as well.  Both of the talks I have given at conferences have ended with no questions being asked which, is slightly disappointing because I would welcome suggestions on how to improve my research or just practice defending what I have done.  

So what was my talk about?

The title was "Inferring natal origins and migrations of adult river herring in Albemarle Sound, NC using otolith microchemistry"

And briefly...

I looked at the elemental composition at the otolith core from adult river herring caught during the spawning run in the Chowan, Perquimans, and Scuppernong Rivers.  I found significant differences in elemental compositions between rivers, which allowed for fish from individual year classes to be classified with high accuracy to their river of capture.  Because it seems that fish with similar natal origins are spawning in the same river at the same time, we can hypothesize the fish are exhibiting natal homing.  Of course in order to test this hypothesis it is necessary to ground truth the signal with either water samples or using juvenile otoliths (which would be the preferred method).  I also presented data on what appears to be different migration patterns of adult river herring based on Sr/Ca in the otolith.  However, this data needs more in depth review, and I would like employ a multi-variate approach to analyzing the migration patterns.

Now, you can take my word for it and trust what I am telling is true...Or you can watch it yourself!
That's right all of the talks were recorded and podcasts will eventually become available.  So stay tuned and when my talk is put online I will post it here.


 
 

On the Road Again...

...or in the air tonight

Apparently Florida is currently the only state in the country that currently has no snow on the ground therefore I will be flying there tonight.

But seriously that's not the real reason I'll be traveling to the sunshine state (I actually like snow), rather I will be attending the 2011 American Fisheries Society Southern Division Meeting in Tampa Bay.  I have had mixed feelings about attending this conference because of how early in the semester it is and because I'm not a huge fan of flying, but I'm sure once I get there and into the swings of things it will be an enjoyable experience.

If anyone who reads this (does anyone read this?) is going to be at the conference and wants to chat, offer advice, or set me straight that would be awesome!  Also, I will be presenting a section of my research bright and very very early on Sunday morning, so I look forward to having a big crowd eager to hear my ramblings about river herring and otolith microchemistry.     

Adorable

This adorable little fellow is an adult hairy frogfish and the little guy marching along behind him/her is a juvenile.  At the end of the video the frogfish attempts to lure in prey using it's lure, which extends from the head.  It's pretty interesting behavior for a muppet or fish rather.

But they don't even have bones...

This video shows laser ablation of shark vertebrae.  Laser ablation is the same method used when analyzing trace elements in otoliths.  However, since sharks don't have otoliths (they have a similar structure called a statolith), the vertebrae is often used for aging and I'm guessing elemental analysis of a vertebrae would yield the same type of data that can be obtained from an otolith.  The video is kind of long and monotonous, but I was interested because it is a relatively new concept to me, and I have a few shark obsessed colleagues. 

When Your Powers Combine...

Atlantic bluefin tuna Thunnus thynnus are a highly migratory, pelagic, marine fish species.  Although I have never personally indulged myself by eating this fish, I have little doubt they are delicious.  How can I make such an assessment?  Well, Atlantic bluefin tuna are one of the most endangered animals on the planet and most assessments suggest they are on the brink of extinction.  The obvious solution to this problem would be to close down the Atlantic bluefin tuna fishery, but alas, as with most fisheries issues the solution is not so cut and dry.  The demand for bluefin tuna is incredibly high and in some countries, like Italy, the fishery represents a culturally important event.  Because of the importance and current status of Atlantic bluefin tuna, significant effort has been put forth to address questions regarding migrations and stock structure of the species. 

Studying the movements of highly migratory species is a difficult task to say the least, but solutions to these difficulties are quite interesting.  A suite of methods including otolith microchemistry, genetics and electronic tagging has been used to decipher the life history of this species.  Block et al. (2005) suggested that using each of these methods individually would be insufficient, and combining these methods paints a more powerful, more complete picture of the life history of bluefin tuna in the Atlantic Ocean.

Using otolith microchemistry, Rooker et al. (2003) identified unique chemical signatures in the otoliths of age-1 Atlantic bluefin tuna from the western and eastern Atlantic.  This information is important, because it can be used to classify adult bluefin tuna to natal origins and suggests that there are probably two separate spawning stocks.  This information is augmented by the findings of Carlsson et al. (2007) who used both nuclear loci and mtDNA to distinguish differences between Atlantic bluefin spawned in the Gulf of Mexico and the Mediterranean Sea.  Finally, electronic tagging by Block et al. (2005) revealed that bluefin tuna have trans Atlantic migrations and may show spawning site fidelity to the Gulf of Mexico and the Mediterranean Sea. 

Of course there is significant room to expand on all of this research, but when the current information is combined, the life history of Atlantic bluefin tuna becomes clearer.  Using otolith microchemistry and genetic analysis to examine the origins of adult tuna should provide information on the mixing of individual stocks, which could answer questions like which side of the Atlantic is producing more fish?  This information would complement findings from electronic tagging studies quite nicely.  Whatever direction this research takes, it is pretty clear that one method will not provide all of the answers needed to make proper management decisions.  It is only in combining their powers that a clear life history and stock structure can be identified for this critically important species.

Block BA, Teo SL, Walli A, Boustany A, Stokesbury MJ, Farwell CJ, Weng KC, Dewar H, & Williams TD (2005). Electronic tagging and population structure of Atlantic bluefin tuna. Nature, 434 (7037), 1121-7 PMID: 15858572

Carlsson J, McDowell JR, Carlsson JE, & Graves JE (2007). Genetic identity of YOY bluefin tuna from the eastern and western Atlantic spawning areas. The Journal of heredity, 98 (1), 23-8 PMID: 17158466

Rooker, J.R., D.H. Secor, V.S. Zdanowicz, G. De Metrio, & L. Orsi Relini (2003). Identification of Atlantic bluefin tuna (Thunnus thynnus) stocks from putative nurseries using otolith chemistry Fisheries Oceanography, 12 (2), 75-84

Holiday Gift Idea

If your looking for the perfect holiday gift for the otolith lover in your life, looking to expand your own fashion horizons, or looking for new ways to express your fondness for the ear stones of fish then this is the place for you.

 

 

Otolith Necklace

Very Nice

Earring

Fancy