Monday, June 6, 2011

Welcoming the NHL back to Winnipeg!

In order to properly celebrate the return of NHL hockey to Winnipeg I decided I should go up and have a visit.


Not really.

Although that would be fun my trip to Winnipeg is all business. 

Very briefly...

Myself and other members of the lab are heading to the University of Manitoba tomorrow.  The purpose of the trip is to learn how to use the LA-ICP-MS.  The river herring otoliths for my project have all been analyzed at the University of Manitoba and I haven't been up there yet.  I'm excited to see how the machine works and getting the chance to run some of my own otoliths, so I can stop feeling like a worthless slacker.  I will try and post pictures and updates when I return...

Sunday, May 29, 2011

2011 Larval Fish Conference

Because this was a relatively small conference I will keep it brief.

I spent much of this past week in Wilmington NC attending the 35th Annual Larval Fish Conference.  I had a great time Wilmington is a great city and the conference was very interesting.  Early life history is my primary interest so I was pretty interested in most of the talks.  There were a few talks focusing on otolith microchemistry as a means of tracking a shift to the marine environment by salmon and striped bass.  These were interesting but I had seen the striped bass talk previously.

There were also a few talks about modeling larval dispersal which I though was really cool.  I don't know what it is but projects combining biological data with physical data really grab my attention.  There were a few talks about eco-morphology and ontogenetic shifts in juvenile fish.  Most of these talks focused on the development of the jaw and all have come up with some interesting results.
 
There was a section on maturation, fecundity and egg development, which was interesting but seemed repetitive after a certain point.  What I did find interesting was a talk about the influence of maternal diet on the success of offspring.  This was tested with an experiment known as the "larval olympics" which is something I was familiar with from previous work but it was cool to see it brought up again.

There were a lot of talks focused on the match mismatch hypothesis, and there was a special section on cephalopod early life history.  While I have no real interest in cephalopods it was interesting to see what other people are working on, and really larval cephalopods aren't really that different from larval fish.

I liked the conference, I learned a lot.  I maybe didn't get as much feedback on my project as I would have liked but whatever.  The people I talked to at the very least seemed interested.  I think there were people from something like 14 different countries and 20 different states so it was great to see what people around the world are working on.

Now if I can only find a way to go to the conference next year when it is in Norway.

Saturday, May 21, 2011

Quickly

Just a quick update on what I have been doing.

I've been polishing and reading juvenile river herring otoliths for most of the last two weeks, or at least since the last time I posted anything.  At some point I will post pictures and give a write up of the method with some suggestions about how to go about working with tiny river herring otoliths.

This week I will be attending the 35th Annual Larval Fish Conference being held in Wilmington NC.  I'm really looking forward to it, I have never been to Wilmington and I hear it's awesome.  Also, my primary fisheries interest is early life history so the conference is right up my alley.  I am presenting a poster at the conference so if you are there check it out.  I may try to post something while in Wilmington, but if I cannot I will recap the event in retrospect.

In the meantime check out this site created by students in the lab of Dr. Anthony Overton dedicated to their work on larval river herring in the Chowan River.  The site is pretty new but it already has a lot of interesting content.  Enjoy!   

Wednesday, May 11, 2011

Clean Water?

A few quick updates.

Smoke from a forest fire in the Outer Banks is settling over Greenville this morning giving the city the unmistakeable scent of a camp fire, which isn't so bad, I just hope there is minimal damage to Outer Banks communities from the actual fire. 

While I was thinking about camping, roasting marshmallows, and traveling to Wisconsin tomorrow I came across this article regarding my second (maybe third) favorite state.  The article is about the Wisconsin assembly rejecting requirements for communities to disinfect drinking water. 

I'm not sure how to feel about this.

At first I was shocked, I thought most tap water was disinfected.  Then I remembered growing up with  people who used well water, which was definitely untreated.  Also, the city of Syracuse (where I lived for 4 years as an undergraduate) does disinfect the water it obtains from Skaneateles Lake with chlorine, but because Skaneateles Lake is one of the cleanest lakes in the world the city is not required to filter the water.  

According to the article untreated water in Wisconsin was found to contain viruses and communities with high concentrations of viruses in their water have high rates of illness.  Of course the bill was rejected by republicans who felt that treating water would be to costly.  But, while initial costs of treatment would be high there would be long term healthcare savings according to researcher Mark Borchardt.

I'm torn.  I believe that EVERYONE has the right to clean water.  However, I think if water has been rigorously tested and it's clean why treat it?  The only solution is probably long term monitoring of water quality, which may be more costly and at some point it may be cheaper just to treat the water.  I do think it's shocking that clean water and the health of the states citizens would even be debated, especially with strong evidence demonstrating the risks of untreated water.  It seems like a question with a clear, obvious answer.  Doesn't it?

As far as otoliths are concerned, I am attempting to grind and polish juvenile river herring otoliths in hopes of counting daily growth rings.  Hopefully there will be pictures to come...

Monday, May 2, 2011

Manganese as a Recorder of Hypoxia

ResearchBlogging.org

I haven't been doing much writing about otoliths lately (at least not here), despite the goal of this blog being to write about otoliths.  In fact, recently I have been writing more about invasive species, which is a topic I absolutely hate!

Really the only excuse I can come up with for not writing about otoliths is laziness.  I wanted to write about otoliths, I really did, I just needed some inspiration...which came in the form of some current events.  My interest was peaked when I read the title; "Research: Fish Can Detect And Record Marine 'Dead Zones'".  Fish you say?  Record you say? All the key words were there, this definitely had to be about otoliths...and it was...inspiration at last!  

So I dug deeper and found the paper the article was reporting on, by Limburg et al. (2011) entitled Tracking Baltic hypoxia and cod migration over millennia with natural tags.

The paper focuses on hypoxia and declines in cod stocks in the Baltic Sea.  Along with over fishing, habitat degradation is hypothesized to have led to declines of cod in the Baltic Sea.  The Baltic Sea experiences natural and anthropogenic caused hypoxia events (depleted oxygen), which is thought to have a negative impact on fish.

During hypoxic events manganese is released from the sediment into the water.  Once in the water it is free to be incorporated into fish otoliths.  The researchers used the concentrations of Mn in cod otoliths, from the Neolithic Age, the Iron Age, the 1980's, the early 1990's and the late 1990's, to examine hypoxia events in the Baltic Sea.  It's pretty awesome in and of itself that otoliths from the Neolithic and Iron Ages can be found, but to analyze them and get meaningful data is pretty mind blowing, and can certainly be used when investigating changes in the environment throughout time.

The pattern of Mn in the otoliths followed what one would expect.  The Neolithic otoliths had low Mn, and otoliths from the late 1990's had the highest concentrations of Mn.  The increasing Mn throughout time indicates that hypoxc events are more frequent now than in the past, likely due to anthropogenic impacts.

For me, the most interesting finding was that elevated Mn was found in areas of the otolith relating to early years of life, particularly the first year.  Using Ba/Sr ratios (used to differentiate freshwater and salt water) in  these otoliths, it was hypothesized these fish utilize low salinity areas with riverine inputs as nursery grounds.  These areas may be exposed to low oxygen conditions, thus having higher Mn concentrations.  

So what does this tell us?

If the modern fish were captured alive (which I'm assuming they were), it could be concluded that young fish are able to cope with hypoxic events.  It is possible there is some advantage gained by young fish being able to tolerate hypoxic conditions.  Young cod may enter hypoxic waters to avoid predation or avoid competition for food resources (I'm pretty sure this concept has been demonstrated with common snook, but I was unable to locate a reference).   It would be interesting to examine growth rates and condition of juvenile cod exposed to different oxygen levels, in order to investigate differences in habitat quality.  However, the researchers did note that Mn in the water can linger after hypoxic events, so Mn in the otolith does not necessarily mean the fish was directly exposed to hypoxia.   

Using Mn in otoliths to examine and record hypoxia is interesting to say the least, and this paper provides a specific example of the record keeping ability of otoliths.  I haven't really noticed any trends with Mn in my own research yet, but I think as I look at data from later in the summer (August-October) it may start to show up in water samples and otoliths because of low oxygen levels in the water during this time period.

Limburg KE, Olson C, Walther Y, Dale D, Slomp CP, & Høie H (2011). PNAS Plus: Tracking Baltic hypoxia and cod migration over millennia with natural tags. Proceedings of the National Academy of Sciences of the United States of America PMID: 21518871

Wednesday, April 27, 2011

Fighting Back

Having worked on the Great Lakes for a decent chunk of my young career I am all to familiar with invasive species and the devastating effects they can have on an ecosystem.  Unfortunately most of the news concerning invasive species is negative and in systems like the Great Lakes it seems as though someone left the front door open for invasive species to swim on in.  In fact, it's probably one of the major reasons I wanted to moved on from working on the Great Lakes.  Invasive species are depressing and the situation never seems to improve.  That is not to say the marine environment doesn't have its own invasive species problems, as we've seen from the invasion of lionfish.

But the news isn't all bad.

It seems as though Lake George in New York has had success in turning back invasive species.  When Asian clams were discovered in the lake scientists quickly mobilized to eradicate the threat.  The location of the clams in the lake was identified, and mats are being laid over the top to "snuff" out the tiny invaders.
But it doesn't end there.

Lake George has had past success in avoiding invasive species.  Eurasian watermilfoil has been contained in the lake using barriers, and zebra mussels were wiped out by volunteer divers who picked them off of rocks.  It's pretty incredible when you think about it.

Granted Lake George is a smaller system so it is probably easier to contain and eradicate invasive species than in larger systems.  However, I think it speaks to the importance of long term monitoring and having proactive user groups that these threats were quickly identified and dealt with.  Hopefully Lake George has the same success with the Asian Clam.  

Friday, April 15, 2011

Phosphorus in Wisconsin

I was reading a post at the Sierra Clubs Great Lakes Program blog and found the reference to this article about Wisconsin potentially allowing increased phosphorous releases into state waters pretty interesting.  I'll briefly explain the political issues (as far as I can understand them) before getting into the science but you should definitely read the article for yourself.

For those following the Wisconsin budget situation, it is common knowledge that Wisconsin Gov. Scott Walker is heavily backed by the Koch brothers, the libertarian billionaires known for their philanthropy and support of the tea party "movement".  The brothers own most of Koch industries which encompasses Georgia Pacific lumber which has paper mills in Wisconsin.  Phosphorus is one of the by products produced by these plants, the phosphorus is usually disposed of by discharging into   nearby waterbodies.  Essentially, Scott Walker and his colleagues have been working to delay legislation that would limit phosphorus emissions, presumably with the goal of getting rid of this legislation all together.  Many questions have arisen about Walkers motives because the Koch brothers back Walker and have a lot to gain if Walker is successful in delaying this legislation (read the article for more detail).        

So why should we care if more phosphorus is added to the environment?

Primary production is the conversion of the suns energy to organic material, usually by photosynthesis.  In addition to sunlight, phosphorus and nitrogen are needed for primary production.  In freshwater environments phosphorus is a limiting element.  This means that regardless of the amount of nitrogen in the environment if there is not enough phosphorous primary production will be limited.  In aquatic systems primary productivity can be viewed as algal and aquatic plant growth.  The more phosphorous in the system the more plant growth we should see.  Many freshwater systems have extra phosphorous added to them from outside sources (like paper plants), which increases primary productivity, this is known as eutrophication.   

That's good right?  We want more primary productivity don't we?  Zooplankton eat algae and fish eat zooplakton.  If there is more algae we get more zooplankton and more fish...Right?  This is somewhat true (see Onondaga Lake and Lake Erie), eutrophic lakes (whether it's natural or artificial eutrophication) seem to support a lot life.

But there are plenty of negatives.

Increased primary production can lead to visible algal and vegetation mats in the water that can emit odors and are just plain unsightly and can be a nuisance to boaters, swimmers, fishermen and other recreational users. 
From a fisheries perspective eutrophication can lead to fish kills.  At night algal respiration can use up  dissolved oxygen in the water, which decreases the amount that can be used by fish, and other organisms.  Also, oxygen is used by microbes that break down dead algae and plants on the bottom of rivers and lakes, this can cause reduced oxygen in locations.

It's pretty clear that eutrophication can have some devastating effects on the environment, and that eutrophication can be caused by increased phosphorus input.  While many restrictions have been put on what can be dumped into waterways, it seems like we are constantly on the brink of these regulations being relaxed because it's "good for business".  In the current political climate I am sure industry will lobby hard for relaxed environmental regulations in the name of progress, and if they don't get there way I would be willing to guess that layoffs will follow (gotta keep those profits up).  It comes down to one simple question; Should private industries be able to pollute/destroy public resources so they can maintain higher profits?

I hope the answer is a resounding no. 

Tuesday, April 12, 2011

A little more on Carp

It's been a fairly busy/interesting/hectic/scary/informative couple of weeks; I wrote a statistics paper (lame!), I presented at our schools research and creative achievement week, I got a crash course in how to trouble shoot ICP-OES, Dr. Norman Halden, one of the worlds experts on mass spectrometry came for a visit, I defended my proposal (at long last), and had some fun with chemistry

Needless to say I haven't posted anything in a while.  However, I have been following some of the recent developments in the potential invasion of the Great Lakes by Asian carp.

Less than a week ago the army corps of engineers activated a new electric barrier on the Chicago sanitary and ship canal to deter the upstream movement of Asian carp into Lake Michigan.  This brings the number of electric barriers on the canal to three.  To my knowledge the original barrier was supposed to crap out around 2007 or 2008 but has kept on chugging, and I am sure repairs have been made since then.  At the same time the original barrier was supposed to bite the dust a second barrier was being added just downstream of the first.  The newest barrier is slightly downstream of the other two.  The multi-barrier array allows for repairs to individual barriers and is a safe guard if for some reason fish are able to bypass one barrier.  The barrier design works in this portion of the canal, because it is a relatively narrow section and the barriers can span the entire width. 

While the barriers appear to work in preventing fish from moving upstream, they may not be as effective in preventing the movement of fish downstream.  A fish moving downstream may become stunned by the electricity and simply drift with the current passed the electric barriers, waking up on the other side.  Also, the Des Plaines river, which runs parallel to the canal may serve as a passage for Asian carp.  During flooding events the Des Plaines River spills into the canal upstream of the electrical barriers.

Today, I read about anglers in Canada advocating permanently breaking the connection between the canal and Lake Michigan.  While this may seem a extreme, I support this idea.  Shipping traffic in the canal is not nearly what it used to be (at least that's what I'm told), and this seems to be the only way to prevent invasive species from naturally moving between the Mississippi River and the Great Lakes. 

It's an interesting debate, and there are many stakeholders from multiple U.S. states and Canada.  Many questions remain as to the best way to keep the carp out of the Great Lakes, whether they could actually survive in the lakes, and what impact they could have on the lakes.  I am certainly interested in how this plays out. 

Monday, March 21, 2011

Happy World Water Day!

Today is World Water Day

Not really sure what a proper celebration for world water is, but I would assume beer could be involved.

The first world water day was designated on March 22, 1993 as a day for bringing attention to the importance of sustainable management of freshwater resources. 

The 2011 theme is "Water for Cities:  Responding to the Urban Challenge".  The theme is meant to bring attention to water issues facing the planets ever expanding urban areas.

Having grown up in the Great Lakes region I never really had an appreciation for how scarce water could be.  The lakes are huge water bodies that seem as though they could never be tapped out.  It wasn't until my senior year of high school when I wrote a paper about water conservation that I began to realize just how scarce water could be.  This realization was further hammered home when I moved to North Carolina.  I moved here after the serious droughts that struck the southeast a few years ago, but I can understand how freshwater could run low here.

Because I can't leave fish out of this post completely I will say that while it is important to conserve water for human use, it is also important to conserve water resources for the animals that call water home.  It goes without saying that water is pretty important to fish (duh!), and when we pollute or waste water not only are we hurting a resource that we need, but a resource fish rely on.  By protecting water resources for ourselves we protect fish habitat, kind of like killing two birds with one stone.

In honor of world water day I am thinking of what I can do to help protect water resources, along with enjoying them by doing some fishing.

Tuesday, March 15, 2011

It's that Time of Year!

As the title says it is that time of year!

The days are longer, warmer (allegedly), trees are blooming, and hickory and American shad are starting to be caught in North Carolina rivers

While I have not been fortunate enough to hook into an American or hickory shad yet, I have put in considerable effort and it has given me the opportunity to be outside in the beautiful spring weather. 

More importantly, where there are shad, river herring are sure to follow.  Spawning alewife and blueback herring should begin making their runs up North Carolina rivers any day now (if they haven't already).  This could be an interesting year for river herring as fish that were spawned in 2007, the year harvest moratoriums were enacted in NC, will now be age-4 which puts them right at the age when these species are starting to become sexually mature.  Substantial numbers of age-4 river herring would be a strong indicator of the effectiveness of the moratorium.   

Here are a few videos to get you amped up for the 2011 river herring run!



Sunday, March 13, 2011

Looking back at Tidewater 2011

I recently returned from the 25th annual meeting of the Tidewater Chapter of the American Fisheries Society held at the Virginia Institute of Marine Science.  The conference was pretty sweet and the area was beautiful.  I will give a very brief recap of some of the talks that I found particularly interesting.

I'll start of by saying I thought the talks were as a whole were better than last year.  That comment is meant to take nothing away from last years presenters but more as a compliment to this years presenters.

Posters from ECU students included those by Andrea Dell'Apa, Jocelyn Kim, Joey Powers and Jeff Dobbs.  They all did a phenomenal job! 

Wayne Mabe, newly crowned president elect of the Tidewater chapter Jacob Boyd and Chuck Bangley all did an amazing job presenting their respective research.  Check out Chucks recap for a more detailed look at some of the poster and oral presentations that I fail to mention.

Because this blog is first and foremost supposed to be about otoliths I'll start with those presentations that involved otoliths.   

Chris Conroy from CBL presented on habitat use by juvenile striped bass in the Patuxent River.  Using otolith Sr:Ca ratios Chris was able to identify three predominant patterns of juvenile striped bass migration; freshwater residents, freshwater to brackish movements, and freshwater to brackish to freshwater movements.  He also matched these movements with specific ages and sizes indicating ontogenetic habitat shifts.  This project is very thorough and I am interested in the statistical analysis performed.  I found this work interesting because an alumni from our lab found similar patterns of dispersal in striped bass but not necessarily the diversity of patterns observed in this study.

Ben Gahagan also from CBL (previously at UConn), presented research on estimation of age at emigration of river herring in Connecticut rivers.  For obvious reasons I was interested in this project as Ben and I are both using otolith microchemistry to investigate the life history of river herring.  Using Sr:Ca ratios and daily age rings at the core of adult river herring otoliths Ben found that juvenile river herring spend varying amounts of time in nursery habitats before emigrating to the ocean rather than emigrating in one pulse.  It was also found that timing of emigration influenced physical attributes and life history of the fish as adults.

W.E. Smith (can't remember his name but I think it was Will) presented research on the migration of the bigmouth sleeper which is an amphidromous fish native to Puerto Rico.  Using PIT tags it was found that bigmouth sleeper are relatively sedentary.  While listening to this presentation all I could think was that it would be so interesting to combine this data with otolith microchemistry data, so I was pretty happy when I found out otolith chemistry was future goal of the project.  I think combining the two methods (traditional tagging with otolith chemistry) could provide really complete data on the life history of this fish and am interested in the outcome.  I have been thinking a lot about whether elemental concentrations are variable enough along the length of a stream that otolith chemistry could be used to track movements of fish within streams, so I am intrigued by this project.

In non-otolith projects...
(sorry I can't remember first names for most of these presenters)

B. Greenlee presented on introduced blue catfish in Virginia tidal river systems.  This was interesting because it demonstrated the importance of long term data sets for measuring the impact of invasive species on a system.  These systems have seen huge increases in blue catfish densities which could have huge ecological impacts.

A.R. Colton presented on the synchronization in the dynamics of blue crab populations.  This was a really well done presentation and despite our projects not really having anything to do with each other I think some of the analysis could be relevant to my project.

Allison Deary (?) presented a review of the ontogney of the oral jaws of Sciaenids.  I am generally interested in ontogeny and think the comparisons between species are important in explaining life history.

and finally...

J. Martin presented about the common names of fish in Japan.  While the project wasn't necessarily scientific I thought it was awesome to look at cultural traits that go into naming fish in Japan, particularly Lampridifromes (oar fish and other similar elongate species).  The links between Japanese culture and the names of these fish are pretty remarkable, and I wonder if the cultural importance of these fish may be important for their conservation?

All in all I really enjoyed the conference and hope that I am able to attend next year when it is held in North Carolina.

Thursday, March 3, 2011

Nurseries and Schools

Nothing groundbreaking about otoliths in this post but it will be about fish...and schools...and nurseries (and it might be a little political).

My primary interests in terms of fisheries science is probably identifying nursery areas used by fish, and in fact this topic has become the primary focus of my research.  

What is a nursery area you may ask?  The traditional definition is something along the lines of an area where juvenile fish are found at high densities, more successfully avoid predation, or have faster growth rates.  This definition is simple and fits rather well.  Nursery areas can be identified by the presence of high densities of individuals, that are better able to survive and grow because of some component of the habitat.  Submerged aquatic vegetation, coral reefs, rocky structures, and wetlands are all examples of habitats that serve as nursery areas for.  These habitats provide shelter from predators and adequate food that allows juvenile fish to survive and grow.

When identifying the most important nursery habitats a better definition may be the one proposed by Beck et al. (2001) which states; important nursery areas are those where production of individuals that recruit to the adult population is greater than production from other habitats in which juveniles occur.  Let me explain further using an example (this is a hypothetical example don't read to deeply into the biology).  We observe two similarly sized seagrass beds, we'll call them north and south, both provide nursery habitat for juvenile spot.  The north and south seagrass beds have similar densities of juvenile spot, but more juveniles from the south seagrass bed survive to become mature adults than from the north.  Despite similarities in juvenile densities we would say that the south seagrass bed is a more important nursery habitat because more spot survive to adulthood and are able to spawn themselves.  It is generally accepted that an animal is successful if it is able to reproduce, therefore when judging the success of fish the individuals that reproduce are considered successful.

This definition is though provoking and interesting (I'll admit I was a little giddy when I first read the paper) but it is difficult to apply because of the difficulty in tracking fish throughout their lives from the juvenile to adult stage.  However, two methods; otolith microchemistry (which I am attempting to use) and genetic analysis have shown promise in matching adult fish to nursery areas.

But why go through all that trouble?  Why do we even care about nursery areas?  We care about nursery areas because it is the habitat used by fish during a life stage when they are particularly vulnerable.  In addition, nursery areas like seagrass beds, coral reefs and wetlands are often habitats that are threatened by the human activities.  So much research has been focused on identifying and protecting nursery areas because they are essential for maintaining healthy fish populations.  Basically, by investing in the protection of juvenile habitat we're hoping more adults will be produced.

Now, I am going to completely switch gears and talk about humans and more importantly human nursery areas.

Comparing fish and humans is a bit of a stretch because survival of fish and survival of humans are based on very different factors, but similarities can be drawn between the two.  When thinking of human nursery areas two places come to mind, a child's (juveniles) home or school.  At home a child presumably receives some form of parental care and is fed and sheltered.  In school children learn both academic and social skills and what they learn/do in school largely shapes the type of adult they become.

Looking back to the original definition of nursery habitat we can attempt to apply it to schools.  Nursery areas are identified by high densities of individuals, that are better able to survive and grow.  Schools generally have high densities of individuals, they provide some type of shelter (both literally, and figuratively), and students grow mentally, socially and physically while in school.

But can we apply the definition suggested by Beck et al. (2001) to schools?  The measure of success of a human is harder to define than for a fish.  If a fish survives to reproduce it is considered a success, but does the same hold true for humans?  Some people would say yes, but measures of success are relative and based on opinion.  Because I am writing about schools and often times it seems as though success is based on dollars and cents, I am going to consider a successful human to be one who joins the workforce (doesn't matter how much money and individual makes).  Using these criteria we would consider the most important human nursery areas (schools) to be the ones that produce the most adult humans that join the workforce.   

Based on these comparisons it seems that schools provide essential nursery habitat for humans and are an important part of our life cycle.  So why should we care?  In order to maintain healthy populations we have to protect these nursery habitats, similar to fish we invest in juvenile habitats to protect the future.  The similarities don't end there, just like nursery habitat used by fish schools are becoming more and more threatened.  Budget cuts have been a prominent feature in the news recently and apparently the primary target seems to be schools.  Because I am most familiar with Wisconsin (having lived there) I have been closely following the financial situation.  Wisconsin gov. Scott Walker has proposed $800 million in cuts to schools as a way to eliminate the deficit.  Investing in schools seems essential in order to ensure the success of future generations, and allowing schools to slip away seems similar to destroying essential nursery habitat.

References

Beck, M.W., K.L. Heck Jr., K.W. Able, D.L. Childers, D.B. Eggleston, B.M. Gillanders, B. Halpern, C.G. Hays, K. Hoshino, T.J. Minello, R.J. Orth, P.F. Sheridan, and M.P. Weinstein.  2001.  The identification, conservation, and management of estuarine and marine nurseries for fish and invertebrates.  Bioscience 51(8):633-641.

 
 

Monday, February 21, 2011

Randoms

I was trying to kill time before I give a seminar later today...so naturally I went to Youtube and started looking at videos related to otoliths:

This one is long but it gives an in depth description about how inductively coupled plasma-mass spectrometry works  definitely worth checking out:



Because all to often we forget that otoliths are more important to fish than to scientists here is this video (not fish but it's the same concept), also it explains how this blog got its name:



Also check out this admittedly older post from deep sea news about hearing in deep sea fish.  The picture with the article makes it worth checking out.

And finally because everyone loves big fish (and otoliths!) check out the Florida Fish and Wildlife Conservation Commission sites overview of their research on tarpon.  I was most interested by the otolith part but there is something for everyone here.

Friday, February 18, 2011

Something of Interest

If you are interested in research utilizing otolith microchemistry check this presentation by Holly Rolls from the University of South Florida, presented at the 2011 SDAFS meeting.  The talk is about defining nursery habitats of snook using otolith microchemistry.  I was disappointed that I did not get to see this talk while at the meeting because it covers a two of my primary interests otolith microchemistry and nursery habitat.  I am glad the podcast is available as the presentation was very well done and Holly has some pretty interesting findings.  Enjoy!

Sunday, February 13, 2011

2011 Southern Division AFS - Public Speaking is Difficult

As promised in a previous post I said I would post the link for the podcast of my presentation from the 2011 Southern Division AFS meeting.  Well they have been posted, so if you are interested click here.

My own assessment?  It's difficult to listen to myself give a presentation, it was a little choppy, and some of my slides were messed up but all in all it could have been worse.

Enjoy!

Wednesday, February 9, 2011

My Battle with Math

*NOTE* the following is my opinion based on personal experience, and is in no way meant to be preachy, if you feel differently feel free to share.

*ANOTHER NOTE* I'm sure this topic has been beaten to death but I want to add my two cents.

Let me preface this by saying I have struggled with math throughout my academic life and in no way consider myself to be an expert.  As an elementary school student I was always relegated to the lowest level math classes and was so inept that I was forced to receive math tutoring from the ever so nerdy math center, which in 6th grade amounted to social suicide.  However, as much as I dreaded it at the time the extra help was effective.  While I wouldn't say I was a math whiz for the rest of my elementary, middle, and high school life I made it through and would like to think I learned a little something.

When I enrolled in college as an environmental biology undergrad I was placed in an introductory calculus class.  Because of my previous struggles, I was nervous about the class but I applied myself and did well (by my meager standards).  Students in my major had the option to either take two classes of calculus, physics or organic chemistry, physics was generally considered to be the easiest option for aspiring biologists so most of my peers opted for two classes of physics instead of calculus.  While it's clear that all three of these disciplines are integrated into biology and taking as many classes as possible in all three disciplines would be ideal, I had to choose one so I chose calculus.  My thought process as a naive first year college student was that if I was going to get into fisheries science I was probably going to be dealing with a lot of numbers and what better place to learn about numbers than calculus even if I was going to struggle through.  I did struggle and I had to work hard to get through, but I think it was well worth the time.

Which brings me to my current situation.  Very early in my graduate career I was given this advice by a seasoned graduate student "you can never know to much statistics".  This was something that really resonated with me, and after this sentiment was re-iterated to me by more than a few fisheries professionals, I decided I would really dedicate myself to attempting to not only be able to use statistics but to really understand them as well.  I have now taken four statistics courses during my graduate career and have found them to be the classes where I have learned the most.  I have also worked independently to try and understand the statistics I would need for my own research, and while my understanding isn't where I want it to be quite yet, I think I have done pretty well.          

So why am I writing this?  I get the impression, whether it's true or not, that many biologists are satisfied with the bare minimum when it comes to statistics.  I think this apparent apathy comes from a fear of math (a phobia that I have also been afflicted with).  If you are lucky enough to be a student you have the opportunity to learn the necessary statistics and should take advantage of opportunities to learn new mathematical techniques.  The most impressive studies are those that have a solid design and the statistical tests and analysis used are appropriate for answering the question.  Biologists shouldn't be afraid of tackling an area they may be unfamiliar with,  as math and biology will always be intertwined.

Wednesday, January 26, 2011

ICP-OES

video

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.

Thursday, January 20, 2011

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.


 
 

Wednesday, January 12, 2011

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.