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.


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.