Tuesday, March 1, 2011

Courses: Marine Ecology

I taught Marine Ecology in the summer of 2008 and again in the summer of 2009.  An advantage of the summer course is that the weather is exceptionally nice in Long Island at that time.  Flax Pond is a beautiful salt marsh, only a short trip from the Stony Brook campus.  I used this as an opportunity to for students to gain a good experience in the salt marsh.  In the first week of class, we scheduled two trips to Flax Pond Salt Marsh.  This way we could work it into the schedules of the majority of the class.
In the week before the trip we had an in depth discussion of salt marsh ecology in general and the specifics of Flax Pond.  Topics included:
  • salt marsh zonation and the distribution of plants and animals over the landscape 
  • the physical and chemical properties of the sediments and the "redox potential discontinuity"
  • the distribution and reproductive behavior of the marsh's two fiddler crab species
  • how biological interactions affect the distribution of the coffee bean snail
  • the formation of salt pans and their use by juvenile horseshoe crabs
  • distribution of organisms in the rocky intertidal at the inlet and non-random survival of barnacle spat
  • organisms of special concern, like osprey and diamondback terrapins
The students prepared (variably) for the muddy conditions and armed with their new knowledge of marsh activities, we explored the topics in person.
Field trip students
Students search the high marsh for coffee bean snails.
Students showing their coffee bean snails, Melampus bidentatus

I show the major claw of a fiddler crap, Uca pugilator


Droving fiddler crabs.

2005 class (from the archives!)

Smelling the Hydrogen Sulfide of the RPD!

Observing the expanses of Flax Pond

Friday, November 19, 2010

Course: Restoration of Aquatic Ecosystems

In the fall of 2008, Jeff Levinton and I taught a course called "Restoration of Aquatic Ecosystems."  Foundry Cove is a tidal marsh on the Hudson River in New York, across from West Point.  Pollution began in colonial days when it was the site of a metal foundry.  By the 1960's it was the site of a battery factory.  Literally millions of tons of solid and liquid Cadmium waste were dumped into the marsh.  It was eventually declared a superfund site and cleaned up in the mid 1990's.  Our class goal was to evaluate the success of the restoration.

View of the Hudson and the coves, facing south from Breakneck Ridge.  South Cove, Constitution Marsh and Foundry Cove are visible in the left of the picture (from top to bottom).  West Point and the Hudson River are on the right.  Cold Spring NY is seen in the bottom.

The class consisted of 12 talented undergraduates from Stony Brook University.  after learning about the background history of the marsh, the class was divided into three teams.  These teams were constructed to take advantage of collaborative learning.  Students were each accountable to their group-members, inspiring greater motivation.  The students each had specific roles in their own areas of strength and helped to teach the others in their groups.  Despite this grouping, the students in the course showed strong willingness to assist other groups as well as their own.  The goals of the groups were as follows:

Group 1: Determine the amount of Cadmium still present in the marsh, by sampling soil, water and suspended particles.
Group 2: Compare the diversity and abundance of benthic invertebrates in Foundry Cove with that of another, non-impacted marsh.
Group 3: Evaluate the tolerance of benthic organisms to Cadmium (specifically, the oligochaete Limnodrilus hoffmeisteri)

We took several field trips to Foundry Cove.  We collected many water and sediment samples, we used a polgar grab to obtain samples of benthic organisms and we collected buckets and buckets of fresh mud to create live cultures of L. hoffmeisteri.

Group 1 prepared their samples and had them analyzed by spectrometry. They found a surprising level of Cadmium was still present in the marsh and in the water exiting the marsh on the falling tide- approximately 8 ppm.  However, it was a huge reduction, especially considering that at one time mud near the battery factory's outflow pipe had Cd concentrations up to 250,000 ppm.

Group 2 found that Foundry Cove had reasonably similar composition, diversity and abundance of benthic animals to South Cove, the control marsh.  There was one exception: they found many more zebra mussels (a troublesome invader) in Foundry Cove.  They suggested that the reason for this is that the sediment used to refill the marsh after the cleanup had larger and more abundant rocks than South Cove.  South Cove had thousands of years of soft sediment accumulation; the new rocks in Foundry Cove provided new substrate for zebra mussels.

Group 3 conducted a 24-hr survival analysis of the worms from Foundry Cove, comparing those exposed to Cadmium to un-exposed controls.  During the height of pollution, the worms of Foundry Cove evolved resistance to Cadmium toxicity and could survive much longer when exposed.  The students found that post cleanup, the worms seem to have lost this resistance.

Jeff Levinton produced the results from a similar class that had been conducted in Foundry Cove in the 1980's, during the height of pollution.  We compared the results of the too classes.  Two things were apparent: 1) The restoration of Foundry Cove was a significant improvement and 2) the current students did much more work and a much better job than the old students.  

This was a great class for me to teach.  In addition to the fun of working (and canoeing) in the Hudson River, the students all really grew as scientists.  They were shy and unsure of themselves at the beginning of the course, and I even questioned some of the students' motivation.  By the end of the course, they were all confident and competent in the lab and field.  I would have taken any one of them as a research assistant in the laboratory.  The students loved the course too.  This was the first experience doing "real science" for many of them, and for the others, it was the most fun.

Lauren, of group 3, and I collected many buckets of mud, from which Group 3 cultured worms to use in their survival experiments.
One of the first visits to the marsh.  Here the students are learning about the natural history of the marsh.
Group1 (and Jeff Levinton) spent a whole tide cycle at the inlet to the cove to measure the volume of water exchanged.  They used this information along with their analysis of Cd concentration to estimate daily export.

Group 2 searches their benthic sampled for infaunal organisms like oligochaetes, crustaceans and many others.

Collecting a water sample.
Some of the students developed good leadership skills in the course.

In their final presentation, Group 2 compared their results to those of the 1980's class.

Monday, November 15, 2010

Course: Ecology Lab, Fall 2007

In the Fall of 2007 I was co-instructor of "Ecology Lab" with Norah Warchola.  Ecology Lab had existed as a course, but had not been taught for a few years.  We used materials from the previous versions of the course and developed new projects and activities.  During the semester we had numerous field trips during which the students carried out experiments and observational studies.
These included:

Weld Nature Santuary to observe bee foraging and flower constancy
Stony Brook Village's Mill Pond to experiment with duck foraging and observe the ideal free distribution
Cathedral Pines County Park to observe the frequency of different color morphs of the salamander, Plethodon cinereus, and compare it to the population on the Stony Brook Campus
The Long Island Pine Barrens, to compare patches burned in the Sunrise Fire of 1995 and unburned areas
Flax Pond Salt Marsh, to observe many aspects of marine and wetland ecology

On weeks without field trip we conducted laboratory activities to teach the students basic statistics.
A particularly fun activity was the "Diversity Brownie," which we carried out indoors on a stormy winter day.  Norah and I baked brownies with different ingredients, including peanuts, chocolate chips, M&Ms, marshmallows and others (after having checked out any potential dietary restrictions of the class members).  Each ingredient represented a "species."  The students "dissected" brownies of different size and composition and collected data that they used to construct species-area curves, to compare diversity using standard indices and to compare community similarity, using the Bray-Curtis Index.

The students in this class carried out semester-long field projects.  Early in the semester the students submitted lists of topics that they found interesting.  Norah and I discussed those with each student and from those,, they developed proposals outlining the background and methods for field experiments and observational studies.  We returned these to the students with suggestions on methods and other information to assist with the project.  The students submitted mid-project progress reports, giving us another opportunity to help the students with problems and to encourage them in areas where the project excelled.  Once complete, the students submitted results summaries that we used to offer analytical advice.  The rough drafts of their final reports were "reviewed" by class-mates.  All of these steps offered us points of intervention to help students that were struggling and encourage those that were excelling.  The final reports were excellent.
A student offers flowers to a bee to see whether it prefers locally abundant species or one that it has not encountered recently.
Students observing bees at the Weld Santuary, Smithtown, NY

These students have found some salamanders and are measuring them, after having noted the color morph.

Measuring a salamander, Plethodon cinereus
The class enters Flax Pond Salt Marsh

The class observes intertidal zonation at the inlet jetty of Flax Pond.

The class is listening to their instructor, J. Matt Hoch, explain soft sediment ecology. 

The class members search for the coffee bean snail, Melampus bidentatus, to observe its distribution in the Spartina