Collecting soil samples in estuary and wetland

There are many methods to collect soil samples in different environments. One can collect soils in forests, estuaries, wetlands, and even deep ocean. I would like to share some methods I have used in estuaries and wetlands.

The box corer shown below is very light (~10 kg) and can be used in a small boat. Having a pulley can be useful if we collect many samples but mandatory at all.

Left: soil box corer which is made with PVC material. It's great for collecting a small amount of soil from shallow-to-mid water depths.
Right: Gigantic coring device. We can collect a huge amount of soil from the deep oceans.
Middle: soil samples that were sub-sampled from the box corer.

Coring device made with PVC pipe

I find that collecting soil samples in wetlands is a lot simpler but more difficult because there are  roots. The PVC coring device is simply made with 10cm diameter PVC pipe attached to a flange (handle). We also need a locking plug which creates a suction to prevent soils falling out of the pipe. 

Bioluminescence lagoons in Puerto Rico 2

It was way more brighter than I thought!  

Laguna Grande

For a week-long intense field work, more than 15 undergraduate students and 7 instructors had worked together to conduct various experiments, including environmental monitoring, phytoplankton and zooplankton metabolism, and sediment-water nutrient flux, in Laguna grande, Puerto Rico. I would like to share pictures showing a time line of our experiments. 

Collecting sediment cores

Sediment core samples collect at three sites (tape colors indicate sites) 

Set up incubation for light-dark experiment

Collect water samples 

We had also monitored water properties throughout the lagoon and, interestingly, there was a wide range of difference in depth, salinity, oxygen, and turbidity. I did not expect such a big difference in all aspects of ecosystem properties in the small ecosystem from the head (near the channel of the Caribbean Sea) to the other end (near mangrove forest) of the lagoon. Our preliminary sediment-water flux results also suggest that there was 5-fold difference between sites in the flux of respiratory products, such as ammonium and dissolved inorganic carbon. In fact, this experience makes me think that I want to do whole ecosystem study similar to 'Ecology of a New England salt marsh (Nixon & Oviatt 1973).' It was too short period to fill all processes into the diagram but hopefully I can work there again in near future.

Uncompleted conceptual diagram

Most of all, I would like to thanks all participants and Drs. Moser and Cornwell in the program for providing me the wonderful research experience in the Caribbean island.

Dirty job in oceanography

People may think oceanographers as scientists using cutting-edge equipment on a comfortable research cruise.
Oceanographic equipment are very expensive because it works under water which is basically stressful environment to machines using electricity due to pressure and 'water' itself. Although this job can be physically challenged due to the characteristics of environment where we work, many research cruises have been built as much as comfortable for scientists. But there are still many oceanographers who want to be dirty, work harder, and avoid any comfort zone at least during the cruise.  

Dr. Jeff Cornwell and Mike Owen (faculty research assistant) at Horn Point Laboratory have been collecting estuarine sediments from all over the U.S. more than two decades. Studying bio-geo-chemical mechanisms occurring under the benthic environment is crucial to understand entire ecosystem responses due to high biogeochemical activities of micro and macro organisms under the sediment. As we cannot understand atmospheric reactions (e.g., climate) without knowing the interaction between atmosphere and earth's surface, we cannot find about the function or productivity of 'water' without the understanding of 'sediment'.

This is why we collected sediment core samples from Chesapeake Bay 'no oxygen' zone to find out the biochemical characteristics of the area.

Sediment Cores

Since the accumulation rate of sediment is on the order of 0.5 to 1 cm per year, these sediment cores which are about 30 cm long is at least 15 to 20 years old (maybe older than you!). It not only has a history of the Bay itself, but also kindly provides all scientific information if we are willing to get.

And don't forget that mud is good for your skin, too!!!

My 17 yr old dog, Ggang-ggang.

Sediment and strange man.

Today morning, 4 Delaware University journalists (newspaper publishers?) got on the cruise to see what we are doing. Maybe they are going to report our story on their newspaper.

They took lots of pictures of our works, especially, sediment collection.

This is the picture of Evan Krappe who passionately took pictures on the wet stern. To make it worse we were collecting anoxic bottom sediment which smells like rotten eggs. I'm looking forward seeing his pictures soon.

Location:Blue Star Memorial Hwy,3,United States