Archive for the ‘Research’ Category

Pardon Our Mud

Tuesday, May 26th, 2015

To add variety to the blog and to offer a fresh perspective from our visitors, we are inviting guest bloggers to write posts describing their visits and thoughts while at the reserve.  The guest blog is brought to you by Alison Rogerson, Program Manager for the DNREC’s Wetland Monitoring and Assessment Program.  Enjoy! (Maggie Pletta, DNERR Education Coordinator & Blog Editor)

Pardon Our Mud

Spring time in an emergent tidal wetland marks a time nestled between frozen and barren, and lush with vegetation and buzzing with life.  It is during this window that we sprang into action and for three busy days installed a “living shoreline” beside the kayak ramp at the Blackbird Creek Reserve in Townsend.  But how did this come about and what does it mean?

Photo Credit Susan Love, DNREC

Photo Credit Susan Love, DNREC

A living shoreline is a technique used to either protect or restore a shoreline from forces such as erosion.  In this case, the shoreline on either side of the kayak ramp was shifting and washing away due, in part, to river currents going by.  To prevent further erosion and to protect the adjacent habitat the Delaware Department of Natural Resources and Environmental Control (DNREC) put in place a series of natural materials that will help to trap suspended sediments from the river water and encourage wetland plants.  These factors together will build and secure a healthy shoreline habitat that not only looks nice, but also protects the kayak ramp.

Living shorelines can be built from a variety of materials.  In this case we used “logs” of natural fiber casing stuffed with shredded coconut fibers, in addition to sand, dirt and wooden stakes. The logs are staked in to make sure that ice and waves don’t wash them away, and the matting underneath keeps the logs from sliding and sinking.   It’s messy, hard work for sure, you definitely want to have extra muscles on hand, but it is rewarding!  We had a strong crew out there and in three days we were able to install a cell on either side of the kayak ramp.  One cell already has a native wetland plant, Arrow arum (Peltandra virginica,) growing, and as mud begins to build inside the log cell the plants will slowly shift up with the new ground.  The cell on the other side of the ramp was empty so we trucked in clean sand and topped it with a little soil to give us a nice high base.  After things have a chance to settle in we will come back in June and plant native wetland species such as Spartina and more Peltandra.

Pardon our Mud_ABR (2)

Photo Credit Susan Love, DNREC

Although it isn’t the prettiest to look at right now, just wait until this fall or next spring.  As plants start to fill in the site will begin to look less muddy.  In time it won’t even be noticeable, especially at high tide.  We hope this will be a great example for visitors to see and learn from.  Living shorelines offer a solution to preventing erosion, protecting shorelines, improving water quality, and providing habitat for fish and plants.   And because of all these rewards to the habitat DNREC encourages landowners to consider one for their shoreline needs.

Next time you are in the area stop on by the Blackbird Reserve and check it out!

Alison B. Rogerson
Program Manager
DNREC, Division of Watershed Stewardship
Wetland Monitoring and Assessment Program


To view more photos of the installation process visit out Facebook Page to check out our Blackbird Living Shoreline Installation Album!

An Internship Beyond Expectation

Friday, August 2nd, 2013

crab project2crab project1

By: Akida Ferguson

Working as an intern at the Delaware National Estuarine Research Reserve (DNERR) has been a rewarding and exciting experience. As an intern I have been able to garner hands-on experience in the field I intend to be employed. Working closely with Mike Mensinger, an Environmental Scientist at the Reserve, I have been able to practice science in both the field and the lab. As a junior at Delaware State University, I am majoring in Natural Resources with a concentration in Environmental Science. It is rare to find an internship that exposes you to this much practical experience and I am grateful for the opportunity.

Every day is an adventure in which I learn something new.  This internship has expanded my research knowledge by my participation in secretive marsh bird surveys, trawling studies (fish and crabs), water quality monitoring, and weather data collection. In addition, I have also assisted in educating middle school students on the research we conduct at the Reserve.  This internship has given me meaningful experiences that I can use in the future.

As part of the internship program I am required to conduct my own research project.  I am investigating the effect of Phragmites australis (an invasive plant species) on blue crab survivability. By tethering crabs to the marsh at various sites along Blackbird Creek, I aim to find if certain species of vegetation aid juvenile crabs in predator evasion better than others.  I will be presenting a research poster at an undergraduate student symposium this summer.

The staff at the Reserve has been awesome and friendly, and I have even made a few turtle friends.  I come in everyday eager for what’s in store.  I know that this experience has better prepared me for my future endeavors.  I would like to thank the National Oceanic and Atmospheric Administration’s Environmental Cooperative Science Center for funding this internship and the Delaware National Estuarine Reserve for hosting it.


A day in the life of a horseshoe crab biologist

Tuesday, June 4th, 2013

Have you ever wondered what it might be like to be a horseshoe crab biologist? Well, I have the wonderful opportunity to be one!   A typical day begins at 8 am loading equipment at the St. Jones Reserve to a chorus of chirping birds and tree frogs.  What does a horseshoe crab biologist use?  We use plenty of small buckets for sediment samples, a couple ropes marked off at three meter intervals, some stakes painted orange, a clicker-counter, metal sediment slicer, and most important, a sediment core sampler!

Once at the beach, the sampling areas are established according to the high tide line and signs of horseshoe crab activity.  The marked ropes are set up to establish three meter by twenty meter transects.  Each biologist collects 20 five-cm deep sediment core samples randomly throughout each transect and places them into a bucket with a label with the date, beach name and transect designation.  This is repeated on 3-4 beaches a day.

The sample buckets are then brought back to the lab for processing.  The first step is to remove as much gravel, sand, and fine organic particles from the horseshoe crab eggs as possible.  This is done by emptying the sample bucket into a tall series of progressively finer wire-mesh sieves and using water to spray the eggs through the screen while separating out the rocks, shells and gravel.  If there is a large amount of gravel remaining in the egg sample (egg-size 1.6 mm), the sample is then run through a specially designed elutriation system (fondly referred to as Eggbert) which uses water to separate out the less dense eggs from the denser sediments.  Once the eggs have been separated out they are ready for counting!  If the number of eggs in the sample is small (< 4,000), the eggs are counted by hand.  If the number of eggs in the sample is large, there are counted volumetrically in a graduated cylinder.  The egg count data and location data is tracked for each beach each year and provides information regarding the availability of horseshoe crab eggs as a food source for migrating shorebirds. 

So, where is the fun?  Imagine walking onto a beach and seeing thousands of horseshoe crabs lining the shore, hunting for tagged crabs after sampling, photographing hundreds to thousands of shorebirds while they forage for eggs.  Like music?  Lab time offers a great opportunity to sing along to your favorite tunes while sieving samples and counting eggs!  Change the lyrics to a classic tune to create your own horseshoe crab theme song or collect shells, fossils and cool rocks from the sediment samples while sieving eggs.  Perhaps making bucket towers or cracking egg jokes while sifting and counting helps make the work more fun.  But most importantly, making lifelong friends while conducting important scientific work is the best benefit!  And, that is what it is like in a day in the life of a horseshoe crab biologist.  

By Amy Brossard

Movie stars at the St. Jones Reserve

Friday, November 9th, 2012

Did you see the movie stars at the St. Jones Reserve this past Saturday?  They attended the premiere of the new St. Jones River video entitled The Price of Progress…The Promise of Protection in which they starred.  The 20-minute video explored the St. Jones River through time. The river is both rich in natural history and cultural history.  If you missed the show you still have an opportunity to see it as we will be showing it again this winter.  Copies will also be available for educational use.

In addition to the premiere of the new video during the St. Jones Open House, we also showcased the research being conducted at the Reserve as well as the sea level rise inundation mapping tool; the facility and estuarium were opened for tours; and there were crafts for our younger visitors.  The Open House was held in conjunction with the Delaware Native Plant Society’s annual plant sale.  Thank you to all who visited us at the Open House and Plant Sale!

Shhh…there is a secret in the marsh!

Wednesday, June 13th, 2012
When I was approached by one of our researchers to assist with the Secretive Marsh Bird survey I had to ask, “Are we secretive or are the birds secretive?”   I know you were thinking the same thing.   I was quickly informed that the birds are the ones who are secretive.  They include birds such as the clapper rail, king rail, American bittern, and least bittern just to name a few.  These birds exhibit secretive behaviors and are difficult to visually survey.   In fact, the majority of the survey is conducted by sound.  I have found that you must be a great listener to conduct this type of survey!

So needless to say, this past Monday I was excited to assist with such an interesting project.   We launched our boat just after 5 am into the St. Jones River, and we were off to survey set points along the marshes for these “secretive” birds.  It was quite an enjoyable experience as we diligently listened for the birds and was quite delighted to see a few.  The most exciting sighting was a mother clapper rail with her chicks following closely behind.  Our resident bird expert said this was quite an unusual sight as it is rare to see the chicks (don’t forget…they are secretive).  It was certainly an interesting morning on the River and an experience I won’t soon forget.  In fact, I’m looking forward to going back out in July.  It’s amazing the wildlife you see early in the morning.   You never know what might be lurking in the marsh.

Scientist Log #6: You are never too old to play in the mud!

Thursday, May 10th, 2012

Have you ever wondered what the marsh was like many years ago? Probably not, but we (scientists) have a way of determining how much sediment has been collected on the marsh surface over long periods of time (also known as accretion). Recently, we collected three sediment cores within the St. Jones Reserve as part of a long term bio-monitoring project. In order to collect these cores, we used a large tri-pod to help pull up a PVC pipe that was pushed into the marsh to collect and hold the sample. This may sound simple, but there needs to be the right amount of suction to keep the core sample inside of the PVC pipe as we lift it up. Sometimes this process can take multiple tries! After each core is collected we put rubber caps on each end until the soil sample is ready to be processed. Analyses of these core samples for lead-210 and cesium-137 helps determine accretion rates and the age of various depths within the sediment over the past 50-100 years.

Processing the cores can be a messy and smelly job, but it is fun to work with marsh mud. Thankfully, we can open the windows to help reduce the smell. The first part of the processing requires the sediment core to be cut up into 2cm sections and dried in a scientific oven. Then the samples are sent to the University of Delaware campus in Lewes, DE for the final analysis.

Graduate Research Fellow Conducts Sediment Research

Tuesday, April 24th, 2012

Understanding coastal marsh development is an important part of determining their future. Brandon Boyd, a University of Delaware graduate student,  has been conducting research on Delaware’s coastal marshes – from saltmarshes near the bay mouth to tidal fresh farther up river. In conjunction with his advisor, Dr. Christopher K. Sommerfield, Brandon is studying sediment cores to determine the rate of sediment accumulation (collection) on the marsh surface. As shown in the picture, these cores are collected by pushing a five foot PVC pipe into the ground and removing it with a metal tripod. The collected soil is processed and radioactivity in the sediment layers is measured at the University of Delaware’s lab located in the College of Earth, Ocean and Environment in Lewes, Delaware. The radiation measured is naturally occurring.  The chronologies or date-assigned depths from these sediment cores are used to understand how sediment moves in the coastal system. Other researchers use the sediment core date data  for measuring nutrient burial or tracking pollutants.

As a NERR graduate research fellow for the Delaware NERR, Brandon is looking at the variability in the development of the marsh surface over the past 100 years. The development of the marsh can vary greatly from water front to high marsh.  Analyzing the differences in marsh surface development will assist in determining how well the marshes will adapt to sea level rise. So, the next time you’re out in one of Delaware’s marshes, watching the waterfowl or kayaking down a tidal creek, remember to be grateful for all that mud that sticks to you and your gear…without it, we wouldn’t have marshes!

Opportunity to Make a Difference

Wednesday, March 21st, 2012

It is that time of year when the Reserve gears up for all things horseshoe crab related.   Every spring around May and June, the Delaware Bay beaches are covered with spawning horseshoe crabs.  During this time trained volunteers help assess the horseshoe crab population by participating in the horseshoe crab spawning survey.  The survey began in the 1990’s to assist scientists in monitoring changes in population of spawning horseshoe crabs in the Delaware Bay. Delaware’s well-trained and enthusiastic volunteers have made this program one of the most successful volunteer based wildlife surveys in the country.   As part of the bay-wide survey, the Reserve coordinates the volunteer efforts on three bay beaches (Kitts Hummock, Ted Harvey, and North Bowers).   The preparation for the survey begins in March by seeking volunteers who are interested in participating in research and are up for an adventure!

It is important that volunteers are trained for the survey as the data is being used in management and policy decisions.  The Reserve staff holds two volunteer training sessions in April each year for anyone interested in assisting with the Horseshoe Crab Spawning survey.   The trainings take place at the St. Jones Reserve, 818 Kitts Hummock Road, Dover.  You are only required to participate in one of the following trainings:

Thursday, April 5, 2012 from 6 – 7:30 p.m. at the St. Jones Reserve           

Saturday, April 14, 2012 from 10 – 11:30 a.m. at the St. Jones Reserve

Are you ready and up for this awesome opportunity to be a citizen scientist?  We hope so!  We could definitely use your help.  To register for a training or for more information visit us on the web.

Scientist Log #5: Benchmarking

Friday, February 10th, 2012

February 10, 2012

Over the past few weeks, we have been busy installing benchmarks throughout Kent County.  We are not finding benches and marking them.  Benchmarks  are monuments scattered throughout the United States that are used for surveys in order to ensure accurate measurements for foundations of houses, roads, and other construction projects.  Benchmarks are also used to verify elevations within a project or to survey unknown points.  The benchmarks we are installing are either replacing old ones that have been destroyed or adding new ones to areas that lack coverage.  These new benchmarks will eventually be used by other surveyors throughout Delaware.

Rescuing a Feathery Friend

Thursday, December 22nd, 2011

Many people living on the coasts and near oceans have heard of seabirds.  Some of these birds are what scientists call pelagic which means that they live mostly in the open sea or ocean; however, they will come to land to breed.  That is why it was such a surprise to see one of our researchers bring a juvenile northern gannet into the Reserve.  The northern gannet is a seabird known for their remarkable diving capabilities  to feed on various fish species.  These birds are primarily white with black wing tips, a yellowish head, and greyish eyes.  However, the one brought into the Reserve was a juvenile and therefore it was brownish with white spots.  This young gannet was found in a salt marsh near the Delaware Bay.  An unusual spot to find a gannet as it is a pelagic species; and it’s not breeding season.  Unfortuantely, the little gannet  might have a respiratory issue and was taken to Tri State Bird Rescue where it is being nurtured back to health.  For more information on northern gannets visit the US Fish and Wildlife Service website and for more information on bird rescue work visit the  Tri State Bird Rescue and Research website.