By Rachael Bucci
On July 19th, 2012, several EPA staff and interns demonstrated sampling techniques in Jamaica Bay to members of the Rockaway Waterfront Alliance Summer Youth Program. The Rockaway Waterfront Alliance (RWA) is a group of Rockaway residents dedicated to protecting the health of their waterfront. They engage community members of all ages by encouraging participation in educational, recreational and conservational activities in the area. This trip with us was one of the many opportunities they use to educate local youth. Because Rockaway is economically disadvantaged, the RWA’s work toward and advocacy for local environmental justice is extremely important to the community’s environmental health.
When I first heard of this boating trip to Jamaica Bay, I was bursting with excitement. Yes! Jamaica, here I come! Beaches, waterfalls, zip lining, hopping nightlife! Time for a disclaimer: I am an intern from the Southeast. Northeast geography is as foreign to me as the things people eat on Fear Factor. In hindsight, I realize I was being completely unrealistic about the range of the EPA boat the Clean Waters. We would not, in fact, be sailing to the Caribbean. What we did get to do, however, was spend time with a group of engaging young people with astounding intellectual curiosity.
The crew of the Clean Waters demonstrated what a typical sample collecting trip would entail. First, we discussed all the aspects of sampling: planning, procedures, training, quality assurance, data processing, and result interpretation. Then the students set off to work on a visual and general assessment of the sampling site. How deep is the water, what color is it, what is the latitude and longitude? After that it was on to the fun stuff: water sampling. This training and demonstration included two general types of sampling—in situ and grab. In situ, translated loosely from the Latin to “on site,” means that the monitoring is done on location and without moving the object. Grab sampling is when the object is moved from its location to be analyzed elsewhere. It is the difference between taking a picture of a fish (in situ) and catching the fish and bringing it to a laboratory (grab). Often, these samples can be compared as a means of checking each other.
For the first water quality test, the students placed a Secchi disk into the water. The Secchi disk is a type of in situ sampling. This disk is divided into quarters which are painted alternating black and white. The students lowered the disk into the bay until they could no longer see the pattern. By finding this depth, they found the transparency of the water.
Having recorded this property, they moved on to the next test. They lowered the YSI multiparameter sonde (one of the many types of multiparameter sondes)—a vital piece of equipment for water quality analysis—from a cable into the bay. From the handheld electronic display, the students were able to measure the dissolved oxygen content and saturation, the specific conductivity, the temperature and the salinity of the water.
After completing the readings from the YSI, they removed it from the water and lowered a Kemmerer—a water sampler—to the same depth. They allowed the Kemmerer to fill with water from this depth, closed it, and raised it back onto the boat. They filled dissolved oxygen bottles and a few containers to do more testing. This is one way to check the in situ YSI samples against the grab samples as well as take a few new readings that the YSI doesn’t cover.
Then came the really fun part: getting to use all the awesome equipment on this floating laboratory. The first test for the grab sample was the salinity. Carefully pouring some of the water onto the prism of a refractometer, the students were able to see the salt content of the water. This is a way to check the in situ sampling of YSI. Then they measured the temperature of the water sample using both an electronic and an alcohol thermometer. To measure the dissolved oxygen content of the water and compare it to the YSI’s readings, the students used both the manual and the automatic dissolved oxygen titrators after observing the sample preparation. When these measurements were completed, they recorded their findings and discussed them with each other and with the crew of the Clean Waters.
The final sampling and demonstration of the trip was the hunt for benthic macroinvertebrates. The benthic zone is the ground beneath all the water, so any creature that is called “benthic” lives on the floor of the water body. Macroinvertebrates are animals that lack a spinal column and are very small, but still visible to the naked eye or under a microscope. Observing benthic macroinvertebrates is an important part of water quality monitoring because these animals are a good indicator of the health of the water body. The Clean Waters is equipped with a modified Van Veen dredge which is used to find such aquatic life. The crew lowered this dredge into the bay and pulled up sediment from the bottom. Sediment samples require thorough sieving so that all of the sediment is washed away, leaving only animal and plant life.
The students eagerly looked for critters in the slowly filtering sediment. They found a worm, a jellyfish, a clam, and several tiny shrimp. Then, from beneath the pitch black sludge and oily sheen emerged a few small crabs. Everyone took a few minutes to watch them scurry back and forth—and to get a few pictures—before returning them safely to the water.
When we were finished, we said goodbye to the RWA students and chaperones and set sail, not for Jamaica, but for our home port. Our educational demonstration was very enjoyable, especially because it is always a treat to talk to students who are as excited to be learning about the environment first-hand as you are to be teaching it to them.
About the author: Rachael Bucci is an Environmental Justice and Citizen Science intern in EPA Region 2’s Edison office. She is a rising senior studying physics at Northwestern University in Evanston, Illinois.
Editor's Note: The opinions expressed in Greenversations are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.