Water Quality Testing with Girls Inc.

On the morning of August 9, 2017, I ventured out into Lynn to help out a Girls Inc. group with water quality. I was asked to come as a guest scientist and was able to share some knowledge I've gained over the years and in my time at Save the Harbor/Save the Bay. The students from Girls Inc. were a part of the Beach Sisters group and had been going to different areas on the Lynn coast to sample water. Most of the girls were very excited to get out into the field and do some water quality testing!

Our first stop was off a small pier in Lynn. Here various stations were set up and after some water was collected and the girls paired up and cycled through the tests with each pair testing for nitrate, phosphate, dissolved oxygen, turbidity, and salinity. A variety of instruments were used such as a refractometer and hydrometer to test salinity, thermometers, a pH probe, secchi tube for turbidity and various chemical test kits to measure other parameters. I was very impressed with everyone as they knew exactly what they were doing with all the instruments available on site. A plankton tow was also used to collect plankton from the surface water to be viewed under the small microscopes we had on site.

Setting up testing stations

Checking salinity with a refractometer

Checking turbidity with the secchi tube

Using a Van Dorn water sampler

At this site, we were able to use a Van Dorn water sampler. The purpose of this instrument is to collect water from below the surface. This provided the girls the opportunity to compare the differences between the surface sample and the one taken below. Although the current was pretty strong when we got there and were not able to sample at the bottom of the water column, the girls understood the purpose of the device and they were able to investigate the differences between the water samples taken at different depths.

Van Dorn water samplers take water sample from below the surface!

Once we finished up at the pier, we were off to our next stop which ended up being a marshy area in Lynn. We ventured up a small path and found the marsh. Here, the girls were able to note the various plants such as marsh lavender. Similar to the first site, stations were set up and then those who were brave to march on the marshy mud went out to collect water. There was a marsh panne where water was also collected. We set up a trap with some pretzels in the panne and were able to catch a couple of small mummichogs. The girls noticed the water was saltier in the panne than it was in the marsh, which was expected, but it demonstrated again how easily water quality can change even when the samples are taken a short distance from each other.

Setting up water quality testing

Brave volunteers collecting our first water sample

Walking back to dry land

Collecting water from the marsh panne

Checking the trap

One of many mummichogs!

A larger mummichog (Fundulus heteroclitus)

Overall I had a blast with the Girls Inc. group. It was great to see young high schoolers get excited about science and I was very happy to teach them some facts about water quality and marine biology. I am hoping these types of projects help lead some of these girls into the STEM field because with their natural curiosity, I know they'll go far!

-Diana