Sound Stories

The blog of the Long Island Sound Study

A Chilly Day On the Sound

Yes, this winter was mild (never mind the surprise early spring snow!). But there were some cold days on land and on sea. CT DEEP's Environmental Analyst Katie O’Brien-Clayton describes what it's like to monitor water quality on board a research vessel in winter.

Staff from the RV John Dempsey retrieving the “bongo” net contain samples of zooplankton from the Sound. Photo credit: CT DEEP.

It’s 4.a.m. The alarm sounds. AWW-UU-GAAA. AWWW-UUU-GAAA. Pitch black. I rush quickly out of bed to shut off my annoying alarm before I wake my entire family. After a quick shower, I pull on multiple layers of warm clothes before heading out the door to drive to the dock to join my colleagues on board the Research Vessel John Dempsey for the monthly survey of water quality in Long Island Sound.  I’ve got to be there by 6 AM. At least it’s not snowing this morning, the seas should be calm, and we’re heading east so we should have a great sunrise, even if the temperature is only 21ºF.

The state agency I work for, the Connecticut Department of Energy and Environmental Protection (CT DEEP), has been conducting water quality monitoring in the Sound since 1991. The monitoring is year-round, even during the coldest parts of the winter, because winter conditions can lead to poor water quality in the summer (more on that later).

CT DEEP winter seasonal staff deploying the rosette sampling array into the Sound. The containers on the array are the Niskin bottles. Photo credit: CT DEEP.

A typical survey takes us three days to complete; we take the ship to as many as seven locations per day, traveling as much as 15 miles between stations, to check on the health of Long Island Sound. We deploy heavy monitoring equipment called a rosette sampling array to the bottom depths of the Sound to collect water samples. As we sort out these samples in the onboard lab to prepare them to be analyzed later, the Captain steers the ship to the next station to make sure we keep on schedule. This is no cakewalk in the best of conditions, but just wait until you have to sample in the winter…. with below-freezing temperatures and an average 2.5-foot chop; with occasional 4-foot seas. Crew safety is of the utmost concern, especially around cold water.

While our fluorescent orange Coast Guard-approved float coats aren’t debuting on the New York fashion runways, they must be worn during deployment of any gear. We do not want to find ourselves in situations similar to Cold Water Boot Camp. Additionally, gloves, whether they are fishermen’s waterproof insulated gloves or nitrile gloves worn over stretch knits, are a must when deploying the rosette. Bare skin on cold, wet metal… no triple-dog dares aboard this research vessel. 

It’s not so easy to deploy and retrieve our rosette sampling array which is used to collect water samples and houses our multi-parameter sonde (an instrument probe). The rosette sampling array is basically a 200-pound metal circle to which we attach 5-L Niskin sampling bottles. An electro-mechanical signal is sent through a cable to the trigger mechanism on the rosette, closing the bottles and collecting a sample. During winter surveys the trigger mechanism can freeze, when this happens we break out the heat gun and gently melt any ice that accumulated on the plastic pins.

Another challenge to sampling during the winter involves the sonde.  While the sonde itself operates in water temperatures between -5 and 50ºC, it needs to be stored at temperatures above 0ºC. Being on the deck while transiting from station to station subjects it to temperatures and wind chills below zero; we’ve lost quite a few pH probes to freezing. So we bring it inside the cabin after every cast when the thermometer shows air temperatures below 0ºC.

Matt Lyman, an environmental analyst at CT DEEP, pours a water sample into a flask with a filtration device for analysis. In the background, O’Brien-Clayton is preparing to replace filter assemblies into the flasks in order to analyze more samples. Photo credit: CT DEEP.

Have you ever tried to pour water from one Snapple bottle into another while riding a roller coaster? I haven’t either, but it’s analogous to filtering water in rough seas. After we collect the water in the Niskins, we bring them into our shipboard laboratory where the water is filtered. The filtrate and filters are sent to the University of Connecticut for analyses.    

A 64-micrometer sieve is used to concentrate a zooplankton sample taken from the bongo net after it was put through a 64-micrometer sieve. The sample will be placed in the sample collection bottle. Photo credit: CT DEEP.

So why do we sample in the winter anyway? We are concerned about hypoxia, which is when the Sound’s dissolved oxygen levels fall below 3 mg/L.  Hypoxia is harmful to fish and other wildlife, and can even lead to fish kills. Fish that can scatter avoid the “dead zone” entirely. While hypoxia occurs in the summer, winter is a period in which some of the conditions that cause hypoxia, such as the growth of plankton blooms stimulated by excess nutrients such as nitrogen can occur.  Our winter surveys are aimed at capturing the winter/spring plankton bloom as well as spikes in nutrient concentrations associated with the spring thaw that increases the amount of runoff from snow and ice melt into rivers and streams and eventually the Sound.  The timing and magnitude of the bloom have implications for the severity and extent of hypoxic conditions seen over the summer.

It’s 4:30 PM. The sun is disappearing behind the clouds. As we finish up our day out on the Sound and enter Milford Harbor, I’m happy that we won’t have to break ice getting to the dock today and I long for the warm sunny days of summer sampling.

Katie O’Brien-Clayton is an Environmental Analyst with the CT Department of Energy and Environmental Protection Long Island Sound Monitoring Program. She has been with the program since 2006. She received her Bachelor of Science degree in Marine Science from Southampton College in 1999.

Information about the initial monitoring plan developed for Long Island Sound is available on the Long Island Sound Study website. Information about the CT DEEP LIS Sampling Program is available on our website at

A Really Cold Day Onboard the Dempsey

This photo was taken in December 2014 onboard the RV John Dempsey. Matt Lyman prepares to deploy a bongo net over the side to collect zooplankton samples aboard the research vessel John Dempsey. Samples of zooplankton, microscopic animals, are collected year-round at six sites throughout Long Island Sound. Photo credit: CT DEEP.

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