How healthy is the Upper Lehigh River? Ask a fish

Located in northeastern Pennsylvania, the Lehigh River originates in a series of glacial bogs and marshes in the area of Pocono Peak Lake in the Gouldsboro area about 15 miles southeast of Scranton. The elevation at the Lehigh River headwaters is approximately 2,200 feet above sea level, and drops nearly 1,000 feet during its 103-mile journey to its confluence with the Delaware River in Easton. The Lehigh’s watershed is approximately 1,345 square miles in area and consists of approximately 2,000 miles of streamways. It is a significant sub-basin within the Delaware River watershed. – From fishandboat.com the website of the Pennsylvania Fish and Boat Commission.

AS THEY PREPARE for work, they look more like Ghostbusters than scientists.

But scientists they are, checking the fish population in the upper Lehigh River in the remote Township of Coolbaugh, Pa.

Fish tell stories about the waterways they inhabit, and here to “read” those stories were men and women from The Academy of Natural Sciences of Drexel University, in Philadelphia.

The Ghostbuster apparatus that three of them hoisted on their backs were for stunning the fish, so that the fish could be netted and placed in a bucket full of river water, and counted and measured later. All eight scientists were outfitted with waders and rubber gloves so that any stray electricity wouldn’t cause harm.

PHOTO GALLERYAs you might expect, there’s a lot of precision to the work. Since they are repeating a fish count that was held here two years ago, it’s important that the same stretch of river is studied.

Sixty-eight meters downstream from the small bridge used as a landmark, they stretch the measuring tape for the full 100 meters they would survey. At the 100-meter mark, they  stretch a net across the stream. It’s important that new fish don’t swim into the survey area. And once they are done with the count, the fish in buckets are released down stream of that net, free to swim.

This is but one stream of four in the area that this team will be surveying this week.  Next week, there will be still more streams to survey.

These fish surveys are part of immense ecological testing that is being conducted throughout the Delaware River watershed in wadable rivers and streams. There are other crews that will survey this same stretch of stream checking what the water chemistry is, another team will be checking algae, another testing for tiny life forms called diatoms. Each subset will give information about the health of the stream.

The Delaware River Watershed Initiative has divided the watershed into eight separate pieces. This one where the Lehigh flows is in the Upper Lehigh cluster. This team will be visiting and measuring in earmarked streams in each of those clusters.

This stream runs clear — at least to the eye. David Keller, the team leader, explains that he would expect the fish they catch today to indicate a healthy river. They took the same sorts of measurements two years ago, and Keller explained that both of those measurements form a baseline to check on the stream’s health for many visits in the future. He thought that the likely threat he would be on the lookout for here would be increased  human development. Some of the significant threats in other areas of the Delaware watershed are polluted street run-off draining into storm drains and then into the river; agricultural run off;  sedimentation, animal waste and run-off from fertilizer and other soil treatments.

Improving water quality downstream

The sites that teams visit are called integrative streams. These sites are chosen down stream of work that all sorts of volunteer organizations tackle to improve stretches of smaller streams that flow into the Lehigh. Says Keller: “This is a way for us all to see if the work they’re doing is helping to make this river healthier.”

And if this river is healthier as it flows into the Delaware, the Delaware itself can get healthier. That’s how watersheds work. They drain vast areas into small streams and rivers, which then empty into larger and larger bodies of water. Ultimately, when a healthy Delaware River flows into the Delaware Bay and the ocean beyond, the adverse effects of human activity on the oceans can be as least partly mitigated.

In addition, good streams give better water for people to drink.

Just like the water itself, if you go “upstream” of this project, you find the organizations and foundations that feed this work with the money that funds it. In fact, this whole project was funded by a $35 million grant from the William Penn Foundation in Philadelphia, which partnered with the Open Space Institute to kick off the project.

And just as large bodies of water are fed by countless streams, there are dozens of grantees who are doing their part in creating a healthier watershed in New York, Pennsylvania, Delaware  and New Jersey.

Back to the Lehigh: All eight scientists formed a line across the river. The three with the stun apparatus moved slowly through the water, their colleagues netting the stunned fish and pushing into all the nooks and crannies that the fish live in. And even though the current in the river is strong. most of the fish caught here, live here. Even a small stretch of stream can provide a variety of habitats for darters and madtoms that like the river bottom and dace and minnows that live near the rocks that are scattered throughout the river. Today, the Cutlips Minnow was the most common fish collected.

An intense count

It takes about an hour and half for the team to make their careful way upstream, probing and prodding. This is the first of three passes the team makes in the day. A process called removal sampling is used to estimate the total number of fish species found in the 100 m stretch. Since the first pass doesn’t collect all the fish in the river, there are two more passes. Each successive pass collects fewer fish, ultimately allowing the scientist  to estimate the total present. This yields a fairly solid set of numbers that  can be used in the future.

For the count they gather those buckets and take the lively fish and gently lay them across what looks like a wooden shoe box, with two sides removed. There’s a measuring bar inlaid into the wood and each fish is measured against it — some are so active they will flap right off the board, but they are soon found in the wet grass, measured and returned to the river water.

It’s a pretty intense time. The clock is running and the scientists pair up, one reaches for the fish, one measures and calls out both the quick nick name of the fish (an abbreviation of its proper scientific name) and its length. Some minnows are very tiny. Listen to the call:

“EXMAX — 8.0”

“LUCOR — 8.5”

“RHATR — 9.7”

Another member of the team is writing down the information. The process is done in about half an hour.

The team is way less interested in what will be called the raw data. For the interested layman bystander, on the other hand, the count this day is: 826 total fish collected, of which there were 19 species. The Cutlips Minnow was the most common species with 207 collected.

But what is also interesting to note is how careful these fishermen and women are about the catch. Yes, the fish spend some time in buckets. But there is a sense of urgency to get to the counts and to release the fish as quickly as possible. What’s more, the scientists are in the biggest hurry with the biggest fish. Those are the fish who will deplete the oxygen in the river water in those buckets most quickly, so there is a danger of suffocation. There is a small percentage of fish who don’t make it, but most return to their stream — ready to be counted when this or another team returns.

Thanks to the team for letting me be a part of their day: David Keller, Paul Overbeck, Allison Stoklosa, Frankie Lazaukas, Dan Lipshutz, Kirk Raper, Stephen Dench and Raffaela Marano.