The Great Spring - Home to the Earth's Oldest Fish

 

by Brian T. Lynch, MSW

The Great Spring in Kenvil is a relatively small wetlands area where cool spring water rises from an aquifer below to create the Black River in Roxbury Township in New Jersey. The spring is on the southern tip of over 800 acres of industrial land once owned by the Hercules Powder Company. Explosives were manufactured on that land for over 150 years. In all that time, the spring remained undeveloped.

Because it is located on private and restricted property, the existence of the Great Spring is not well known, and the ecology of the spring has never been studied, to my knowledge. This leaves me to wonder: What surprises might be found in a wetlands area that has been nearly undisturbed since the last ice age?

Black River in Kenvil, NJ, approximately 700' from the Great Spring. (Brian Lynch)

I’ve been a volunteer stream monitor for the Raritan Headwaters Association (RHA) since 2017. I thought the Black River began at Black River Pond but later discovered it started as a beautiful, fully formed stream flowing from a spring on the Hercules property. The spring contributes over two-billion gallons of water to the Raritan River each year. The RHA soon established a new stream monitoring sight 700 feet downstream from the spring, and I have been researching its history and geography ever since.

Unidentified fish in the Black River just downstream from the Great Spring (Brian Lynch)

Over the years, I have seen a few fish in this upper reach of the Black River that I can’t identify. I showed photographs to a fish biologist who couldn’t identify them either, perhaps because of the quality of the pictures.

Recently, a family living near the stream noticed some eel-like creatures at the monitoring site. They took pictures and sent them to the RHA and me. What they saw were four adult American Brook Lampreys. These freshwater lampreys are not the despised parasitic lampreys that live in oceans and swim up freshwater streams to attach themselves to game fish. Brook lampreys are smaller and live their entire lives in cool, unpolluted streams with sand or gravel streambeds.

American Brook Lamprey (with family's permission)

Lampreys are the most ancient group of vertebrates alive today. They have existed for over 360 million years, well before the first dinosaurs. Scientists know them as living fossils because they have remained unchanged from their earliest appearance in the fossil records. Lampreys have no jaws. They have seven gill holes behind their eyes instead of the familiar gill slits of modern fish. They are considered an endangered species in some states. In 2016, the New Jersey Endangered and Nongame Advisory Committee recommended a Special Concern status for this species, but no formal rule proposal has been filed to date. I spoke with a representative at DEP who said the Brook Lamprey may be classified as a species of special concern because there may not be enough data about their prevalence to list them as endangered.

Lampreys are increasingly being studied by scientists around the world. There is a growing imperative to study them. I came across a zoological research article in the NIH’s National Library of Medicine that states the potential importance of these ancient fish:

“The rapid development of cell biology and biochemistry technology, especially genomics and proteomics, has pushed lamprey research to new heights. Lampreys have a powerful and unique immune system and many valuable genes. Based on lamprey genome research, important human disease-related genes might be discovered. In addition, the pathogenesis of human diseases can be revealed by establishing lamprey genetic models of human diseases, which could provide the theoretical basis for in-depth study of the pathogenesis and treatment of diseases and development of new drugs. In recent years, lamprey numbers have drastically reduced, so lamprey research is important.”

What else might we discover in this nearly forgotten wetland? The Great Spring has been in private corporate hands for generations. Yet, it is a prolific public water source and an important ecological area. It is time we set this land aside as a protected public resource.

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NOTE: The native Leni Lenape called this spring in Kenvil the “Great Spring.” It contributes over two-billion gallons of water a year to the Raritan River upon which 1.8 million people rely on downstream. The aquifer supplying the spring starts below Picatinny Lake and the Green Pond area of Rockaway Township and stretches all the way down through Chester, Flanders, Long Valley, and into Hunterdon County. Much of the municipal drinking water in this area comes from wells tapped into this aquifer from the Alamatong well field in Randolph and commercial wells in Flanders.

Each year I complete a visual assessment of the stream and its surroundings and then collect samples of the macroinvertebrates that live in the stream bed. Samples are then sent to a laboratory where the types of critters collected are identified and numbered. This information, along with chemical water testing, is vital evidence for judging water quality. The results are posted annually on the RHA website.