The Return of the American Shad to the Musconetcong River

PHOTO/New Jersey Division of Fish and Wildlife biologist Pat Hamilton holds a shad near the Warren Glen Dam

After a 250+ year absence, American shad have returned to the Musconetcong River in Hunterdon and Warren counties. This milestone in the ecological recovery of the river is the result of the removal of dams on the lower Musconetcong several years ago, followed by the removal of the Hughesville Dam in Warren County last year.

Removing the dams opened nearly six miles of the Musconetcong to migratory fish, such as American shad, that spend much of their lives in the ocean but return to rivers and their tributaries to spawn. The shad’s return is a good sign of the overall ecological health and diversity of the river.

Princeton Hydro was proud to partner with the Musconetcong Watershed Association and so many other incredible organizations who came together on the Hughesville Dam Removal project. To date, Princeton Hydro has investigated, designed and permitted five dam removals on the Musconetcong.

The next Musconetcong dam targeted for removal is the 32-foot high Warren Glen Dam, less than a mile farther upstream. It is the largest dam in the river; by comparison, the Hughesville Dam was 15-feet tall.

Princeton Hydro President Geoff Goll, P.E. published this commentary piece titled, “The Return of the American Shad to the Musconetcong River:”

Update (June 15, 2017)NJDEP issued press release on the finding of American shad on the Musky. Bob Shin, NJDEP Commissioner, stated, “[t]he return of shad, a benchmark species indicative of the overall ecological health and diversity of a waterway, is an exciting milestone…. This achievement is the direct result of an ongoing partnership among state and federal agencies, nonprofit groups, and dam owners – all committed to making this beautiful waterway free-flowing again.

On June 7, 2017, Princeton Hydro celebrated along with the Musconetcong Watershed Association (and an excellent story of the MWA, human history of the river, and the efforts to preserve the history and ecology can be found here) and other project partners, the discovery of American shad on the Musconetcong River in NJ, over 250 years after they were blocked from this major tributary of the Delaware River – On September 8, 2016, then Secretary of the Interior, Sally Jewell, held a press conference to celebrate the initial breach of the Hughesville Dam on the Musconetcong River (time lapse of removal is here). The press conference was held as the Department of the Interior via of the US Fish and Wildlife Service provided the funding to remove this obsolete structure through their Hurricane Sandy Recovery funding and the Natural Resource Damage Assessment and Restoration program. In addition to the Honorable Sally Jewell, NJDEP Commissioner Bob Martin, and US Army Corp of Engineers, Philadelphia District Commander Lt. Colonel Michael Bliss, were also on hand to speak about the importance of the Hughesville Dam removal and dam removal in general. To have such dignitaries at the highest levels of our Federal and State government speak at a project our firm designed was truly an honor and privilege. It was a great day to celebrate the next obsolete dam on the Musconetcong River to fall to the progress of river restoration. However, this would pale in comparison to the news we received on Wednesday, June 7, 2017, when the NJ Division of Fish and Wildlife confirmed the presence of the American shad (Alosa sapidissima) above the Hughesville Dam!

Ms. Patricia Hamilton, Fisheries Biologist of NJ Fish And Wildlife, reported that they “spotted small schools of American Shad (at most 6 at a time) and captured 4 several hundred yards downstream of the Warren Glen Dam”, five miles from the confluence of the Delaware River. This is the first documentation of American shad on this river in over 250 years! So, what is the big deal you may ask.

The American shad is the Mid-Atlantic and Southeastern United States’ salmon; it is actually a clupeid, a forage type fish closely related to herrings and sardines. Like herrings and sardines, they are a very oily fish, high in omega-3 fats, and low in contamination. It is also a fairly large clupeid, reaching three to eight pounds as adults. Like the salmon, American shad are anadromous, meaning they live the major part of their lives in the ocean and spawn up the coasts’ rivers. The American shad is not a spectacularly looking fish to say the least, and in fact, looks like a “generic” illustration of a fish, unlike the sleek and sexy salmon. It doesn’t even jump. However, this fish is a long distance and endurance swimmer, who’s migration from its hatching in rivers of the East Coast to its primary habitat in the Atlantic Ocean up in the Gulf of Maine, makes it one of the Earth’s great travelers. It can swim nearly 20,000 kilometers in its first five years of life and can dive to depths of up to 375 meters. And like all of its clupeid kindred, it is both a key prey species for many large fish and cetaceans in the Atlantic’s pelagic zone (open ocean) and an important commercial fish. But it is the existence of over-fishing, pollution and dams that had brought this species to its knees in many of the major eastern US rivers.

While the Delaware River shad and herring species have rebounded somewhat from low populations in the mid-1900s with the advent of the US Clean Water Act, they continue to struggle to regain their numbers, and in fact, there is now a moratorium on catching river herring in the Delaware River, and NJ has a moratorium on the harvesting of shad and herring on its tributaries to the Delaware River and Atlantic Ocean. As far as tributary access is concerned, the largest tributaries to the Delaware, the Schuylkill and Lehigh Rivers, are still blocked by dams to their mouths with very little efficiency of fish ladders provided; with their dams having very little success in gaining support for the removal of their blockages. So, any gains in additional spawning habitat for such anadromous species is viewed as a significant victory. The opening of the Musconetcong River to migrating fish will be a large contributor to the rebound of American shad, and other river herring species.

As one of the original 13 colonies, NJ was an integral partner in the start of the United States and early industrial revolution. It has been documented through our research during the dam removal regulatory permit application process on this waterway that the Musconetcong River has been dammed just about all the way to its confluence with the Delaware River since the mid-1700s, and likely much earlier. So, before there was anyone who understood the importance of unimpeded rivers for fish migration, this particular route was cut-off in its entirety, and then remained so for well over 250 years. So, it is understandable that there was no reason to assume that anadromous fish, such as shad, would resume the use of the river in a short period of time; however, there existed the right habitat for them, should they be afforded access…and the hope of the partners working on this river. There were doubters, to be sure, but “lo and behold”, we now know these mighty fish took advantage of an opening almost immediately.

Now, I am not stating that American shad immediately realized that the Hughesville Dam was gone and took a B-line from the Delaware River to the highest unimpeded location. First, other dams downstream of the Hughesville Dam had been removed over the past several years. These dams included the Finesville Dam (for an excellent video of the story of this dam removal, check out this video by the US Fish and Wildlife Service), removed in 2011 and the Reigelsville Dam remnants (there were two additional remnants found when the first foundation was removed) soon after the Finesville Dam was removed. So, it is likely that American Shad had started moving up the river to the base of the Hughesville Dam between 2011 and 2016. Still the response by American shad is nothing short of spectacular. For the over 250 years this species has not been able to use this river, at all, and now, within a span less than six years of dam removal activities, this fish is raring to comeback and, hopefully, spawn and increase their numbers.

And the efforts are not nearly complete for the Musconetcong River. The finding of the American shad five miles upstream from the Delaware River shows that this river can and, now, does support this fish. This generic looking fish, yet awesome product of evolution should only fuel the fire of continued restoration efforts, proof-positive that the labor and funds spent here, in this river, gets results. Such funds and labor (an staggering amount of time, blood, sweat, and tears) are required in order to get the river restoration work done. These projects have received the majority of their backing from the federal government, through grant programs, natural resource damage funds, and direct Congressional authorized funds. Without support from Washington, D.C.,, and Trenton, none of this work would be possible. And to get these funds, required work by the many team partners to prepare applications, meet with federal agencies, and educate the public through open and transparent meetings and communication. This was an impressive effort by the residents of this watershed, professionals who provided their expertise, and the state and federal employees who have dedicated their lives to this kind of work.

The Musconetcong River, with its recovering ecosystem, and its human and non-human inhabitants continue to amaze me in how we should all strive to strike balance between man and nature; and all this is being accomplished in the most densely populated state in the nation.

The finding of American shad gives me reason to cheer, and is why I do what I do. This is it, the return of a species that at one time we had no assurance would return, has returned. This is hope for us, after all.

Read more about Princeton Hydro’s river restoration and dam/barrier services on our website. Please contact us anytime if you have a project you’d like to discuss.

NJ Audubon undertakes $470G study of climate change impact on wetlands

Princeton Hydro is proud to be a partner on this incredible project

If you’ve ever gone birdwatching at any east coast wildlife refuge, then you probably understand the value of coastal impoundments. These man-made wetland habitats are contained by embankments and have gates that allow managers to manipulate water levels. In addition to being valuable, these structures are also very vulnerable to sea level rise and extreme weather.

Through a $470,000 federal grant, the New Jersey Audubon is implementing an initiative to study the vulnerability of these impoundments to climate change induced environmental impacts. Funded by the U.S. Department of the Interior via the National Fish and Wildlife Foundation, the Coastal Impoundment Vulnerability and Resilience Project (CIVRP) aims to map and catalog all state, federal, and privately owned coastal impoundments from Virginia to Maine. The project is a cooperative effort of a diverse team of partners including researchers from New Jersey Audubon, National Wildlife Federation, Conservation Management Institute (Virginia Tech), U.S. Fish and Wildlife Service and Princeton Hydro.

The CIVRP will ultimately reduce climate vulnerability and enhance the natural ecosystem function of these precious and treasured wetland habitats. Read the full article from MyCentralJersey.

Princeton Hydro specializes in the restoration, creation and enhancement of tidal and freshwater wetlands. Contact us to learn more, and read about some of our award-winning wetland-related projects here.

Four Ways Climate Change Could Affect Your Lake

The Local Effects of Climate Change Observed Through our Community Lakes

Climate change is an enormous concept that can be hard to wrap your head around. It comes in the form of melting ice caps, stronger storms and more extreme seasonal temperatures. If you’re an avid angler, photographer, swimmer, boater or nature enthusiast, it’s likely that because of climate change you’ll bear witness to astonishing shifts in nature throughout the greater portion of your lifetime. This is especially true with respect to lakes.

2015-07-07-10-01-20Lakes are living laboratories through which we can observe the local effects of climate change in our own communities. Lake ecosystems are defined by a combination of various abiotic and biotic factors. Changes in hydrology, water chemistry, biology or physical properties of a lake can have cascading consequences that may rapidly alter the overall properties of a lake. Most of the time the results are negative and the impacts severe. Recognizing and monitoring the changes that are taking place locally brings the problems of climate change closer to home, which can help raise awareness and inspire environmentally-minded action.

Princeton Hydro has put together a list of four inter-related, climate change induced environmental impacts that can affect lakes and lake communities:

1. Higher temperatures = shifts in flora and fauna populations

The survival of many lake organisms is dependent on the existence of set temperature ranges and ample oxygen levels. The amount of dissolved oxygen (DO) present in a lake is a result of oxygen diffusion from the atmosphere and its production by algae and aquatic plants via photosynthesis. An inverse relationship exists between water temperature and DO concentrations. Due to the physical properties of water, warmer water holds less DO than cooler water.

This is not good news for many flora and fauna, such as fish that can only survive and reproduce in waters of specific temperatures and DO levels. Lower oxygen levels can reduce their ability to feed, spawn and survive. Populations of cold water fishes, such as brown trout and salmon, will be jeopardized by climate change (Kernan, 2015).

358-001-carp-from-churchvilleAlso consider the effects of changing DO levels on fishes that can tolerate these challenging conditions. They will thrive where others struggle, taking advantage of their superior fitness by expanding their area of colonization, increasing population size, and/or becoming a more dominant species in the ecosystem. A big fish in a little pond, you might say. Carp is a common example of a thermo-tolerant fish that can quickly colonize and dominate a lake’s fishery, in the process causing tremendous ecological impact (Kernan, 2010).

2. Less water availability = increased salinity

Just as fish and other aquatic organisms require specific ranges of temperature and dissolved oxygen to exist, they must also live in waters of specific salinity. Droughts are occurring worldwide in greater frequency and intensity. The lack of rain reduces inflow and higher temperatures promote increased evaporation. Diminishing inflow and dropping lake levels are affecting some lakes by concentrating dissolved minerals and increasing their salinity.

Studies of zooplankton, crustaceans and benthic insects have provided evidence of the consequences of elevated salinity levels on organismal health, reproduction and mortality (Hall and Burns, 2002; Herbst, 2013; Schallenberg et al., 2003). While salinity is not directly related to the fitness or survival rate of all aquatic organisms, an increase in salinity does tend to be stressful for many.

3. Nutrient concentrations = increased frequency of harmful algal blooms

Phosphorus is a major nutrient in determining lake health. Too little phosphorus can restrict biological growth, whereas an excess can promote unbounded proliferation of algae and aquatic plants.

before_strawbridgelake2If lake or pond water becomes anoxic at the sediment-water interface (meaning the water has very low or completely zero DO), phosphorus will be released from the sediment. Also some invasive plant species can actually “pump” phosphorus from the sediments and release this excess into the water column (termed luxurious uptake). This internally released and recycled sedimentary phosphorus can greatly influence lake productivity and increase the frequency, magnitude and duration of algae blooms. Rising water temperatures, declining DO and the proliferation of invasive plants are all outcomes of climate change and can lead to increases in a lake’s phosphorus concentrations and the subsequent growth and development of algae and aquatic plants.

Rising water temperatures significantly facilitate and support the development of cyanobacteria (bluegreen algae) blooms. These blooms are also fueled by increasing internal and external phosphorus loading. At very high densities, cyanobacteria may attain harmful algae bloom (HAB) proportions. Elevated concentrations of cyanotoxins may then be produced, and these compounds seriously impact the health of humans, pets and livestock.

rain-garden-imagePhosphorus loading in our local waterways also comes from nonpoint sources, especially stormwater runoff. Climate change is recognized to increase the frequency and magnitude of storm events. Larger storms intensify the mobilization and transport of pollutants from the watershed’s surrounding lakes, thus leading to an increase in nonpoint source loading. Additionally, larger storms cause erosion and instability of streams, again adding to the influx of more phosphorus to our lakes. Shifts in our regular behaviors with regards to fertilizer usage, gardening practices and community clean-ups, as well as the implementation of green-infrastructure stormwater management measures can help decrease storm-related phosphorus loading and lessen the occurrence of HABs.

4. Cumulative effects = invasive species

A lake ecosystem stressed by agents such as disturbance or eutrophication can be even more susceptible to invasive species colonization, a concept coined “invasibility” (Kernan, 2015).

For example, imagine that cold water fish species A has experienced a 50% population decrease as a result of warming water temperatures over ten years. Consequently, the fish’s main prey, species B, has also undergone rapid changes in its population structure. Inversely, it has boomed without its major predator to keep it in check. Following this pattern, the next species level down – species B’s prey, species C – has decreased in population due to intense predation by species B, and so on. Although the ecosystem can potentially achieve equilibrium, it remains in a very unstable and ecologically stressful state for a prolonged period of time. This leads to major changes in the biotic assemblage of the lake and trickle-down changes that affect its recreational use, water quality and aesthetics.

• • •

Although your favorite lake may not experience all or some of these challenges, it is crucial to be aware of the many ways that climate change impacts the Earth. We can’t foresee exactly how much will change, but we can prepare ourselves to adapt to and aid our planet. How to start? Get directly involved in the management of your lake and pond. Decrease nutrient loading and conserve water. Act locally, but think globally. Get out and spread enthusiasm for appreciating and protecting lake ecosystems. Also, check out these tips for improving your lake’s water quality.


References

  1. Hall, Catherine J., and Carolyn W. Burns. “Mortality and Growth Responses of Daphnia Carinata to Increases in Temperature and Salinity.” Freshwater Biology 47.3 (2002): 451-58. Wiley. Web. 17 Oct. 2016.
  1. Herbst, David B. “Defining Salinity Limits on the Survival and Growth of Benthic Insects for the Conservation Management of Saline Walker Lake, Nevada, USA.” Journal of Insect Conservation 17.5 (2013): 877-83. 23 Apr. 2013. Web. 17 Oct. 2016.
  1. Kernan, M. “Climate Change and the Impact of Invasive Species on Aquatic Ecosystems.” Aquatic Ecosystem Health & Management (2015): 321-33. Taylor & Francis Online. Web. 17 Oct. 2016.
  1. Kernan, M. R., R. W. Battarbee, and Brian Moss. “Interaction of Climate Change and Eutrophication.” Climate Change Impacts on Freshwater Ecosystems. 1st ed. Chichester, West Sussex, UK: Wiley-Blackwell, 2010. 119-51. ResearchGate. Web. 17 Oct. 2016.
  1. Schallenberg, Marc, Catherine J. Hall, and Carolyn W. Burns. “Consequences of Climate-induced Salinity Increases on Zooplankton Abundance and Diversity in Coastal Lakes”Marine Ecology Progress Series 251 (2003): 181-89. Inter-Research Science Center. Inter-Research. Web. 17