How’s the Fishing? Tips for Managing Your Lake’s Fishery

The fishery of a lake is an intrinsic, incredibly dynamic element of a lake system, and managing a lake’s fishery can be a very complex endeavor. There is actually a lot more to it than simply stocking game fish. Although there is no “one way” in fisheries management, there are key guidelines that can be followed to maximize the recreational potential of your lake’s fishery and increase the success of your fishery management and stocking efforts. Over the past two decades, Princeton Hydro has been working with lake, pond, and reservoir managers to help them to align water quality, fishery, and ecological goals.

Princeton Hydro’s Founder, Dr. Steve Souza, recently gave a presentation on fisheries management at the Spring Meeting of the New Jersey Coalition of Lake Associations (NJCOLA). We’ve compiled a few essential elements from his presentation and have made the complete presentation available for free download.

Let’s dive in!

Benefits of a Healthy Fishery

Recreational fishing is an outdoor activity that can be enjoyed by people of all ages. When children are introduced to fishing, it helps cultivate a connection to the environment, thereby promoting outdoor activity and environmental stewardship among today’s youth.

Anglers have always served as important advocates for the conservation of natural resources. The sale of fishing licenses financially supports wildlife habitat conservation and enhancement as well as the protection and improvement of water quality. This increases the ecological services and functions of lakes and adds to their societal and recreational benefits.

A healthy fishery can have significant positive impacts on water quality. In a balanced, healthy fishery the ratio of forage and game fish affects the entire food web, helping to maintain the proper balance of zooplankton and phytoplankton. The “top down” ecological control associated with a balanced fishery minimizes algae blooms, sustains good water clarity and stable water quality. However, when the fishery is out of balance, the water quality and overall ecological health of the lake often suffers.

Before You Stock, Know Your Lake and Start with a Baseline

Before you do any fish stocking, it’s best to conduct a fishery survey. A fishery survey provides the vital data needed to design a stocking and management plan.

A balanced lake fishery is dependent on good water quality, ample habitat, and the correct ratio of predator and prey fish species. A properly designed and implemented fishery survey generates the data needed to quantify the overall composition of the existing fish community (predator vs. prey), the make-up of the forage (food) base, and the density and robustness of the lake’s top piscivores (prized game fish).

The resulting data helps identify if your fishery is balanced, which fish to stock, and how many of each species to introduce. It will also provide the benchmarks needed to solidify your management goals and, later on, help determine if the goals are being met. To stay on track, we recommend that a comprehensive fishery survey be conducted once every three years. Be sure to use the correct types and combination of “active” and “passive” sampling gear and thoroughly sample both the open water and nearshore areas of the lake.

The survey should include the collection and analysis of water quality data, and the mapping of available habitat. Water column water quality “profiles” provide vital information pertaining to the lake’s thermal and dissolved oxygen properties; key factors for a healthy, vibrant fishery. Here are some basic water quality guidelines:

  • Dissolved oxygen: ≥ 4 mg/L with 6-7 mg/L being ideal
  • For warm water fishery: Uniform temperatures at all depth (minimal or no thermal stratification)
  • For cold water fishery: Deep water temperature of 15 C, and dissolved oxygen ≥ 5 mg/L
  • pH: 6 to 8
  • Clarity: ≥ 3 feet (1 meter) Secchi disc transparency
  • Total Phosphorus: < 0.05 mg/L
  • Chlorophyll a: < 20 µg/L

Water quality sampling should also include an assessment of the lake’s zooplankton and phytoplankton communities, the base of your lake’s food web.

Floating Wetland Island

During the survey, take the time to quantify and map the distribution of existing forage, spawning, and refuge habitat. Lack of adequate habitat can significantly impede the fishery’s sustainability. This begins with the bathymetric mapping of the lake, which is basically an underwater survey of the bottom of the lake. This mapping shows where and how much shallow water versus open water habitat exists.  It can also help identify the location and distribution of important habitat types, such as shoals, rock piles, sandy open areas and natural structures (tree falls and snags). The data also helps determine where to create and introduce habitat, which can be in the form of brush piles, floating wetland islands, and other types of features that increase the spawning, recruitment, and foraging success of the fishery.

Stocking Your Lake

Once the fishery survey is completed, habitat is mapped and water quality analyzed, stocking can begin. In order to determine the specific stocking levels and rates that are right for your waterbody, here are some factors to consider:

  • Ensure your stocking efforts create or augment the correct ratio of predator (game) and prey (forage) fish.

  • Stock cautiously, focusing on a simple composition of predator and prey species. For most warm water lakes, largemouth bass should serve as the top predator and fathead minnow should be the primary prey.

  • Avoid problem fish, such as golden shiner, alewife and brown/black bullhead. Although these fish are often promoted as suitable forage species, they can be easily get overstocked and cause major disruptions of the fishery and to the degradation of water quality.

Go here for a more in-depth look at how to properly stock your fishery.

In Summary

A healthy sustainable fishery isn’t only a function of the types and amounts of fish stocked in a lake; it is directly a function of water quality, the availability and quality of spawning, foraging and refuge habitat, the ratio of forage to predator fish, and the overall composition and balance of the food web.

Begin with a fishery survey; the resulting data enables a correctly planned and implemented stocking program. Conduct routine surveys to assess the status of the fishery and the success of the program. Also, annual water quality testing provides the information needed to make wise pro-active fishery management decisions. It will also provide insights into the lake’s environmental conditions to ensure they are supportive of a healthy, productive and sustainable recreational fishery.

Learn More

If you’re interested in learning more about Princeton Hydro’s fisheries management or lake management services, please contact us.

Click here to download a full copy of Dr. Souza’s presentation, titled “How’s the Fishing? Maximizing the Recreational Potential of Your Lake’s Fishery,” which he recently presented at the NJCOLA Spring Meeting. The presentation provides an in-depth set of guidelines for fishery management, covering topics like data collection methods, habitat creation and enhancement, maximizing habitat quality, and details on various stocking species to consider for your lake.

NJCOLA unites lake communities throughout New Jersey through education and by formulating legislation favorable to the protection and enhancement of the State’s lake resources. NJCOLA meetings, held on a regular basis in the spring and fall, educate members on various topics and issues affecting lake communities ranging from legal to environmental.

The Spring NJCOLA meeting was well attended with over 60 participants representing lakes throughout New Jersey, including a number of lakes that are managed by Princeton Hydro – Lake Mohawk, Lake Hopatcong, White Meadow Lake, Lake Swanannona, Kehmah Lake, Culver Lake and Swartswood Lake.

To learn more about Princeton Hydro’s Pond and Lake services, including water quality sampling, bathymetric surveying, floating wetland islands, and fisheries, visit: http://bit.ly/pondlake 

 

“Floating Classroom” Launches into Lake Hopatcong

The Lake Hopatcong Foundation (LHF) recently launched its newest initiative – a floating classroom. The custom-built 40-foot education vessel, named ‘Study Hull’, gives students an interactive, hands-on education experience to explore Lake Hopatcong, learn about freshwater ecology, and learn how to protect the watershed.

During its maiden voyage field trip, which was held on May 21, fourth-graders from Nixon Elementary and Kennedy Elementary schools utilized the boat’s laboratory instruments to study water hydrology, temperatures, plankton, and dissolved oxygen levels. They performed a series of tests and experiments designed to help them learn about the general health of the lake. They used Secchi Disks to determine the depth to which light is able to penetrate the water’s surface. They also learned about runoff and nonpoint source pollutants, how to protect the lake’s water quality, and how to be good stewards of the water.

Princeton Hydro helped the LHF design a teaching curriculum on water quality.  Dr. Jack Szczepanski, Senior Aquatics Scientist, and Christopher L. Mikolajczyk, CLM, Senior Project Scientist, trained the staff and volunteers on the curriculum and demonstrated various water quality monitoring techniques that can be conducted with the students.

“We’re really proud to be a part of this exciting initiative,” said Mikolajczyk. “It’s really important to get kids interested in science at an early age and teach them about their surrounding environment – where their drinking water comes from, how it gets polluted, the impacts pollution has on the lake’s ecosystem, and what steps can be made to protect the lake’s water quality. We’re hoping the floating classroom field trip program will make a lasting, valuable impression with these kids.”

In the first year of operation it is expected that the Study Hull will host 1,000 fourth grade students. The long-term goal is to develop lesson plans for students in every grade from kindergarten through high school. Starting in July, the LHF is also offering the public tours of the floating classroom on Mondays at Hopatcong State Park.

The purchase of the floating classroom was made possible by financial support from USATODAY Network’s “A Community Thrives” program, which awarded the LHF with a $50,000 grant. The program recognizes three categories: arts and culture, education, and wellness. In each category, the first place winner received a $100,000 grant and the second and third place winners received $50,000 grants. The James P. Verhalen Family Foundation and the Szigethy Family also provided significant donations to help bring the floating classroom to life.

 

The LHF and Princeton Hydro are longtime partners. Starting back in 1983, Princeton Hydro’s Dr. Stephen Souza conducted the USEPA funded Diagnostic Feasibility study of the lake and then authored the Lake Hopatcong Restoration Plan. That document continues to be the backbone of why and how to restore the lake, manage the watershed, reduce pollutant loading, and address invasive aquatic plants and nuisance algae blooms.

Lake Hopatcong has one of the longest, continuous, long-term ecological databases in New Jersey; almost 30 years of consistently collected water quality data. The data is crucial in assessing the overall ecological health of the lake and proactively guiding its management, identifying and addressing emerging threats, documenting project success (a mandatory element of funding initiatives) and confirming compliance with New Jersey State Water Quality standards.

Princeton Hydro’s most recent work for Lake Hopatcong includes the implementation of green infrastructure stormwater management measures, installation of floating wetland islands to improve water quality, and invasive aquatic plant species management programs, community educational training, and surveys.

For more information about the Lake Hopatcong Foundation or the floating classroom, click here. For more information about Princeton Hydro’s lake management services, go here.

Princeton Hydro Supports Creation of Stormwater Utilities in New Jersey

For Immediate Release: May 15, 2018

PRESS STATEMENT 

On behalf of Princeton Hydro, LLC, a leading water resources engineering and natural resource management small business firm in New Jersey, we support the passing of New Jersey’s stormwater utility creation bill, S-1073. If S-1073 is administered in a responsible manner, we believe that it will enhance water quality and reduce flooding impacts in New Jersey.

Since our inception, Princeton Hydro has been a leader in innovative, cost-effective, and environmentally sound stormwater management. Long before the term “green infrastructure” was part of the design community’s lexicon, our engineers were integrating stormwater management with natural systems to fulfill such diverse objectives as flood control, water quality protection, and pollutant reduction. Our staff has developed regional nonpoint source pollutant budgets for over 100 waterways. The preparation of stormwater management plans and design of stormwater management systems for pollutant reduction is an integral part of many of our projects.

We have seen the benefits of allowing for stormwater utilities firsthand. In Maryland, the recently implemented watershed restoration program and MS4 efforts that require stormwater utility fees have provided a job creating-industry boom that benefits engineers, contractors, and local DPWs. At the same time, Maryland’s program is improving the water quality in the Chesapeake Bay, and stimulating the tourism and the crabbing/fishing industry.

New Jersey has the very same issues with our water resources as Maryland. Just like the Chesapeake Bay, our Barnegat Bay, Raritan Bay, and Lake Hopatcong have serious issues with stormwater runoff that is degrading our water quality and quality of life.  Our stormwater infrastructure is old and falling apart, and all stormwater utilities need continual maintenance to save money in the long run.

It is important to point out that this current bill is not a mandatory requirement, and would simply provide a mechanism for various levels of government (county, municipality, etc.) to collect a stormwater utility fee in order to recover runoff management costs.

This bill (S-1073) should not be reviewed only in the context of cost, as this bill meets all three elements of the  triple-bottom line of sustainability; social, environmental, and financial. Allowing stormwater utilities in New Jersey will create jobs, help reduce flood impacts, enhance water quality, improve our fisheries, and preserve our water-based tourism economy. 40 states have already implemented stormwater utilities, and we believe that it is time for New Jersey to join the ranks.

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Musconetcong River Volunteer Cleanup

The Musconetcong Watershed Association (MWA) held its 26th Annual Musconetcong River Cleanup on April 14. Volunteers conducted cleanup efforts at various locations all along the Musconetcong River from its start at Lake Hopatcong down to where it meets the Delaware River. Princeton Hydro, a proud sponsor of the event, has investigated, designed and permitted five dam removals along the Musconetcong River.

Princeton Hydro led a volunteer team near the Warren Glen Dam site and former Hughesville Dam site. The team picked-up garbage along the road and riverbank, and pulled trash from the riverbed. In 2016, we designed and oversaw the Hughesville Dam removal and streambank restoration project, which enabled the return of American shad to the river for the first time in decades.

“We enjoyed the beautiful, warm, and sunny Saturday morning bonding with our Princeton Hydro colleagues and friends, while giving back to the Musconetcong Watershed Association,” said Geoffery Goll, President of Princeton Hydro. “Our successful partnership with MWA on multiple dam removals in critical locations has expedited the restoration and protection of the Musconetcong River.”

MWA hosts cleanups throughout the year. If you have an idea for a volunteer cleanup day, please email info@musconetcong.org.

Understanding and Addressing Invasive Species

Photo from: New York State Department of Environmental Conservation, water chestnut bed at Beacon

Spring is officially here! Tulips will soon be emerging from the ground, buds blossoming on trees and, unfortunately, invasive plant species will begin their annual growing cycle. No type of habitat or region of the globe is immune to the threat of invasive species (“invasives”). Invasives create major impacts on ecosystems throughout the world, and freshwater ecosystems and estuaries are especially vulnerable because the establishment of such species in these habitats is difficult to contain and reverse.

This blog provides an introduction to invasive aquatic species, including information that will help you prevent the spread of invasives in the waterways of your community.

Defining Invasive Species

Invasive species can be defined as non-native occurring in an ecosystem that is outside its actual natural or native distributional range. Although the colonization of an ecosystem by non-native species can occur naturally, it is more often a function of human intervention, both deliberate and accidental. For aquatic ecosystems some species have become established as a result of the aquarium trade, fish culture practices and/or transport of plants and animals in the bilge and ballast water of trans-oceanic shipping vessels.

One of the primary reasons invasives are able to thrive, spread rapidly, and outcompete native species is that the environmental checks and predators that control these species in their natural settings are lacking in the ecosystems and habitat in which they become introduced. The subsequent damages they cause occur on many ecological levels including competition for food or habitat (feeding, refuge and/or spawning), direct predation and consumption of native species, introduction of disease or parasites, and other forms of disruption that lead to the replacement of the native species with the invasive species. As a result, invasives very often cause serious harm to the environment, the economy, and even human health. A prominent example is the Emerald Ash Borer, a non-native, invasive beetle that is responsible for the widespread death of ash trees.

As noted above, there are a large number of aquatic invasive species. Some of the more commonly occurring non-native aquatic plant species that impact East Coast lakes, ponds and reservoirs include:

Understanding How Invasives Spread

Either intentionally or unintentionally, people have helped spread invasives around the globe. This is not a recent phenomenon but rather something that has been occurring for centuries. “Intentional introductions,” the deliberate transfer of nuisance species into a new environment, can involve a person pouring their home aquarium into a lake or deliberate actions intended to improve the conditions for various human activities, for example, in agriculture, or to achieve aesthetics not naturally available.

Photo by: Tom Britt/CC Flickr, zebra Mussels adhered to a boat propeller“Unintentional introductions” involve the accidental transfer of invasives, which can happen in many ways, including aquatic species attached to the hull of boats or contained in bilge and ballast water. A high-profile example is the introduction of zebra mussels to North America. Native to Central Asia and parts of Europe, zebra mussels accidentally arrived in the Great Lakes and Hudson River via cargo ships traveling between the regions. The occurrence, density, and distribution of Zebra mussels occurred at an alarming rate, with the species spreading to 20 states in the United States and to Ontario and Quebec in Canada. Due to their reproductive fecundity and filter-feeding ability, they are considered the most devastating aquatic invasive species to invade North American fresh waters. They alter and diminish the plankton communities of the lakes that they colonize leading to a number of cascading trophic impacts that have especially negative consequences on fisheries. Zebra mussel infestations have also been linked to increased cyanobacteria (bluegreen algae) blooms and the occurrence of harmful algae blooms (HABs) that impact drinking water quality, recreational use, and the health of humans, pets, and livestock.

Additionally, higher than average temperatures and changes in rain and snow patterns caused by climate change further enable some invasive plant species to move into new areas. This is exemplified by the increased northly spread of hydrilla (Hydrilla verticillate), a tropical invasive plant species that has migrated since its introduction in Florida in the 1950s to lakes, rivers, and reservoirs throughout the U.S.

Regardless of how any of these invasive species first became established, the thousands of terrestrial and aquatic invasive species introduced into the U.S. have caused major ecological, recreational and economic impacts.

Measuring the Impacts of Invasives

After habitat loss, invasive, non-native species are the second largest threat to biodiversity. According to The Nature Conservancy, “Invasive species have contributed directly to the decline of 42% of the threatened and endangered species in the United States. The annual cost to the nation’s economy is estimated at $120 billion a year, with over 100 million acres (an area roughly the size of California) suffering from invasive plant infestations. Invasive species are a global problem — with the annual cost of impacts and control efforts equaling 5% of the world’s economy.”

Of the $120 billion, about $100 million per year is spent on aquatic invasive plant control to address such deleterious issues as:

  • Human health (West Nile Virus, Zika Virus)
  • Water quality impacts (Canada geese)
  • Potable water supplies (Zebra mussel)
  • Commercial fisheries (Snake head, lamprey, Eurasian ruffe, round goby)
  • Recreational activities (Eurasian watermilfoil, water chestnut, hydrilla)
  • Biodiversity (Purple loosestrife, common reed, Japanese knotweed)

Invasive species can change the food web in an ecosystem by destroying or replacing native food sources. As the National Wildlife Federation explains, “The invasive species may provide little to no food value for native wildlife. Invasive species can also alter the abundance or diversity of species that are important habitat for native wildlife. Additionally, some invasive species are capable of changing the conditions in an ecosystem, such as changing soil chemistry…”

Addressing Invasives

Our native biodiversity is an irreplaceable and valuable treasure. Through a combination of prevention, early detection, eradication, restoration, research and outreach, we can help protect our native heritage from damage by invasive species.

What Can We Do?

  • Reduce the spread
  • Routinely monitor
  • Document and report
  • Spread the word

Reducing the Spread:
The best way to fight invasive species is to prevent them from occurring in the first place. There are a variety of simple things each of us can do to help stop the introduction and spread of invasives.

  • Plant native plants on your property and remove any invasive plants. Before you plant anything, verify with your local nursery and check out this online resource for help in identifying invasive plants.
  • Thoroughly wash your gear and watercraft before and after your trip. Invasives come in many forms – plants, fungi and animals – and even those of microscopic size can cause major damage.
  • Don’t release aquarium fish and plants, live bait or other exotic animals into the wild. If you plan to own an exotic pet, do your research to make sure you can commit to looking after it. Look into alternatives to live bait.

Monitoring:
The Lake Hopatcong Foundation Water Chestnut prevention brochureInvasive plant monitoring is one of the most valuable site­-level activities people can support. Contact your local watershed organizations to inquire about watershed monitoring volunteer opportunities. For example, the Lake Hopatcong “Water Scouts” program was established to seek out and remove any instances of the invasive water chestnut species.

If you are a lake or watershed manager, the best way to begin an invasive plant monitoring project is with an expert invasive plant survey to determine which invasives are most likely to be problematic in your watershed and identify the watershed’s most vulnerable areas. Contact us to learn more.

 

Documenting and Reporting:
It’s important to learn to identify invasive species in your area and report any sightings to your county extension agent or local land manager. For example, in New Jersey there is the Invasive Species Strike Team that tracks the spread of terrestrial and aquatic invasives and works with local communities in the management of these species. Additionally, consider developing a stewardship plan for your community to help preserve its natural resources. Princeton Hydro’s team of natural resource scientists can help you get the ball rolling by preparing stewardship plans focused on controlling invasive species and protecting the long-term health of open spaces, forests habitats, wetlands, and water-quality in your community.

Spreading the word:
Many people still don’t understand the serious implications of invasive species. Education is a crucial step in stopping the spread of invasives, which is why it’s so important to talk with your neighbors, friends and family about the hazards and ecological/economic impacts of invasive species.

Also consider talking with your community lake or watershed manager about hosting an educational workshop where experts can share their knowledge about invasives specific to your area and how best to address them. Princeton Hydro’s Director of Aquatic Programs Dr. Fred Lubnow recently gave a presentation to the Lake Hopatcong Foundation titled, “Invasive Species in Watershed Management.” View it here.

 

We encourage you to share this article and spread your invasive species knowledge so that together we can help stop the introduction and spread of invasive species.

Invasive Species in Watershed Management

A Presentation by Princeton Hydro Director of Aquatic Programs Dr. Fred Lubnow

Available for Free Download Here

Dr. Fred Lubnow, Director of Aquatic Programs for Princeton Hydro, recently held an information session about Hydrilla, the Godzilla of Invasive Species. Hosted by the Lake Hopatcong Commission, the presentation covered how to identify Hydrilla and how to prevent its proliferation.

Many recreational lake users can identify Water Chestnut, but Hydrilla is much more difficult to differentiate from another species, Elodea, which is native to Lake Hopatcong.  Dr. Lubnow’s presentation illustrates how to easily compare Elodea to Hydrilla. Armed with this information, lake users will be able to spread the word and be on the look-out for Hydrilla and other invasives.

To learn more about Princeton Hydro’s Invasive Species Management Services, visit our website or contact us!

Dr. Lubnow Invasive Species Presentation