Efforts to Manage Hydrilla in Harveys Lake Prove Difficult but Effective

Collaboration between state agencies and local organizations in Luzerne County bring in grant money to determine Hydrilla infestation levels in Harveys Lake. Treatment efforts are scheduled for 2019.

Story provided by Princeton Hydro Senior Limnologist Michael Hartshorne, and originally published in the Pennsylvania iMapInvasives Fall 2018 Newsletter

Hydrilla (Hydrilla verticillata)

Hydrilla (Hydrilla verticillata) is a relatively new invasive plant in Pennsylvania with the first documented occurrence in 1989 in Adams County. Still, it was not until recently that lake managers, park rangers, and others in the natural resource field have turned their attention to this aggressive invader. Looking incredibly similar to our native waterweed (Elodea canadensis), hydrilla differs in that it is comprised of 4-8 whorled, toothed leaves in contrast to the smooth edged, 3-leaved whorl of E. canadensis.

 

Harveys Lake, located in the Borough of Harveys Lake (Luzerne County) is a large, deep glacial lake with limited littoral (i.e., shoreline) habitat. A significant body of work has been conducted at the lake with the original Phase I: Diagnostic-Feasibility Lake study conducted in 1992 and a Total Maximum Daily Load (TMDL) issued for phosphorus in 2002.

From 2002 to present, Princeton Hydro has assisted the Borough in the restoration of the lake with a heavy focus on stormwater best management practices (BMPs) supplemented by routine, in-lake water quality monitoring. The goal of the storm water/watershed-based efforts was to reduce the lake’s existing, annual total Hydrilla (Hydrilla verticillata) phosphorus load so it’s in full compliance with the established TMDL.

Mapped locations noted in 2014 and 2015 of hydrilla in Harveys Lake as documented in the Pennsylvania iMapInvasives database.

Over the last 15 years, the installation of these watershed-based projects has led to improved water quality conditions; specifically, phosphorus and algae concentrations have been reduced. While water quality conditions improved Harveys Lake, it was during one of the routine, summer water quality monitoring events conducted in July 2014 that a dense stand of hydrilla was noted at the Pennsylvania Fish and Boat Commission’s public boat launch. More than likely, the plant entered the lake as a “hitchhiker” on the boat or trailer being launched from this public boat launch by someone visiting the lake.

Hydrilla (Hydrilla verticillata) Credit: Nick Decker, DCNR Bureau of State Parks

Since the initial identification and confirmation of the hydrilla, the Borough of Harveys Lake has worked in conjunction with the Harveys Lake Environmental Advisory Council, the Luzerne County Conservation District, the Pennsylvania Department of Environmental Protection, and Princeton Hydro to secure funding for additional surveys to determine the spatial extent and density of growth followed by an aggressive eradication plan.

Grant funds already allocated to Harveys Lake under the state’s Non-Point Source Pollution Program were used to conduct a detailed boat-based and diving aquatic plant survey of Harveys Lake to delineate the distribution and relative abundance of the hydrilla in 2014. During these surveys, the distribution of the hydrilla was found to be limited to the northern portion of the lake with the heaviest densities just off the boat launch with plants observed growing in waters 20-25 feet deep.

A follow-up survey had shown hydrilla coverage to increase from 38% of surveyed sites to 58% of sites in 2016 with hydrilla now present at the lake’s outlet area. Spatial coverage of hydrilla increased from approximately 50 acres in 2014 to 210 acres in 2016, an increase of 160 acres.

This map shows the 2018 proposed treatment area of Harvey’s Lake. Due to funding issues, treatment is now scheduled for 2019. The current hydrilla distribution encompasses the entire littoral zone of Harvey’s Lake.

In hopes of preventing hydrilla escaping into the lake’s outlet stream, the Borough of Harveys Lake funded an emergency treatment of the two-acre outlet area in 2016 utilizing the systemic herbicide Sonar® (Fluridone). A follow-up treatment of 159 acres was conducted in 2017, again utilizing the Fluridone-based systemic herbicide.

The next treatment, which will attempt to cover the majority of the littoral habitat covered by hydrilla, is scheduled for late spring/early summer of 2019. It should be noted that Sonar® is being applied at a low concentration that is effective at eradicating the hydrilla, but will not negatively impact desirable native plant species.

The treatments conducted to date have documented some reductions in the vegetative coverage of hydrilla as well as tuber production relative to the original plant surveys conducted in 2016. However, it is recognized that it will take multiple years of treatment to eradicate this nuisance plant from the lake, as well as a highly proactive, interactive program to educate residents as well as visitors to the lake in preventing the re-introduction of this or other invasive species to Harveys Lake.

 

The successful, long-term improvement of a lake or pond requires a proactive management approach that addresses the beyond simply reacting to weed and algae growth and other symptoms of eutrophication. Our staff can design and implement holistic, ecologically-sound solutions for the most difficult weed and algae challenges. Visit our website to learn more about Princeton Hydro’s lake management services: http://bit.ly/pondlake

Michael Hartshorne‘s  primary areas of expertise include lake and stream diagnostic studies, TMDL development, watershed management, and small pond management and lake restoration. He is particularly skilled in all facets of water quality characterization, from field data collection to subsequent statistical analysis, modeling, technical reporting, and the selection and implementation of best management practices. He has extensive experience in utilizing water quality data in concert with statistical and modeling packages to support load reduction allocations for the achievement of water quality standards or tailored thresholds set forth to reduce the rate of cultural eutrophication. He also has significant experience in conducting detailed macrophyte, fishery, and benthic surveys.

Five Ways to Participate in Lakes Appreciation Month

#LakesAppreciation Month is a great time of year to enjoy your community lakes and help protect them. 

Lakes Appreciation Month was started by North American Lake Management Society (NALMS) to help bring attention to the countless benefits that lakes provide, to raise awareness of the many challenges facing our waterways, and encourage people to get involved in protecting these precious resources.  Unfortunately, the natural beauties that provide clean drinking water and wildlife habitat are at risk. Chemical pollutants, hydrocarbons, stormwater runoff, invasive aquatic species, and climate change are just a few of the the serious threats facing freshwater habitats.  So what can you do to to help?

We’ve put together five tips to help you celebrate Lakes Appreciation Month and get involved in protecting your favorite lakes:

1. Join the “Secchi Dip-In” contest: The “Secchi Dip-In” is an annual citizen science event where lake-goers and associations across North America use a simple Secchi disk to monitor the transparency or turbidity of their local waterway.  This year, Princeton Hydro is offering “Secchi Dip-In” participants a chance to win a $100 Amazon gift card and a one-year membership to NALMSEntry details here.

2. Organize a cleanup event: You can easily organize a lake clean-up in your community! Volunteer cleanups are a great way to get neighbors together around a good cause, raise awareness about the importance of protecting water quality, and make a positive impact on your community waterways. Organizing a volunteer event is a lot easier than you may think. Check out these tips for how to get started.

3. Get involved with your local lake: You can help support your favorite lake by joining a lake or watershed association. As an organized, collective group, lake associations work toward identifying and implementing strategies to protect water quality and ecological integrity. Lake associations monitor the condition of the lake, develop lake management plans, provide education about how to protect the lake, work with the government entities to improve fish habitat, and much more.

4. Monitor and report algae blooms: With the BloomWatch App, you can help the U.S. Environmental Protection Agency understand where and when potential harmful algae blooms (HABs) occur. HABs have the potential to produce toxins that can have serious negative impacts on the health of humans, pets, and our ecosystems. Learn more and download the app.

5. Get outside and enjoy: Whether you enjoy swimming, relaxing on the shoreline, canoeing, or fishing, there are countless ways you can get outside and enjoy your community lakes. Encourage others to appreciate their local waterbodies by taking photos of your lake adventures and sharing them on social media using the hashtag: #LakesAppreciation.

 

Go here to learn more about NALMS and get more ideas on how to celebrate your local lakes. If you’re interested in learning more about Princeton Hydro’s broad range of award-winning lake and pond management services, please contact us. 

NYSFOLA Awards Dr. Stephen Souza with Highest Honor at 2018 Annual Conference

The New York State Federation of Lake Associations (NYSFOLA) Board of Directors awarded Dr. Stephen Souza, Founder, Princeton Hydro with its ‘Lake Tear of the Clouds’ Award. This award, named after the highest lake in the state, is NYSFOLA’s highest honor. It is only given to a person who has shown the highest dedication to New York’s lakes and watersheds, assisted NYSFOLA in its mission, and produced exceptional performance in his or her field of endeavor.

In bestowing this award to Dr. Souza, NYSFOLA recognizes his accomplishments and efforts in the management and restoration of lakes throughout the State of New York and his support of the initiatives promoted by NYSFOLA. The award was presented at the NYSFOLA’s 35th annual conference, which was held on May 4th and 5th at the Fort William Henry Hotel in Lake George.

During his acceptance speech, Dr. Souza said, “I am truly humbled and appreciative to have even been considered worthy of this award.  In accepting the ‘Lake Tear of Clouds’ Award, I want to extend my deepest thanks to NYSFOLA, the NYSFOLA Board of Directors, Nancy Mueller (NYSFOLA Manager), and all of you here tonight.  It is people like yourselves, who advocate for clean lakes, that have made my career so rewarding. I would be remiss if I also did not take the time to thank my wife Maria and my family for their support over the years and of course the dedicated lake scientists that I have the pleasure to work with day in and day out at Princeton Hydro. That of course includes Dr. Fred Lubnow, who I have had the pleasure of working side-by-side with since 1992, Chris Mikolajczyk and Mike Hartshorne, both of whom are here tonight, and the rest of my Princeton Hydro colleagues.”

Dr. Souza first attended the NYSFOLA conference in 1985, and has been working to assess, restore and protect watersheds throughout the state of New York for over 35 years. Some of the notable projects managed by Dr. Souza over that time include projects conducted at Honeoye Lake, Sodus Bay, Greenwood Lake and Sleepy Hollow Lake. He is currently working with New York State Department of Environmental Conservation on a major statewide harmful algae bloom (HAB) management effort.

“We thank you for your longtime support of NYSFOLA and our member lake association, Steve,” said Nancy J. Mueller, Manager. “And, we congratulate Princeton Hydro on its 20th anniversary.”

ABOUT NYSFOLA

The New York State Federation of Lake Associations, Inc. was founded in 1983 by a coalition of lake associations concerned about water quality, invasive species, and other issues facing New York’s lakes. Today, more than 200 lake associations across the state are members of the only statewide voice for lakes and lake associations. NYSFOLA also has corporate members and individual members who support our efforts.

New York Hosts Harmful Algal Blooms Summit

Photo: Veronica Volk, Great Lakes Today

Photo credit: Veronica Volk, Great Lakes Today

The Western New York Harmful Algal Blooms (HABs) Summit, the last of four Statewide HABs summits, was held last month in Rochester, NY. The summits kicked off Governor Cuomo’s $65 million initiative to protect the NY State’s lakes, ponds and reservoirs, and those that rely on these waterbodies for recreation and drinking water, from the ecological and health impacts associated with HABs.

“Protecting New York’s natural resources is key to ensuring residents have access to safe water, and through this collaborative summit, we are addressing the growing threat of harmful algal blooms,” said Governor Cuomo in a recent press release.

Tim Schneider, Owasco Lake Watershed Inspection Program

Photo: Tim Schneider, Owasco Lake Watershed Inspection Program

Each regional summit involved a day-long session of expert presentations and panel discussions on a variety of HAB related topics, and culminated in an evening session, which was open to the public and provided community members an opportunity to learn more about the Governor’s initiative and pose questions to NYSDEC about HABs and the management of HABs. The evening sessions were available to view via a live online stream as well.

For each summit, the Governor invited regional experts to participate along with NYSDEC and Department of Health experts. The experts were brought together to initiate the development of tailored HAB action plans. Although the focus was placed on the management of Governor Cuomo’s 12 priority waterbodies, the goal was to identify HAB management plans applicable for all of the State’s waterbodies, large or small. The discussions that evolved through the four summits set the stage to inform decisions related to preventing and properly responding to HABs across the state.

Participating by the invitation of Governor Cuomo and the NYSDEC in last month’s Western New York Summit were:

  • Dr. Steve Souza, Princeton Hydro
  • Art DeGaetano, Cornell University
  • Christopher Gobler, SUNY Stony Brook
  • Dave Matthews, Upstate Freshwater Institute
  • Greg Boyer, SUNY ESF
  • Nelson Hairston, Cornell University
  • Sally Flis, The Fertilizer Institute
  • Tim Davis, Bowling Greene State University, Ohio

During the Western New York Summit, Dr. Souza, Princeton Hydro co-founder, provided insight on the causes of HABs and, in particular, discussed the management techniques that have been successfully implemented by Princeton Hydro to combat the onset and mitigate the impacts of HABs.

About Governor Cuomo’s Harmful Algal Blooms program:
Governor Cuomo’s program builds on New York’s $2.5 billion Clean Water Infrastructure Act investments in clean water infrastructure and water quality protection. The Harmful Algal Blooms initiative is supported with funds from both the Clean Water Infrastructure Act and the $300 million Environmental Protection Fund. Through the Governor’s leadership, New York has developed the most comprehensive HABs outreach and monitoring programs in the country, led by DEC sampling of ambient waters across the state and DOH sampling at regulated beaches and public water systems.

2018 NYSFOLA Annual Conference

The New York State Federation of Lake Associations (NYSFOLA) will host its 35th Annual Conference May 4-5 at the Fort William Henry Conference Center in Lake George.

This year’s conference, which is titled, “Protecting Our Lakes for 35 Years – Our Past, Present and Future,” will feature a diverse exhibitor hall, networking opportunities, a silent auction and a variety of educational sessions. Princeton Hydro is exhibiting and giving five presentations:

  • Nutrient Inactivation: A Pennsylvania Case Study by Dr. Fred Lubnow, Director of Aquatic Programs
  • You Have Your Lake Data, Now What? Creating a Watershed Plan by Chris Mikolajczyk, Senior Aquatic Scientist
  • One Watershed, Many Lakes: A Strategic Plan for the Kettle Lakes of Southern Onondaga and Northern Cortland Counties by Michael Hartshorne, Senior Limnologist
  • Proactive Management of Harmful Algal Blooms by Dr. Stephen Souza, Founder
  • Hydrilla Control in Harveys Lake, PA by Dr. Fred Lubnow

Environmental professionals, students, recreation enthusiasts, lakeside residents and community members are all invited to come together to explore a variety of topics related to managing and protecting watersheds. Additional educational session topics include, Citizen Science Water Quality Monitoring, Managing Water Chestnut and Other Invasives, Severe Weather Events Emergency Preparedness, and much more. Click here to view the complete agenda.

If you’re attending the conference, be sure to visit the Princeton Hydro booth to discuss the latest advancements in pond, lake and watershed management. If you’re interested in participating, you can register here. Registration closes on April 27th.

Stay tuned for a conference recap and photos!

ABOUT NYSFOLA
NYSFOLA was founded in 1983 by a coalition of lake associations concerned about water quality, invasive species, and other issues facing New York’s lakes. Today, more than 200 lake associations across the state are members of the only statewide voice for lakes and lake associations. NYSFOLA also has corporate members and individual members who support our efforts.

2018 Watershed Congress Synopsis

The Delaware Riverkeeper Network hosted its annual Watershed Congress event, which is focused on bringing environmental enthusiasts together in an effort to advance the best available information and techniques for protecting and restoring watersheds. The one-day conference combines science, policy, and practical applications into one program that consists of an engaging keynote discussion, exhibits, poster sessions and 21 concurrent presentations covering a broad range of watershed topics.

Princeton Hydro gave two presentations during the event:

Ecology/Management of Cyanotoxin Producing Blue-Green Algae in the Schuylkill River 

Dr. Fred Lubnow, Director of Aquatic Programs, presented on the basic ecology of nuisance blue-green algae and how to monitor, manage and prevent cyanotoxins particularly in potable water supplies.

As identified in the Schuylkill River Watershed Source Water Protection Plan, approximately 1.5 million people depend on the Schuylkill River watershed as a source of potable water. Elevated nutrient (nitrogen and phosphorus) loading can stimulate the growth of nuisance algal blooms in the river, and higher phosphorus concentrations can cause blue-green algae blooms (also known as cyanobacteria). Cyanobacteria produce cyanotoxins, which can cause serious health implications for humans, pets and livestock. Drinking water contaminated by very high cyanotoxin concentrations can actually be lethal.

Fred’s presentation covered the ecology and management of blue-green algae in a riverine ecosystem in order to prevent the potential impacts of cyanotoxins on potable supplies of water. He provided management actions within the context of USEPA’s recommended drinking water health advisories for select cyanotoxins. Participants also received general recommendations on what they can do to minimize their contribution to potential cyanotoxin-producing blue-green algal blooms in the Schuylkill River.

Click here to download a complete copy of Fred’s presentation!

If it’s a BMP, Will it Protect Water Quality?

Michele Adams of Meliora Design and Princeton Hydro’s Senior Project Manager, Dr. Clay Emerson, PE, CFM, taught an interactive presentation and group discussion on stormwater Best Management Practices (BMPs) and issues.

The presentation covered a variety of stormwater management topics and techniques, including the Pennsylvania Department of Environmental Protection’s Interim Final BMP 6.4.11 Draft Slow Release Concept, which allows for slow release when infiltration is not feasible. They also discussed evolving standards for bioretention/rain garden soils, the lack of requirements for construction oversight, inspection of stormwater BMPs, and the challenges of long-term stormwater BMP maintenance and performance.

Stormwater management has evolved from its peak-flow based infancy into a more comprehensive approach that addresses volume and water quality in addition to peak flow rate. The number of built examples of different types of stormwater management and green infrastructure has greatly increased in Pennsylvania. However, experience suggests that under the current state of practice, many stormwater management designs are not able to meet the goal of water quality protection.

The main goal of the session was to provide participants with the information they need to understand and ask the right questions in order to protect their watersheds as development occurs.

About the Watershed Congress

The Watershed Congress advances the best available information and techniques for protecting and restoring watersheds. The focus on networking across disciplines means that the Congress melds science, policy and practical applications into one program. Every year, a growing and changing group of individuals attends to gain new knowledge, acquire tools, and practice techniques that will allow them to take active roles in the stewardship of their natural resources. View selected presentations from previous Watershed Congresses.

 

Lake Mohawk Country Club Publication Features Princeton Hydro

The Lake Mohawk Country Club (LMCC) recently published an article in The Papoose, the organization’s newsletter, that featured Princeton Hydro Founder Dr. Steve Souza and announced that he received the North American Lake Management Society’s “2017 Lake Management Success Stories Award” for his work with Lake Mohawk.

The award specifically recognizes the exceptional service provided to Lake Mohawk, the New Jersey Coalition of Lake Associations (NJCOLA) and the Lake Mohawk Preservation Foundation (LMPF). The nomination for the award was submitted by Barbara Wortmann, Interim GM of the LMCC, Ernest Hofer PE, Science Advisor to LMPF and Board President of NJCOLA, and the full Board of Trustees of NJCOLA.

As the article states, Steve and the Princeton Hydro team have worked to develop and implement successful lake management strategies to restore and protect the health of the lake and its surrounding watershed. Lake Mohawk is now a role model for all of New Jersey’s lakes.

While accepting his award Dr. Souza stated, “this would not have been possible had it not been for the foresight of the Lake Mohawk Country Club and the support we have received over the years from the Lake Board, the current General Manager Barbara Wortmann, Steve Waehler and the Lake Committee, Ernie Hofer and Gene DePerz of the Lake Mohawk Preservation Foundation, and of course the late Fran Smith.” Steve went on to thank his staff at Princeton Hydro, especially Chris Mikolajczyk, CLM and Dr. Fred Lubnow, for their efforts over the years.

More About Lake Mohawk Lake Restoration:

Nutrient pollution is one of the main problems affecting lakes throughout the United States. In small amounts, nitrates and phosphates can be beneficial to many ecosystems. However, in excessive amounts, nutrients cause eutrophication. Eutrophication stimulates an explosive growth of algae (algal blooms) that depletes the water of oxygen and cause serious water quality issues. Lake Mohawk was suffering from eutrophication issues.

In the early 1990’s, Princeton Hydro was contracted by the LMCC to conduct a detailed water quality and trophic state assessment of the lake. The data was used to prepare a comprehensive lake management master plan.

A unique element of the plan was the design and installation of a “one-of-a-kind” continual, dosing alum pumping system, which reduced and controlled the lake’s sizable internal total phosphorus load and the phosphorus originating from stormwater and other external sources. This innovative nutrient control program was the first of its kind in New Jersey, and, to this day, remains in operation and is the foundation of the lake’s restoration. Following suit from Lake Mohawk’s success, a similar system was also designed and installed in White Meadow Lake and that system is also largely responsible for its restoration.

The success of this program was recognized by the USEPA through an Environmental Excellence Award, by the NJDEP through an Environmental Initiative Award, by the NALMS through a Technical Merit Award, and now by NALMS with the 2017 Lake Management Success Stories Award.

Read more about the accomplishments at Lake Mohawk in the LMCC’s recent Papoose newsletter.

 

Princeton Hydro Founder Invited to Speak at EPA’s Harmful Algal Blooms Workshop

Princeton Hydro Founder Dr. Steve Souza was an invited speaker at the USEPA Region 2 Freshwater Harmful Algal Blooms (HABs) and Public Drinking Water Systems workshop last week in Manhattan. The objective of the workshop was to share information about the monitoring and assessment of freshwater HABs and the efforts to minimize their effect on public drinking water and the recreational uses of lakes.

Steve’s presentation focused on the proactive management of HABs, providing useful tips for and real-world examples of how to address HABs before they manifest, and, if a HAB does manifest, how to prevent it from further exacerbating water quality and cyanotoxin problems.

The workshop was well attended with 80 people on site and 40 others participating via webinar link. Steve was joined by nine other invited speakers, most of whom were representing the USEPA, NYSDEC and NJDEP, who gave presentations on a variety of HABs related topics, including the optimization of water treatment operations to minimize cyanotoxin risks surveillance and assessment of HABs, and communicating HABs risks in recreational lakes and drinking water reservoirs.

If you’re interested in learning more about HABs, you can view a complete copy of Steve’s presentation, titled Proactive Management of Harmful Algae Blooms in Drinking Water and Recreational Waterbodies, by clicking the image below. Please contact us anytime to discuss how Princeton Hydro’s Invasive Weed and Algae Management Services can be of service to you.

The USEPA Region 2 serves New Jersey, New York, Puerto Rico, the U.S. Virgin Islands, and eight tribal nations. Get more info on key issues and initiatives in USEPA Region 2.

 

 

Tracking and Managing Harmful Algae Blooms

A Presentation by Princeton Hydro Founder Dr. Stephen Souza
Available for Free Download Here

The presentation covers all things related to identifying, addressing and preventing Harmful Algae Blooms (HABs), including:

  • Understanding what defines HABs, Cyanobacteria and Cyanotoxins
  • Dispelling common misconceptions about HABs
  • Educating on the health implications associated with HABs, specifically related to drinking water and recreational water usage
  • Learning about PARETM – Princeton Hydro’s unique strategy for addressing HABs
    • (P)redict – Forecasting a bloom
    • (A)nalyze – Measuring and quantifying a bloom
    • (R)eact – Implementing measures to prevent and control a bloom
    • (E)ducate – Providing community outreach and public education

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

 

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