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!

 

Client Spotlight: Roaring Brook Lake, Putnam Valley, NY

A Comprehensive Lake Management Plan Designed by Princeton Hydro

roaring-brook-lake Since 1998, Princeton Hydro has been working with the Town of Putnam Valley, often referred to as the Town of Lakes, to restore and maintain its waterbodies. The most recent area of focus is Roaring Brook Lake, a 115-acre man-made lake surrounded by a wooded landscape community that includes 260+ homes. The lake provides a variety of recreational opportunities for boaters, anglers, swimmers and outdoor lovers and is the center point of the Roaring Brook Lake District.

The Town of Putnam Valley and the Roaring Brook Lake District hired Princeton Hydro to conduct a thorough analysis of the lake’s ecological health, identify problems affecting the quality of the lake, and develop a detailed plan to improve and protect the lake. Specifically, Princeton Hydro will implement a detailed assessment of the lake that involves water quality monitoring, bathymetric mapping (measurement of lake depth and sediment thickness), aquatic plant surveys, and quantification of the lake’s hydrologic and pollutant budgets. These data will be utilized collectively to produce a comprehensive management plan for Roaring Brook Lake and its watershed.

Water Quality Monitoring

Water quality data are used to interpret the existing chemistry of the lake, identify water quality trends, pinpoint problems and assess nutrient levels.

At Roaring Brook Lake, Princeton Hydro will specifically collect in-situ data from the surface to the bottom of the water column. The resulting temperature, dissolved oxygen, pH and conductivity data will be used in combination with laboratory generated data to assess the lake’s thermal stability and investigate the potential for internal phosphorus loading. In addition, samples will be collected to identify phytoplankton and zooplankton in the lake; some of the plankton is considered a nuisance while others are considered valuable relative to the lake’s food web.

Bathymetric Assessment

The bathymetric assessment will generate accurate lake water depth, and provide sediment thickness and distribution data for the entire body of water. These data are then used to evaluate the need for dredging, asses how and where aquatic plants become colonized and other management options that can affect long-term decisions regarding the restoration and protection of Roaring Brook Lake. The bathymetric data are also used in the various trophic models that help predict the lake’s response to incoming nutrients.

Specifically, Princeton Hydro will utilize hydrographic surveying methods to conduct the bathymetric assessment of Roaring Brook Lake. A specialized dual frequency fathometer will be used to measure water depth and the thickness of the unconsolidated sediment present throughout the lake. The fathometer is directly tied into GPS, so data are consistently collected at the exact position of the survey transects. The GPS data and accompanying water depth data will be placed into a GIS format for the generation of morphometric data and bathymetric maps of the lake.

Aquatic Plant Mapping

Aquatic plants hold sediments in place, reduce erosion and provide habitat for fish and other important wildlife and insects. Although native aquatic plants are imperative to a lake’s health, an overabundance of these plants and the presence of invasive plants can have very negative impacts.

Princeton Hydro will be conducting a complete mapping of the aquatic plant community within Roaring Brook Lake to identify the plant species present in the lake, their relative abundance and location, and provide a basis for future evaluation of changes in the plant community. This data will greatly inform lake management activities moving forward. Additionally, with this data, Princeton Hydro will be able to assess the effectiveness of the resident grass carp – currently stocked in the lake – in keeping the submerged vegetation under control.

 

Hydrologic and Pollutant Budget

The hydrologic budget represents the water balance of a lake, accounting on an annual scale for all of the inputs and losses of water. The hydrologic data is used extensively in conducting trophic state analyses and is important in determining the feasibility and utility of many in-lake restoration techniques. At Roaring Brook Lake, Princeton Hydro will investigate and quantify four key components of the hydrologic budget, including direct precipitation, overland runoff (stormwater, snowmelt, etc.), tributary inflow and groundwater seepage.

Once the hydrologic budget is complete and land-use has been categorized and quantified, a pollutant budget can then be developed. The development of a detailed pollutant budget is a critical component of any lake management plan. For the purpose of the Roaring Brook Lake study, the term pollutant refers to the nutrients nitrogen and phosphorus as well as total suspended solids. The pollutant budget represents a quantification of the input of pollutants from various sources to the lake. Because the amount of nitrogen and phosphorus present in the lake stimulates eutrophication and results in water quality impacts, proper quantification of the nutrient load is critical for the development of a site-specific and cost effective management plan.

Data Analysis

The data analysis for Roaring Brook Lake will focus on identifying an acceptable in-lake condition (i.e. specific level of algal biomass in the lake) and correlate this to the lake’s annual phosphorus load through a robust water quality model.

The data analysis will involve the review of both historical and current data and will be used to identify correlations and relationships between existing pollutant concentrations/loads and unacceptable water quality conditions (i.e. algal blooms, high rates of turbidity, nuisance densities of aquatic plants, etc.). Water quality thresholds and goals will be established for assessing the long-term progress of the lake management plan.

Lake Management Plan

roaring-brook-lake-1Properly managing your lakes and ponds starts with developing a customized management plan and involves a holistic approach to ensure continued success.

A good management plan is informed by substantial data collection and analysis (as described above); includes any necessary permit requirements and a proposed timetable for implementation; provides recommendations for priority ranking of particular activities and restoration measures; and discusses predicted benefits of the plan’s implementation and how each activity is linked to the established water quality goals. A well-crafted and thorough lake management plan will also include a review of the various Federal, State, County and local grants, programs and initiatives that may provide funding for the identified in-lake and watershed projects.

• • •

Princeton Hydro’s work with Roaring Brook Lake marks the 16th project they’ve conducted for the Town of Putnam Valley. Princeton Hydro’s proven success in watershed management stems from the cumulative training and experience of its staff, and its ability to develop watershed management solutions that are both practical and effective, which has led to the firm’s very high success rate in improving water quality.

If you’re interested in developing a customized, comprehensive management plan for your lake or pond, please 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

Pesticide-Free Lake Management Solutions

Blue Water Solutions for Green Water Problems

Managing your lakes and ponds without the use of pesticides

 

Proper lake and pond restoration is contingent with having a well prepared management plan. If you don’t start there, you’re just guessing as to which solutions will solve your problem. Successful, sustainable lake and pond management requires identifying and correcting the cause of eutrophication as opposed to simply reacting to the symptoms (algae and weed growth) of eutrophication. As such, Princeton Hydro collects and analyzes data to identify the problem causers and uses these scientific findings to develop a customized management plan for your specific lake or pond. A successful management plan should include a combination of biological, mechanical and source control solutions.  Here are some examples:


Biological Control:

Floating Wetland Islands (FWIs) are a great example of an effective biological control solution. They have the potential to provide multiple ecological benefits. Highly adaptable, FWIs can be sized, configured and planted to fit the needs of nearly any lake, pond or reservoir.

BROOKS LAKE FWI

Often described as self-sustaining, Floating Wetland Islands:

  • Help assimilate and remove excess nutrients that could fuel algae growth
  • Provide habitat for fish and other aquatic organisms
  • Help mitigate wave and wind erosion impacts
  • Provide an aesthetic element
  • Can be part of a holistic lake/pond management strategy

Read an article on Floating Wetland Islands written by our Aquatics Director Fred Lubnow.

Mechanical Control:

Another way to combat algae and invasive weed growth is via mechanical removal. One of the mechanical controls Princeton Hydro employs is the TruxorDM5000, an eco-friendly, multi-purpose amphibious machine that provides an effective, non-pesticide approach to controlling invasive weeds and problematic algae growth.

The TruxorDM5000: TRUXOR

  • Is capable of operating in shallow ponds and lakes where the access and/or operation of conventional harvesting or hydroraking equipment is limited
  • Is highly portable and maneuverable, yet very powerful
  • Can cut and harvest weeds and collect mat algae in near-shore areas with water depths less than three feet
  • Includes various attachments that allow the machine to easily collect and remove a variety of debris
  • Can be outfitted for sediment removal/dredging

Check out the Truxor in action here! 

Source Control:

Because phosphorus is typically the nutrient that fuels algae and weed growth, excessive phosphorus loading leads to problematic algal blooms and can stimulate excessive weed growth. One of the most sustainable means of controlling nuisance weed and algae proliferation is to control phosphorus inputs or reduce the availability of phosphorus for biological uptake and assimilation. The measures that decrease the amount or availability of phosphorus in a lake or pond are defined as “source control” strategies.

Deerfield Lake, PA – PhosLockTM treatment Through data collection and analysis, we can properly identify the primary sources of phosphorus loading to a lake and pond, whether those sources are internal or external.  Our team of lake managers, aquatic ecologists and water resource engineers use those data to develop a management plan that quantifies, prioritizes and correctly addresses problem sources of phosphorus.

PhosLockTM and alum are often utilized as environmentally-safe and controlled means to limit phosphorus availably. Although PhosLockTM works similar to alum, it does not have some of the inherent secondary environmental limitations associated with alum. PhosLockTM is a patented product that has a high affinity to bind to and permanently remove from the water column both soluble reactive and particulate forms of phosphorus. This makes it a very effective pond and lake management tool.

Read more about controlling harmful algae blooms.

These are just a few of the examples of non-pesticide lake and pond management strategies that Princeton Hydro regularly utilizes. Properly managing your lakes and ponds starts with developing the right plan and involves a holistic approach to ensure continued success. For more ideas or for help putting together a customized, comprehensive management plan, please contact us!