About Pearly Pond

Basic Statistics

Pearly Pond is a 191-acre lake in Rindge, NH.  Most of the watershed for Pearly Pond is undeveloped.(click here for a map of the watershed).  Franklin Pierce University, and 52 residences are located near the lake.  It is a shallow lake, only 17 feet deep at the deepest point, and averaging 7 feet deep.  There is no public boat access.  The Franklin Pierce beach is open to the public and there is a lifeguard on duty from noon to 5 on most summer days.  It supports a variety of warmwater fish, including largemouth bass, chain pickerel, yellow perch, pumpkinseeds, horned pout, and others.  Turtle species commonly seen in the lake include snapping turtles and Eastern painted turtles.  Wood turtles are found in the area but not commonly in the pond.  Otter, beaver, mink and other wildlife species are also common.  At least 72 species of birds have been seen on or near the pond, click for a list of the Birds of Pearly Pond (compiled by Dr. Bill Preston).   Click for a blank checklist of birds of the area to use in your own birdwatching adventures!

History of Pearly Pond

by John Harris, Director of the Monadnock Institute of Nature, Place and Culture at Franklin Pierce University

Prior to the Revolutionary War, Samuel Tarbell of Lunenburg, Massachusetts moved to Rindge and constructed a gristmill on a stream just below the lake we now know as Pearly Pond.  Water from Tarbell Pond, as it was called then, flowed under the wooden mill wheel and provided power to grind local corn, wheat and rye.  In 1780 a dispute arose between Lieutenant Tarbell and the Town of Rindge regarding the need for a bridge across the road to Fitzwilliam.  Because Tarbell was responsible for impounding the water for his mill, he was required by law to construct the needed bridge. Tarbell became a Rindge selectman in 1787 and held several other important town positions. Tarbell’s gristmill and adjoining sawmill continued to operate for over one hundred years, and evidence of the dam and mill foundation are still visible off of Abel Road today.

Pearly Pond, like many other ponds in the Monadnock Region, served as a repository for White pine logs after the Hurricane of 1938.  Because so much timber was toppled in the devastating storm, the market for pine sawlogs plummeted across New England in 1939.  Loggers preserved downed trees by sinking them in area ponds to prevent insect damage, with the goal of recovering them at a later date. Many of these trees remain submerged in Pearly Pond to this day.  Each year one or two trees surface and are in great condition. There was an active sawmill operating beside Pearly Pond after the storm, and photographs taken at the time show a twenty-five foot mountain of sawdust near the current FPU athletic fields.  


What do we know about water quality in Pearly Pond?

The amount of pollutants and the general health of the lake have been monitored by volunteers from the Pearly Pond Association, through the NH Volunteer Lake Assessment Program (VLAP) since 1992.  The following is an excerpt from the 2012 VLAP report for Pearly Pond.  

  • CHLOROPHYLL-A: Chlorophyll levels increased as the summer progressed and were indicative of an algal bloom in July and August. However, historical trend analysis indicates a significantly decreasing (improving) chlorophyll level since monitoring began. We hope to see this continue!
  • CONDUCTIVITY/CHLORIDE: Conductivity and chloride levels were slightly elevated in the deep spot, Mountain Rd. and Outlet stations. Rt. 119 is located along the southern end of the lake and road salting likely contributes to conductivity and chloride.
  • TOTAL PHOSPHORUS: Epilimnetic (upper water layer) and hypolimnetic (lower water layer) phosphorus levels increased greatly as the summer progressed and were much greater than the NH lake median. Deep spot phosphorus levels have increased annually since 2008. Historical trend analysis indicates epilimnetic phosphorus levels tend to fluctuate from year to year. Phosphorus was elevated in Mountain Rd. possibly due to low water levels and wetland impacts.
  • TRANSPARENCY: Transparency decreased in July likely due to increased algal growth. Historical trend analysis indicates a relatively stable transparency since monitoring began.
  • TURBIDITY: Epilimnetic turbidity was elevated in July and August due to the increased algal growth. Hypolimnetic turbidity was elevated in July and August possibly due to algal bloom conditions, but also natural processes. 
  • PH: pH levels were lower than desirable and potentially critical to aquatic life.
  • RECOMMENDED ACTIONS: To offset the internal phosphorus load from the hypolimnion, focus efforts on minimizing the phosphorus load from the surrounding watershed. Educate watershed residents on ways to reduce phosphorus loading from their properties through do it yourself stormwater management projects. Utilize DES’ “NH Homeowner’s Guide to Stormwater Management” as a reference. Keep up the great work!

What are some possible sources of pollution, and some potential solutions?

Students at Franklin Pierce researched a few areas on campus and identified some potential problems, as well as recommended solutions.  Click on the links below for a visual representation of their results and recommendations. 


The Milfoil Problem

Variable Milfoil Poster
Download the Variable Milfoil Poster

Pearly Pond has several infestations of the invasive plant, variable leaved milfoil, Myriophyllum heterophyllum.  This plant is an exotic plant that has no native predators to keep it under control.  If left unchecked, it will grow so much it could outcompete native species, decrease fish habitat, and lead to tangled, unpleasant recreational experiences for boaters and swimmers.  The Pearly Pond Association has worked with the NH Dept. of Environmental Services to keep these patches from spreading.  Click here for a link to the full milfoil report from NHDES - MilfoilReportPearlyPond_LTMP_January2013