WATER QUALITY SUMMARY

MOOSEHEAD, Greenville

MIDAS: 0390, Sample Station # 1

The Maine Department of Environmental Protection (ME-DEP) and the Volunteer Lake Monitoring Program (VLMP) have collaborated in the collection of lake data to evaluate water quality, track algal blooms, and determine water quality trends. This dataset does not include bacteria, mercury, or nutrients other than phosphorus.

In summary, Moosehead Lake is clearly a very low productivity system. Even when compared to the largest lakes in the state, it is among the lowest in total phosphorus and chlorophyll_a and very high in clarity. The water quality of Moosehead Lake is considered to be above average, based on measures of SDT, total phosphorus (TP) and Chlorophyll-a (Chla). The potential for nuisance algal blooms on Moosehead Lake is low.

Moosehead Lake is characterized by conductivity and alkalinity on a par with most low color Maine lakes. While strongly stratified throughout summer, the lake develops very little oxygen loss in the deep waters. It also appears that the lake was remarkably similar from station to station and from month to month in 2003. This is perhaps due to the very low nutrient status of the lake and its inputs. This low nutrient input result in is less opportunity for any differences in basin shape or circulation between regions to express themselves as different water quality.

Although Moosehead is the largest lake in Maine, we had relatively little data to characterize the water quality until recently. Early work by Cooper (1945) characterized the lake for fisheries. The US EPA and DEP in the 1970’s sampled for productivity and nutrients in the Greenville Cove area of the lake. Since then, there have been volunteer monitors at some stations taking clarity readings. The Maine DEP, DIFW and the Moosehead Coalition collected data from a number of locations on the lake in 2003. Sampling stations included five “Primary stations” which were sampled monthly (May-Sept.) along with a station in the vicinity of Kineo near the Moose River inlet. In addition, five “Secondary stations” were sampled in May and August.

There was little variation between stations on any one day and over the year changes in the lake’s phosphorus, clarity, and oxygen levels were relatively minor. The overall mean clarity was 8.5 m, (28 ft) and the individual readings ranged from the lowest 5.2 m (17 ft) off Rockwood in May to 11.4 m (37.4 ft) off Moose Island in September. Total phosphorus averaged only 4.5 ppb (range 3.5-9 ppb) and Chlorophyll_a was generally very low, in the 1.2-2.5 ppb range. Color was between 9 and 14 SPU, which means the lake has little natural color. Significant oxygen depletion was not seen at any of the stations, and deep water was as high as 9 + ppm even in late August. Monitoring will continue in 2004.

Sample Station # 3

Water quality monitoring datasets for Moosehead Lake Sample Station # 3 has been collected since 1976. During this period, 3 years of basic chemical information was collected, in addition to Secchi Disk Transparencies (SDT). In summary, the water quality of Moosehead Lake is considered to be above average, based on measures of SDT, total phosphorus (TP) and Chlorophyll-a (Chla). The potential for nuisance algal blooms on Moosehead Lake is low.

Water Quality Measures: Moosehead Lake Sample Station # 3 is a non-colored lake (average Color is 20 SPU) with an average SDT of 6.7m (22.0ft). The range of water column TP ranges from 3 - 6 ppb with an average of 4 parts per billion (ppb), while Chla ranges from 1.1-1.4 ppb with an average of 1.3 ppb. Recent dissolved oxygen (DO) profiles show little DO depletion in deep areas of the lake. The potential for TP to leave the bottom sediments and become available to algae in the water column (internal loading) is low. Oxygen levels below 5 parts per million stress certain cold water fish, and a persistent loss of oxygen may eliminate or reduce habitat for sensitive cold water species.

Sample Station # 14

Water quality monitoring datasets for Moosehead Lake Sample Station # 14 has been collected since 1994. During this period, 2 year of basic chemical information was collected, in addition to Secchi Disk Transparencies (SDT). In summary, the water quality of Moosehead Lake is considered to be above average, based on measures of SDT, total phosphorus (TP) and Chlorophyll-a (Chla). The potential for nuisance algal blooms on Moosehead Lake is low.

Water Quality Measures: Moosehead Lake Sample Station # 14 is a non-colored lake (average color 14 SPU) with an average SDT of 7.3m m (24.1ft). The range of water column TP is from 3-7 ppb (parts per billion) with an average of 6 parts per billion (ppb), while Chla, which indicates algae abundance, is 1.3 ppb, which is very low. Recent dissolved oxygen (DO) profiles show no DO depletion in deep areas of the lake. The potential for TP to leave the bottom sediments and become available to algae in the water column (internal loading) is low.

See the Maine DEP Explanation of Lake Water Quality Monitoring Report for measured variable explanations. Additional lake information can be obtained by contacting Maine DEP at 207-287-3901 or VLMP at 207-783-7733, and at these Websites: http://www.lakesofmaine.org and http://www.maine.gov/dep/water/lakes/index.html and http://www.mainevolunteerlakemonitors.org .

Filename: moos0390, Revised: 3/04, By: rjb