This assessment was conducted in June 2015 to assess the fish population within Height of Land Lake. Height of Land Lake is a large (3,520 acre) shallow lake located in central Becker County. The lake is relatively lightly developed, and much of the north shore is included in the Tamarac National Wildlife Refuge. Height of Land is in lake class 41. Lakes of this class are relatively large, shallow, productive, and subject to periodic winterkills. Other class 41 lakes in the surrounding area include Rock, Shell, Wolf, and Tamarac.
Height of Land Lake experienced a severe winterkill in 1996, while less severe, partial winterkills occurred in 1986, 1989, 1993, 1997, 2001 and 2014. Height of Land Lake has experienced changes in its fish community in response to the severe winterkill events, and recovered naturally following the partial winterkills. The severe winterkill in 1996 mostly eliminated Walleye, Largemouth Bass, and panfish populations. Walleye fry and fingerlings, Bluegill, Black Crappie and Largemouth Bass adult broodstock were stocked in spring of 1996. Test netting is done following each partial kill to assess the severity of the winterkill, and to help determine if it is necessary to stock broodstock of any species.
Walleye fry are stocked during odd-numbered years, and also during even-numbered years after a severe winterkill. There is a modest level of natural reproduction of Walleye within the lake, and combined with fry stocking, the Walleye population in Height of Land Lake has fluctuated within the normal range for lakes of similar characteristics. In 2015, the Walleye catch rate (3.9 per gill net) was just slightly below the historical average for Height of Land Lake (4.7 per gill net). Walleyes sampled in 2015 were slightly smaller than those sampled five years prior, with an average length of 14.9 inches and an average weight of 1.3 pounds. Walleyes from seven different ages were sampled.
Northern Pike sampled in 2015 were generally abundant and small, with an average length of 18.4 inches, and an average weight of 1.3 pounds. Yellow Perch abundance has been on a downward trend since the 1986 survey, but it remains within the normal range of lakes with similar characteristics. As well as being a primary forage species for Walleye and Northern Pike, Yellow Perch are a popular angling target in Height of Land Lake. The average size of Yellow Perch increased slightly from the previous survey, and is 6.9 inches. Few perch larger than 10 inches were found in 2015, unlike some past reports.
Black Crappie and Largemouth Bass numbers have historically been low in Height of Land Lake, but are within the normal range for lakes of similar characteristics. During the 2015 survey, a historically high number of Bluegills were sampled. While average size is small at 6.1 inches, a small proportion of the sample exceeded eight inches. Bluegills grow rapidly in Height of Land Lake, and fish under age five years old should continue to provide good fishing within the next couple of years if no winterkill occurs.
Yellow, Black, and Brown Bullheads are all found in Height of Land Lake. While Black and Brown Bullhead catch rates are low, Yellow Bullheads were sampled at a historical high in 2015. Commercial Fish Removal was permitted during 2015 for Bullheads, removing 300 pounds of Bullheads for human use. Bullheads removed were under 0.5 pounds each.
Before flowing through Height of Land Lake, the Otter Tail River begins at Elbow Lake and flows south through several lakes such as Little Bemidji, Many Point, and Round Lake. Tullibee, Lake Sturgeon, and Muskellunge all exist in these upstream lakes either naturally or through stocking. Therefore, not surprisingly, recent assessments have also documented Tullibee, Lake Sturgeon, and Muskellunge within Height of Land Lake. Tullibee were documented in 1975 and 2010, but not sampled during this assessment. Lake Sturgeon were sampled in this assessment (two fish captured) and in 2005 (one fish captured). In addition, one Muskellunge was documented during a separate assessment in 2015. Although fish must travel downstream through the Otter Tail River over 15 river miles, through three shallow, heavily vegetated lakes within Tamarack National Wildlife Refuge before reaching Height of Land Lake, it is likely the documented presence of Muskellunge and Lake Sturgeon are a result of fish moving downstream through the Otter Tail River. While no angler reports of Lake Sturgeon or Muskellunge have been recorded, it is possible that anglers may encounter these species in the future. Documented movement of multiple fish species through the Ottertail River emphasizes the importance of habitat preservation within this system.
With continuing shoreline and watershed development, this diverse, productive, and valuable fishery will need help on several fronts to be sustained. Anglers can help to maintain balance in fish populations by voluntarily releasing a portion of medium and large fish and keeping smaller ones for eating. This is particularly true for Northern Pike and Bluegill. Shoreline owners and other watershed dwellers can help to maintain or improve water quality and fish habitat by leaving shoreline buffer zones, by leaving stands of native aquatic vegetation intact, by taking precautions to prevent invasive species introductions, and by using wise land management practices.