About Otsego Lake
OTSEGO LAKE WATER QUALITY DATA
See The Plan for the Management of the Otsego Lake Watershed
O-TE-SA-GA or Otsego Lake?
Native Americans inhabiting the Otsego Lake watershed called the lake O-TE-SA-GA. It provided them with an abundance of food and water. It is certainly our area's greatest natural resource. Currently, Otsego Lake's 74 square mile watershed is home to more than 5,000 people, enjoying its beauty and bounty. The Lake is also the beginning or “headwaters” of the mighty Susquehanna River, which runs from our Leatherstocking Country via Pennsylvania to the Chesapeake Bay. It is the single largest fresh-water source for that magnificent bay.
Otsego Lake's Geology
Ten thousand years ago Otsego Lake was formed when a tongue of the continental glacier scoured out the Susquehanna River Valley and the Finger Lakes Region. Glacial scouring exposed limestone which has protected the lake by neutralizing the effects of acid rain. The limestone in the watershed and basin of Otsego Lake are dissolved by the waters flowing into it where it settles to the lake bottom as a white marl.
Stratified Lake Sediments (Click Thumbnail to Zoom)
Otsego Lake Water Quality Data
BFS Staff monitor Otsego Lake bi-weekly throughout the year (monthly when it's frozen) for a variety of physical and biological parameters. Some of the results of this routine monitoring will be available here, updated sporadically. Follow the link below to see past water quality monitoring updates. You will need Adobe Acrobat Reader (free download) to view these files.
Description of Monitoring Procedures
Past water quality updates
Conditions in Otsego Lake as of February 14, 2018: Complete ice cover formed sometime overnight between Dec. 31st and Jan. 1st - our official record will indicate January 1st 2018 as the freeze date.
The temperature thoughout the water column (from 6 feet to 160 feet, or 2 meters to 48 meters) varied by a single degree C - from 2.49 to 3.48 degrees C. The progression of lake temperature throughout the year can be seen in the graphs below. Each line represents water temperature from the lake's surface to 48 meters depth on dates from April through November 2017. Oxygen was available throughout the water column as of November 30, though the concentration of dissolved oxygen in the bottom 30 feet was less than 5 mg/l (lake trout prefer higher dissolved oxygen concentrations). As cooling continues, the lake will become isothermal - or the same temperature - from top to bottom and oxgyen will be replenished throughout. Once the lake temperature drops to 4 degrees C, ice can easily form on a calm frigid night.
Recap of Winter 2016-2017: Without complete ice-cover, 2016-2017 marks only the third winter on record during which the lake did not freeze completely. Records of ice cover on Otsego Lake date back to 1842; annual length of ice-cover since 1850 is presented in the graph below. Between 1842 and 2001, complete ice-cover existed each winter. Zero days of complete coverage were recorded for the winters of 2001-2002,
2016-2017. The US EPA's Climate Change Indicators Report includes Otsego Lake in its analysis of Lake Ice (https://www.epa.gov/climate-indicators/climate-change-indicators-lake-ice). The full dataset is also included in the National Snow & Ice Data Center's Global Lake and River Ice Phenology Database.
The “Real” Otsego Bass
William Cooper arrived at the south end of Otsego Lake in 1785 and founded the settlement that was to become Cooperstown. The original 200 families nearly starved one spring. Cooper wrote that, “unusual shoals of fish were seen moving in the clear waters of the Susquehanna... I was surprised to find that they were herrings... In less than two days each family had an ample supply.” Those fish were probably shad, which are like herring and a close relative of the Otsego bass.
Otsego bass are actually whitefish which are native to the lake. However, in the 1900s hundreds of thousands of other whitefish were added to augment native populations. The Otsego bass -- also called greybacks or humpbacks by local anglers -- are a close relative of the cisco which had been introduced inadvertently when whitefish populations were being augmented. The cisco have declined dramatically in recent years because of the illegal introduction of alewives, another herring-like fish. The alewife population exploded and severely reduced the cisco food source; in recent years, predation on alewife by stocked walleye has drastically reduced the alewife population. A shift in the forage base for game fish is underway and the stage may be set for a rebound of Otsego Bass. Lake whitefish successfully spawned in 2014 - 2016 and multiple size classes were obtained via anglers and NYS DEC netting efforts. Rainbow smelt abundance has also been on the rise.
While Otsego bass and cisco are no longer the focus of anglers, the lake supports many game fish. These include lake trout, walleye, brown trout, large and small mouth black bass, rock bass, sunfish, chain pickerel, yellow perch, carp and bullhead.
The Food Web at the Bottom of Otsego Lake
Plankton serve as the basis of the food web for those animals living in the open water of the lake, but an entirely different assemblage of organisms lives on the bottom. In shallow water, many species of rooted aquatic plants and algae live, transforming the sun’s energy and providing food and cover for a whole diversity of small animals which are fed upon by the larger fish. Plant plankton, which form the basis of a lake's food chain, reflect the green color of all plants which fix energy from the sun.
In deep water, dead plankton rain down from above. Their remains are food for the pea clams, midge larvae (bloodworms) and freshwater earthworms that occur by the millions. In turn, these animals serve as food for the Otsego bass, lake trout and other bottom feeding, cold-water fish.
In 2007, zebra mussels (Dreissena polymorpha) were discovered in Otsego Lake and are likely to result in changes to the food web within the lake system. The BFS is monitoring the colonization of substrates (lake bottom, boat hulls, docks, etc.) by zebra mussels in order to provide area residents with timely information that will help them to protect themselves and their personal property (boat engines, plumbing, etc.) from zebra mussel-related impacts. Native freshwater pearly mussels (family Unionidae), also filter-feeders, have been negatively impacted by zebra mussels. Six species of clams once occupied the soft substrates of Otsego Lake, however, no live clams were observed during a 2016 survey of the unionid community.
Download a hydrographic map of Otsego Lake
Otsego Lake Contour Map with 10' Contours (MS Word)
Otsego Lake Contour Map with 10' Contours (pdf)
Otsego Lake Contour Map with 25' Contours (jpg)
Otsego Lake Contour Map with 25' Contours (MS Word)
This image is based on data from USGS digital elevation models of Otsego Lake and the Cooperstown region.