Our story begins at an unreasonable point in time, some 550 million years ago when what is now New York State was at the bottom of an epicontinental sea. Gradually, the entire state, along with much of the northeast, fully emerged from the sea by about 200 million years ago. For the next 100 million years or so, the somewhat level land that was Upstate New York, was then eroded by the flow of many centuries of torrential precipitation. The wearing away of the land created twelve nearly parallel river valleys, which included the mighty Seneca and Cayuga Rivers. The easternmost set of six flowed northward into a depression which was the precursor of the Great Lakes Basin. The other six rivers, including the crooked Keuka and Canandaigua Rivers, flowed southward into what is now the Susquehanna drainage. These great river valleys eventually became the eleven Finger Lakes plus one dry valley (Onondaga Valley).
Whatever life that was present in these rivers and on the land at that time was completely obliterated during a period occurring about one million years ago. This was the time of the most recent ice age. At this point, the second of two prehistoric glaciers, each of continental magnitude, extended over much of North America. This included New York State and part of Pennsylvania. This period of glaciation lasted nearly a million years in the region. It further contributed to the geographical delineation of what are now the Finger Lakes as well as numerous other geographic features of New York State.
The ice sheet which extended outward onto the continent from its center in Labrador, achieved thicknesses in New York of up to 2500 feet just before the onset of the most recent global warming era, some time before 11,000 years ago. As the glacier retreated northward, it released voluminous quantities of liquid water which flowed southward. This copious flow of water would provide the first vehicle for the re-population of aquatic fauna into the Finger Lakes.
As the front of the ice mass retreated, the young rivers produced by the melt flowed southward to fill the valleys that the glacier recently helped to shape. These numerous streams encountered other existing freshwater bodies, rivers and streams. The mingling and capture of many watersheds by the abundant flow of fresh water to the Seneca and Cayuga valleys initiated the re-colonization of aquatic organisms to the new waters of then, Lake Ithaca and Lake Watkins. These ancient lakes overflowed to the south.
So much water was released by the continued global warming that several high lake stages occurred including Lake West Danby that extended from the Great Lakes area to the south of Ithaca and Watkins Glen. This was succeeded by a large, high level lake called Lake Newberry. This massive upstate lake was a combination of high water Cayuga and Seneca Lake, and was impounded on the north by the wall of the retreating glacier . The lakes at this time, were one contiguous body of water as far south as Ovid, NY. In shape, Lake Newberry was the giant geographic replica of an extracted molar tooth with the “roots” extending into the south ends of the present lakes. Lake Newberry provided for the exchange of whatever species were present in Lake Ithaca and Lake Watkins at the time. In addition, the big lake overflowed into the Susquehanna drainage, thus providing another avenue for fresh water fishes to enter Seneca and Cayuga Lakes. Ancient drainage to the Hudson-Mohawk River systems was also a resource of fish supply to the Finger Lakes.
The retreating ice wall eventually reached the Great Lakes area which was experiencing its own beginning of faunal re-population and high waters. At this point, the new terminal location of the ice provided for the eastward drainage of the Finger Lakes through the Great Lakes Basin. This allowed for the entry of fishes via St. Lawrence into Lake Iroquois (oversized Lake Ontario) and Lake Wayne (oversized Lake Erie) and eventually into Lake Cayuga and Seneca Lake.
High water of the Great Lakes Basin accounts for much of the re-population of fishes to the Finger Lakes after the glacier. Lake Erie and Lake Ontario provided a lush reservoir of fishes it recently inherited in early post-glacial times. At this time, many species immigrated to the Great Lakes from the Mississippi and giant post-glacial freshwater lakes in the north, that covered 2/3 of Canada. These lakes were Lake Agazzis and Lake Ojibway. Marine connections were also present to Hudson Bay in northeast Canada.
It is thought that the original cold water fishes of Cayuga and Seneca such as the lake trout, brook trout, trout perch, whitefish, sculpin and burbot (freshwater cod) came from the north during high waters of the Great Lakes and their drainage. Warm water fishes such as the members of the sunfish family (includes smallmouth and largemouth bass, rock bass and crappie), originally came to the Finger Lakes from Lake Ontario, the Hudson, Delaware and Susquehanna Rivers. Other warm water fishes, including most of the members of the Pike family, gar family, and bowfins immigrated to the Great Lakes from the Mississippi and eventually to Cayuga and Seneca during periods of high water.
At the current water levels prior to the construction of the canals, whatever fishes could make it up the roughly 137 foot/ 25 mile rise of the Oswego River from Ontario to Cayuga, as well as the roughly 60 foot/9 mile rise from Cayuga to Seneca, became common to both lakes.
An overall historic look at the Finger Lakes Region shows that Cayuga and Seneca watersheds, at one time or another were connected to the Mississippi, the Genesee, and the Hudson Rivers, in addition to the Susquehanna, and Lake Ontario Basin. Historical ichthyologists believe that the majority of initial re-colonization of fishes of the Great Lakes Basin (includes the Finger Lakes) is the result of prolonged very high water periods, seasonal flooding, stream capture, and ancestral drainage. In this process, some species moved out into waters that they had not previously inhabited and proliferated greatly because of the lack of competition. Other populations became extinct due to competition and change of conditions such as stream velocity, water temperature, and water turbidity. The canals led to the invasion of numerous species to Seneca and Cayuga, including the Sheepshead (drum), sea lamprey, and a host of others.
Some fish have their own little story:
It is debated whether the rainbow smelt is native to Cayuga Lake or the species was introduced. Regardless, the smelt was not found in Seneca Lake until the 1970’s. Legend has it that a group of guys from the East Lake Road area of Seneca Lake collected a barrel of live smelt from Cayuga Lake in the late 1960’s and dumped them into Seneca Lake. Although at one period, smelt abounded in both lakes, today they are found only in Cayuga in small numbers. Their existence in Seneca today is doubtful. The species probably first entered Cayuga by the lake’s long association with an arm of ancient Lake Iroquois. This was independent of Seneca Lake except for the inclined babbling brook that connected the two lakes. The rainbow smelt is marine in origin.
It is also a debate over the origin of the alewife (sawbelly). Some say the Alewife was introduced by conservationist Seth Greene as food for the Lake Trout. Others claim it made its own way up the canals to Cayuga and Seneca. The sawbelly, which constituted 90% of the fish biomass of Lake Michigan in 1964, was first recorded as present in Seneca Lake in 1868, several decades after the construction of the Cayuga-Seneca Canal. The alewife population of both lakes is said to be well established and stable. The massive mortalities of the species that once occurred in late spring and summer no longer occur. The species originates from the Chesapeake Bay.
The minnow family is well represented by over 20 species in Cayuga and Seneca Lakes. Numerous species came to the lakes both by natural means and by the emptying of bait pails. The largest member of this family, the common carp, first entered Cayuga Lake in 1888 when three farm ponds in southern Cayuga and Tompkins Counties containing the fish, overflowed during a heavy rain into Salmon Creek, Fall Creek, and a tributary of the Cayuga Inlet, thus allowing the entry of the species into Cayuga Lake. The canal with its locks, already existent, allowed for the penetration of the species into Seneca Lake. The common carp originates from Asia.
The Atlantic Salmon is thought by many to be indigenous to the Great Lakes Basin. If not, it must have been introduced into Lake Ontario from Maine or Sweden some time after Columbus. It henceforth proliferated to population levels of great magnitude in Seneca, Cayuga, Owasco, and Onieda Lakes. As late as the 1700’s, it was reported as being so abundant in Seneca and Cayuga that settlers filled a canoe with fish by simply clubbing the salmon over the head in any of the many tributary streams of the lakes. The construction of the canals and locks changed the fast flowing oxygen-saturated, pristine waters of the Oswego River and connecting watersheds to an environment of more quiet and somewhat more cloudy waters. This terminated the natural propagation of salmon in the Finger Lakes. Today the species, along with most other salmonids of the lakes, owes its presence to stocking.
The rainbow trout from the Pacific coast, and the brown trout from Europe, were introduced purposefully as sport fish. Recently, other species such as the round gobie, have been introduced from Eur-Asia by way of the emptying the ballasts of ships into the Great Lakes waters and thus to our Seneca and Cayuga Lakes via the canals. The immigration and dispersal of fishes to our two big lakes continues today. The tale goes on.
Sources: Von Engeln (1961); Reed (1909); Hubbs (2004)