Watershed Conservation Plan - Destination Erie

Great Lakes in 1879 as a food fish (USEPA 2006). Carp migrate into the area's larger streams (e.g., Elk
and Conneaut Creeks) during the spawning season, and may degrade habitat for native species (USEPA
2006), although it is unknown whether this poses a significant problem to the study area's streams.
The sea lamprey (Petromyzon marinus) is one of the more problematic invasive fishes in Lake Erie,
and colonized the lake via the Welland Canal sometime between 1829 and 1921 (Fetterolf 2006). This
eel-shaped, parasitic fish feeds by attaching to the sides of other fish using its "suctorial" mouth, through
which blood and body fluids are extracted. The sea lamprey was partly blamed for the historic decline of
the native lake trout in the Great Lakes, and considerable time and effort has been expended since 1958
by the Great Lakes Fishery Commission to control this invader (Fetterolf 2006). Adult lamprey in Lake
Erie utilize tributary streams for spawning purposes, and three of Pennsylvania's streams–Conneaut,
Raccoon, and Crooked Creeks—have been key locations where lampricides have been applied to kill
lamprey larvae (Leighton 2006; PFBC 2003). There is interest in developing alternative control methods
for the sea lamprey, such as migration control barriers, apparently being considered for Conneaut Creek
(Leighton 2006; PFBC 2003).
The most recent invasive fish species that has had a significant effect on nearshore waters and
tributaries of Lake Erie is the round goby (Neogobius melanostomus), which entered Lake Erie in 1993
and spread to all three basins of the lake by 1999 (USEPA 2006). This fish is a benthic feeder and
profited from the already extensive population of invasive dreissenids (zebra and quagga mussels), its
principle prey in the lake. Pennuto (2006) found that round goby have penetrated up to 2 km inland in
Lake Erie tributary streams in New York, and that the gobies have caused a decline in fish taxa richness
and macroinvertebrate abundance in the streams. Phillips et al. (2003) found round gobies in four
Pennsylvania Lake Erie streams (Elk, Walnut, Sixteenmile, and Twentymile Creeks) during a survey
conducted in 2000–2001. The invasive fish had moved 2.3 km (1.2 mi) upstream in Elk Creek, and
constituted 17% of the total number of fish collected. In Twentymile Creek, goby numbers made up 30%
of the total fish count, but had penetrated only 0.7 km (0.4 mi) upstream, where a waterfall impeded
further passage. Phillips et al. (2003) found that the goby was feeding exclusively on aquatic insects, and
considered the fish a threat to native fish species in Pennsylvania tributary streams.
6.1.8 Projected Impact of Climate Change on Fish and Wildlife
Fish and wildlife depending on nearshore habitats and coastal wetlands may be the populations most
dramatically affected by climate change, since Lake Erie levels are expected to possibly decline half a
meter by the 2050s (McAuley 2006), and close to a 1 m (3.3 ft) or more by the end of the twenty-first
century (Sousounis and Glick 2000, Ciborowski and Tyson 2006). It is unclear exactly how this would
affect the many species of birds, reptiles, and amphibians that utilize coastal habitats (e.g., many current
Presque Isle wetlands would be left high and dry), or what the impact would be on nearshore fish
spawning habitat and access to Lake Erie tributaries by migrating fishes. It would be advisable for natural
resource managers to assess what the likely effects will be to begin planning to minimize resource losses.
Predicted continuing air and water temperature increases are expected to contribute to declines in
fisheries of cold and cool water fish species (e.g., trout and walleye) in the Great Lakes basin (Kling and
Wuebbles 2003; Shuter et al. 2003; Sousounis and Glick 2000), and the possible expansion of warm
water fisheries (e.g., bass and sunfish). Increases in stream water temperatures will be less in areas where
groundwater is a major contributor to stream flow (Johnson et al. 2003, Shuter et al. 2003). Efforts to
maintain high amounts of forest cover in the watershed and shading of streams by riparian vegetation may
help reduce the effects of climate warming on stream fisheries on a local scale (Johnson et al. 2003). Of
particular concern is the likelihood that lower water levels and higher temperatures will accelerate the
accumulation of mercury and other contaminants in aquatic food chains (Kling and Wuebbles 2003).
These predictions suggest an imperative for the Pennsylvania Fish & Boat Commission to assess the longterm
fate and direction of trout stocking programs in the Pennsylvania Lake Erie watershed.
Warmer water temperatures will likely result in new invasive species threats, as warm water fishes
expand their distribution in the Great Lakes (Shuter et al. 2003). Some already present invasive species
that are pre-adapted top warmer climates (i.e., the Asiatic clam) may cause more serious problems as their
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