The fish community in Grenadier Pond has undergone considerable change in the past 150 years. Grenadier Pond and the West Pond once had a natural channel connection to Lake Ontario. In addition, fluctuations in lake-levels could have submerged the historical beach and lake water could have flooded into the ponds. The fish communities in the ponds would have reflected those that could enter into the ponds and marsh to feed and return to the lake for some or all of their life cycle (e.g. salmon, sturgeon, pike, suckers, minnows). With the direct connection to the lake replaced by sewers and weir control structures, the fish are trapped in the ponds and rely on them for all of their life cycle requirements.
The most recent detailed survey fish species in Grenadier Pond was undertaken in 1976 when Wainio et al. (1976) undertook an inventory using seine and hoop nets. Table 3.2 provides a listing of the fish species recorded in Grenadier pond from that time to the mid-1990s.
Poor water quality and loss of habitat have had an impact on fish populations in High Park’s ponds and streams. The study undertaken in 1976 indicated that 17 species of fish, including game species such as northern pike, large- and smallmouth bass and yellow perch inhabited Grenadier Pond. Studies in the 1990s suggested that the fish community in Grenadier Pond had become unbalanced. Top predators such as largemouth bass and northern pike had declined sharply, while forage species such as pumpkinseeds and bluegills were proliferating. Since then, bass and pike have been released into the Pond.
With more recent restocking and restoration efforts, the fish population in Grenadier Pond appears to be making a comeback. Twelve species have been recorded in recent years. In particular, largemouth bass are showing up in a variety of sizes, a good indicator of successful reproduction of this top-level predator. Overall, the results show a good mix of predatory, specialist, and generalist species.
During the summer months, Grenadier Pond is a popular fishing spot. Fishing is restricted to the designated area (see map below). No boats are permitted on the pond. Anglers must have a current Ontario Resident's Anglers License and observe sport fishing regulations. Fishing line must be properly disposed of to protect wildlife. For more information, contact the Ontario Ministry of Natural Resources at 416-314-2000.
Fish currently found in Grenadier Pond
Northern pike 1
Largemouth bass 1
Common carp 2
1 Predators that eat other fish
2 Non-native species
NOTE: The list of species shown above may be overlooking bottom-feeding fish (such as gobi, a European species) which would not be detected by the regular monitoring techniques used by the TRCA.
TRCA (photo taken during fish monitoring)
Toronto & Region Conservation Authority
Ellis Ave./Grenadier Pond Environmental Assessment Study, Section 3