An update on the extremely unfortunate introduction of Pumpkinseed Sunfish into our Trout Lake:
A year ago, when it became known that Pumpkin Seed Sunfish had been introduced into Trout Lake, I was unaware that Stickleback were routinely sampled from Trout Lake to establish a baseline for other lakes with resident Stickleback. A very few of these other lakes have very rare ‘species pairs’ of Stickleback. These are considered to be among the rarest fish in the world and those that survive occur in a very few lakes in the Georgia Strait Region.
In a recent sampling at Trout Lake (May 1) I collected hundreds of Sunfish and no Stickleback. Indicating that Pumpkinseed Sunfish are rampant, and Stickleback are essentially declining or already at the point of extirpation. The research body that documents our rare and less rare stickleback is UBC Zoology. Currently the Loon Foundation is monitoring this concern. Along with Stickleback, extirpation, there is increased predation pressure on invertebrates. There are hosts of insects, snails, leeches and other useful prey species that are equally threatened. Eventually this invasion will reduce the viability of native species and stocked Cutthroat Trout that will not have sustenance enough to thrive or even survive in Trout Lake.
Moreover, there is a great danger of Pumpkinseed Sunfish spreading to other Lakes and streams. What can be done?
Removing fish from any lake involves an enormous co-ordinated effort and could take years. This has been done in Britain in some of the lakes in the Norfolk Broads and it involved weeks and weeks of electrofishing. The fact that sunfish appear to be so easily caught in minnow traps is encouraging though In the past in other areas of B.C. lake poisoning has been used.
Briefly, in less than two years the biology of Trout Lake has been radically altered with a very difficult recovery ahead. To recover the native biology of Trout Lake may take the elimination of all fish and much of the fauna in the lake and would require the reintroduction of native species. Trapping, netting and electrofishing might in time reduce or eliminate the Invasive Pumpkinseed Sunfish that are now threatening most native species in Trout Lake. However, step one is to never introduce a non-native species into our waters in the first place.
Sincerely, John R. Dafoe,
Coastwise Guide and Consulting
Call or text. 604-740-6530