**The title, authors, and abstract for this completion report are provided below. For a copy of the completion report, please contact the GLFC via e-mail or via telephone at 734-662-3209**
Test of Pheromone Traps to Capture the Invasive Round Goby
Lynda D. Corkum1 and Timothy B. Johnson2
1 Department of Biological
2 Ontario Ministry of Natural Resources, Lake Ontario Fisheries Station, R.R. #4, 41 Hatchery Lane, Picton, Ontario, Canada K0K 2T0
sought to develop and test odour traps that target
the invasive fish, round goby (Neogobius melanostomus), resulting in a reduction in their
abundance in critical habitats or limiting and possibly preventing their spread
into new waterways. There is great value in reducing the reproductive success
of round goby, the fastest spreading vertebrate ever reported in the
Our findings support the notion that reproductive male life-like models (made of silicon) with the presence of reproductive male urine (over a range of concentrations) lure gravid females to a nest in a laboratory flume (i.e. where flow is unidirectional). The visual cue (the reproductive male model) was more effective in luring gravid females than the non-reproductive model in clear water in the lab flume. Because male sex steroids are released in urine, we anticipate that chemical odours will be more effective in field situations where water is turbid than visual cues are in attracting gravid females.
Because odour traps will be deployed in different habitats (still and running water), we studied odour preference of round gobies in a large static arena (an above ground pool). Minnow traps separated by 90° and placed at each of four compass points around the pool with Lake Erie water were seeded with male, female, food (beef heart/yellow perch) or left empty (a control). Study results indicated that most round goby did not enter any of the traps. The traps seeded with black males (intended to be reproductive) were, after post-experiment dissection, found not to be spermiating. When data were re-analysed insuring that traps seeded with males were reproductive, data were still highly variable. Most fish did not enter traps.
also determined the response of round gobies to food odours
from lake whitefish Coregonus
and rainbow trout Oncorhynchus mykiss eggs in a lab flume and in traps deployed in
Lake Erie at
Exploration of the potential to develop a slow release tablet to administer odours in field settings was done in partnership with a contract pharmaceutical manufacturing company. A slow-release tablet has been formulated and subject to disintegration testing (basic breakdown properties), however, unanticipated high costs for a dissolution test needed to verify the slow release property have prevented a complete evaluation of the tablet performance.
Overall, our findings show that there is potential of using reproductive male urine in a tablet in a male model to lure females to traps. Without this scent, we have shown that traps seeded with food or adult gobies are not effective in luring conspecifics to traps.