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A Lake Nipissing Partners in Conservation case study Correspondence address:

Summer 2010 collapse of the Lake Nipissing zooplankton community subsequent to the introduction of the invasive zooplankter Bythotrephes longimanus Jean-Marc Filion. A Lake Nipissing Partners in Conservation case study Correspondence address: 135 West Peninsula Rd, North Bay, ON P1B 8G4

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A Lake Nipissing Partners in Conservation case study Correspondence address:

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  1. Summer 2010 collapse of the Lake Nipissing zooplankton community subsequent to the introduction of the invasive zooplankter Bythotrepheslongimanus Jean-Marc Filion A Lake Nipissing Partners in Conservation case study Correspondence address: 135 West Peninsula Rd, North Bay, ON P1B 8G4 lnpc.northbay@gmail.com April 4, 2012

  2. 2010 – Sampling Stations – Lake Nipissing Sturgeon Falls North Bay S6 N Manitou Is S8 Goose Is S3 S2 S4 S1 S5 French River Callander Bay 5 km South Bay 2 Surface area 873 km Average depth 4.5m 5% of all Ontario angling

  3. Direction of travel Horizontal strata sampling method Float Net Weight

  4. Net being hauled horizontally 150 m at a depth of 1 m in this instance.

  5. Depth data logger inserted in net to monitor depth of haul

  6. Taking the animals out of the net, and washing them into a large, white, plastic tub

  7. Samples, once concentrated with 80 micron filter

  8. The Players

  9. Bythotrepheslongimanus Adult barb barb barb Time Juvenile barb barb With each molt, an additional barb is added Young barb

  10. Large transparent predator – is out-competed by Bythotrepheslongimanus

  11. Geotrichia Conochilusunicornis Blue green algae Colonial rotifer

  12. Lake herring (Cisco) (Coregonusartedi) - to 18 inches approximately Yellow perch (Percaflavescens ) – to 12 inches approximately Rainbow smelt (Osmerusmordax) – to 8 inches approximately

  13. Yellow walleye Stizostedionvitreum This fish was live-released

  14. Results S8 - Summer 2010 abundances of Bythotrepheslongimanus and its impact on zooplankton abundance

  15. 2010 – Sampling Stations – Lake Nipissing Sturgeon Falls North Bay S6 N Manitou Is S8 Goose Is S3 S2 S4 S1 S5 French River Callander Bay 5 km South Bay

  16. an./m3 Population expansion Population crash 2010

  17. an./m3 Population expansion Population crash

  18. Bythotrephes eats zooplankton So what is the zooplankton population doing during this time?

  19. S8 - Zooplankton abundance per date per stratum Relative scale 2010

  20. S8 - Zooplankton abundance (averaged over the strata ) Relative scale Population crash due to Bythotrephespredation Partial recovery later in the summer 2010

  21. Large Daphnia galeatamendotaepopulation S8, May 30th, 2010 in the 5m stratum

  22. Mostly daphnia 300 Bythotrephes 40 Bythotrephes 10 Bythotrephes Mostly daphnia 100 Bythotrephes 3900 Bythotrephes 150 Bythotrephes

  23. June 13 400 Bythotrephes 170 Bythotrephes 1000 Bythotrephes Fewer daphnia June 20 720 Bythotrephes 1900 Bythotrephes 750 Bythotrephes Zooplankton depleted in all strata

  24. By the end of June, the spiny water flea had pretty well eliminated most of the zooplankton in the water column 3100 Bythotrephes 990 Bythotrephes 480 Bythotrephes

  25. 1500 60 150 Bythos 60 300 70 Bythos By July 11, 2010, Bythotrephesitself had crashed to much lower abundances. Only small remnant zooplankton populations remain over much of the lake.

  26. S8 Results Come August some harvestable walleye started consuming Bythotrephes Aug. 7, 2010 Kevin O'Grady captures a 35 cm walleye with only Bythotrephes in its stomach. Aug. 13, 2010 StéfaneFilion captures a 30 cm walleye with only Bythotrephesin its stomach.

  27. Food web implications Energy flow Before introduction of Bythotrephes walleye perch herring smelt snails insect larvae copepods cladocera minnows

  28. Food web implications Energy flow walleye After introduction of Bythotrephes smelt perch herring Lost to sediments Bythotrephes Nutrients may recycle in early fall - wind / shallow depths snails insect larvae copepods Cladocera minnows

  29. Food web implications(before Bytho) walleye 1 kg perch 10 kg zooplankton 100 kg phytoplankton 1000 kg

  30. Food web implications(after Bytho – no collapse) walleye 0.1 kg perch 1 kg Bytho 10 kg zooplankton 100 kg phytoplankton 1000 kg

  31. Food web implications(after Bytho – after collapse)Energy flow constricted walleye 0.001 kg = 1 g perch 0.01 kg Bytho10 kg * 1/100 0.1 kg zooplankton 100 kg phytoplankton 1000 kg

  32. Fisheries management implications(present system) Healthy walleye pop + Healthy ecosystem Max. sustainable yield = 100,000 kg

  33. Fisheries management implications(present system) Healthy walleye pop + Healthy ecosystem Max. sustainable yield = 100,000 kg Stressed walleye pop (harvest set at 2/3 of m.s.y.) = 66,000 kg

  34. Fisheries management implications(present system) Healthy walleye pop + Healthy ecosystem Max. sustainable yield = 100,000 kg Stressed walleye pop (harvest set at 2/3 of m.s.y.) = 66,000 kg NFN gets 2 fish for every 1 fish sport fishery NFN harvest quota set at 44,000 kg Sport fishery quota set at 22,000 kg

  35. Fisheries management implications(Energy flow restricted) Healthy walleye pop + Unhealthy ecosystem Max. sustainable yield = 50,000 kg (too high?)

  36. Fisheries management implications(Energy flow restricted) Healthy walleye pop + Unhealthy ecosystem Max. sustainable yield = 50,000 kg Stressed walleye population (harvest set at 2/3 of m.s.y.) = 33,000 kg

  37. Fisheries management implications(Energy flow restricted) Healthy walleye pop + Unhealthy ecosystem Max. sustainable yield = 50,000 kg Stressed walleye population (harvest set at 2/3 of m.s.y.) = 33,000 kg NFN gets 2 fish for every 1 fish sport fishery NFN harvest quota set at 22,000 kg Sport fishery quota set at 11,000 kg

  38. Fisheries management implications(Energy flow restricted) NFN gets 2 fish for every 1 fish sport fishery NFN harvest quota 22,000 kg Sport fishery quota 11,000 kg 2011 harvest results NFN quota set at 40,000 kg or so Caught 21,000 kg

  39. Fisheries management implications(Energy flow restricted) Healthy walleye pop + Unhealthy ecosystem Max. sustainable yield = 50,000 kg Very stressed walleye population (large walleye?) (harvest set at 1/3 of m.s.y.) = 17,000 kg ??? NFN gets 2 fish for every 1 fish sport fishery NFN harvest quota set at 11,000 kg Sport fishery quota set at 6,000 kg (Just one of many management options)

  40. Fisheries management going forward • We are at a critical point • Doing nothing is the worst option • We are out of time • Nobody wants the take the medicine • Need a plan and a way to sell it /implement it

  41. Food web implications A number of problems may arise from the introduction of Bythotrephes. Bythotrephes invasion elevates trophic position of zooplankton and fish: implications for contaminant biomagnification Michael D. Rennie • Angela L. Strecker• Michelle E. Palmer Biol Invasions (2011) 13:2621–2634 DOI 10.1007/s10530-011-0081-0 “We demonstrated that increases in trophic position of the magnitude reported here can lead to substantial increases in fish contaminant concentrations.” Nineteen lakes studied, focused primarily on lake herring (Coregonusartedi)

  42. Food web implications of the addition of smelt to the ecosystem Ecosystem effects of Rainbow Smelt (Osmerusmordax) invasions in inland lakes: A literature review Rebekah C. Rooney and Michael Paterson Canadian Technical Report of Fisheries and Aquatic Sciences 2845 (2009) “Rainbow smelt invasion may affect the accumulation of persistent lipophilic contaminants and heavy metals such as mercury in top predators.”

  43. Walleye in this range must be released Meals per month Children (to age 15) and women of child bearing age March 2011, MOE Guide to eating sport fish in Ontario. Consumption advice in the tables is based on an average meal size of 227 grams for an average size adult of 70 kilograms (154 pounds).

  44. Want a copy of the full report? Jean-Marc Filion lnpc.northbay@gmail.com Bow to the queen !

  45. S4 - Zooplankton community structure Lake Nipissing Outlet – French River Headwaters Sturgeon Falls North Bay S6 N Manitou Is S8 Goose Is S3 S2 S4 S1 S5 French River Callander Bay 5 km South Bay

  46. S4 – A biodiversity refuge S4 is located in an area of crucial importance to Lake Nipissing as it serves as both a fish and zooplankton refuge, thus helping to preserve biodiversity. It is near the outlet of Lake Nipissing, which drains in a southwesterly direction via the French River. The bathymetry of this area is unusual in that a cold water refuge is available due to the deeper waters available in this location. The maximum depth that we were able to find using our Hummingbird depth sounder was 54m. In the summer this area becomes a cold water refuge for the lake herring (cisco) and the smelt. Warmer waters on top and oxygen depletion at depth keep the fish sandwiched in a definite band, as indicated by this picture taken of our Hummingbird sonar unit.

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