1 / 21

Lake IBI Sampling for the Sentinel Lakes

Lake IBI Sampling for the Sentinel Lakes. Nick Proulx Ecological Resources November 2007. Sample all 24 lakes in 2008 Sentinel Lakes goals ID fish indicators Use of IBI as long term tool for changes in lake status Review lake IBI development & future direction Methods

abram
Download Presentation

Lake IBI Sampling for the Sentinel Lakes

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Lake IBI Sampling for the Sentinel Lakes Nick Proulx Ecological Resources November 2007

  2. Sample all 24 lakes in 2008 • Sentinel Lakes goals • ID fish indicators • Use of IBI as long term tool for changes in lake status • Review lake IBI development & future direction • Methods • Gear modifications • Sampling effort • Sampling design • End points & Eco’s participation Question: Why am I here?

  3. “History” of Lake IBI Development • 1997 - 2003 • 87 surveys • Lakes 48 – 200 hectares • Index period June 15 – Sept 15 • Sampling protocol standardized • 11 different lake classes • 2 pubs

  4. Recent Lake IBI Sampling • New funding source = new goals • 138 surveys • 22 Different Lake Classes • 5 Lk Classes with only 1 lake sampled • 61 lks >500 acres • 26 lks > 1000 acres • 5 lks > 5000 acres • 13 repeats

  5. Methods • Methods Standard • GN/TN standard Fisheries Lake Survey • 50’ standard Fisheries beach seine • Backpack shoreline • Modified Methods • Nearshore work • Smaller mesh seines • Deployment of backpack

  6. Gear Modification - seines • Horseshoe Lake • 15’ captured 6 spp/station – 105 IBI • 50’ captured 5.1 spp/station – 100 IBI

  7. Gear Modification - seines • Hay Lake • 15’ captured 4.7 spp/station – 108 IBI • 50’ captured 3.5 spp/station – 87 IBI

  8. Gear Modification - seines • Long Lake • 15’ captured 5.8 spp/station – 111 IBI • 50’ captured 5.7 spp/station – 115 IBI

  9. Question: Do we need to standardize nearshore sampling regardless of habitat encountered? Seine Backpack Shocker Other Water too deep Usually skip, but can deploy from boat with 50’ seine Deploy from boat Purse seine Silt too deep Skip Deploy from boat Lots of CWD Use 15’ seine around CWD if possible Standard use, unless CWD prohibits movement – then deploy from boat Dense floating leaf vegetation Use 15’ seine with short hauls Standard use Dense emergent vegetation Skip Standard use – may need to go on the outside of the emergent Dense submersed vegetation Usually skip, but can use the 15’seine w/ short hauls if there are gaps in the veg Standard use Large boulders/cobble Short hauls, either seine Deploy from boat if boulders/cobble are loose Purse seine Sand beach 50’ seine, small mesh if in possession Standard use Docks Alter station starting point to one side or the other of dock to maximize sampling area Alter station starting point to one side or the other of dock to maximize sampling area

  10. Other Gear Additions Question: Should we implement “other” equipment to capture rare fish?

  11. Lake Type N Avg # of stations for 90% species sampled Avg # of stations for 95% species sampled NE Lakes (78-599 Acres) 3 7 8 Large Lks Meso >1000 Acres 6 13 15 Large Lks Eutrophic >1000 Acres 5 10 12 Sampling Effort • Drake work 2007 • 8 – 30m sampling stations describe 96% fish spp richness • Less sites in eutrophic lks – spp evenness

  12. Examples of spp accumulation curves

  13. 32 IBI*

  14. Sentinel Lakes suggested # of stations Question: Can we have different sampling efforts for each lake? Question: Do we need to oversample these lakes to get at year to year variation?

  15. Pelican Lake – large lake issues Veg dwellers All species Nongame fish

  16. Large Lakes – Ten Mile, White Iron, Carlos, Madison, & Artichoke Question: Do we need to alter our site selection to make sure vegetated bays are included? Perform recon on bays, use existing veg data, bias issues/IBI purpose... Ten Mile

  17. Year to year variation

  18. Year to year variation (cont) • Snail Lake 2005 • 10 species • 1326 individuals • 7 stations • Snail Lake 2006 • 9 species • 510 individuals • 12 stations • Different seines used • Fish Lake 2006 • 12 species • 457 individuals • 10 stations • Fish Lake 2007 • 9 species • 655 individuals • 16 stations • Purse seines, limited seining Question: How much year to year variation exists with nearshore work – how best to measure this and will the current protocol be enough to answer the question? What would be the end pnt - IBI score, species comp, richness?

  19. Work Plan • Sample all 24 lakes at least once – 2008 • Data entry/storage • IBI calc • Report results • No funds required from SLICE

  20. Other idea’s • Additional sampling • Suggested analysis • Before field season • Box plots IBI score in each Sentinel lk category • After field season • 2009 IBI sampling? • How to accomplish this • TN/GN questions

More Related