Larval Fish of the Lower Niagara River Betsy Trometer, Dimitry Gorsky, Shana Chapman and Eric Snyder USFWS Lower Great Lakes Fish and Wildlife Conservation Office Niagara River Fish Community • Great Lakes Restoration Initiative – Lake Trout and Lake Sturgeon - since 2010 • Our interest in Lower Niagara River – Remnant sturgeon population – Large number of lake trout in river in fall likely spawning • May spawn in river, but not confirmed • Recent surveys identified 60 species • Support concurrent studies Objective • Describe the composition and distribution of larval fish in the lower Niagara River. • Sampled in 2010, 2011 and 2012 • In 2012, focused sampling for Lake Trout Lake Ontario Ft. Niagara Niagara-on-thelake Peggy’s Eddy Stella Niagara Ontario, Canada Lewiston Art Park Devil’s hole Whirlpool Niagara Falls Niagara Falls Passive Sampling Gear Light Trap Minnow Trap • • • • Stationary Overnight sets - approx. 24 hrs Light trap floats at surface Minnow trap and drift nets on bottom • Set in slow moving water Drift net Active Sampling Gear • Pulled through water • Slower moving water, eddies • Surface and Bottom Trawls • Tow 10-15 minutes with boat, with flow • Ichthyoplankton net • Tow midwater with boat • Set overnight Larval Seine • Larval seine • wadeable • walk // to shore • 10 meter section Surface Trawl Ichthyoplankton Net Bottom Trawl Sampling Effort Year 2010 2011 Sampling Gear Sampling Dates No. of Sampling Sets Dates Drift Net 5/19 5 Ichthyoplankton Net 5/20 Larval Seine 2012 No. of Sets Sampling Dates No. of Sets 4/27-6/14 15 3/7-5/9 45 2 6/13-8/19 14 3/13-4/26 23 N/A N/A 6/30-8/11 28 4/25 6 Light Trap 7/2, 8/13 11 5/17-8/5 82 N/A N/A Minnow Trap 6/11, 7/2 6 N/A N/A N/A N/A Surface Trawl N/A N/A 6/15, 9/2 5 N/A N/A Bottom Trawl 6/8, 7/16, 15 8/24 6/15 6 N/A N/A Drift Net Ichthyoplankton Net Larval Seine Light Trap YOY and Larval fish Catch by Gear Year 2010 Sampling Gear No. of CPU No. of Fish Fish/set Fish 32 0 0 Drift Net 2011 2012 CPU No. of Fish/set Fish 2.13 12 CPU Fish/set 0.22 0 0 18 1.29 2 0.09 Larval Seine N/A N/A 554 19.79 0 0 Light Trap 25 2.27 51 0.62 N/A N/A Minnow Trap 0 0 N/A N/A N/A N/A Surface Trawl N/A N/A 1* 0.2 N/A N/A Bottom Trawl 8* 0.53 0 0 N/A N/A Ichthyoplankton Net * All YOY fish (other collections are a combination of larval fish and YOY) Major Taxonomic Groups Family (# species) Silverside (1) Sucker (3) Sunfish (3) Herring (1) Minnow (5) Pike (1) Killifish (1) Goby (1) Bullhead & Catfish (1) Gar (1) Smelt (1) Perch (2) Trout and Salmon (2)* Unknown 2010 17 13 2011 63 233 43 140 206 1 1 23 1 1 2 6 27 12 2012 19 Gear Selectivity Gear Famiily/Spp Brook silverside Sucker Family Rock Bass Largemouth Bass Smallmouth Bass Alewife Minnow Species Bluntnose Minnow Common Carp Common Shiner Emerald Shiner Hornyhead Chub Northern Pike Banded Killifish Round Goby Brown Bullhead Longnose Gar Rainbow Smelt Darter spp. Yellow Perch Lake Trout Drift net Ichthyoplankton net X Larval seine XX XX XX X XX XX XX Light Trap X XX X XX XX X X X X X X X XX X X X X X X X X XX X X Bottom Trawl X X X X Surface Trawl Catch by Month Species/Family Brook Silverside Sucker Family Rock Bass Largemouth Bass Smallmouth Bass Alewife Minnow species Bluntnose Minnow Common Carp Common Shiner Emerald Shiner Esocidae Banded Killifish Round Goby Brown Bullhead Longnose Gar Rainbow Smelt Darter spp. Yellow Perch Lake Trout (1 Coregonid)* March April May June 1 138 July 59 232 4 3 32 1 76 August 4 17 3 1 1 1 1 3 5 1 31 4 12 1 5 1 1 1 2 3 8 6 27 1 1 Conclusions • • • • 24 species were identified Larval seine collected most species All gear had some limitations Lake trout larval and eggs collected were confirmed with genetic analysis • Confirmed lake trout spawn along Art Park shoreline and upstream of Devil’s Hole Sampling Gear X Larval Seine Light Trap X Minnow Trap Surface Trawl Ichthyoplankton Net Bottom Trawl X Drift net X