Larval Fish of the Lower Niagara River Betsy Trometer, Dimitry Gorsky, Shana Chapman and Eric Snyder...

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

Niagara Falls

Lewiston

Ft. Niagara

Ontario, Canada

Whirlpool

Art Park

Devil’s hole

Peggy’s Eddy

Stella Niagara

Niagara Falls

Niagara-on-the-lake

Passive Sampling Gear

Drift net

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

Active Sampling GearSurface Trawl

Bottom Trawl

Ichthyoplankton Net

Larval Seine

• 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 • wadeable • walk // to shore• 10 meter section

Sampling EffortYear 2010 2011 2012

Sampling Gear Sampling Dates

No. of Sets

Sampling Dates

No. of Sets

Sampling Dates

No. of Sets

Drift Net 5/19 5 4/27-6/14 15 3/7-5/9 45

Ichthyoplankton Net 5/20 2 6/13-8/19 14 3/13-4/26 23

Larval Seine 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, 8/24

15 6/15 6 N/A N/A

Drift Net

Ichthyoplankton Net

Larval Seine

Light Trap

YOY and Larval fish Catch by GearYear 2010 2011 2012

Sampling Gear No. of Fish

CPU Fish/set

No. of Fish

CPU Fish/set

No. of Fish

CPU Fish/set

Drift Net 0 0 32 2.13 12 0.22

Ichthyoplankton Net

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

* All YOY fish (other collections are a combination of larval fish and YOY)

Family (# species) 2010 2011 2012Silverside (1) 63

Sucker (3) 233 Sunfish (3) 17 43 Herring (1) 140 Minnow (5) 206

Pike (1) 1 Killifish (1) 1 Goby (1) 13 23

Bullhead & Catfish (1) 1 Gar (1) 1

Smelt (1) 2 Perch (2) 6

Trout and Salmon (2)* 27 19Unknown 12

Major Taxonomic Groups

Gear SelectivityGear

Famiily/SppDrift net

Ichthyoplankton netLarval seine

Light Trap

Surface Trawl

Bottom Trawl

Brook silverside XX Sucker Family XX X Rock Bass X XX XX XLargemouth Bass X X Smallmouth Bass XX XX Alewife XX X Minnow Species XX XX Bluntnose Minnow X Common Carp X Common Shiner X Emerald Shiner X X X Hornyhead Chub X Northern Pike X Banded Killifish X Round Goby X X XX Brown Bullhead X Longnose Gar X Rainbow Smelt X X Darter spp. X X Yellow Perch X Lake Trout XX X

Species/Family March April May June July AugustBrook Silverside 59 4Sucker Family 232 Rock Bass 1 4 17Largemouth Bass 3 Smallmouth Bass 32 3Alewife 138 1 1Minnow species 76 1Bluntnose Minnow 1Common Carp 1 Common Shiner 4Emerald Shiner 3 5 12Esocidae 1 Banded Killifish 1Round Goby 31 5Brown Bullhead 1Longnose Gar 1 Rainbow Smelt 1 1Darter spp. 2 1Yellow Perch 3 Lake Trout (1 Coregonid)* 8 6 27

Catch by Month

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

Drift net

Larval Seine Surface Trawl

Light Trap

Minnow Trap

Bottom Trawl

Ichthyoplankton Net

XX

X

X