Dams and Fish Understanding our impounded legacy in the Penobscot River Joseph Zydlewski josephz@maine.edu Many to acknowledge… Berlynna Heres Lisa Izzo George Maynard Alejandro Molina-Moctezuma Daniel Stich Dan Weaver Kevin Job Andrew O’Malley Betsy Barber Anadromous fish populations declines over the past two centuries Four great threats to ecosystems David Wilcove 2007 No Way Home Habitat destruction Overexploitation Climate Change Human created obstacles Migratory Animals
Migration NURSERY ADULT FEEDING Corridor Dam Construction History • 18301830-1835:-1835: Old Town/ Veazie wing dams • 1876: Bangor Waterworks (rkm 43) • 1887: Great Works Dam (rkm 60) • 1912: Milford Dam (rkm 62) • 1913: Veazie Dam (rkm 48)
Veazie Historical Society Veazie Historical Society Dam removals in Maine
1995 1999 2008 2009 2010 2012 2013
Bangor Dam Edwards Dam Fort Halifax Dam Winterport Dam Great Works Dam Veazie Dam Penobscot River Kennebec River Sebasticook River Marsh Stream Penobscot River Penobscot River Mill and Meadow Dams Sedgeunkedunk Stream Connectivity on the Penobscot River West Enfield
Howland Penobscot River Restoration Project
Removal of Great Works Dam (2012) & Veazie Dam (2013) Gillman Falls Milford
No survival estimates for Stillwater Great Works American eels on Penobscot River Orono
Veazie Shortnose sturgeon
Fall 2015 upstream movements Detections of tag # 21266 River Km Milford Dam
former Great Works Dam
former Veazie Dam
Date Alewife and Blueback herring River Herring Alewife returns to Milford Dam Atlantic salmon Release & Recapture
Great Works Dam Remnants
Stillwater Confluence
Veazie Dam Remnants Radio Tagging of Adult Salmon Delays at Milford Dam
2015 Milford Dam Passage & Delays
2002 – 2004 (Pre-PRRP) • PIT study by D. Gorsky • Milford fishway = Denil
2014 – 2015 (Post-PRRP) • Current radio telemetry study • Milford fishway = Fish Lift Impact of Dams on Survival -Surgical implantation of acoustic tag in Atlantic salmon smolt Atlantic salmon smolt losses at dams in the Penobscot River Sometimes rides are not gentle Descaling injuries
420
400
380
360
340
320 Descale Control 300 Plasma Osmolality - mOsmols/kg - Osmolality Plasma 0 2 4 6 8 Days since descaling Poor tolerance to seawater Movement Rates (Weldon release)
W. ENFIELD MILFORD DAM DAM
125
100
75
50
25 Movement Rate (km/day) Rate Movement 0 FRESHWATER ESTUARY
HATCHERY WILD Survival Depends on Previous Experience
Passed three dams Passed no dams 1.00
0.99
0.98
0.97 Apparrent Survival Apparrent
0.96
0.00 Free Flowing Reach Howland Dam Estuary survival depends on number of dams passed American shad
American shad prevented from migration in Penobscot River DIDSON observations at Veazie Dam
Only a few dozen American shad passed the Veazie Dam in decades DIDSON Observations at Veazie Dam:
Atlantic Salmon American shad
American shad captures at Milford Dam
8000
6000
4000 Captures
2000
0 2014 2015 2016 2017 Loss of older age classes ? American eel
Migratory Behavior
Days Direct impacts of turbines
4
3
1 Survival Estimates Per Kilometer
Downstream Dam Impacts Sea lamprey