Dams and Fish Understanding our impounded legacy in the Joseph Zydlewski josephz@.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: (rkm 60) • 1912: Milford Dam (rkm 62) • 1913: (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