The Lower Kennebec River, Maine 2002‐2019: Fish Assemblage and Habitat Responses to Dam Removal and Diadromous Fish Management 2020 NEAB Conference March 6, 2020 Chris O. Yoder and John Dattilo Center for Applied Bioassessment and Biocriteria Midwest Biodiversity Institute Columbus, OH Kennebec River @Sidney, ME Kennebec River (2002-19) . Wyman Dam to Merrymeeting Bay (30 sites, 2 test areas) . Follow-up Waterville to Augusta (2002-19) Androscoggin River (2003) . Errol, NH to Merrymeeting Bay (51 sites) 46.00 Sebasticook River (2003; 2008-15) . Douglas Pond to Winslow (9 sites) Penobscot River (2004) 400+ Samples . N. Br. To Hamden (40 sites); included W. Br., E. Br., 5 additional tributaries Northern Maine Rivers (2005-6) . St. John (14 sites), Allagash (8 sites), Aroostook (10 sites), St. Croix (12 sites) Southern Maine Rivers (2006) . Presumpscot R., Saco R. (32 sites) Miscellaneous Maine Rivers (2007) . Mattawamkeag R., Rapid R., Moose R., Moosehead Outlets, Dead R., E. Br. Penobscot (22 sites) Sampling Methods Standardized Approach: • Pulsed D.C. boat electrofishing – effort indexed to distance • Electrode array customized for Maine river conditions • Intensive survey design – mainstem & non‐wadeable tribs. • Field water quality and habitat data • July 1 – September 30 index period Gulf of Maine Watershed “Unique” Character of Maine Riverine Fish Assemblages . Post‐glacial ingress produced the “baseline” fish fauna . Maine Rivers “constrained” to Gulf of Maine. One brief connection to St. Lawrence & none to Connecticut & western river basins. Curry (2007): Late glacial impacts on dispersal and colonization of Atlantic Canada and Maine by freshwater fishes. Quaternary Research Gulf of Maine Watershed 67(2): 225‐233. Cold Water Species: Salmon and Trout Landlocked salmon Rainbow trout (Intracontinental Introduced) (Intercontinental Introduced) Brook trout Brown trout (Indigenous Native) (Intercontinental Introduced) Cold Water Species: Non-Salmonids (Indigenous Natives) Common white sucker (adult life stage) Slimy sculpin Lake chub Burbot Cold Water Species: Non-Salmonids (Indigenous Natives) Round Whitefish Longnose Sucker Blacknose Dace Longnose Dace Widely Distributed Species: Cyprinidae Fallfish Common shiner (Indigenous Native) (Indigenous Native) Creek chub Fallfish Golden shiner (Intraregional origin) Common shiner (All Indigenous Native) Green sunfish Northern pike (Intracontinental origin) (Intracontinental origin) Non-native Warmwater Species Black crappie Common carp (Intracontinental origin) (Intercontinental origin) Warmwater Species Several “warmwater” species common to this latitude in other regions are not indigenous (blackbass, pike, muskellunge, crappie). Smallmouth bass (adult life stage) (Introduced Naturalized c. 1870) “Traditional” IBI vs. Interim Maine IBI “Traditional IBI Metrics: Interim Maine IBI Metrics: 1. Native species richness 1. Indigenous species richness 2. Darter Species 2. Native cyprinids (less fallfish) 3. Sucker Species 3. %Adult white/longnose biomass 4. Sunfish Species 4. %Blackbass 5. %Intolerant species 5. %Fluvial specialist/dependent 6. %Tolerant species 6. %Macrohabitat generalists 7. %Omnivores 7. %Benthic insectivores 8. %Insectivores 8. Temperate stenotherms 9. %Top carnivores 9. %Native salmonids 10. %Hybrids 10.Non‐guarding lithophils 11. %Diseased individuals 11.%DELT anomalies 12. Number of individuals 12.Non‐indigenous species Biological Condition Gradient Conceptual Model: Maine Rivers Native inland freshwater & diadromous species (Atlantic salmon, alewife, American 1 shad, American eel, brook trout, native cyprinids, white & longnose sucker) Same as tier 1 except: non-native salmonid species with naturalized 2 populations may co-occur with brook trout. Some native diadromous species are reduced in abundance; shifts towards intermediate tolerances and mesotherms; brook trout are 3 reduced or replaced by non-native naturalized salmonid species. Some native diadromous species are rare or absent; moderately tolerant species predominate; 4 brook trout are absent; non-native mesotherms & eurytherms present; anomalies present. Native diadromous species are absent or brook trout are absent; non-native if present by interventions; some native 5 salmonids are non-reproducing; cyprinids are absent, replaced by non-native eurytherms usually tolerant and moderately tolerant species; predominate; anomalies present. Native diadromous species rare or absent; tolerant (toxic impacts); non-native species predominate and may become numerous 6 eurytherms predominate; (enrichment); species richness reduced in some cases anomalies frequent. Moderate-High Gradient Riverine Ecotype] Condition of the Biotic Community [ LOW Human Disturbance Gradient HIGH Native Cyprinidae Blackbass “Positive” “Negative” metric metric Interim Maine Rivers IBI Metrics & Scoring Scoring Adjustments Metric Scoring Equation Score = 0 Score = 10 Native Species Richness 10 * (‐0.2462 + (0.0828*numspec2))) <3 sp. >15 sp. Native Cyprinid Species (excluding (10 * (0.4457 + (0.0109*allcyp_ff) ‐ (0.00005629 * 1 2 Eq Eq fallfish) (allcyp_ff )))) Adult white & longnose sucker (10 * (0.3667 + (0.008*ws_lns_pb) ‐ (0.000023592 * >128 2 0 biomass (ws_lns_pb )))) kg/km (10 * (0.9537 + (0.00000000039*nat_salm) ‐ %Native Salmonids 2 0 >20% (0.000078892 * (nat_salm )))) %Benthic Insectivores 10 * (0.010966*benth_pc_n) 0 >91.2% %Blackbass 10 ‐ (10 * (‐0.09684 + (0.5638*log10(blackbass)))) Eq 0 %Fluvial Specialist/Dependent (10 * (0.2775 + (0.0073*fluv_pc_n))) 0% Eq %Macrohabitat Generalists 10 ‐ (10 * (0.1017 + (0.0096*macro_gen))) >90% Eq Temperate Stenothermic Species (10 * (0.7154 + (0.4047*(log10(steno))))) 0 sp. >5 sp. Non‐guarding Lithophilic Species (10 * (0.2979 + (0.8975*log10(lith_ng)))) <1 >10 10 ‐ (10 * (0.1063 + (0.3271*Non‐indigenous_sp) ‐ Non‐indigenous Species 2 >5 0 (0.029*(Non‐indigenous_sp )))) %DELT Anomalies 10 ‐ (10 * (0.8965 + (0.1074*log10(delta)))) Eq 0 1 No scoring adjustments are necessary; scoring determined by equation (Eq) across entire metric scoring range of 0‐10. Kennebec River Fish Assemblage Biomass Riverine Segments Impounded Segments Fish Assemblage RIVERINE SEGMENT 1 Other species (9) Landlocked salmon Rainbow trout Brown trout IMPOUNDED SEGMENT 1 Smallmouth bass Ot her sp ecies (9) Chain pickerel Wh ite sucker Bingham Banded # killifish Condition Ranks for 36 American eel Ameri ca n eel White sucker Smallmouth bass X 400% Kennebec R. Yellow perch KG/KM = 6.58 # NELR Segments American eel 7 KG/ KM = 18.2 12 3 4 6 ## Solon 5 RIVERINE SEGMENT 2 # N = 12 Other species (9) Allagash_Fish R. Initial post‐Edwards Dam removal responseIMPOUNDED SEGMENT 2 # Aroostook R. 11 N. Anson # Oth er sp ecies (9) Yellow perch 11 White Wh ite W. Br. Penobscot sucker sucker Anson # Madison Upper Connecticut R. 6 Smallmouth Common Skowhegan bass American # eel shiner # X 200% Penobscot Tribs. 16 Smallmouth bass 5-6 # # 22 # Redbreast sunfish St. John R. KG/KM = 18.1 Fish Assemblages in New England Rivers are Fallfish Lower Kennebec R. 2002-3 14 4 # American 11 eel E. Br. Penobscot # Middle Kennebec R. 9 NUMBER/KM = 247 3 Fairfield # IMPOUNDED SEGMENT 3 St. Croix R. 14 Other species (8) Rainbow trout RIVERINE SEGMENT 3 # 2 Lower Kennebec R. 2008-9 14 Heavily Influenced by Dams and Flow1 # Waterville # Kennebec R. Tidal 7 Winslow Other species (14) # 12 Smallmouth Upper Connecticut Tribs. American eel bass X 200% 6 Smallmouth bass # Penobscot R. Tidal # Penobscot R. 25 9 Sidney # Redbreast sunfish Upper Middle Connecticut R. KG/KM = 24.9 NELR ME IBI Rankings:# Upper Androscoggin R. 27 Upper Saco R. 10 White sucker Augusta Edwards Dam site Striped bass # Lower Connecticut Tribs. 25 Tidal Segment Upper Kennebec & Branches 7 # th TIDAL SEGMENT Pawcatuk_Wood R. 15 Gardiner LowerOther species (13) Kennebec –Pawtuxet R. 7 7 American eel # Striped bass Lower Saco R. 26 American eel White sucker Lower Connecticut R. 25 Richmond Taunton R. th 11 KG/KM = 105 # Lower Merrimack R. 5 Upper Kennebec –Common carp 11 Presumpscot R. 36 Sandy R. 11 Bowdoinham # # Tidal Connecticut R. 14 Cathance R. # # # Merrymeeting Bay KG/KM = 62.8 (N = 36 NELR River Reaches) 9 Sebasticook R. 2003 Quinebaug_Shetucket 16 Lower Androscoggin R. 30 Blackstone R. 16 Lower Middle Connecticut R. 42 Upper Merrimack R. 24 Housatonic R. 7 100 80 60 40 20 0 Hydroelectric Projects Maine Rivers Index of Biotic Integrity (IBI) + # Boat Electrofishing Sites Diadromous Index of Biotic Integrity (IBI) Visual evidence of impoundment in the form of settled pulp logs from historic log drives (pre‐1975) still linger near Sidney, ME nine miles upstream Sequence of recovery from impoundment to riverine characteristics at Sidney, ME some nine (9) miles upstream. 1997 Pre-Removal 2007 Post-Removal 2012 Post-Removal (Impounded) (+7 years) (+12 years) Gravel bars and islands are reforming some 18 years later Exposed sediment layering is evidence of deposition at head end of impoundment Milled wood occurs under layers containing pulp logs from historic log drives (pre-1975) 2018 Post-Removal (+18 years) Excellent Good Fair Poor Very Poor Habitat Quality 2002‐18 Pre‐dam Removal N = Allagash_Fish R. 12 Reference Sites 24 Aroostook R. 11 W. Br. Penobscot 11 St. John R. 22 Penobscot Tribs. 16 Lower Kennebec R. 2002-3 14 E. Br. Penobscot 11 Middle Kennebec R. 9 St. Croix R. Diadromous 14 Kennebec R. Tidal 12 3 567 restoration rivers – Lower Kennebec R. 2008-9 5 Penobscot R. Tidal are key BCG 4 6 Penobscot R. 25 Upper Androscoggin R. attributes missing? 10 Upper Saco R. 10 Upper