Rise and Fall of Salmon Restoration on the St. Croix

Transcription

1 Rise and Fall of Salmon Restoration on the St. Croix

2 Setting the stage: Into 1800s. Largest runs on the Atlantic coast between the Saint John and Penobscot River systems. Mid 1800s Industry: 1, Fish: Wrongs righted; ready to restore

3 Into 1800s: For millenia, Passamaquoddy fished annually at their Siquoniw Utenehsis (Spring Village) at Salmon Falls salmon, shad, and gaspereau, were exceedingly abundant in the St. Croix; the average catch at the Salmon Falls was 200 salmon per day, for three months in each season. xxx

4 mid 1800s 1964: 1800s: dams built on lower section of river, with limited or no fish passage St. Stephen & Calais discharge extensive untreated wastes

5 mid 1800s 1964: Woodland pulp mill, dam: intermittent fish passage, no waste treatment Grand Falls dam: no fishway, 99% of sea-run fish habitat eliminated

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7 : Fishways built or rebuilt at the first 3 dams; re-opening access to spawning habitat Pollution treatment facilities installed at Woodland mill and river communities, ending fish kills that occurred into the early 1970s. River ready for fish restoration!

8 Large-scale restoration: Government led and funded Stocking: 1 million fry ¼ million parr ½ million smolt 444 adults

9 Large-scale restoration: Returns: Research trap installed at Milltown 938 1SW 1502 MSW 2440 Total

10 Large-scale restoration: Counts at two upstream dams Radio-telemetry studies Fish health

11 Large-scale restoration: What worked? Large investment in smolt stocking Large investment in research

12 Large-scale restoration: and then came the cuts

13 Local collaboration with government, funded by grants and in-kinds Focus on re-developing a native strain Low cost, innovative solutions

14 Stocking: 200,000 fry ½ million parr ¼ million smolt 1274 adults Returns: 281 1SW 342 MSW 559 Total (+ 349 aquaculture escapees)

15 What worked: habitat assessment 30 miles (95% of mainstem salmon habitat) assessed. Identifies prime salmon spawning and nursery habitat Identifies relationships with other fish habitat, especially smallmouth bass

16 What worked: local broodstock Returning adults collected at Milltown, spawned and returned to river 400,000 parr, 33,000 smolt from these matings drive the restoration effort

17 What worked: on-site parr rearing Rearing facility at Milltown raises 0+ parr, at low cost, after government options end

18 What worked: site-specific stocking Fish stocked directly to prime nursery habitat

19 What worked: adult stocking Cooperative effort NMFS, Maine Atlantic Salmon Commission, Maine DMR, St. Croix International Waterway Commission, Domtar, NB Power, Atlantic Salmon of Maine

20 What worked: adult stocking Cage-reared spawners of Downeast stock released in 2000 (750) and 2001 (524), to spawn naturally

21 What worked: adult stocking Tracking, redd, emergence, e-fish and smolt studies to 2003

22 What worked: adult stocking Tracking, redd, emergence, e-fish and smolt studies to 2003

23 What worked: adult stocking Tracking, redd, emergence, e-fish and smolt studies to 2003

24 Some other lessons: Marine phytoplankton blooms impact wild salmon runs: Adult broodstock loss, 2003 Alexandrium bloom at aquaculture site 2003 Smallmouth bass have entirely adapted to salmonid habitat, displacing other species, to become the river s primary fish

25 What failed: restoration Potential for self-sustaining population severely compromised by smallmouth bass predation. Efforts ended.

26 Postscript Last fish stocked (St. Croix 0+ parr) in 2006 Salmon trap counts end the same year Rearing tanks and equipment given to others Last St. Croix salmon recorded in 2008, a MSW female recovered from dam racks, presumed to be from the 2004 parr stocking.

27 Future opportunities Other native diadromous species