Old Stream is a highly productive cold water tributary to the Machias River located in Washington County, Maine. The Machias River contains a portion

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2 Old Stream is a highly productive cold water tributary to the Machias River located in Washington County, Maine. The Machias River contains a portion of the Gulf of Maine Distinct Population Segment for endangered populations of Atlantic salmon (Salmo salar). The Machias River is within the Downeast Salmon Habitat Restoration Unit (SHRU) Annual escapement to Old Stream has been high; around 30 adults annually. Juvenile densities are among the highest in the Downeast SHRU There is strong evidence that juvenile production is positively related to natural escapement rather than through hatchery related strategies such as fry stocking.

3 Old Stream contains 544 metric units (100m 2 ) of rearing habitat. Substrates consist of predominantly large cobbles and small boulders interspersed with gravel shoals that provide spawning substrates. Average annual temperatures between May and August range from 12 to 20.3 Celsius. Old Stream is fairly productive supporting both Atlantic salmon and brook trout (Salvelinus fontinalis). The calculated Conservation Spawning escapement (CSE) is 36 adult salmon CSE = Number of adult salmon needed for replacement CSE= [(2.4 eggs * m 2 ) / 7,200 eggs / female] * 2, where 7,200 eggs per female is the average fecundity (from Baum and Meister 1971)

4 Fry stocking has been used in Maine as a stock enhancement tool since Numbers vary Redds were buffered by as little as 200 meters evolving to not out planting fry within a sub reach. Adult escapement increased in these reaches where buffering occurred

5 80,000 70,000 60,000 50,000 Annual fry stocked into Old Stream by sub-reach Route 9 to Chainlakes. Route 9 to Chainlakes. 40,000 30,000 20,000 10, Canaan Dam - End of Pine Riffles End of Pine Riffles - Honeymoon Brook Honeymoon Brook - Route 9 Bridge Route 9 Bridge - Chain Lakes Stream Chain Lakes Stream - Stinking Jam Pitch Stinking Jam Pitch - Joe Hill Pitch Joe Hill Pitch - End Longfellow Rips

6 70 60 Annual adult escapement into Old Stream based on spawner surveys Conservation Spawning Escapement = Canaan Dam - End of Pine Riffles Honeymoon Brook Confluence - Route 9 Bridge Chain Lakes Stream Confluence - Stinking Jam Pitch Joe Hill Pitch - End Longfellow Rips End of Pine Riffles - Honeymoon Brook Confluence Route 9 Bridge - Chain Lakes Stream Confluence Stinking Jam Pitch - Joe Hill Pitch

7 Density parr / 100m2 Number of redds Redd numbers (diamonds) with resulting large parr densities for Old Stream. Sea-run Origin Canaan Dam - Honeymoon Brook Chain Lakes Stream - End Longfellow Rips Honeymoon Brook - Chain Lakes Stream Spawn Year total Redds

8 Because juvenile data indicates a relationship between natural production and increased escapement, Because there are confounding factors such as fry drift from up stream stocking activities and general movement by salmon parr over two seasons, Because Old Stream has been at or close to CSE All stocking of hatchery products was suspended after 2008.

9 Juvenile densities continue to be high especially in historically productive reaches After two years without hatchery products, mean densities parr /100m 2 Mean density for fry origin 1995 to 2009, 5.79 parr / 100m 2 Mean density for natural origin over all parr / 100m 2 First cohort of sea-run adults expected in Stay tuned! Mean Density 1+ parr per 100m2 for naturally reared vs. hatchery origin in Old Stream p < Fry 0.05 Natural Student, Newman, Keuls grouping of mean large parr densities within sample reaches Group Mean n Sample reach A Honeymoon Brook to Chain Lakes Stream B Chain Lakes Stream to Longfellow Rips B Canaan Dam to Honeymoon Brook

10 Adult returns to the DPS have been low. However, returns to Old Stream have been at CSE. Natural production appears to be the difference in survival and return rates for Old Stream Large parr densities consistent from year to year with natural reproduction reaches such as the Route 9 Sub-reach more productive than fry origin reaches. Early data ( ) continues to support that natural reproduction is and has been driving Old Stream salmon densities

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