Coho Salmon Smolt Countin Program

Adult coho salmon return to Millard Creek to spawn each year from October to late December.  The resultant fry emerge from the gravel early the following spring and begin to feed and grow.  After spending a year in freshwater, those that survive predation, disease and the effects of summer drought and winter storms migrate to the estuary as smolts to begin the ocean phase of their life cycle.  Here they remain for about a year and a half, growing rapidly before returning to the creek as three-year-old adult salmon.

To help assess the productivity of the watershed for coho salmon, the Millard-Piercy Watershed Stewards began a program to count smolts as they migrated seaward, first in Millard Creek in starting 1999 then in Piercy Creek, the main tributary of Millard, beginning in 2001.  The smolt counts have been undertaken annually since that time.  The process consists of installing wood and wire mesh v-shaped weirs across the streams.  Downstream migrating salmon are directed to the centre of the “v” where a 6-inch flexible plastic pipe leads to a holding box constructed of wood and wire mesh.  Once each day, from mid to late April until about mid-June, volunteers check the holding boxes to identify and count the fish.  Coho smolts are also examined for the presence or absence of an adipose fin to determine if they are wild (with adipose fin) or hatchery  (no adipose fin) origin. .  In addition to coho salmon smolts, coho fry are often captured.  Other incidental species caught include chum and pink salmon fry, cutthroat and rainbow trout, sculpins, lampreys, sticklebacks and crayfish.

In 2014, both weirs were installed  April 16 with counting started the following day. To date (May 2), the number of smolts counted has been low which is typical early in the season.  Peak counts usually occur about mid-May but the timing varies with high counts normally associated with heavy rainfall which increases creek water levels.  This is the last year that both hatchery and wild coho smolts will be present as hatchery operations were stopped after the 2012 brood year.

Smolt counts in recent years have been considerably lower than in the early years of the program.  Since 2005, the Millard count has ranged between 319 in 2007 and 2,457 in 2006 while at Piercy the range has been from 17 in 2007 to 442 in 2011.  The highest counts since the program started were 15,808 in 2000 at Millard and 2,513 in 2001 at Piercy.

 

 

 

Written by Robin Harrison

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