2016 Alewife Count

Reports for 2016 are listed below, in chronological order

FIRST REPORT

This is the first St. Croix River anadromous fisheries report for 2016, covering fish counts at the Milltown (head-of-tide) fishway for the seven-day period ending May 16.  

RIVER HERRING

The Milltown research trap is operated for an 8-10 week period each year to record the run of alewives (or gaspereau) and closely-related blueback herring, collectively called river herring.  Other fish entering the trap are also recorded.

The trap was activated along with the fishway on April 14, 2016, and is tended daily. The first fish was recorded on May 11, within a week of the arrival time of past runs.  We anticipate good fish numbers in the next 2-3 weeks as the weather and water continue to warm up.

A comparison of alewife/blueback herring returns to this date with other recent years:

To May 16 # river herring 
2016 125
2015 16
2014 7
2013 4
2012 136
2011 1657

Ten year (2006-2015) average to this date: 141

OTHER FISH

Five white suckers and two brook trout were also recorded in the trap this week. These freshwater fish presumably dropped below the dam via open gates into the brackish water below and returned back up the fishway to the river. 

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SECOND REPORT

This is the second St. Croix River anadromous fisheries report for 2016, covering fish counts at the Milltown (head-of-tide) fishway for the seven-day period ending May 23.  

RIVER HERRING

The Milltown research trap is operated for an 8-12 week period each year to record the run of alewives (or gaspereau) and closely-related blueback herring, collectively called river herring.  Other fish entering the trap are also recorded.

The trap was activated along with the fishway on April 14, 2016, and is tended daily.  The first fish was recorded on May 11, within a week of the arrival time of past runs.  Larger numbers of fish appeared on the weekend but few have moved up the fishway yet. 

A comparison of alewife/blueback herring returns to this date with other recent years:
 

To May 23  # to date
2016 394
2015 142
2014 23
2013 882
2012 23,596
2011 14,710

Ten year (2006-2015) average to this date: 7,059

OTHER FISH

Five white suckers, two brook trout, one smallmouth bass and one common shiner were also recorded in the trap this week. These freshwater fish presumably dropped below the dam via open gates into the brackish water below and returned back up the fishway to the river.

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THIRD REPORT

This is the third St. Croix River anadromous fisheries report for 2016, covering fish counts at the Milltown (head-of-tide) fishway for the seven-day period ending May 30.  

RIVER HERRING

The Milltown research trap is operated for an 8-12 week period each year to record the run of alewives (or gaspereau) and closely-related blueback herring, collectively called river herring.  Other fish entering the trap are also recorded.

The trap was activated along with the fishway on April 14, 2016, and is tended daily. The first fish was recorded on May 11, within a week of the arrival date of previous runs. Large numbers of fish were seen below the dam early in the week and, after some fishway attraction adjustments, over 11,000 moved up the fishway in a little 24 hours on May 26-27. This movement was expected to continue, however while fish continued to gather below the dam and fishway conditions were good, few entered the ladder and the next three days reflected counts in the hundreds, for a weekly total of 14,304. Two factors may have influenced their movement: river flows were extremely low (roughly half of normal for this time of year, although fishway flows were unaffected) and water temperatures were roughly 2-3 degrees Celsius higher than usual. If anyone has experience with this situation, we would like to hear from you.

A comparison of alewife/blueback herring returns to this date with other recent years:
 

To May 30   # to date  
2016 14,696
2015 32,779
2014 19,971
2013 5,107
2012 34,786
2011 15,937

Ten year (2006-2015) average to this date: 7,059

OTHER FISH

Two white suckers, two brook trout, four smallmouth bass and two common shiners were also recorded in the trap this week. These freshwater fish presumably dropped below the dam via open gates into the brackish water below and returned back up the fishway to the river.

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FOURTH REPORT

This is the fourth St. Croix River anadromous fisheries report for 2016, covering fish counts at the Milltown (head-of- tide) fishway for the seven-day period ending June 6.  

RIVER HERRING

The Milltown research trap is operated for an 8-12 week period each year to record the run of alewives (or gaspereau) and closely-related blueback herring, collectively called river herring.  Other fish entering the trap are also recorded.

The trap was activated along with the fishway on April 14, 2016, and is tended daily. The first fish was recorded on May 11, within a week of the arrival date of previous runs. 

Large numbers of fish were seen below the dam on many days this week but were hesitant to move. Nearly11,000 passed up the fishway on the afternoon of June 1 but only small numbers on other days. River flows continued to be extremely low and temperatures high, which may have had an influence. These conditions have resulted in fish mortalities in a St. Croix tributary below the dam. Hopefully the cooler, wetter weather that is forecast for the coming week will encourage the fish to run.

A comparison of alewife/blueback herring returns to this date with other recent years:
 

To June 6  # to date
2016 27,279
2015 49,654
2014 20,023
2013 16,531
2012 35,961
2011 23,687

Ten year (2006-2015) average to this date: 22,401

OTHER FISH

Thirteen smallmouth bass and three brook trout were also recorded in the trap this week.   These freshwater fish presumably dropped below the dam via open gates into the brackish water below and returned back up the fishway to the river.

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FIFTH REPORT

This is the fifth St. Croix River anadromous fisheries report for 2016, covering fish counts at the Milltown (head-of-tide) fishway for the seven-day period ending June 13.  

RIVER HERRING

The Milltown research trap is operated for an 8-12 week period each year to record the run of alewives (or gaspereau) and closely-related blueback herring, collectively called river herring.  Other fish entering the trap are also recorded.

The trap was activated along with the fishway on April 14, 2016, and is tended daily. The first fish was recorded on May 11, within a week of the arrival date of previous year’s runs.

Thunderstorms on Tuesday and Wednesday raised the low river level to near normal and lowered the water temperature from 20 to 17 degrees Celsius. This sparked a small run of 2495 fish through the fishway on Wednesday. However, for the next five days few fish were seen below the dam and less than 600 passed upstream. Because the Milltown dam is located just above head of tide, it is not uncommon for river herring to drop back to the estuary for a few days at a time. We hope that some of these will come back up in the next week, but it is now very likely that this year’s run will not have the higher numbers hoped for.

A comparison of alewife/blueback herring returns to this date with other recent years:
 

To June 13 # to date  
2016 30,517
2015 76,804
2014 26,798
2013 16,568
2012 36,158
2011 25,074

Ten year (2006-2015) average to this date: 26,639

OTHER FISH

Two white suckers and five brook trout were also recorded in the trap this week. These freshwater fish presumably dropped below the dam via open gates into the brackish water below and returned back up the fishway to the river.

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SIXTH REPORT

This is the sixth St. Croix River anadromous fisheries report for 2016, covering fish counts at the Milltown (head-of- tide) fishway for the seven-day period ending June 20. 

RIVER HERRING

The Milltown research trap is operated for an 8-12 week period each year to record the run of alewives (or gaspereau) and closely-related blueback herring, collectively called river herring.  Other fish entering the trap are also recorded.

The trap was activated along with the fishway on April 14, 2016, and is tended daily. The first fish was recorded on May 11, within a week of the arrival date of previous year’s runs.

Very few fish were seen below the dam and only 2-42 were counted daily at the research trap for most of the week. The only exception was on Sunday when an upstream water release raised the extremely low river flows by up to 60% for much of the day. This triggered a small run of 1895 alewives that afternoon and evening before the flows dropped again.

Typically this is the last week of the principal St. Croix run, however fish coming up the fishway will be counted and reported into July.

A comparison of alewife/blueback herring returns to this date with other recent years:
 

To June 20   # to date  (T = season total)
2016 32,517
2015 88,675
2014 26,893
2013 16,651
2012 36,168 T
2011 25,124

Ten year (2006-2015) average to this date: 28,757

OTHER FISH

Two smallmouth bass and two brook trout were also recorded in the trap this week. These freshwater fish presumably dropped below the dam via open gates into the brackish water below and returned back up the fishway to the river.

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SEVENTH REPORT

This is the seventh St. Croix River anadromous fisheries report for 2016, covering fish counts at the Milltown (head-of- tide) fishway for the seven day period ending June 27.  

RIVER HERRING

The Milltown research trap is operated for an 8-12 week period each year to record the run of alewives (or gaspereau) and closely-related blueback herring, collectively called river herring.  Other fish entering the trap are also documented.

The research trap and fishway were activated simultaneously on April 14, 2016 and the trap has been tended daily since. The first 2016 river herring ascended the fishway on May 11, within a week of the arrival of the previous year’s runs.

With the continuing lack of rain, river flows have remained extremely low – less than half the 56-year average for this period – and the low water below the dam has made it difficult for fish to enter the fishway. No fish were seen schooling below the dam this week but small numbers continued to appear in the research trap.

Counts will continue into July until the river herring run has clearly ended.

A comparison of alewife/blueback herring returns to this date with other recent years:

To June 27  # to date  (T = season total)
2016 32,988
2015 92,492
2014 27,036
2013 6,674
2012 36,168 T
2011 25,134

Ten year (2006-2015) average to this date: 29,205

OTHER FISH

One smallmouth bass was also recorded this week.   This freshwater fish presumably dropped below the dam via open gates into the brackish water below and returned back up the fishway to the river.

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NINTH REPORT

This is the ninth and final St. Croix River anadromous fisheries report for 2016, covering fish counts at the Milltown (head-of- tide) fishway from April 14 to July 11.   

RIVER HERRING

The Milltown research trap and fishway were activated simultaneously on April 14, 2016 and the research trap was then operated for 12 weeks before being lifted for the season on July 11. The fishway remains in operation until mid-November, without monitoring.

The first 2016 river herring ascended the fishway on May 11 and the last was counted on July 7. Only one river herring was recorded in the past week.

A comparison of alewife/blueback herring returns with other recent years:

Year Season total #
2016 33,016
2015 93,503
2014 27,312
2013 16,677
2012 36,168
2011 25,341

Ten year (2006-2015) average: 29,341

OTHER FISH
No other sea-run fish were encountered at the Milltown trap in the 2016 season.

Four species of freshwater fish were recorded in 2016, these presumably having dropped below the dam via open gates into brackish water and returning back up the fishway to the river. Recorded for the season were 14 white sucker, 24 smallmouth bass, 13 brook trout and three common shiner.

FUTURE REPORTS 

A short 2016 research summary will be issued in August-September. If you would like to receive a copy, please let us know. If you have specific questions about the Milltown operation or fish counts, please send them to Lee Sochasky, the Milltown Project Manager, at lee.sochasky@rogers.com