Nequasset Fish Count Results

2012-2018

 

Annual Fish Count

Each year since 2012, volunteers have counted fish at the Nequasset Fish Ladder during the annual alewife run. Counts take place from 6am to 8pm. Volunteers sign-up for two hour blocks and then count fish for two 10 minute periods in the block. We enter the results from these counts into a model developed by the Massachusetts Division of Marine Fisheries and are able to estimate the total number of fish that make it into Nequasset Lake each year. It takes most alewives about 4 years to grow to adults and then return to the lake to spawn, and it looks like we might be seeing evidence of that 4 year cycle in the fish count numbers.

Total Fish Counted Each Year

Estimated # Fish Into the Lake

Year

Fish Counted

Estimated Fish into the Lake

2012

2,766

29,916

2013

5,572

40,841

2014

19.061

150,950

2015

9,308

126,395

2016

8,796

43,320

2017

3,230

25,545

2018

15,077

220,000


Annual Harvest

The Woolwich Fish Commission coordinates an annual harvest at Nequasset Dam each year. The harvest operates from Thursday through Sunday each week. Most of the fish are sold for bait, and some are sold salted and smoked. Find out more about the history of the harvest here.

 

Total Fish Harvested Each Year

 

yEAR

Fish Harvested

2012

133,320

2013

86,100

2014

117,360

2015

173,880

2016

80,160

2017

92,040

2018

163,020


Escapement

Escapement is an estimate of the percent of all the alewives that arrive at Nequasset Dam each year that are able to make it over the dam and into the lake. To get the total number of fish that arrive at the dam, we add together the number of fish harvested and the number of fish that make it into the lake. The Maine DMR has figured out that at least 15% of the fish need to make it into the lake for the run to be sustainable. Weather, issues with the fish ladder, and timing of the run can all influence the escapement.

Annual # of Fish

% Escapement

Year

% Escapement

2012

18%

2013

32%

2014

56%

2015

42%

2016

35%

2017

22%

2018

57%


Alewives’ Arrival Date

Water temperature plays an important role in the date that the fish first start climbing the fish ladder. Because they have more energy when the water is warmer, they don’t climb the ladder if the water is too cold. Fish usually start climbing the ladder at Nequasset when the water temperature is in the mid 50s.

Year

Date

Lake Temperature (°F)

2012

April 18

56

2013

April 30

55

2014

May 8

55

2015

May 7

58

2016

May 3

52

2017

May 10

53

2018

May 2

55


End of Count

The count typically ends when there are very few fish entering the lake, and the number of fish leaving the lake far outnumbers the number entering.

Year

Date

2012

June 2

2013

June 7

2014

June 9

2015

June 8

2016

June 4

2017

June 7

2018

June 3


Number of Awesome Volunteers

The annual alewife count at Nequasset would not be possible without many amazing volunteers. Thank you to everyone who has taken part!

Year

Volunteers

2012

73

2013

69

2014

95

2015

72

2016

78

2017

118

2018

86

Total Volunteers

591

Highest Count in 10 Minutes

# Years with the Same Time of Day with the Highest Average Count