Tuesday, October 3, 2017

Study finds Vermont wild brook trout populations stable since 1950’s

Posted by Wayne G. Barber


MONTPELIER, Vt. – Fisheries biologists from Vermont Fish & Wildlife recently completed a decade-long survey of wild brook trout throughout the state and have found that present day populations of the species are comparable to those of over five decades ago.
 
“Based on the results of recent sampling, compared to data from past sampling work, we’ve found that wild brook trout populations in Vermont have remained stable since the 1950’s,” said Rich Kirn, fisheries biologist with Vermont Fish & Wildlife. “This is an encouraging conclusion for Vermont given that populations of wild brook trout have declined significantly across much of the species’ historic range.”
 
The survey, which is summarized in the full report “Evaluation of Wild Brook Trout Populations in Vermont Streams,” included sampling of 138 streams within 17 watersheds between 2005 and 2016, each of which were originally sampled between 1952 and 1960 by former biologist James MacMartin.
 
The watersheds include: Batten Kill, Black River, Connecticut, Deerfield River, Lamoille, Memphremagog, Missisquoi, Nulhegan, Opmompanoosuc, Ottauquechee, Otter Creek, Passumpsic, Poultney, Waits, Wells, White and Winooski.
 
Wild brook trout, which are most often found in small upland streams at higher elevations, require cool, clean water and are a direct indicator of high quality aquatic habitat and optimal environmental conditions.  The official state cold water fish, brook trout are also a favorite of Vermont anglers and were rated as their most preferred fish species in angler surveys conducted in 1991, 2000 and 2010.
 
Sampling of the 17 watersheds has shown present-day brook trout populations throughout Vermont to be highlighted by abundant natural reproduction and multiple age-classes, including the contribution of older, larger fish.
 
Kirn says the survey results may also show a potential correlation to past water quality and aquatic habitat initiatives.
 
“While most population measures have shown to be consistent between the two time periods, significantly higher densities of young brook trout were observed in current populations which may reflect improved environmental protections put in place since the 1950’s, particularly legislation and programs focusing on water quality and aquatic habitat protection,” Kirn said.
 
Kirn emphasized that continuing these protections will help to ensure that wild brook trout populations remain strong in Vermont.
 
“The long-term health of Vermont’s wild brook trout populations will depend on the health of their habitat,” said Kirn. “In addition to the work of state, federal and private natural resource organizations, Vermont landowners can help to keep brook trout populations strong by maintaining trees and other vegetation along streambanks which provide shade, food and cover, as well as stabilize streambanks and filter pollutants. It will take the help of all Vermonters to make sure our native trout thrives into the future.”

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