Status of alewife and rainbow smelt in U.S. waters of Lake Ontario, 2015

NYSDEC Lake Ontario Annual Report 2015-12a
By: , and 

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Abstract

In 2015 the joint USGS and NYSDEC surveys for Alewife and Rainbow Smelt were combined for the first time into a comprehensive spring pelagic prey fish survey. The adult Alewife abundance and weight indices in 2015 increased slightly from 2014 levels, and adult Alewife abundance has remained relatively stable for the past five years. Adult Alewife condition in both spring and fall increased from 2014 values and was above long-term means. Yearling Alewife abundance was the lowest observed in the 38-year time series. Alewife year class strength at age 1 is related to the number of spawning adults and summer temperatures and winter duration in the first year after hatching. Moderate year classes were produced during 2009-2011, and 2012 was the largest year class in the time series. However, severe winters in 2013-2014 and 2014-2015 contributed to two successive very small year classes for the first time in the time series. We expect adult Alewife abundance and biomass to decline in 2016 as older and larger fish decline in the population. The number of spawning adults increased in 2015, summer temperatures were slightly below average, and the anticipated winter duration is below average (i.e., milder winter) for 2015-2016, so these conditions will likely produce a low to moderate year class. A third successive weak year class could be problematic for the Lake Ontario Alewife population and may be of concern to binational lake managers. Rainbow Smelt were also assessed and the population continues to persist at a low and stable level.

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Additional publication details

Publication type Report
Publication Subtype State or Local Government Series
Title Status of alewife and rainbow smelt in U.S. waters of Lake Ontario, 2015
Series title NYSDEC Lake Ontario Annual Report
Series number 2015
Chapter 12a
Year Published 2016
Language English
Publisher New York State Department of Environmental Conservation
Publisher location Albany, NY
Contributing office(s) Great Lakes Science Center
Description 11 p.
Larger Work Type Report
Larger Work Subtype State or Local Government Series
Larger Work Title 2015 Annual report: Bureau of Fisheries, Lake Ontario unit and St. Lawrence River unit, to the Great Lakes Fishery Commission’s Lake Ontario Committee
First page 12a-1
Last page 12a-11
Conference Title Lake Ontario Committee Meeting
Conference Location Niagra Falls, ON
Conference Date March 31 - April 1, 2016
Country United States
Other Geospatial Lake Ontario
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