Recovery and status of shortnose sturgeon in the Hudson River

Secor, David H. and Woodland, Ryan J. (2005) Recovery and status of shortnose sturgeon in the Hudson River. Solomons, MD, University of Maryland Center for Environmental Science, (Technical Report Series, 493-05) (CBL-05-083).

[img]
Preview
PDF (The document's language is English .) - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
Download (4Mb) | Preview

Abstract

Shortnose sturgeon (Acipenser brevirostrum), an endangered species, has experienced a several-fold increase in abundance in the Hudson River in recent decades. This population growth followed a substantial improvement in water quality during the 1970s to a large portion (c. 40%) of the species' summertime nursery area. Age structure and growth were investigated to evaluate the hypothesis that improvements in water quality stimulated population recovery through increased survival of young of the year juveniles. Specimens were captured using gill nets bi-monthly from November 2003 to November 2004 (n = 596). Annuli in fin spine sections were used to generate estimates of sturgeon age. Based upon a marginal increment analysis, annuli were determined to form at an annual rate. Age determinations yielded a catch composed of age 5-30 years for sizes 49-105cm Total Length (n = 554). Individual growth rate (von Bertalanffy coefficients: TL, = 1045mm, K = 0.07) for the population was similar to previous growth estimates within the Hudson River as well as proximal estuaries. Hindcast year-class strengths, based upon a recent stock assessment (Bain et al. 2000) and corrected for gill net mesh selectivity and cumulative mortality indicated high recruitments (28,000-43,000 yearlings)during 1986-1992, which were preceded and succeeded by c.5-year periods of lower recruitment (5,000-1 5,000 yearlings). Recruitment patterns were corroborated by trends in shortnose sturgeon bycatch from a Hudson utilities-sponsored monitoring program. Results indicated that Hudson River shortnose sturgeon abundance increased due to the formation of several strong year-classes occurring about five years subsequent to improved water quality in important nursery and forage habitats in the upper Hudson River estuary. (PDF contains 108 pages.)

Item Type: Monograph or Serial Issue
Title: Recovery and status of shortnose sturgeon in the Hudson River
Personal Creator/Author:
CreatorsEmail
Secor, David H.secor@cbl.umces.edu
Woodland, Ryan J.woodland@cbl.umces.edu
Series Name: Technical Report Series
Number: 493-05
Date: 2005
Publisher: University of Maryland Center for Environmental Science
Place of Publication: Solomons, MD
Funders: Hudson River Foundation for Science and Environmental Research, Inc.
Issuing Agency: University of Maryland Center for Environmental Science. Chesapeake Biological Laboratory
Uncontrolled Keywords: Sturgeon; Recovery; Growth estimates; Recruitment patterns; Hudson River; Albany; Aging
Subjects: Ecology
Management
Fisheries
Aquaculture
Item ID: 3005
Depositing User: Kathleen Heil
Date Deposited: 12 Mar 2010 12:12
Last Modified: 29 Sep 2011 18:02
URI: http://aquaticcommons.org/id/eprint/3005

Actions (login required)

View Item View Item

Document Downloads

More statistics for this item...