Abstract

AbstractAnadromous blueback herring Alosa aestivalis are declining throughout much of their range, and fishery closures in some systems have failed to produce population recovery. A potential contributing factor is increased predation pressure from sympatric striped bass Morone saxatilis. We integrated data on the predator–prey interaction between striped bass and blueback herring during vernal migrations into the Connecticut River with data on the in‐river striped bass fishery to assess the potential for mitigation of blueback herring mortality via increased striped bass harvest. Striped bass abundance, size structure, diets, and angler catches were assessed within a river segment during spring 2005–2008. We estimate that striped bass consumed 400,000 blueback herring (90% confidence interval = 200,000–800,000) annually in our study area during the spring migration season. The predator–prey interaction between striped bass and blueback herring was predator size dependent. Blueback herring were most commonly found in the stomachs of striped bass between 650 and 999 mm total length. Intermediate size‐classes (650–799 mm) made the greatest contribution to population‐level consumption. Highly abundant small striped bass (400–549 mm) consumed herring infrequently, yet still made substantial contributions to population‐level consumption. Anglers caught 17,000 striped bass in our study area during March–June 2008; only 11% of these fish could be harvested under the current 28‐in (710‐mm) minimum length limit. Allowing anglers to harvest up to 15,000 sublegal striped bass from a “bonus harvest” slot limit would reduce annual predatory losses of blueback herring by up to 10%. Alternatively, a smaller bonus harvest of legal‐sized striped bass could achieve reductions in consumption of up to 7%. The recreational fishery in our study area, however, may not be intense enough to realize such harvest levels.Received March 21, 2011; accepted October 18, 2011

Highlights

  • Anadromous blueback herring Alosa aestivalis are declining throughout much of their range, and fishery closures in some systems have failed to produce population recovery

  • Blueback herring were eaten by striped bass over most of the size range we captured by electrofishing

  • Herring were most commonly eaten by striped bass 650–999 mm (25–39 in) long; herring were recovered from 19% of these fish, and most of the striped bass containing more than one herring were in this size range (Figure 4)

Read more

Summary

Introduction

Anadromous blueback herring Alosa aestivalis are declining throughout much of their range, and fishery closures in some systems have failed to produce population recovery. Management scenarios producing increased striped bass harvests may ameliorate the natural mortality operating on river herring populations and improve their recovery prospects. Recognizing the potential to reduce predatory pressure on a species of conservation concern and provide anglers a new harvest opportunity, the Connecticut Department of Energy and Environmental Protection (CDEEP) instituted experimental regulations on the spring recreational fishery for striped bass in the Connecticut River. The experimental regulations instituted by CDEEP allowed anglers to harvest two striped bass per day within a 22–28-in (560-710mm) slot limit from the Connecticut portion of the Connecticut River during May and June This “bonus harvest” program was created by transferring an unused commercial quota (approximately 24,000 lb [10,886 kg]) to the recreational fishery; the bonus harvest was capped at 4,000 fish so as not to exceed the quota. The bonus harvest was first implemented in 2011, after diet sampling and abundance estimates of striped bass described below revealed the potential for considerable predatory losses of blueback herring

Objectives
Methods
Results
Conclusion
Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.