Effects of Catch and Release on
Physiological Responses and Acute Mortality of Striped Bass, Morone saxatilis
Julie A. Thompson, Steven G. Hughes, Eric B. May,
Maryland Cooperative Fish and Wildlife Unit, University of Maryland, Eastern Shore,
Princess Anne, Maryland; Voice 410-651-6339, 410-651-7664, 410-651-6069; FAX 410-651-7662;
E-Mail jthompsn@umes-bird.umd.edu,
shughes@umes-bird.umd.edu, emay@umes-bird.umd.edu
Reginal M. Harrell, Horn Point Laboratory, University of
Maryland, Center for Environmental Science, Cambridge, Maryland;
Voice 410-226-8474; E-Mail harrell@hpl.umces.edu
Keywords: respiratory acidosis, metabolic
acidosis, striped bass, mortality, catch and release
The Atlantic striped bass Morone saxatilis has historically
supported some of the most important recreational and commercial fisheries from Maine to
North Carolina. Steady declines in the abundance of striped bass, particularly Chesapeake
Bay stocks, began in the early 1970's, primarily due to excessive fishing mortality. This
prompted legislative and administrative actions which included catch and release policies
that were implemented to offset the impact of angling on a limited fishery. Fish caught by
commercial or recreational methods often struggle to the point of complete exhaustion.
This can result in severe physiological disturbances and a significant percentage may die
from the ordeal. The objective of this study was to determine the effect of angling time
on blood pH, HCO3 -, pCO2, TCO2, pO2, and O2
saturation. A secondary objective was to monitor mortality of the fish angled at 0-30s, 1
min, 2 min, 3 min, 4 min, and 5 min. The effect of size (< 23", >23') on the
stress responses and acute mortality was also examined. There was a significant effect
(p<.05) of angling time on all the blood parameters and acute mortality. There was no
significant effect (p>.05) of size on the blood parameters and acute mortality. As
playing time increased, trends in blood parameters indicated both respiratory and
metabolic acidosis.
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