337 
National Marine 
Fisheries Service 
NOAA 
Fishery Bulletin 
n* established in 1881 -<?. 
Spencer F. Baird 
First U S- Commissioner 
of Fisheries and founder 
of Fishery Bulletin 
Effects of temperature and hypoxia on the 
metabolic performance of juvenile striped 
bass (i Morone saxatilis) 
Email address for contact author: anweilerk@dnr.sc.gov 
Abstract —Striped bass (Morone sax¬ 
atilis) found in estuaries and rivers of 
North America face many environmen¬ 
tal challenges. These challenges may 
have led to local extirpations of striped 
bass, as has been observed in the 
Ashley River in South Carolina. The 
link between environmental challenges 
and extirpation may be physiological 
capacities, such as standard metabolic 
rate (SMR), maximum metabolic rate 
(MMR), and aerobic metabolic scope 
(AMS). The objective of this study was 
to determine the effect of tempera¬ 
ture and oxygen availability on the 
metabolic capacities of striped bass, 
thereby assessing the physiological 
capability for survival under varying 
environmental conditions. After being 
acclimated to water temperatures 
of 20°C, 25°C, and 32°C, striped bass 
swam at their acclimation tempera¬ 
ture while being acutely exposed to 
dissolved oxygen (DO) levels of 2.5, 3.0, 
and 4.0 mg/L. The highest values of 
SMR, MMR, and AMS were observed 
at 32°C, a temperature approaching 
the upper lethal limit. The MMR, AMS, 
and exhaustion time were significantly 
reduced at DO concentrations below 
4.0 mg/L. These results indicate that 
juvenile striped bass are metabolically 
limited as DO concentrations fall below 
4.0 mg/L. However, juvenile striped bass 
in the Ashley River may be minimally 
affected by this potential challenge 
because these conditions are rarely 
observed. 
Manuscript submitted 25 February 2019. 
Manuscript accepted 7 November 2019. 
Fish. Bull. 117:337-347 (2019). 
Online publication date: 5 December 2019. 
doi: 10.7755/FB. 117.4.6 
The views and opinions expressed or 
implied in this article are those of the 
author (or authors) and do not necessarily 
reflect the position of the National 
Marine Fisheries Service, NOAA. 
Katie V. Anweiler (contact author) 1 
Karl Brenkert 1 
Tanya L. Darden 1 
Eric J. McElroy 2 
Michael R. Denson 1 
' Marine Resources Research Institute 
South Carolina Department of Natural Resources 
P.O. Box 12559 
Charleston, South Carolina 29422 
2 Department of Biology 
College of Charleston 
66 George Street 
Charleston, South Carolina 29424 
The striped bass (Morone saxatilis ) is an 
ecologically and economically import¬ 
ant finfish species along the Atlantic 
coast of North America. Its native range 
extends from the St. Lawrence River in 
Canada to the Gulf of Mexico (Setzler 
et al., 1980). Striped bass have also been 
introduced into rivers and reservoirs 
throughout the United States and are 
a valuable recreational fishery in many 
areas. North of Cape Hatteras, in North 
Carolina, up through New England, 
adults leave their native estuaries and 
migrate along the coast, ascending into 
rivers to spawn (ASMFC 1 ; Coutant, 
1985). South of Cape Hatteras, striped 
bass rarely undertake coastal migra¬ 
tions and remain associated with rivers 
and estuaries (Coutant, 1985). 
Across the range of this species, 
dissolved oxygen (DO) concentration 
and temperature are important water- 
quality parameters that affect the 
survival and reproductive success of 
striped bass (Coutant, 1985; Coutant 
and Benson, 1990). Both field obser¬ 
vations and experimental results from 
inland impoundments, rivers, and estu¬ 
aries indicate that striped bass become 
physiologically stressed by hypoxic con¬ 
ditions of DO levels of approximately 
3 mg/L and that they cannot inhabit 
areas with DO concentrations less 
than approximately 2 mg/L (Coutant, 
1985). Although resource managers 
and fisheries biologists commonly mea¬ 
sure oxygen preferences and limits and 
develop habitat suitability index mod¬ 
els in terms of DO concentration (e.g., 
ASMFC 1 ; Coutant, 1985; Greene et al. 2 ; 
Ruane et al., 2013), it should be noted 
1 ASMFC (Atlantic States Marine Fisheries 
Commission). 1981. Interstate fisheries 
management plan for the striped bass of 
the Atlantic coast from Maine to North 
Carolina. Atl. States Mar. Fish. Comm., 
Fish. Manage. Rep. 1, 329 p. [Available 
from website.] 
2 Greene, K. E., J. L. Zimmerman, R. W. 
Laney, and J. C. Thomas-Blate. 2009. Atlan¬ 
tic coast diadromous fish habitat: a review 
of utilization, threats, recommendations 
for conservation, and research needs. Atl. 
States Mar. Fish. Comm., Habitat Manage. 
Ser. 9, 463 p. [Available from website.] 
