Physiological Ecology of Marine Vertebrates
Dr. Amanda Southwood, Assistant Professor
Dept. of Biology and Marine Biology, UNCW
Dobo Hall Rm. 114/115, tel (910) 962-4064
e-mail: southwooda@uncw.edu
What is “physiological ecology”?!?!
Education
1993 BSc Marine Biology, Auburn Univ.; 1997 MSc Zoology, Univ. of British Columbia; 2002 PhD Zoology, Univ. of British Columbia
Peer-reviewed Publications
physiology def. the study of how living organisms function
Southwood, A.L., Andrews, R.D., Paladino, F.V., Jones, D.R. 2005. Effects of diving and swimming behaviour on body temperatures
of leatherback sea turtles in tropical seas. Physiol. Biochem. Zool. 78(2): 285-297.
Jones, D.R., Southwood, A.L., Andrews, R.D. 2004. Energetics of Leatherback Sea Turtles. In Experimental Approaches to
Conservation Biology. M.S. Gordon & S. M. Bartol, eds. Berkeley. University of California Press, Ltd. pp 66-82.
Southwood, A.L., Darveau, C.A., Jones, D.R. 2003. Metabolic and cardiovascular adjustments of juvenile green turtles to seasonal
changes in temperature and photoperiod. J. Exp. Biol. 206: 4521-4531.
Southwood, A.L., Reina, R.D., Jones, V.S.,Jones, D.R. 2003. Seasonal diving patterns and body temperatures of juvenile green
turtles at Heron Island, Australia. Can. J. Zool. 81(6): 1014-1024.
Southwood, A.L., Andrews, R.D., Lutcavage, M.E., Paladino, F.V., West, N.H., George, R. H., and Jones, D.R. 1999. Heart rates and
diving behaviour of leatherback sea turtles in the Eastern Pacific Ocean. J. Exp. Biol. 202:1115-1125.
ecology def. the study of the interactions between living organisms and their environment
Physiological ecologists strive to integrate data collected on different levels of biological
organization to understand how animals function, survive, and thrive in their environment.
Thermal biology of leatherback sea turtles
Primary Research Interests
I use a combination of field and laboratory techniques to study the metabolic biochemistry, cardio-respiratory
physiology, and diving patterns of sea turtles, with a focus on thermal effects.
I am committed to applying knowledge gained through objective scientific research to further the cause
of marine conservation and foster responsible stewardship of oceans.
The leatherback turtle (Dermochelys coriacea) is the largest extant species of sea turtle (≤1000 kg).
Leatherbacks are oceanic wanderers, migrating from tropical breeding areas to foraging grounds at high latitude.
Models predict that leatherbacks could maintain elevated body temperatures (TB) while migrating through cold water due
to their large body size and the use of peripheral tissues as insulation.
Energetics is the study of how organisms acquire and allocate energy.
Leatherback turtle (photo R. Andrews)
The rate at which energy is expended, or the metabolic rate, is often measured to evaluate
energetic requirements and the impact that an organism may have on its environment.
SUMMER
Depth (m)
Seasonal shifts in FMR are
accompanied by shifts in dive
patterns (longer dives and more
time in shallow habitats during
winter compared with summer).
TW (°C)
Green turtles (Chelonia mydas) at Heron Island,
Australia experience a decrease in field metabolic
rate (FMR) during winter compared with summer.
31
30
29
28
27
26
25
0
2
4
6
8
10
12
TW (°C)
Depth (m)
Green turtle (photo V. Grundmanis)
26.2°C
21.4°C
15.3 ± 1.9
16.7 ± 2.9
30
29
1.2
0.8
0.4
0.0
0
20
40
60
80
32
30
28
26
24 *Downward spikes in stomach T trace represent food/water ingestion events*
B
00:00
08:00
16:00
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08:00
16:00
00:00:00
04:00:00
08:00:00
12:00:00
16:00:00
20:00:00
00:00:00
00:00
FMR (kJ/day) 2274 ± 701 1459 ± 488
Marine Conservation
SUMMER
1 5 /1 2 /2 0 0 0
25
24
23
22
21
20
19
0
2
4
6
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Mean TW
31
I would like to expand these studies to include biochemical, physiological, and behavioral
measurements for leatherback turtles migrating through temperate water so that we may
explore the extent of this reptile’s thermoregulatory capabilities.
WINTER
Mass (kg)
stomach TB (oC)
Seasonal energetics of sea turtles
o
Depth (m) Swim speed (m . s-1) TB ( C)
My colleagues and I found that
leatherbacks in tropical seas maintain
TB 1-4°C higher than ambient water
temperatures, however food ingestion
and variation in diving patterns and
activity level affected TB.
1 6 /1 2 /2 0 0 0
1 7 /1 2 /2 0 0 0
1 8 /1 2 /2 0 0 0
1 9 /1 2 /2 0 0 0
Bycatch of non-target species, such as sea turtles and sharks,
in commercial fishing operations is a topic of great concern.
Basic science research coordinated and funded by the NOAA
Fisheries has been directed at identifying gear and bait
modifications that may reduce bycatch.
Longline fishing vessel
W IN T E R
8 /8 /2 0 0 1
9 /8 / 2 0 0 1
1 0 /8 / 2 0 0 1
1 1 /8 / 2 0 0 1
1 2 /8 /2 0 0 1
Seasonal changes in metabolism and behavior may vary greatly depending on local
environmental conditions. I am interested in investigating seasonal variation in energetics
and diving behavior of sea turtles at different geographic locations, including coastal N.C.
NOAA R/V Oscar Elton Sette
An understanding of sea turtle energetics is important for assessing growth and
reproduction, population recovery trends, and management strategies for these
endangered animals.
Hooked olive ridley turtle
As part of this NOAA initiative, I conducted trials with captive loggerhead turtles to
investigate the importance of chemoreception in food-finding abilities and to assess
the feasibility of using chemically-modified baits to prevent fisheries interactions.
Bigeye tuna
Hooked tiger shark
I also coordinated trials onboard the NOAA vessel Oscar Elton Sette to test the
efficacy of recently developed chemical shark deterrents in reducing bycatch of
non-target shark species in longline fishing gear. This research is on-going.
Future research efforts will be directed towards determining the physiological and behavioral consequences for sea turtles captured in
fishing gear, with the ultimate goal of refining mortality estimates used in current fisheries management practice.