Green turtles (Chelonia mydas) at Heron Island, Australia experience a decrease in field metabolic rate (FMR) during winter compared with summer.

Physiological Ecology of Marine Vertebrates

Marine Conservation

physiology def. the study of how living organisms function

ecology def. the study of the interactions between living organisms and their environment

Dr. Amanda Southwood, Assistant ProfessorDept. of Biology and Marine Biology, UNCWDobo Hall Rm. 114/115, tel (910) 962-4064e-mail: southwooda@uncw.edu

Education1993 BSc Marine Biology, Auburn Univ.; 1997 MSc Zoology, Univ. of British Columbia; 2002 PhD Zoology, Univ. of British Columbia

Peer-reviewed PublicationsSouthwood, 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 seasonalchanges 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.

Primary Research Interests

Seasonal energetics of sea turtles

Thermal biology of leatherback sea turtles

Seasonal shifts in FMR are accompanied by shifts in dive patterns (longer dives and more time in shallow habitats during winter compared with summer).

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.

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What is “physiological ecology”?!?!

Physiological ecologists strive to integrate data collected on different levels of biological organization to understand how animals function, survive, and thrive in their environment.

26.2°C

15.3 ± 1.9

2274 ± 701

21.4°C

16.7 ± 2.9

1459 ± 488

Mean TW

Mass (kg)

FMR (kJ/day)

SUMMER WINTER

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.

Energetics is the study of how organisms acquire and allocate energy.

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.

An understanding of sea turtle energetics is important for assessing growth and reproduction, population recovery trends, and management strategies for these

endangered animals.

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.

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.

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.

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.

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*Downward spikes in stomach TB trace represent food/water ingestion events*

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.

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.

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.

NOAA R/V Oscar Elton Sette Bigeye tuna

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.

I am committed to applying knowledge gained through objective scientific research to further the cause of marine conservation and foster responsible stewardship of oceans.

Longline fishing vessel Hooked olive ridley turtle

Hooked tiger shark

Green turtle (photo V. Grundmanis)

Leatherback turtle (photo R. Andrews)