ESR 36:121-135 (2018)  -  DOI: https://doi.org/10.3354/esr00892

Physiological stress in the smalltooth sawfish: effects of ontogeny, capture method, and habitat quality

Bianca K. Prohaska1,*, Dana M. Bethea2, Gregg R. Poulakis3, Rachel M. Scharer3, Ryan Knotek4, John K. Carlson5, R. Dean Grubbs1

1Florida State University Coastal and Marine Laboratory, St. Teresa, Florida 32358, USA
2NOAA National Marine Fisheries Service, Southeast Regional Office, Protected Resources Division, St. Petersburg, Florida 33710, USA
3Fish and Wildlife Research Institute, Florida Fish and Wildlife Conservation Commission, Charlotte Harbor Field Laboratory, Port Charlotte, Florida 33954, USA
4University of Massachusetts Boston, School for the Environment, Boston, Massachusetts 02125, USA
5NOAA National Marine Fisheries Service, Southeast Fisheries Science Center, Panama City, Florida 32408, USA
*Corresponding author:

ABSTRACT: Similar to other elasmobranchs, the smalltooth sawfish Pristis pectinata is slow growing, matures late in life, and produces relatively few young, all factors that have contributed to its sensitivity to dramatic population declines from overfishing and habitat loss. Currently, the physiological stress response of these fish to capture or to other physiological challenges such as habitat loss, climatic changes, or pollution is unknown. In the absence of these data, conservation plans may be less effective, making populations susceptible to further declines. We examined basic stress physiology over ontogeny and as a function of capture using different fishing gears. We also examined stress parameters to test whether degraded habitat and water quality from altered habitats may have resulted in chronic stress in juveniles. Results suggested that the stress response to capture by all methods was low, particularly for blood lactate, compared to other elasmobranchs examined to date. Metabolic stress was found to change over ontogeny, with young of the year (YOY) eliciting the highest responses. Glucose, pCO2, bicarbonate, potassium, and hematocrit indicated that gillnet capture induced greater stress responses than longline capture. Significantly higher metabolic stress was observed in YOY and juveniles captured in the 2 nurseries most influenced by anthropogenic activities, the Peace and Caloosahatchee rivers, than in the 2 relatively pristine nurseries in Everglades National Park. Overall, the low physiological stress responses to all capture methods investigated in this study suggest that this species is resilient, which should promote optimism for recovery of the population.


KEY WORDS: Pristis pectinata · Stress physiology · Metabolic stress · Chronic stress · Anthropogenic effects · Nursery · Habitat loss · Blood chemistry


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Cite this article as: Prohaska BK, Bethea DM, Poulakis GR, Scharer RM, Knotek R, Carlson JK, Grubbs RD (2018) Physiological stress in the smalltooth sawfish: effects of ontogeny, capture method, and habitat quality. Endang Species Res 36:121-135. https://doi.org/10.3354/esr00892

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