D. P. Costa, R. S. Wells, G. A. J. Worthy, R. R. Holser, D. M. Waples, A. J. Read, M. D. Scott, A. B. Irvine · Frontiers in Marine Science · 2026

Metabolic rates and water influx of free-ranging bottlenose dolphins in Sarasota Bay, Florida

Resumo original em inglês

Bioenergetics is an important tool for examining animals’ ability to respond to environmental disturbances, whether human or natural. Here, we report seasonal variation in the field metabolic rate (FMR) of 14 common bottlenose dolphins (Tursiops truncatus) of known age (6–23 yrs) and sex (4 females and 10 males) over a 2-year period (10 in summer, 4 in winter) in Sarasota Bay, Florida, using the doubly labeled water method. Animals were caught, dosed with isotopes, released, and resampled shortly thereafter. In addition to FMR, this method provides data on total water influx, which can be used to estimate prey intake, seawater ingestion, and lipid mass, a measure of body condition. Total water influx was higher in summer compared to winter (207 ± 32 mL/kg-d vs 117 ± 14 mL/kg-d). Bottlenose dolphins were slightly heavier in winter than summer (179.4 kg winter vs 172.4 kg summer) and had a higher proportion of body fat (22.2% winter vs 4% summer). The bottlenose dolphins exhibited field metabolic rates of 3.98 ± 0.69 W/kg in winter and 5.66 ± 1.03 W/kg in summer, which were 4.2- and 5.3-fold greater than previously measured resting metabolic rates for this species under human care. The higher metabolic rates we observed in summer could result from increased metabolic costs associated with seasonal variation in prey availability or quality and/or the increased metabolic costs of skin repair and rejuvenation associated with warmer water. Our results suggest that bottlenose dolphins lead an energetically expensive lifestyle similar to that of sea lions and fur seals. As environmental temperatures rise, the already high FMR of Sarasota Bay bottlenose dolphins may limit their ability to compensate, particularly if warming is associated with reduced prey availability and/or quality.

Espécies citadas

• Tursiops truncatus · golfinho-nariz-de-garrafa
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  Nomes populares variam entre regiões e uma mesma palavra pode designar espécies diferentes. Confira sempre o nome científico: Tursiops truncatus.