Arctic seals, including spotted (Phoca largha), ringed (Pusa hispida) and bearded (Erignathus barbatus) seals, are directly affected by sea ice loss. These species use sea ice as a haul-out substrate for various critical functions, including their annual molt. Continued environmental warming will inevitably alter the routine behavior and overall energy budgets of Arctic seals, but it is difficult to quantify these impacts as their metabolic requirements are not well known—due in part to the difficulty of studying wild individuals. Thus, data pertaining to species-specific energy demands are urgently needed to better understand the physiological consequences of rapid environmental change. We used open-flow respirometry over a four-year period to track fine-scale, longitudinal changes in the resting metabolic rate (RMR) of four spotted seals, three ringed seals and one bearded seal trained to participate in research. Simultaneously, we collected complementary physiological and environmental data. Species-specific metabolic demands followed expected patterns based on body size, with the largest species, the bearded seal, exhibiting the highest absolute RMR (0.48 ± 0.04 L O₂ min⁻¹) and the lowest mass-specific RMR (4.10 ± 0.47 ml O₂ min⁻¹ kg⁻¹), followed by spotted (absolute: 0.33 ± 0.07 L O₂ min⁻¹; mass-specific: 6.13 ± 0.73 ml O₂ min⁻¹ kg⁻¹) and ringed (absolute: 0.20 ± 0.04 L O₂ min⁻¹; mass-specific: 7.01 ± 1.38 ml O₂ min⁻¹ kg⁻¹) seals. Further, we observed clear and consistent annual patterns in RMR that related to the distinct molting strategies of each species. For species that molted over relatively short intervals—spotted (33 ± 4 days) and ringed (28 ± 6 days) seals—metabolic demands increased markedly in association with molt. In contrast, the bearded seal exhibited a prolonged molting strategy (119 ± 2 days), which appeared to limit the overall cost of molting as indicated by a relatively stable annual RMR. These findings highlight energetic trade-offs associated with different molting strategies and provide quantitative data that can be used to assess species-specific vulnerabilities to changing conditions.

中文翻译：

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北极海豹的蜕皮策略推动了新陈代谢的年度模式

北极海豹，包括斑点海豹（Phoca largha），环状海豹（Pusa hispida）和胡须海豹（Erignathus barbatus））密封件，直接受到海冰损失的影响。这些物种使用海冰作为各种关键功能（包括它们的一年生蜕皮）的排出基质。持续的环境变暖将不可避免地改变北极海豹的例行行为和总体能量收支，但是由于对新陈代谢的需求还不十分了解，因此难以量化这些影响-部分原因是难以研究野生个体。因此，迫切需要与特定物种的能量需求有关的数据，以更好地了解快速环境变化的生理后果。我们在四年的时间里使用开放式呼吸测定法来追踪经过训练以参与研究的四个斑点海豹，三个环状海豹和一个大胡子海豹的静息代谢率（RMR）的精细，纵向变化。同时，我们收集了互补的生理和环境数据。特定物种的代谢需求遵循基于体型的预期模式，其中最大的物种是胡须，其绝对RMR最高（0.48±0.04 LO₂ min ^-1）和最低的质量比RMR（4.10±0.47 ml O ₂ min ^-1  kg ^-1），然后点样（绝对值：0.33±0.07 LO ₂ min ^-1 ;质量比：6.13±0.73 ml O ₂ min ^-1  kg ^-1）和呈环状（绝对值：0.20±0.04 LO ₂ min ^-1；质量比：7.01±1.38 ml O ₂ min ^-1  kg ^-1）密封件。此外，我们在RMR中观察到了清晰一致的年度模式，这些模式与每个物种不同的蜕皮策略有关。对于在相对较短的间隔内蜕皮的物种（斑点（33±4天）和环状（28±6天）海豹），与蜕皮相关的代谢需求显着增加。相比之下，大胡子的密封表现出延长的蜕皮策略（119±2天），这似乎限制了整体的蜕皮成本，如相对稳定的年度RMR所示。这些发现凸显了与不同蜕皮策略相关的能量取舍，并提供了可用于评估特定物种对变化环境的脆弱性的定量数据。