Article

ECOLOGY physiology and climate change

Animal Ecophysiology, Alfred-Wegener-Institute for Polar and Marine Research, 27515 Bremerhaven, Germany.
Science (Impact Factor: 31.48). 11/2008; 322(5902):690-2. DOI: 10.1126/science.1163156
Source: PubMed

ABSTRACT Studies of physiological mechanisms are needed to predict climate effects on ecosystems at species and community levels.

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    • "foraging rate, microhabitat usage) and/or gene pool (i.e. populationlevel increase in better-performing genotypes; Pörtner and Farrell, 2008). While the effects of ocean acidification on Antarctic animals that use calcium carbonate to form their shells is receiving increasing attention [e.g. "
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    ABSTRACT: Anthropogenic CO 2 is rapidly causing oceans to become warmer and more acidic, challenging marine ectotherms to respond to simultaneous changes in their environment. While recent work has highlighted that marine fishes, particularly during early development, can be vulnerable to ocean acidification, we lack an understanding of how life-history strategies, ecosystems and concurrent ocean warming interplay with interspecific susceptibility. To address the effects of multiple ocean changes on cold-adapted, slowly developing fishes, we investigated the interactive effects of elevated partial pressure of carbon dioxide (pCO 2) and temperature on the embryonic physiology of an Antarctic dragonfish (Gymnodraco acuticeps), with protracted embryogenesis (∼10 months). Using an integrative, experimental approach, our research examined the impacts of near-future warming [−1 (ambient) and 2°C (+3°C)] and ocean acidification [420 (ambient), 650 (moderate) and 1000 μatm pCO 2 (high)] on survival, development and metabolic processes over the course of 3 weeks in early development. In the presence of increased pCO 2 alone, embryonic mortality did not increase, with greatest overall survival at the highest pCO 2. Furthermore, embryos were significantly more likely to be at a later developmental stage at high pCO 2 by 3 weeks relative to ambient pCO 2. However, in combined warming and ocean acidification scenarios, dragonfish embryos experienced a dose-dependent, synergistic decrease in survival and developed more slowly. We also found significant interactions between temperature, pCO 2 and time in aerobic enzyme activity (citrate synthase). Increased temperature alone increased whole-organism metabolic rate (O 2 consumption) and developmental rate and slightly decreased osmolality at the cost of increased mortality. Our findings suggest that developing dragonfish are more sensitive to ocean warming and may experience negative physiological effects of ocean acidification only in the presence of an increased temperature. In addition to reduced hatching success, alterations in development and metabolism due to ocean warming and acidification could have negative ecological consequences owing to changes in phenology (i.e. early hatching) in the highly seasonal Antarctic ecosystem. Cite as: Flynn EE, Bjelde BE, Miller NA, Todgham AE (2015) Ocean acidification exerts negative effects during warming conditions in a developing Antarctic fish. Conserv Physiol 3: doi:10.1093/conphys/cov033.
    Conservation Physiology 08/2015; 3:cov033. DOI:10.1093/conphys/cov033
    • "TPCs are generally highly asymmetric, with performance increasing gradually to a maximum at the optimum temperature and decreasing rapidly above that temperature (Angilletta, 2006; Martin and Huey, 2008). Such non-lethal performance responses to temperature can have important consequences for fitness (Clark et al., 2013 and references within; Kingsolver et al., 2007; Pörtner and Farrell, 2008). Beyond the organismal level, environmental temperatures interact with thermal tolerance and sensitivity to determine species' ranges and geographic distributions (Cahill et al., 2013). "
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    ABSTRACT: Temperature is one of the primary environmental variables limiting organismal performance, fitness, and species distributions. Yet, understanding temperature effects requires thorough exploration of thermal constraints and organismal responses that can translate to fitness and non-lethal long-term consequences under both constant and changing thermal regimes. We examined the thermal ecology of the fiddler crab Uca panacea, including critical thermal limits, thermal sensitivity of locomotion, operative environmental temperatures, preferred body temperatures, and acclimation ability. Operative environmental temperatures frequently reached the critical thermal maximum (41.8±0.8°C, mean ± s.e.m.), especially in unvegetated microhabitats, indicating the need for behavioral thermoregulation to maintain diurnal activity patterns. Preferred body temperatures (21.1-28.6°C) were substantially below the thermal optimum (30-40°C), although further research is needed to determine the driver of this mismatch. Critical thermal limits shifted 2-4°C in response to exposure to low (20°C) or high (35°C) temperatures, with full acclimation occurring in approximately 9d. This capacity for rapid acclimation, combined with the capacity for behavioral thermoregulation, is a strong candidate mechanism that explains the broad habitat use and could help explain the successful pantropical distribution of fiddler crabs. Copyright © 2015 Elsevier Ltd. All rights reserved.
    Journal of Thermal Biology 06/2015; DOI:10.1016/j.jtherbio.2015.06.004 · 1.54 Impact Factor
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    • "Early developmental stages, such as fertilization, embryogenesis, and morphogenesis, are generally the most sensitive life history phases (Pörtner and Farrell 2008; see Byrne 2011 for review). Temperature can have both positive and negative impacts linked with different physiological processes with potential consequences for fitness (settlement and energy investment in juveniles) (Pörtner and Farrell 2008). Ocean warming improves fertilization (Hagström and Hagström 1959; Mita et al. 1984; Cohen-Rengifo et al. 2013), speeds up larval growth, development , and settlement, and may also impact larval swimming behavior and duration of planktonic life, up to an organism's thermal threshold (Staver and Strathmann 2002; O'Connor et al. 2007; Sheppard-Brennand et al. 2010; see Byrne and Przeslawski 2013 for review). "
    Marine Biology 06/2015; 162:1463-1472. · 2.39 Impact Factor
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