Acclimation to predicted ocean warming through developmental plasticity in a tropical reef fish

Abstract

Determining the capacity of organisms to acclimate and adapt to increased temperatures is key to understand how populations and communities will respond to global warming. Although there is evidence that elevated water temperature affects metabolism, growth and condition of tropical marine fish, it is unknown whether they have the potential to acclimate, given adequate time. We reared the tropical reef fish Acanthochromis polyacanthus through its entire life cycle at present day and elevated ( 1 1.5 and 1 3.0 1C) water temperatures to test its ability to thermally acclimate to ocean temperatures predicted to occur over the next 50-100 years. Fish reared at 3.0 1C greater than the present day average reduced their resting oxygen consumption (RMR) during summer compared with fish reared at present day temperatures and tested at the elevated temperature. The reduction in RMR of up to 69 mg O 2 kg À1 h À1 in acclimated fish could represent a significant benefit to daily energy expenditure. In contrast, there was no acclimation to summer temperatures exhibited by fish reared at 1.5 1C above present day temperatures. Fish acclimated to 1 3.0 1C were smaller and in poorer condition than fish reared at present day temperatures, suggesting that even with acclimation there will be significant consequences for future populations of tropical fishes caused by global warming.

Vulnerability to climate warming and acclimation capacity of tropical and temperate coastal organisms

“…Such effects have been documented in marine fish by Donelson et al (2012) who found that the tropical damselfish Acanthochromis polyacanthus, although highly sensitive to small increases in water temperature, could rapidly acclimate over multiple generations. Such discovery indicates that tropical marine species are more capable of coping with global warming than previously suggested and illustrates a potential limitation of short-term trials in predicting the long-term impacts of climate change.…”

“…Donelson et al (2012) revealed that fish acclimated to higher temperatures were on average smaller and in poorer condition than fish kept at present day temperatures. Smaller size and poorer condition mean that fewer fish will potentially survive to maturity at elevated temperatures, with fewer and smaller offspring being produced compared with good condition counterparts, raising concerns about communities' future structure and composition (Donelson et al, 2012). Similar costs of acclimation to higher temperatures were also observed in temperate fish.…”

“…Lower growth rates, poorer condition and higher mortality were reported for European sea bass, Dicentrarchus labrax (Vinagre et al, 2012a,b), higher mortality and lower growth rates were also reported for the Senegal sole, Solea senegalensis (Vinagre et al, 2013b) and higher mortality was reported for Senegal sea bream, Diplodus bellottii . Ultimately, the short-term temperature extremes that an organism can tolerate will depend on its phenotypic plasticity, but in the long run, evolutionary shifts in thermal limits will depend on the presence of additive genetic variance, with the selection of thermally tolerant genotypes over multiple generations being decisive (Rezende et al, 2011;Donelson et al, 2012). The crucial issue is whether the rate of evolutionary adaptation will be fast enough to keep up with the rate of environmental warming (Stockwell et al, 2003).…”

Effects of climate change on fish reproduction and early life history stages

“…For example, laboratory experiments on spiny damselfish show that fish reared at higher temperature since birth have a greater capacity to maintain reproduction at temperatures over 308C compared with individuals that have only a few weeks thermal acclimation (J. Donelson et al 2011). Furthermore, the thermal history of the parents is important, with embryos and larvae from parents reared at high temperatures exhibiting greater thermal tolerance or improved performance at high temperatures in several species (Rombough 1997).…”

The Effects of Climate Warming on Plant-Herbivore Interactions

“…Whether P. japonica successfully acclimates to high temperatures remains to be tested. Alternatively, developmental plasticity may allow future generations to increase performance at high temperatures (Donelson et al 2011). …”