Effects of ocean acidification on the early life history of a tropical marine fish

Abstract

Little is known about how fishes and other non-calcifying marine organisms will respond to the increased levels of dissolved CO 2 and reduced sea water pH that are predicted to occur over the coming century. We reared eggs and larvae of the orange clownfish, Amphiprion percula, in sea water simulating a range of ocean acidification scenarios for the next 50 -100 years (current day, 550, 750 and 1030 ppm atmospheric CO 2 ). CO 2 acidification had no detectable effect on embryonic duration, egg survival and size at hatching. In contrast, CO 2 acidification tended to increase the growth rate of larvae. By the time of settlement (11 days post-hatching), larvae from some parental pairs were 15 to 18 per cent longer and 47 to 52 per cent heavier in acidified water compared with controls. Larvae from other parents were unaffected by CO 2 acidification. Elevated CO 2 and reduced pH had no effect on the maximum swimming speed of settlement-stage larvae. There was, however, a weak positive relationship between length and swimming speed. Large size is usually considered to be advantageous for larvae and newly settled juveniles. Consequently, these results suggest that levels of ocean acidification likely to be experienced in the near future might not, in isolation, significantly disadvantage the growth and performance of larvae from benthic-spawning marine fishes.

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

“…Sensitivity of fish eggs to elevated CO 2 varies markedly between species, but species tested to date typically have 24-h LC50 (lethal concentration resulting in 50% mortality) values well above 10 000 ppm CO 2 (Ishimatsu et al 2008). Furthermore, Munday et al (2009a) did not detect any effect of exposure to 1000 ppm CO 2 on the embryonic duration or survival of clownfish (Amphiprion percula) eggs. Eggs of pelagic spawners might be more sensitive to CO 2 stress than the eggs of benthic spawners such as clownfishes, because pelagic eggs probably experience less fluctuation in environmental pCO 2 than benthic eggs, but this hypothesis has not been adequately tested.…”

“…Furthermore, two recent studies have not detected significant negative effects on life history traits of larval reef fishes reared in conditions simulating near-future CO 2 in the ocean. Munday et al (2009a) did not detect negative effects on the size at hatching, growth rate, size at settlement, or critical swimming speed of clownfish, Amphiprion percula, larvae reared from hatching in seawater aerated with up to 1000 ppm CO 2 . Similarly, juvenile spiny damselfish, Acanthochromis polyacanthus, reared for 3 weeks at up to 850 ppm CO 2 were the same size as fish reared in current-day CO 2 controls, did not suffer higher mortality, and exhibited no differences in skeletal or otolith development compared with controls .…”

Projected climate change in Australian marine and freshwater environments

“…Tropical fish may also be affected, in ways that are only becoming apparent as a result of novel experiments (e.g. Munday et al 2009;Pankhurst and Munday 2011). Aragonite saturation horizons will occur at shallower depths in future, especially in the Antarctic and Australian southern margins, threatening a wide range of larval and adult benthic and pelagic calcifying organisms (e.g.…”

Assessing carbon dioxide removal through global and regional ocean alkalinization under high and low emission pathways

“…Potential impacts include changes in calcification, fecundity, organism growth and physiology, species composition and distributions, food web structure, and nutrient availability (Doney et al, 2012;Fabry et al, 2008;Iglesias-Rodriguez et al, 2008;Munday et al, 2009Munday et al, , 2010. Within this century, the impacts of ocean acidification will increase in proportion to emissions (Gattuso et al, 2015).…”