Ecological surprises like this help, to some degree, to balance out the doom and gloom nature of ocean acidification research. But they also suggest that laboratory experiments\u2014which make up the bulk of scientific research on the topic\u2014are only telling part of the story. This raises a key question: can sound predictions for the future state of the ocean be made based on experiments run in tanks?<\/p>\n
A new paper published in the journal Global Change Biology<\/em><\/a> argues they cannot. As Australian Institute of Marine Science coral reef ecologist and lead author Sven Uthicke<\/a> says, laboratory studies are often conducted in highly controlled conditions, outside of ecological contexts. Thus they don\u2019t take secondary effects on marine organisms into account. This means environmental factors or ecosystem dynamics that would balance out (or compound) the effects of acidification are being overlooked.<\/p>\n Coral dissolves in a laboratory trial in which it is exposed to acidified water. Photo by Anne Cohen, Woods Hole Oceanographic Institution<\/p><\/div>\n Such was the case in Papua New Guinea, where Uthicke studied the effect of acidity on sea urchins that live near volcanic vents, where pH levels are naturally low. Based on aquarium trials, sea urchins are normally considered highly susceptible to the threat of acidification. Yet Uthicke and his colleagues found that these urchins, which have had time to acclimatize to the conditions near the vent, grow at a healthy rate\u2014even faster than at surrounding sites with more normal pH levels.<\/p>\n What got the urchins over the acidification hump, according to Uthicke, was the \u201csecondary effect\u201d of an increased food supply at the vent site: the same elevated carbon dioxide levels that caused the increased acidity also triggered the growth of algae, on which the spiny creatures could feast. <\/p>\n Conclusions based singularly on lab studies, it seems, may not accurately reflect how organisms will fare in the wild. But are the dramatic results of lab trials exaggerating the risk of ocean acidification?<\/p>\n \u201cFor sure there have been what some may consider as exaggerations,\u201d says Kevin Flynn<\/a>, a marine biologist at Swansea University in Wales. \u201cBut at the same time, there have been instances where we have underestimated or misunderstood the potential impacts based on lab studies. In either case, it\u2019s irrefutable that oceans are becoming more acidic. So we have to be very wary.\u201d<\/p>\n![](\"\/wp-content\/uploads\/baby_corals_melting_away_in_a_lab_tank_full_of_acidified_water.jpg\")
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