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Wall-Palmer D, Metcalfe B, Leng MJ, Sloane HJ, Ganssen G, Vinayachandran PN, Smart CW
Vertical distribution and diurnal migration of atlantid heteropods
Understanding the vertical distribution of aragonite shelled planktonic gastropods is essential when considering the effects of imminent ocean acidification and climate change. Using museum collections, Wall-Palmer and co-workers detected two patterns of atlantid heteropod vertical migration. Small species remained in shallow waters of <140 m at all times, whereas larger atlantids migrated to deep waters during the day, returning to shallow waters at night. Oxygen isotope ratios of atlantid shells revealed that calcification takes place within the upper 150 m of the water column, close to the Deep Chlorophyll Maximum, where food is abundant. This region is projected to experience the earliest and greatest anthropogenic ocean changes, strongly indicating that atlantid heteropods will be adversely affected in the near future.