Marine Biology

, Volume 156, Issue 4, pp 579–587

Synergistic effects of ultraviolet radiation and conditions at low tide on egg masses of limpets (Benhamina obliquata and Siphonaria australis) in New Zealand

Original Paper

DOI: 10.1007/s00227-008-1109-6

Cite this article as:
Russell, J. & Phillips, N.E. Mar Biol (2009) 156: 579. doi:10.1007/s00227-008-1109-6


The effects of ultraviolet radiation (UVR), desiccation and conditions in tidal pools on embryonic survival were examined for two common pulmonate limpets that lay intertidal benthic egg masses on rocky shores in New Zealand: Benhamina obliquata and Siphonaria australis. Field surveys and manipulative experiments were conducted between December 2006 and September 2007 in the Wellington region of New Zealand (41°17′S, 174°47′E). Egg mass deposition sites in the field were species-specific: B. obliquata deposited eggs primarily in shaded crevices, whereas S. australis predominantly deposited egg masses in the sun and in tidal pools. For both species, however, embryonic mortality was greater in egg masses that had been in full sun compared to shade. For S. australis, there was also high mortality in egg masses in tidal pools or desiccated compared to those that remained submerged in flowing seawater at low tide. In outdoor experiments, embryonic mortality was also always greatest for egg masses exposed to full sun, and lowest for those in shaded treatments. Mortality was also higher if egg masses were in simulated tidal pools, and for S. australis, if desiccated, compared to those submerged in flowing seawater. Periods of particularly sunny conditions with high temperatures also resulted in higher overall mortality. Finally, egg masses of both species that were initially deposited in the shade had greater mortality in response to subsequent UV exposure compared to egg masses initially deposited in full sun. Results from this study suggest that the egg masses of these two species are highly vulnerable to UVR, as well as other intertidal stressors. Embryos of both of these species may be at risk of high mortality particularly during summer when extreme conditions of UV intensity and high temperature coincide with low tide cycles.

Supplementary material

227_2008_1109_MOESM1_ESM.doc (24 kb)
Supplementary material S1. Results of ANOVA on effects of light exposure, microhabitat and site on embryonic mortality of field-collected egg masses (DOC 24 kb)
227_2008_1109_MOESM2_ESM.doc (24 kb)
Supplementary material S2. Means of physical parameters ( ± 95% CI) during the field surveys at Island Bay, and the experiments. Air and tidal pool temperatures during the surveys were recorded at low tide. Ambient seawater temperatures taken at VUCEL from 2 dates spanning the survey dates are included for comparative purposes. For the experiments, shown are means of each parameter over the course of each experiment using daily measurements taken at 14:00 hrs. Note there was no exposure to tidal pools in Experiment two, so tidal pool temperature is not reported (NR=not reported). UV data shown for the surveys encompasses the 5 dates prior to and including the survey date, and for the experiments, the 5 days of the experimental period (DOC 24 kb)
227_2008_1109_MOESM3_ESM.doc (24 kb)
Supplementary material S 3 Results of ANOVA for the effect of light exposure, intertidal microhabitat and time of survey on embryonic mortality of Siphonaria australis from field-collected egg masses (n = 10) (DOC 24 kb)

Copyright information

© Springer-Verlag 2008

Authors and Affiliations

  1. 1.School of Biological Sciences and Coastal Ecology LaboratoryVictoria University of WellingtonWellingtonNew Zealand
  2. 2.Ministry for the EnvironmentWellingtonNew Zealand