Dog whelks affected by biological “inflation”

18 August 2014

A new complex study published in Global Change Biology and led by Dr Ana Queiros (UKOA and Plymouth Marine Laboratory Benthic Ecologist) suggests that progressive ocean warming and acidification under three possible CO₂ emissions scenarios for the end of the century will cause increased biological costs in a key UK coastline predator, the dog whelk, with the potential to have a negative impact upon coastal biodiversity as a whole.

It was observed that under the stressors of ocean acidification, with and without warming, the whelks spent more time trying to find their prey, due to their reduced ability to “sniff out” food. This resulted in an increase in feeding time to make up for the increased cost of foraging, which in turn would make the whelks more susceptible to predators as they spend more time exposed. Shell formation and density was also affected, making them an easier meal for predators.

Understanding long-term ecosystem impacts of living in a warmer and high CO₂ ocean is challenging as experimental research has tended to be confined to shorter, individual species studies. These are great at providing a fundamental understanding of the effects of stressors on marine creature and ecosystems, however, they do not reflect the complex nature and interactions of the real world.

In this novel, highly integrated investigation, researchers have combined results from rigorously controlled long-term ocean acidification and warming research on how the organism functions, growth, mortality, predatory behaviour and shell structure, with projections provided by ecosystem scale models and future climate scenarios defined by the Intergovernmental Panel on Climate Change (IPCC). This innovative approach enabled the scientists to set of each of those individual findings within the context of environmental complexity expected to be observed over much larger time and spatial scales.

The diversity of data in the study provides a more complete assessment of how climate change impacts may propagate through communities, as opposed to individual species research, because it considers the impacts of stressors on species of interest, but also on the environment and communities around them (e.g. on food resources).

The dog whelk (Nucella lapillus) is listed in the UK Biodiversity Action Plan long list of species of conservation concern and is important in maintaining the coastal ecosystem balance, particularly in relation to mussels, barnacles and intertidal seaweeds.

As well as scientists from UKOA and PML, this collaborative research project was conducted by the Hellenic Centre for Marine Research (Crete), Plymouth University, University of Southampton, Marine Biological Association, National Oceanography Centre and the University of British Colombia.

Image: Micro-CT reconstructions of Nucella lapillus shells. Top row: control treatments exhibiting normal, reticulated shell ornamentation. Bottom row: individuals from the most extreme acidification treatments exhibiting loss of natural ornamentation pattern, worn apex and shallow whorl definition.