Institute for Biodiversity and Ecosystem Dynamics

Chasing sea butterflies in one of the World’s largest oceans

19 January 2015

Two months ago Alice Burridge, PhD candidate at Institute for Biodiversity and Ecosystem Dynamics and the Naturalis Biodiversity Centre Leiden, joined an international oceanographic expedition across the Atlantic Ocean. After two months of chasing sea butterflies known as pteropods, she now looks back at a successful science campaign.

Atlantic Meridional Transect

Burridge sailed from England to the Falkland Islands in seven weeks, collecting zooplankton samples along the way. The campaign was the 24th expedition of the Atlantic Meridional Transect, a long-term multidisciplinary ocean observation programme coordinated and led by Plymouth Marine Laboratory in collaboration with the National Oceanography Centre (Southampton, UK). Its goal is to ‘help provide warning of any fundamental change in Atlantic ecosystem function, resulting in improved forecasts of the ocean's future state and related socio-economic impacts.’

Dissolving shells

Burridge’s participation was part of her PhD position in which she investigates the biodiversity and evolution of sea butterflies or planktonic snails known as pteropods. Their shells are made from aragonite, a carbonate mineral, and are vulnerable to ocean acidification. Climate change causes a gradual acidification of the oceans due to the uptake of atmospheric CO2 in the oceans. Shelled pteropods can therefore serve as bioindicators of global climate change in the World’s oceans, but this requires insights in their current biodiversity. 

A daily routine 

Burridge obtained daily zooplankton samples along the transect in collaboration with an international team of scientists working on other zooplankton groups. These samples contained hundreds of pteropod specimens. For her PhD research Burridge will use the samples to examine distribution patterns of pteropod species, to  investigate genetic diversity of specific groups in particular, and to examine the extent of current effects of ocean acidification on their shells. 

On board the ship Burridge collaborated with an international team of scientists. Despite the heavy workload ‘the inspirational people and work environment’ made the endeavour a great adventure, according to Burridge.

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Published by  IBED