K068: Effects of Climate Change on Antarctic Marine Invertebrate Embryo and Larval Physiology

K068: Effects of Climate Change on Antarctic Marine Invertebrate Embryo and Larval Physiology

Miles Lamare
University of Otago

What we do: We are investigating the impact of UV-R on the planktonic larval stage of Sterechinus neumayeri, a species of sea urchin that is found throughout Antarctic shallow waters. Operating from Scott Base, our research involves diving under the sea ice to deploy optical instruments that measure the amount of UV-R penetrating the sea ice and water column. At the same time, we are rearing Sterechinus larvae in the laboratory for later transplantation under the ice on specially designed racks suspended at different depths. The racks have various UV-filters that allow us to quantify any harmful effects of UV-R under the sea ice. Larvae are also exposed to artificial UV-R in the laboratory to quantify specific effects of UV on development.

Why we do it: This research is challenging the assumption that marine life in Antarctica waters is protected from UV-R by the annual sea ice that is 1-2 m thick and can cover 20 000 000 km2 of the Southern Ocean. While scientists thought that UV-R would penetrate the ice they did not expect it to be of high enough intensity to be damaging to marine life.

Some things we've found out so far: Initial results strongly indicate that this assumption is incorrect, and larval stages of Antarctic marine species might be impacted. This is particularly important given the increase in UV-R over the Antarctic continent when the ozone hole is present, and its likely continuation for the next 25 years. The spring ozone hole over Antarctica results in an increase in the more biologically damaging UV-radiation called UV-B, which is also responsible for skin cancer in humans.

Early findings show that the more damaging wavelengths such as UV-B do penetrate the sea ice at intensities great enough to cause detrimental effects on the larval stages. The findings may indicate that the increase in UV-R over the Antarctic continent and surrounding oceans may have significant effects on marine life. If the delicate larval stages of sea urchins and other marine species are damaged, the lifecycle of many Antarctic species may be interrupted, with long-term impacts on the Antarctic marine ecosystem.

 Metadata and website links

UV radiation penetration into the marine ecosystem of McMurdo Sound

The direct effects of UV radiation (UVR) on embryo and larval development and survival and DNA damage of the sea urchin Sterechinus neumayeri in McMurdo Sound

The degree that UV-B absorbing compounds provide UV-R protection in embryos and larvae of the sea urchin Sterechinus neumayeri

The activity and expression of DNA repair/photoreactivation with the enzyme photolyase in the sea urchin Sterechinus neumayeri, McMurdo Sound

Obtaining action spectrum and biological weighting functions for UVR effects on larvae of a suite of Antarctic invertebrates, McMurdo Sound

The kinetics of UVR induced damage to DNA in the sea urchin Sterechinus neumayeri, McMurdo Sound

The activity and expression of DNA repair mechanisms in two Antarctic Starfish Odontaster validus and Odontaster meridionalis compared with a New Zealand species Odontaster benhami

The fundamental physiology and biology processes of Sterechinus neumayeri embryos and larvae and how they are effected by increased UV radiation, McMurdo Sound

The effects of increased PAR and UV on the xanthophyl cycle of Antarctic ice algae

Investigation of levels of endocrine disrupting compounds in the Antarctic environment and food chain

Analysing toxicological impacts of contaminants on Notothenioid fish: Impacts of Polybrominated diphenyl ethers (PBDEs)