Life in the slow lane

January 22, 2018, British Antarctic Survey
Starfish Odontaster validus. Credit: Terri Souster

A new study from British Antarctic Survey shows how five common Antarctic marine invertebrates (animals without a backbone) use less energy to feed, grow and reproduce than their temperate and tropical relatives. The study is part of wider programme to understand how organisms might respond to future predicted climate change scenarios.

The research team examined the summer and winter metabolic rates of marine animals that live on the sea floor. The five species were the starfish Odontaster validus, the urchin Sterechinus neumayeri, the limpet Nacella concinna, the brittle star Ophionotus victoriae and the sea cucumber Heterocucumis steineni. The team discovered that food quality, rather than quantity, drives activity such as growth and reproduction. This in turn affects metabolic rate.

Reporting this week in The Journal of Polar Biology, the team describes how certain species, such as the starfish and the urchin, consume about 40% more oxygen in the summer than in the winter, other species such as the limpet and the brittle star showed no significant seasonal difference in . The sea cucumber showed juveniles to consume more oxygen in summer than winter but adults vice versa.

The sea floor ecosystem in Antarctica depends almost entirely upon the spring/summer phytoplankton bloom. Many Antarctic sea floor-dwelling marine invertebrates exhibit seasonal cycles related to the extensive phytoplankton bloom, for example, growth and reproduction.

Urchin Sterechinus neumayeri. Credit: British Antarctic Survey

The isolation and constant cold of the marine environment in Antarctica have allowed these species to evolve some general and unique adaptations such as slow growth rates, delayed reproduction and slow development.

A dive team collected adult and juvenile specimens during the austral summer (November – April). During winter (June – October), they cut a hole in the sea ice to dive beneath the ice. Oxygen consumption measurements were taken in the station's Bonner Laboratory aquarium.

Lead author Dr. Terri Souster says:

"The seasons on the Antarctic Peninsula are shifting, with changes in sea water temperature and sea ice conditions. I am extremely fortunate to have been given the opportunity to carry out research on the ecosystems of the shallow rocky coastal shores on the Antarctic Peninsula. Climate change is affecting all regions of our planet, there is an urgent need to understand the affect of these changes on marine ecosystems."

Sea cucumber Heterocucumis steineni. Credit: Gail Ashton

Credit: Terri Souster
Diving through a hole in the sea ice during winter to collect specimens. Credit: Emily Venables

Explore further: More 'losers' than 'winners' predicted for Southern Ocean seafloor animals

More information: Terri A. Souster et al. Seasonality of oxygen consumption in five common Antarctic benthic marine invertebrates, Polar Biology (2018). DOI: 10.1007/s00300-018-2251-3

Related Stories

Study sheds new light on krill larvae survival

November 15, 2017

An international study involving British Antarctic Survey (BAS) scientists has shed light on how the larvae of Antarctic krill – small shrimp-like crustaceans – use sea ice to ensure their successful development and survival ...

Climate is changing fast in West Antarctica

November 23, 2015

When the ship pulls up at Palmer Station each Antarctic spring, the arriving scientists glance up at the massive glacier that covers most of Anvers Island. It has been retreating about 7 meters per year, and this year is ...

Recommended for you

A switch in ocean circulation that helped end the Ice Age

April 24, 2018

Changes in the circulation of the North Pacific Ocean about 15,000 years ago released large amounts of CO2 to the atmosphere, helping warm the planet and end the last Ice Age, according to research by scientists at the University ...

Airborne dust threatens human health in Southwest

April 24, 2018

In 1935, at the height of the Dust Bowl, a team of researchers from the Kansas Board of Health set out to understand the impact of dust on human health. In areas impacted by dust storms, the researchers documented an increase ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.