SA Agulhas II testing equipment for its historic expedition

Bongo nets lowered into the ocean to collect plankton. Pics: Claire Keeton

About 500 orangey Copepods, which look like minute crayfish under a microscope, were among the first specimens collected on the SA Agulhas II research ship on Monday morning.

On a rolling ship off the wild coast, South African scientists started testing their equipment for the International Indian Ocean Expedition II, which departs from Durban on Wednesday.

Marine research assistant Janine van der Poel

First they lowered an “oblique bongo” net, which resembles the drums, behind the ship to about 100 metres down to collect zoo plankton.

“Plankton is everything that drifts with the current and they make up 98% of the biomass in the ocean,” said specialist scientist Sir Dr Hans Verheye.

The east coast of South Africa typically has a greater diversity but lower abundance of plankton, while the west coast has a lower diversity and greater abundance.

Verheye said: “We got an abundance of plankton from our 15-minute haul. There are a lot of bugs in here and maybe some larvae. This is a good haul for this side of the world.”

CTD instrument used to measure the conductivity, temperature and pressure and seawater

Verheye, who is passionate about plankton and head of Biological Oceanography for the Department of Environmental Affairs, said that they were good indicators of climate change, for example, the acidity of the water.

Plankton have to adapt quickly to water conditions because they have a short lifespan.

Several types of nets were being tested during the morning, including one nicknamed Whitney by the crew, two types of dredges, a camera system called a “ski monkey” which could be deployed to 700m deep and an instrument known as a CTD to measure conductivity, temperature and depth, which looked like a bunch of tall, thin scuba tanks.

Control site technician Marco Worship said the operations centre was “the heart and brains” of the research vessel and all data was captured there.

Inside the operations centre, marine research assistant Janine van der Poel, carefully guided the bongo net to the surface with a gear lever.

Plankton under a microscope

The state of the art equipment must be ready for deployment ahead of the research cruise, which is the first African-led research cruise into the Indian Ocean. Scientists from South Africa, Mozambique, Kenya and Tanzania are contributing to the exploratory efforts.

The International Indian Ocean Expedition II is a programme under the UN Intergovernmental Oceanographic Commission which aims to do oceanographic and atmospheric research and the SA Agulhas II will run several cruises until 2020.

By Claire Keeton

TMG DIGITAL

 

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