Antarctic icebreaker RSV Nuyina recorded its first catch of krill through the ship’s unique ‘wet well’ system.
Over 100 specimens of predatory krill species Thysanoessa macrura were caught by Rob King, originator of the wet well concept, and aquarist Anton Rocconi, as the Australian ship approached Antarctica at 59°S.
King said this was the first test of the wet well in Antarctic waters and they caught animals as soon as they started up the water filtration system.
“It demonstrates that we can catch krill without slowing or stopping the ship, which means, weather permitting, we could potentially catch krill 24/7.”
The wet well is a watertight room inside the ship which is connected to inlets in the hull allowing water to gravity-feed into the room and across a filter table at roughly 2000 litres per minute.
Previously, krill were caught using a trawl net with a small ‘cod end’ that provided some protection for krill from being damaged by the net and any excess catch, however King said this method was never ideal.
“The best animals to conduct experiments on physiology, reproduction or behaviour, are those that are freshly caught and in perfect condition, so that we can have confidence that our results reflect what actually happens in the wild.
“We want to ensure that we have the minimal amount of time and disturbance between when we catch the animals and when they end up in experiments or in our on-board aquarium.”
The captured krill will contribute towards the understanding of Antarctic krill and their role in the ecosystem, which will strengthen conservation efforts and ensure Southern Ocean krill fisheries are sustainably managed.