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Sea lettuce trials set to start soon
It has applied to Environment Canterbury for
consent to begin small-scale trials over a threeyear
period in Southshore, McCormacks Bay
and Humphreys Drive. Christchurch City Council project co-ordinator
Ken Couling says the trials will focus on
practical methods that minimise impacts on the
Estuary eco-system. “We’ll be looking at how we can best control
the growth of the sea-lettuce beds and finding
the most effective, practical means of removing
the lettuce stranded on shore. Options to be
considered for controlling growth include
mowing and suction dredging operations by
boat,” he says. At present, the Council can only collect and
remove sea lettuce from the beach at
Southshore three times a year, as it only has
consent from Environment Canterbury for this
area. The last clean up took place just before
Christmas when more than 193 tonnes of sea
lettuce build-up was cleared from the Estuary
foreshore at Southshore, between Godwit and
Tern Streets. Removals are restricted to the high tide areas
on the eastern side of the Estuary, where the
Council has consent to use tractor-mounted
rakes and front-end loaders. “We’ll be looking at whether other
mechanical methods will work on the softer
sediments in Humphreys Drive. Trials of
alternative removal methods such as shorebased
suction may also be undertaken,” says Mr
Couling. For more information contact the Christchurch City Council Customer
Centre on 941 6840, or go to www.ccc.govt.nz/quickanswers/
and search under ‘lettuce’ |