SEA lettuce ‘will always be present’ on the Island’s shoreline, according to the Environment Minister.
Deputy Jonathan Renouf said the issue was ‘highly complex’ but that it was hoped that Jersey’s new wastewater treatment works could help reduce nitrate run-off, which contributes to the greenery that regularly blights St Aubin’s Bay in summer.
He said: ‘The quantity of nitrates entering St Aubin’s Bay both from land run-off and from the wastewater treatment works at Bellozanne impacts the growth of the nuisance weed, sea lettuce. The Government of Jersey has recognised the importance of reducing levels of nitrates for some time, particularly given that the bay receives run-off from a large proportion of the Island.’
He added: ‘The new WWTW is currently being built and will be fully operational by the end of 2023.
‘The new facility will result in lower levels of total nitrogen entering the bay and increased volumes of treatment during storm conditions leading to less “shock loading” of total nitrogen.
‘These improvements will help limit the annual volume of this nuisance weed.’
Deputy Renouf explained that the Natural Environment Department and Jersey Water had worked closely with potato and dairy farmers ‘for some time to reduce levels of nitrates in water across the Island’ and added that the partnership had been ‘very successful’.
The minister made the comments while responding to a written question from Deputy Lyndsay Feltham, who asked what work was being undertaken to reduce the sea lettuce on the Island’s shoreline next summer and in the future.
The harvesting of sea lettuce from the bay had also increased, he said, with the government having ‘disposed of 5,416 tonnes of green seaweed directly to suitable farm land this year’.
‘The excessive growth of sea lettuce in St Aubin’s Bay is highly complex. Multiple factors contribute to its growth, including bay topography, land reclamation, sea temperatures, nutrient inputs and more,’ said Deputy Renouf.
‘It remains that sea lettuce will always be present and that it will vary in quantity from year to year.’
