Heat and farming changes stop sea lettuce growth
St Aubin's Bay enjoys a summer without the green sea lettuce that has previously caused problems.
Recent high temperatures and alterations in farming techniques are thought to have hindered the growth of sea lettuce in St Aubin's Bay, Jersey. Typically, this growth is stimulated by warm, shallow waters alongside runoff from agricultural fields and treated water. The government acknowledged this summer's conditions disrupted the typical development of sea lettuce.
They also affirmed that no sea lettuce had been harvested from the beach up to 2026. Prolonged dry weather, which began earlier than usual, was also cited as a contributing factor. The Environment Department's spokesperson explained that sea lettuce's primary reproduction occurs in May, and the unusually high temperatures during this period likely disrupted its growth and reproduction.
Jersey experienced its hottest May day ever, with temperatures soaring to 29.2C (84.5F) and remaining high throughout the summer. The government also highlighted the efforts of the Action for Cleaner Water group and the agriculture industry in reducing nitrate use on fields, which they believe will aid in reducing the accumulation.
This initiative, a collaboration between Jersey Water, the government, and representatives from Jersey's farming and dairy sectors, aims to improve water quality. The government earlier pinpointed external sources like nutrients from the bay, run-off from streams carrying fertilizers, and treated wastewater from water treatment plants as typical contributors to sea lettuce's growth.
In 2025, nearly 3,000 square meters (32,300 square feet) of sea lettuce was collected from the beach for use on the island's fields.
Written by urgent.news from BBC Science's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
