Sea lettuce menace hits Mount beaches

By Joel Ford and Yvette Wakelin
Unprecedented amounts of sea lettuce have washed up on Mount Maunganui beaches over the past few days, leaving some areas almost completely covered in an ankle-deep layer of green algae.
Emily McNie, Tauranga City Council's coast and harbour park ranger, said the amount of sea lettuce that had washed ashore was considered by many to be exceptional.
"Talking to my colleagues, who have worked here over the years, it is the most they have seen," she said.
Ms McNie said the council hadn't decided what to do about the sea lettuce yet and were waiting to see if the problem would clear itself.
"We're monitoring the situation because there is a whole lot there and that is not normal. It is moving around a lot at the moment and we're not going to go down there and remove a whole lot of it if nature is going to take it away for us," she said.
"I actually had a removal set up for Kulim on Tuesday but the majority of it [the sea lettuce] had moved by Monday," she said.
The council was using a bobcat and digger to remove lettuce in the inner harbour, however, Ms McNie wasn't sure how they would remove the sea lettuce from the Mount beach should they choose to do so.
Ms McNie said the algae would start to decompose almost immediately after it washed ashore and would begin to give off a nasty smell.
"It happens pretty quickly, especially in this heat," she said.
Environment Bay of Plenty has been monitoring sea lettuce in Tauranga's harbour since the early 1990s. Council scientist and manager of environmental investigations John McIntosh said he thought the abundance of the algae showing up on Mount beaches was most likely due to an El Nino weather event.
"It always comes around with El Nino conditions where we get strong westerly winds. It drives coastal waters off shore and causes upwellings of deep ocean water which is the source of nutrients for sea lettuce blooms," he said.
A holidaymaker from Wellington, Tom Kelly said the sea lettuce was an unwelcome surprise that spread for metres in front of their Omanu holiday home.
"It's just everywhere you turn. It's been that way for two or three days now and goes from here [Omanu] down to Tay St - there's just no avoiding it."
A keen swimmer, Mr Kelly said the green slime also interfered with his dips in the ocean.
"Whenever you duck under the water you dive straight into a bunch of sea lettuce.
"It's not very nice at all."
Mount resident and school teacher Simon Franks said it was not often that the small beach was transformed into a sea of green.
"It tends to happen at the Main Beach from time to time ...
"I can't remember the last time it was down here." In past weeks it had "moved in pockets".