The now annual sea lettuce blooms in St Aubin’s Bay are a blight. They adversely affect the local ecology, Islanders who live and work along the Bay, and local and incoming tourism.
The picture here from 2017 is one of many similar, and it could just as easily have been taken in 2020. Yet again, the relevant States Departments have let us down by not acting sooner on the sea lettuce issue.
The conditions
Why is sea lettuce a problem in St Aubin’s Bay? Basically, it’s because the conditions in the Bay are just perfect for sea lettuce:
– A shallow angle to the beach (not in our control)
– Plenty of sunshine (not in our control)
– Enough rain to get plenty of runoff from the land (not in our control, but with caveats*)
– Slow water flow around the Bay (not in our control, but with caveats**)
– Shallow, warm, standing water as the tide recedes (not in our control, but with caveats***)
– Nutrients, particularly nitrates, being washed into the Bay (in our control, but much more policy and help needed from the States)
The caveats
* We would have a lot less runoff (and fewer nutrients in the runoff) if our soils policies were changed. Healthy soils retain water and nutrients meaning less need for irrigation and synthetic fertilisers.
** Water flow slowed down with the land reclamation at La Collette. Concerns about this happening were raised at the time but pooh-poohed.
*** On behalf of successful inventor Tony Legg, we offered the blueprint to a ‘funnel’ trial whereby shallow funnels would be tested to see if they sped up water drainage, thus meaning the sea lettuce did not get hold so easily. The States deliberately set up the trail so it would fail.