Thousands of dead shellfish wash up at Horowhenua beaches [17 March 2017] says:
Thousands of potentially poisonous shellfish have washed up at two Horowhenua beaches.
The MidCentral District Health Board has warned people not to collect or eat shellfish from the west coast’s Waitarere and Hokio beaches, near Levin, after thousands of dead and dying shellfish washed up there.
In a statement, MidCentral medical health officer Dr Rob Weir said the alert covered the area between Waitarere Beach in the north and Hokio Beach in the south.
People were also told not to eat any shellfish that washed up on the beach just outside of these areas, Weir said.
Hokio Beach isn’t that far away, so take care if you’re collecting shellfish at Waikawa Beach.
And a day or two earlier, Waihi beach had a similar issue.
http://www.stuff.co.nz/environment/90491236/shellfish-wash-up-at-waihi-beach
Note it is suggested in that report that “Severe flooding with freshwater is one possible reason, but it could also be natural causes due to stress from overcrowding.”
“At this stage, it is considered that flooding with freshwater is the most likely cause of the event.”