Authorities issue a public warning not to collect or consume shellfish from parts of Marlborough Sounds because the shellfish may contain biotoxins. The notices are intended to protect people from the health risks associated with biotoxin contamination, which can make otherwise normal shellfish unsafe to eat. Coverage from Otago Daily Times and Stuff.co.nz both describe the advisory as applying to specific areas within Marlborough Sounds rather than the entire region. The warning focuses on both harvesting and consumption, urging members of the public not to take shellfish for eating. Stuff.co.nz repeats the same core message, stating that toxins have been detected or are suspected in shellfish from the affected areas, and that people should avoid collecting and eating them until the risk is lifted. The reports do not provide additional details on the specific toxin type, the cause, or the expected duration of the warning, but they consistently communicate the safety concern and the immediate restriction on shellfish use in the designated locations.