The snakes were from Australia, North America, Asia, Italy and Papua New Guinea.
Seven of the nine snakes were already dead when they were caught.
"They may carry a disease that we don't want or it's just we don't have it here and they would thrive."
"It didn't meet our biofouling standards because of higher than allowed levels of algae, barnacles, tube worms, and potential oysters present."
Officers issued 467 infringement notices in November.
In July, 560 hours of overtime was racked up to "meet deficiencies".
"It could shut down our export markets overnight."
Biosecurity NZ modelling revealed that if the disease made its way onto our shores our economy could take a $10 billion hit.
Biosecurity New Zealand is raising more awareness of foot and mouth disease to protect farmers across the country.
