Mr Foster, who has run drug operations in the region for the past four years, said the 14,500 plants recovered this year was significant.
"This year was a good year.
"We're pleased at the total number of plants found and we believe we have made a major dent in the cannabis trade in the region. We will have hurt a number of growers financially and, hopefully, they are starting to get the message."
About 10,000 plants were seized in last year's operation and up to 15,000 had been seized in the past.
Those arrested were charged with numerous offences, ranging from cultivating cannabis, possession of cannabis for supply, possession of utensils and unlawful possession of firearms.
The operation spanned the cannabis growing season and covered much of East Cape, Gisborne and Hawke's Bay.
Mr Foster said one of the most dangerous things police had encountered in drug operations was cyanide poison, left out by growers to deter possums.
Police had also encountered primitive booby traps in the form of boards of wood with protruding nails.
Aotearoa Legalise Cannabis Party central manager Romana Manning said there had not been as much cannabis available this year compared with previous years.
"I have to say this year there is not much out there, so police must have targeted a decent number of suppliers."
The estimated $14.5 million value of the plants could have gone to the Government as revenue if cannabis was legalised, Ms Manning said.
New Zealand cannabis growers planted their crops in October and it was harvest time by Easter the following year.
Mr Foster said police would continue to put pressure on cannabis growers.
"Police work and investigation into cannabis crime is ongoing and it is relentless. We are constantly monitoring the activities of drug dealers who should in no way feel as if the pressure is off them now."
Information about cannabis activity could be left anonymously by phoning the Crimestoppers line on 0800 555 111.
