Fisheries New Zealand says volunteers were critical in protecting Kaikōura pāua from being overfished during the recent season.
The work of volunteer honorary fishery officers is being marked as part of National Volunteer Week, which kicked off on Sunday.
The Kaikōura fishery was closed in 2016 for five years to help it recover in the wake of an earthquake. It was opened for a two-month season that closed this week.
Regional fisheries compliance manager Howard Reid said volunteers inspected catches and educated fishers on the rules, providing invaluable help to the fishery officers patrolling the coastline.
"The coast is vast, and we couldn't have done it without them," Reid said.
"Our honorary fishery officers were along the coast, talking with fishers, checking their catch, educating people on the rules. They're an invaluable asset and a big part of why we've had an over 90 percent compliance rate."
The area between Marfells Beach and Conway River was open for people to gather blackfoot and yellow foot pāua, but there were also areas that were closed or under different rules.
Honorary fishery officers were introduced in Auckland in 1967 to help people to donate their time to support local fisheries.
Each officer contributes a minimum of 100 hours of voluntary work after undergoing intensive training. They hold a warrant under the Fisheries Act and wear a uniform.
"Their work is critical to ensuring sustainability throughout all of our fisheries. Honorary fishery officers are front and centre on New Zealand's coastlines, conducting between 18,000 and 22,500 inspections each year," said Reid.
"They're incredible people - all very passionate about protecting the resource, which is evident through the huge amount of voluntary work they do and some honorary fishery officers exceed that minimum of 100 hours."