Mr Lumbreras said he had also been surprised to see five positions for science teachers in Hawke's Bay currently listed in the Education Gazette.
He believed teaching was not a priority for most students leaving school, who were increasingly choosing careers based on salary packages.
Mr Lumbreras said the PPTA wanted a pay increase for teachers, as pay had not kept up with inflation over the past six years.
The balance between workload and pay was also a big factor in job choice.
More internal assessments were among the things increasing workloads for teachers. Teachers had to create and mark the assignments as well as have them moderated. Teachers were also involved in activities outside the classroom such as sport, cultural groups and debate during the evenings and weekends.
The students - the very people they were pitching careers to - saw the workload they had to deal with.
The PPTA Secondary Staff Report was based on responses from 172 secondary and composite schools.
The report showed advertised jobs were increasing and the mean number of applicants per position was declining. The proportion leaving to go to jobs outside teaching had also increased.
Those leaving for "other reasons", such as retirement, accounted for the largest proportion of leavers.
Principals expressed reservations about the impacts of pending retirements on their schools.
Teachers were also leaving the state system for private schools, the report said.
Principals were, in general, less optimistic about retaining teachers and more pessimistic about recruiting.
Principals frequently mention maths, te reo, sciences and technology as hard to staff subjects. There were several references to the oversupply of physical education teachers.
There was a jump in teachers being used outside of their specialist areas because specialists could not be found, according to the report.
Around one in nine schools had to cancel classes or transfer to a form of distance learning because a suitable specialist teacher could not be found, the report said.NZME