However, Mr Gardam didn't believe serious matters such as students assaulting staff and carrying weapons were local issues as such. "Some students may also be carrying weapons because they feel threatened in their peer group or just a show of bravado," he said.
Principal of Whangarei Girls' High School, Anne Cooper, said a noticeable increase in bad behaviour by younger students such as those in Year 9 in her school last year was "quite unusual".
Eight of the 16 students dealt with last year were expelled from Whangarei Girls' High School for bullying, intimidation and threatening type of behaviour, she said.
One pupil had brought a knife to school.
In comparison to last year, only six students were dealt with for extreme behaviour in 2012.
"We were concerned about the very extreme behaviour of Year 9s and it's something we've never experienced before."
Mrs Cooper couldn't pinpoint specific reasons for the violent behaviour but said mental health issues were probably an issue.
Kaitaia College principal, William Tailby, said frustration, low socio-economic living and that some students emulated gang culture drove them to do "dumb" things in school.
"I am aware that currently a lot of families in my part of Northland are struggling due to the economic times but that doesn't justify their (students) behaviour," he said. "Also, opportunities for those that are not academically bright are a lot less these days than they were when a lot of things were done manually so frustration plays a part in them acting the way they do."
Principal of Pompallier College, Richard Stanton, said a host of factors could contribute to the students' violent behaviour but said he hadn't dealt with any case of a student carrying dangerous weapons to school.