Moerewa School principal Keri Milne-Ihimaera said she was concerned about the drop in income many families faced.
"A loss of income has a direct impact on the children. When money's tight, families are put under stress. They might not be able to afford as many groceries or new books for school," she said.
She could not say how many of the decile-1 school's 220 children had a mother or father working at the plant, but it was a large proportion.
"There wouldn't be many children at our school who don't have a connection."
The effects would ripple well beyond the school, with businesses also likely to be hit.
"The potential for our families to find other sources of income is almost non-existent, so it's really important this is resolved quickly," Ms Milne-Ihimaera said.
A business owner, who did want to be named, said the mood in the town was "pretty morbid". Each time Affco held its seasonal shutdown the impact on the town was immediate and obvious, and she expected a similar effect from the lockout.
Whole families worked at the plant and many had been there for decades. "It's a tight-knit community in there, everybody looks out for each other. What's happening is just sad."
The town had few jobs or businesses as it was, she said.
Bay of Islands-Whangaroa Community Board member Johnson Davis, who represents Kawakawa and Moerewa, said he was deeply concerned about the lockout's impact. "It's one of the biggest employers here, certainly in Moerewa, and a lot of Kawakawa people work there too. We're just hoping it doesn't drag on too long."
Affco is offering a 4.3 per cent pay rise over two years but only if staff sign up to a new collective agreement without dispute. Management believes it is locked in a battle for control and is seeking to draw a line on union influence in the workplace.
It wants to be able to set manning and process line speeds and to employ its workers with greater flexibility.
The union believes Affco wants complete casualisation of its workforce.
The union said it had made considerable concessions on Tuesday but the company had already made up its mind about the lockout.
It fears Affco is using the lockout "to starve the workers into submission".