Rotokawau Virginia Lake is home to 12 waterbird species, including mallards, mute swans, pāpango (New Zealand scaups), pūtangitangi (paradise shelducks) and tētē moroiti (grey teals).
A police spokesperson said this week inquiries were continuing.
Anyone killing or catching game birds, such as wild ducks, swans, pheasants, quail or pūkeko, without a licence can get a maximum $5000 fine, with a further $5000 added for selling meat, eggs and feathers.
Maximum fines are doubled for businesses.
Beissel said he hoped the incident was a one-off.
“It doesn’t matter what kind of bird it is, we don’t want people doing things like that.
Bird Rescue Whanganui-Manawatū can be reached via (06) 345 5037 or 027 453 5821.
Mike Tweed is a multimedia journalist at the Whanganui Chronicle. Since starting in March 2020, he has dabbled in everything from sport to music. At present, his focus is local government, primarily Whanganui District Council.