The alleged incidents all took place in the north east in the past month.
Four men were alleged to have been fishing without permission at the River Deveron at around 8.50pm on Monday July 5.
The river is routinely used to fish for salmon and trout and requires a permit to do so legally.
Following inquiries, four men were traced and charged in connection with the incident and a report has been submitted to the Procurator Fiscal.
In a separate incident, officers received a report of possible salmon poaching in the Craigellachie area of Aberlour around 5pm on Saturday July 24.
Two boys, aged 14 and 16, have been charged in connection with this.
Police Constable Hannah Haywood, the North East’s wildlife crime liaison officer, said: “Operation Wingspan is a campaign to prevent wildlife crime. As part of this, we also work closely with partners to raise awareness of these types of offences and their impact.
“Fish poaching can be highly damaging and impacts Scotland’s vulnerable fish stocks.
“Anyone with any concerns around wildlife crime in their area is asked to report it to officers.”