The government condemned “intimidating and thuggish behaviour” at the demonstration, while stressing the right to peaceful protest.
On Friday, a 42-year-old man from Paulsgrove was charged with violent disorder and assaulting a police officer in connection with the incident. He has been remanded into custody.
A 16-year-old boy was arrested on Saturday in connection with the disorder. He has been released on bail pending further enquiries.
Rowlinson said: “The reality of public order policing is that arrests at the time are not always possible, especially where evidence may need to be reviewed to clearly identify who is responsible for offences.”
The force had reviewed “hundreds of hours’ worth” of footage, he said, adding: “The actions we have been taking as part of our investigation send a clear warning to anyone intent on causing disruption and disorder at any future events.”
Around 500 anti-migrant protesters took to the streets of Portsmouth on Saturday and were met by hundreds of counter-protesters from Stand up to Racism.
Migrants intercepted in the Channel are typically brought to Dover for initial processing.
However, the dinghy that arrived at Eastney Marina had set off from near Cherbourg in the Bay of the Seine, about 170 miles (274km) west of Calais and significantly further west than the usual departure points.