This morning, I found this floating just downstream of the footbridge into Village Green, obviously the origin of the fishing line used to make the trap in the copse. At 18lb breaking strain it would have been difficult to snap and would have caused a lot of damage to anything running into it.
Let’s look after our wildlife.
Southwick Country Park Nature Reserve 
This fishing line business was a deliberate attempt to injure people or animals. It was a crime. Perhaps there are fingerprints on the reel that the police can record to see if the culprit is already on their database.
I think all the line and the reel have been passed to PCSO Mat Till, who always has the option of passing it on to Wiltshire Police’s Rural Crime Team.