The tug Ievoli Black was struck by the 151 gt fishing vessel Osterems SC 41 off Den Helder, Netherlands.   The tug was struck amidships on the port side and slid towards the forepeak while the boom of the fishing vessel demolished the equipment on the deck of the tug.   The Osterems SC  41 had its hull holed above the waterline and had much of its fishing gear damaged.    Both vessels were able to reach the port of Den Helder under their own power.   The Ievoli Black was reported as being on standby while the Osterems SC 41 was heading out to the fishing grounds before the collision.    Reports state no one was injured or pollution released.   The accident is under investigation.