Simon Hart MP is pictured presenting Martletwy man John O'Connor with a national "Points of Light" certificate from 10 Downing Street.
The Prime Minister recognised Mr O'Connor for protecting marine habitats in Pembrokeshire through the creation of a pioneering app which improves the protection of local coastlines.
"I was delighted to present John with this token of the Prime Minister's gratitude for all his hard work," said Mr Hart.
The Points of Light award scheme aims to recognise people whose good deeds or volunteer work may otherwise go unnoticed.
Mr O'Connor, an experienced fisherman for over 50 years, has seen firsthand the damage caused to marine habitats and wildlife by fishing litter, which can take up to 600 years to decompose.
He has used his expertise to develop the 'Pembrokeshire Marine Code App', which features a code of conduct for local and visiting anglers and shares information to help avoid the loss of fishing tackle.
He works closely with the voluntary divers group, 'Neptune's Army of Rubbish Cleaners', led by Dave Kennard who was awarded a 'Points of Light' in June this year, to produce information on the seabed and provide tackle litter bins at popular fishing locations.
Simon Hart MP
House of Commons
15, St John St
or 0207 219 3000