<P> One of the difficulties in implementing MARPOL arises from the very international nature of maritime shipping . The country that the ship visits can conduct its own examination to verify a ship's compliance with international standards and can detain the ship if it finds significant noncompliance . When incidents occur outside such country's jurisdiction or jurisdiction cannot be determined, the country refers cases to flag states, in accordance with MARPOL . A 2000 US GAO report documented that even when referrals have been made, the response rate from flag states has been poor . </P> <P> On January 1, 2015, maritime shipping levels became legally subject to new MARPOL directives because the SECA (Sulphur Emission Controlled Areas) zone increased in size . This larger SECA zone will include the North Sea, Scandinavia, and parts of the English Channel . This area is set to include all of the Republic of Ireland's international waters in 2020 culminating in all of Western Europe's subjection to the MARPOL directive . This has proven controversial for shipping and ferry operators across Europe . </P> <P> Concerns have been raised about the environmental damage moving back to the roads by some of the larger ferry operators that ship substantial amounts of freight and passenger traffic via these routes affected by IMO standards . They claim that MARPOL will drive up ferry costs for the consumer and freight forwarding companies pushing them back onto the European roadways as a financially more cost effective measure compared to increased ferry costs, thereby defeating the object of reducing water pollution . </P>

Convention on the prevention of pollution from ships