BRUSSELS (Reuters) – The European Commission warned Croatia yesterday that enforcing a protected fishing zone in the Adriatic in breach of an accord with European Union members Slovenia and Italy could harm its chances of joining the bloc. Croatia hopes to join the EU in 2010. It is due to apply the zone from January 1 to preserve fish stocks and limit pollution. «I clearly encouraged Croatia to refrain from implementation of this zone, and instead to respect the agreement achieved in 2004 between Croatia, Italy and Slovenia,» EU Enlargement Commissioner Olli Rehn said after talks with Croatian President Stjepan Mesic. «This is a very important issue and I trust it will not cause problems, because otherwise it would have negative ramifications on the EU accession negotiations,» he added, noting the agreement had been a condition for granting Croatia EU candidate status in 2004.