Trawling deep through the Internet I found an OECD document titled "FUEL TAX CONCESSIONS" (©OECD 2012). It relates to the fisheries sector.
In the document I found two intriguing footnotes. Here are they:
"1. The Norwegian submission to this exercise specifically notes that "… in the context of subsidies within the framework of the WTO, tax relief systems may or may not be considered as subsidies. The purpose of such systems is primarily to regulate or „improve‟ the conditions of competition between different national sectors and the WTO does not take as a premise that possible countervailing measures will even out different conditions of competition between like sectors in different countries. To the contrary, the situation where a country taking countervailing measures subsidises its own sector (for the „like product‟) is not addressed by the WTO Agreement."
"2. Several countries (Canada, Denmark, Japan, Korea, New Zealand, Norway and the United States) specified that they do not consider fuel-tax exemptions or other relief reported here as subsidies, but nevertheless provided data, in keeping with the G-20 Leaders‟ request. "
So, are they subsidies, or not?
Here is the link to the document: