Fishing maybe, but farming and ranching won’t work in Iceland.
For one thing, there are no trees!
Agriculture was the mainstay occupation for centuries and censuses from the mid-19th century show that 70-80% of the nation lived from farming then.
Family farming is overwhelmingly the most common arrangement and in some cases two families work the same farm. Most farmers own their land and many farms have been owned by the same families for centuries. The average Icelandic farm is small, with 18 milk cows and 152 sheep in the past decade.
Most farms are engaged in sheep rearing... about 3,250 farms. Of these, 550 were largely dairy-based farms, 1,830 were predominantly sheep farms and 880 were in mixed farming.
In terms of value, cattle farming is the most important segment, accounting for about 35% of the estimated value of production, against 28% in sheep farming.
Grain is grown in very limited quantites in Iceland and most agricultural land is devoted to grass for production of hay and silage ... Other crops include potatoes... turnips and carrots.
Cultivation of vegetables and flowers in geothermally heated greenhouses is extensive. In total, greenhouses produced about 800 tonnes of tomatoes in 1998... cucumbers come second in importance after tomatoes, and the output of 700 tonnes...
Afforestation (or reforestation) is on the increase ...
http://www.iceland.is/economy-and-industry/agriculture/nr/29