NEW YORK ( TheStreet) -- Exchange-traded fund investors have recently been given a path, if they want it, to a previously difficult to access -- but potentially very important investment theme -- with the Global X Fishing Industry ETF ( FISN).

A more accurate name might be Fishing Industry and Aquaculture, as the fund targets all things related to fishing which plays into the idea of an emerging middle class in countries where there has previously been no middle class, and healthier diets that go with newfound prosperity.

The theme is quite narrow in terms of number of publicly traded companies, so the fund is concentrated with only 20 names. The country makeup is probably unlike any other fund that exists with 35% in Norway, 22% in Japan, 13% in Chile, 9% in South Korea along with a few other smaller countries.

Most of the names will be unfamiliar to investors who have not previously considered investing in the theme. The fund has four relatively large holdings weighted at 8% to 12% of the fund. The largest holding is Cermaq from Norway followed by Toyo Suisan Kaisha, Marine Harvest from Norway and Pesquera Camanchaca from Chile.

The exposure to Japan would seem to be a worry, especially the 10% to Toyo Suisan Kaisha, until you look at what that company does and how it has fared in the face of the Sendai earthquake in March.

The company purchases, processes and sells seafood, so the lack of fish farming in the business has insulated from what could have been a much larger slide. In the face of the earthquake it only dropped 7.5% and has since made it back and then some. Nippon Suisan Kaisha and Maruha Group are both more directly exposed and their share prices already reflect the risk as they are down 16% and 22% respectively but they are smaller holdings in the fund at closer to 5%. reported that "in 2008, CNN reported the fishing industry employed 200 million across the globe and generated $80 billion in revenue. China's fish consumption has grown at an average growth rate of 5.7% per year, since 1961." It also noted that "in 2030, the industry will need an additional 27 million tons of production to maintain current levels of consumption."

The big trend of improved diets with more protein is going to continue to gain momentum which will give a tailwind to the related stocks as long term investments. This tailwind will not absolve the theme from cyclical declines in the stock market however as both large Norwegian stocks each fell 80% during the 2008 bear market.

I believe that funds like this open a very important door to investors. During the last eleven years investing in broad domestic indexes like the S&P 500 or mega cap stocks like Pfizer ( PFE), Microsoft ( MSFT) or General Electric ( GE) has not rewarded in investors the way that plenty of narrow themes like fishing or smaller foreign markets have.

Yahoo Finance has data on Cermaq and Marine Harvest going back to 2005 and in that time the stocks have had very volatile rides to 130% and 170% gains, respectively, compared to the S&P 500 which is up 9% in the same time period. I would note that also in that same time period Pfizer is down 14%, Microsoft is down 3% and GE is down 45%.

Investors willing to do the necessary work to go off the beaten path will have a better chance at portfolio success than investors who continue to standby what did well in the 1990s.
At the time of publication, Nusbaum was long Marine Harvest, although positions may change at any time.

Roger Nusbaum is a portfolio manager with Your Source Financial of Phoenix, and the author of Random Roger's Big Picture Blog. Under no circumstances does the information in this column represent a recommendation to buy or sell stocks. Nusbaum appreciates your feedback; click here to send him an email.