Millions of people go whale watching each year in countries around the world, but concerns have been raised that the burgeoning tourist industry could be negatively affecting the whales.

The industry generates approximately 2.1 billion dollars each year, according to the International Fund for Animal Welfare, but some are now asking at what profit are companies willing to destroy whale communities?

As the whale-watching industry continues to grow, it means more and more boats out on the water. This constant stream of boats can impact the whales' eating, resting, and rearing abilities. Additionally there is the risk that boats could inadvertently hit the whales and cause serious physical injury.

In the short term a boat interacting with whales can disrupt their activities, like stopping them foraging for food or resting, Dr. David Lusseau, from the Institute of Biological and Environmental Science at the University of Aberdeen, told BBC News.

This can be no big deal once or twice, but problems start if this is repeated again and again over time. Whale watching is a big industry - in some places boats can go out 10 times a day.

Some countries have put restrictions in place on the amount of boats that can be out on the water, but in other countries it is a free-for-all. Even the countries with restrictions have difficulty monitoring all of the different boats that are out on the vast waters.

At times boats can be traveling too fast or be carrying too many people, and the results can be bad news for the whales.

Badly run trips can translate into all sorts of negative reactions from the whales, Vanessa Williams-Grey, head of the Responsible Whale Watch, told BBC News. They can stop resting or increase their respiratory rate. If they are using more energy this will have an impact on their health.

Not everything about whale watching is bad though. Experts point out that whale watching can increase awareness in the need for conservation efforts. Furthermore if whale watching is financially successful, it could help reduce the need for whale hunting.

The economic benefits for local communities can be really positive, but you need a balance, Dri Lusseau said. If there is over exploitation and the whales are harmed in the long term then the industry will eventually collapse just like fishing.

Russian gas and oil industries also have affect

Not only is the tourism industry hurting the whales, but gas and oil explorations surveys could also be disrupting whale communities.

One of the most tenuous situations occurs around the Sakhalin Island of Russia. A small group of gray whales, only about 130 according to a BBC estimate, feed and mate off the island.

A survey last year by an oil company in that area sent seismic sound waves that forced the whales out of the area. Not only did the surveys potentially hurt the whales' hearing, but also might have permanently forced them away from Sakhalin Island.

The International Whaling Commission was angry about the actions and was shocked that another company decided to do essentially the same thing only a year later. Russian energy company Sakhalin Energy has also decided to survey the waters, much to the IWC's dismay.

We are concerned that one of the companies (Sakhalin Energy) has announced a plan for a new oil and gas platform offshore, IWC delegate Alexandre de Lichtervelde said. That is happening while the full impact of events in 2010 have not been fully assessed.