Complete coverage of the sea animal of the Red List is still limited by a lack of systematic evaluation; however, several groups, whose exploitation is abusive, of mammals, sea birds and turtles have been well studied. Evaluations of the populations of sharks and rays, corral reef species, sea horses, turtles, the queen shell and the grouper and labro have also revealed the existence of risk factors of inherent extinction.

Some of these species, in addition to being used as food or in the preparation of traditional medicine are captured for sales to tourists who purchase them as souvenirs or are taken to local and international markets negotiated as pets.

In addition to the excessive capture, there are other factors that mark these species as having a low reproductive potential, limited areas of protected areas, the destruction and degradation of the habitats and the effects of diseases and invading species.

As a result of all these factors, specialists estimate that in the coming years the risk of extinction in the sea environment will be greater and the species listed will share the list with others seriously threatened, that still exist in the land and sweet water ecosystems.

According to statistics of the United Nations Environment Program (UNEP), 70% of the existing species of the sea are captured in excess. For example, the queen shell or giant shell, a great mollusk of the Caribbean is among the most commercialized for the demand of its meat. Its shell is sold as a curious object and represents 60 million dollars a year in profit.

Also, about 20 million sea horses of different varieties are captured yearly to satisfy the growing demand in traditional medicine and aquariums.

The Asian turtles are highly coveted as food source, for medicines or pets. Other species carefully watched by the experts are the whale shark and the peregrine in high demand for its meat and fins although they are listed in the Convention on International Trade in Endangered Species of Wild Fauna and Flora that regulates their capture.

Although commerce of sea species is internationally regulated, many countries violate the laws claiming that they are captured for "scientific" purposes. Iceland, for example, for the first time in 14 years and despite the opposition of governments, animal protection groups and environmentalists, launched its ships to sea to resume its capture of whales under the excuse that it was doing so for scientific research.

However, the International Foundation of Animal Welfare (IFAW) expressed that there were no reasons for the Icelandic decision. It stressed that this country cannot use science as camouflage for its desire to resume commercial capture of these cetaceans.

Officials of the ecological organization, Greenpeace, manifested in a communiqué that "the whaling activity is part of the past of Iceland and should remain so".

What is now left is to analyze the impact of this action by Iceland in the ecosystems where these animals live and develop as well as the image of the country in the world, where the observation of whales have become one of the main tourist attractions of the island.

The 10 sea species most threatened in the planet are the totoaba and the sea cows that only inhabit Mexican waters in the California Gulf; the guitar fish of Brazil and the spotted deer of Bermuda, the monk seals of the Mediterranean and the frigate bird of the Australian Christmas Island.

Also included are the lute turtle of the Southern Pacific, the whale of the Northern Atlantic, the white tuna of the Northern Pacific and the Johnston pastures of Florida.

Human disturbance throughout time, the structures of the ecosystem and functions have changed in answer to the excessive fishing, according to some studies. Thus, while some species were captured for years until their extinction, others remained ecologically extinct until they could recover by being protected in the 20th century.

Uncontrolled exploitation speeded up and intensified while the human population grow and technological progress appeared to expand the world market.

Although the first great human disturbance was the excessive fishing of the large vertebrates and crustaceans, and with the passing of time other phenomena such as contamination, excessive enrichment of the waters with nutrients, the outbreak of diseases, the destruction of the habitat, the invasion of introduced species and climate changes provoked by mankind.

More recent changes are the modifications in in the food chain due to the capture of whales and fish that has caused, for example, the decline of seals and sea lions.

If we add all this to the rapid growth of the world population and the effects that are becoming more frequent and harsh of global warming -- that is reducing the productivity of the aquiferous systems such as Lake Tankangyika in Africa that has 18 % of the sweet water in the world -- what can we expect in the future?

Our ancestors not only hunted until the extinction of many lands on land but also finished off a great part of the sea fauna in the not so distant past. This can offer us information on what can happen if we continue to excessively exploit the seas and do not contribute to reduce the expulsion of greenhouse gasses into the atmosphere, causes of the present climate changes.