The Swamped Shoreline

Abstract

There are so many of us! It is a well-known topic, much repeated, and is something that seems almost banal, yet it is an inescapable reality. We consume a great deal of energy and products, we need resources of all kinds and generate mountains of waste. One of the biggest problems is that more than half of the world’s population lives less than 200 km from the coast, and all this activity, all that movement, has a direct impact on the sea. Coastal areas are, undoubtedly, one of the more pressured and threatened ecosystems on the planet, as a group of experts warned in 1990 in Kobe. One of the direct effects on our agricultural, industrial and urban areas is the production of nutrients (especially nitrogen and phosphorus), artificial organic contaminants (mainly derived from oil) and heavy metals. When there are nutrients in excess, some species are capable of assimilating them rapidly, multiplying tremendously, such as in single-celled algae’s rapid development. These algae prevent the growth of organisms whose life cycle is slower, and swamp anything that cannot compete in the race to reproduce. In the end, a huge quantity of organic matter is created that then dies and is taken over by bacteria, resulting in hypoxia or anoxia (see below). The cost of reducing nutrients is very high, especially nitrogen and phosphorus. In the United States alone, wastewater treatments across the country in the last thirty years have cost some €360,000 million, a considerable amount.