The Sargasso Sea is an area located in the North Atlantic Ocean characterized by the abundant presence of algae of the Sargasso genus and because it is a generally calm area, with few currents and little wind. Due to these characteristics, early navigators had difficulties in navigation and this area was associated with mysterious stories, including part of the famous Bermuda triangle.
During Portuguese expeditions to the Azores at the beginning of the 15th century, an area of the Atlantic Ocean was discovered in which large populations of macroalgae floating in the water were abundant. These algae were called Sargasso, from which the current name of the sea derives. The first to completely cross the Sargasso Sea were the expeditions of Christopher Columbus in 1492.
However, it is believed that the Sargasso Sea could have been known for several centuries, as there are allusions to this area of the ocean in literature from earlier times. For example, a poem by Rufus Festus Avienus written in the 4th century CE describes an area of the Atlantic covered in algae that could be the present-day Sargasso Sea.
Location and features
The Sargasso Sea is an area of the North Atlantic Ocean bounded to the west by the Gulf Stream from the Gulf of Mexico, to the north by the North Atlantic Current, east by the Canary Islands Current and to the south by the North Equatorial Current. More specifically, it is located between the meridians of 70º and 40º W and the parallels of 25º to 35º N.twoIt is variable.
This combination of ocean currents together forms what is known as the North Atlantic Spin and leaves in the center an area of calm water with few currents. This causes warmer, less dense water to rise to the surface in a slow, clockwise circular motion over deeper, cooler, denser water. This density difference creates a very defined stratification of the waters that will play a very important role in the development of marine life in this area.
The ecological role of the Sargasso Sea
One might think that the Sargasso Sea harbors little life, lacks currents that bring the necessary nutrients, and is on a deep ocean floor. However, it is actually an area full of life, presumably thanks to nutrients coming from the water currents of the lower layers.
In the upper layers, where the water is relatively warm and sunlight hits, algae and phytoplankton (plant plankton) have the ideal conditions to live and grow in large numbers. Algae of the genus Sargasso stand out which grow forming extensive “forests” floating in the upper layers near the surface. These sargassum forests attract numerous species of marine animals for various reasons, creating an area of great ecological importance.
A 2004 expedition led by John Craig Venter, the first of several expeditions, identified more than 1,800 new species in microplankton from samples taken from the Sargasso Sea, which may provide insights into the great biodiversity that exists.
In addition to the great biodiversity, the Sargasso Sea is fundamental in the life cycle of the American eel and the European eel. Both species migrate to the Sargasso Sea to spawn. The hatchlings grow here and migrate to the coasts of Europe and the United States, returning to the Sargasso Sea as adults to spawn. Baby loggerhead sea turtles (careta careta) are also believed to use the currents of the Gulf of Mexico to reach the Sargasso Sea, where they grow to maturity hiding in kelp forests, where they have food and can hide from predators.
Pollution of the Sargasso Sea
Similar to what happens on the so-called Plastic Island of the Pacific, the concentric currents of the North Atlantic Gyre drag into its interior garbage and residues from human activity that are concentrated in the Sargasso Sea. Non-biodegradable waste, mainly plastic, remains in suspension in this vortex, posing a serious threat to its biodiversity.
Currently, there are several organizations and institutions, both governmental and NGOs, whose objective is the environmental protection of the Sargasso Sea. One of the most prominent is the Sargasso Sea Commission, created on March 11, 2014 through the Hamilton Declaration on Collaboration for the Conservation of the Sargasso Sea, a declaration signed by the governments of the Azores, Bermuda, Monaco, the United Kingdom and the United States.