The Chilean Fiords
The long narrow passages of the Chilean fiords, threading intricately from the open Pacific to the faces of the great glaciers that descend from the heights of the Andes, have long provided sheltered harbors for mariners and access to the spectacular scenery and rich resources of southern Chile. For many years this was enough, but in the last few decades detailed oceanographic investigation has revealed that the fiords themselves are a treasure, a marine region unique in the world.
The waters of the fiords fall under the influence of a number of different transformative forces. Saline seawater flows in from the Pacific as the tides rise and fall, but shallow sills of rock block this flow in many places, isolating deep basins in many of the inner fiords. From the mountains, glacial meltwater and rain runoff bring a constant input of fresh water, which lowers the salinity of certain areas, resulting in a complex mosaic of more and less salty waters. Strong currents sweep by the outer coast, bringing larval animals and other organisms from surrounding regions to the north and south.
Investigating the biology of the fiords with our ROV and underwater video, we can easily see the evidence of this complexity. In the innermost part of Garibaldi Fiord, at 500 below the surface, we found shrimp, anemones and southern king crabs dwelling on the soft muddy bottom; this is a simple community, striking in its difference from the richer waters further out the same channels, yet impressive in its ability to thrive in the harsh conditions that pertain so close to the faces of the glaciers.
In Puerto Profundo, closer to the outer coast, I observed that the heavy beds of mussels appeared to grow only inside the fiord, where their tolerance of brackish water is a strong advantage. Only a short swim away we found several species of soft coral flourishing in the strong currents of the fiord’s entrance, and, in the dim green darkness 100 feet down, a very unusual sea cucumber, unlike any I have ever see elsewhere.
On the surface, the scenery of the fiords is very beautiful indeed; but, as is so often the case for travelers, a look beneath the surface quickly reveals fascinating complexity and unexpected treasures.
The long narrow passages of the Chilean fiords, threading intricately from the open Pacific to the faces of the great glaciers that descend from the heights of the Andes, have long provided sheltered harbors for mariners and access to the spectacular scenery and rich resources of southern Chile. For many years this was enough, but in the last few decades detailed oceanographic investigation has revealed that the fiords themselves are a treasure, a marine region unique in the world.
The waters of the fiords fall under the influence of a number of different transformative forces. Saline seawater flows in from the Pacific as the tides rise and fall, but shallow sills of rock block this flow in many places, isolating deep basins in many of the inner fiords. From the mountains, glacial meltwater and rain runoff bring a constant input of fresh water, which lowers the salinity of certain areas, resulting in a complex mosaic of more and less salty waters. Strong currents sweep by the outer coast, bringing larval animals and other organisms from surrounding regions to the north and south.
Investigating the biology of the fiords with our ROV and underwater video, we can easily see the evidence of this complexity. In the innermost part of Garibaldi Fiord, at 500 below the surface, we found shrimp, anemones and southern king crabs dwelling on the soft muddy bottom; this is a simple community, striking in its difference from the richer waters further out the same channels, yet impressive in its ability to thrive in the harsh conditions that pertain so close to the faces of the glaciers.
In Puerto Profundo, closer to the outer coast, I observed that the heavy beds of mussels appeared to grow only inside the fiord, where their tolerance of brackish water is a strong advantage. Only a short swim away we found several species of soft coral flourishing in the strong currents of the fiord’s entrance, and, in the dim green darkness 100 feet down, a very unusual sea cucumber, unlike any I have ever see elsewhere.
On the surface, the scenery of the fiords is very beautiful indeed; but, as is so often the case for travelers, a look beneath the surface quickly reveals fascinating complexity and unexpected treasures.
