Why the deep sea matters

Why the deep sea matters
Deep sea biomes are the biggest on Earth. The deep sea is the largest biome on Earth. It covers an area greater than 360 million km 2 and has a depth of about 3.7km. The deep sea has conditions that are alien to land dwellers, with low temperatures, darkness and pressure making it difficult to explore and access. It is also often called 'interspace,' or Earth's last frontier.

This vast area is probably home to the highest number of animal species and the largest amount of living organism mass in the world. The deep sea also plays a crucial role in providing regulating, provisioning, and cultural services that sustain all life on Earth. For example, it helps regulate the Earth's climate by serving as a sink for carbon and heat. Despite being remote, deep sea ecosystems face similar threats to those found in coastal and terrestrial ecosystems, including climate change, ocean acidification, overfishing, and deep mineral extraction. The demand from human industry, technology, and population growth has led to an increasing interest in fishing and mineral prospecting in these previously untouched areas.

It is not new that deep water research has always been expensive. Deep water explorations in the early 1900s produced the first holotypes, which broke the myth that the ocean was devoid of complex organisms. It is only in the last two decades, with the advent of the submersible, the remotely controlled vehicles (ROVs), and the autonomous underwater vehicles, that data collection has been accelerated. This, combined with the use of novel molecular tools and imaging, led to the discovery of many new species. It is possible that the study of deep ocean environments has entered a "golden age" which could greatly improve our understanding of life on Earth.

The majority of the seafloor area is composed of flat abyssal plains that are made up of sediment and ooze habitats consisting of planktonic shell debris. Nevertheless, there are mid-oceanic ridges and seamounts that break up these plains, offering a solid substrate for sessile animals like corals and sponges to thrive on and creating intricate deep sea reefs. These reefs attract a variety of species that seek food or shelter. The steep slopes of these ridges are where the most valuable minerals can be found. The Eastern Tropical Pacific region, located over various plate boundaries and spreading centers, has deep sea ridges and seamounts that run through it, created by shifting continental plates. The Galapagos Archipelago has an exceptionally high concentration of seamounts and steep island slopes that combine with diverse and productive oceanography to make this area ideal for complex and diverse communities to flourish. The Archipelago's deep water habitat is a valuable reference point for a nearly untouched ecosystem due to its remoteness and the establishment of the Galapagos Marine Reserve, which has banned industrial resource extraction since 1999.

Scientists have been able to confirm, thanks to the various research cruises conducted in Galapagos with ROVs and submersibles between 2000 and 2010, that there are indeed a number of diverse communities on the steep slopes. These include coral forests and sponge forests at depths ranging from 200 m up until 3000 m. Scientists have observed a variety of invertebrate communities and fish species, many of which are new to the area and to science.

In our role as researchers on the Galapagos Deep-sea Systems Research Project at the Charles Darwin Research Station, we have been fortunate enough to observe incredible biodiversity hotspots that come to life and light up rocky walls in the midst of the pitch-black deep water. By increasing our understanding of the marine biodiversity in the Galapagos Marine Reserve (GMR), we hope to enhance the protection, management, and stewardship of these poorly studied and underrepresented ecosystems for the benefit of those of us who live on the surface.

If you would like to explore and visit in the eastern tropical of the archipelago, the Endemic Catamaran offers 7 night itineraries.