22 June 2020
Photo: Alexandra Petrunina
Nancy Mercado Salas, head of the Department of Crustacea at the Center of Natural History (CeNak), will spend about a month on an expedition in the North Atlantic. Her research focuses on tiny animals that live at the bottom of the deep sea. The photo shows the researcher on an earlier expedition to the Kuril–Kamchatka Trench.
Nancy Mercado Salas is setting sail today on the expedition ship Sonne. Her destination is the deep sea of the North Atlantic near Iceland. Together with her colleague Anne-Nina Lörz and other researchers from the international IceAGE Program, Nancy Mercado Salas is investigating the influence of climate change on seabed biodiversity. Her research focuses on meiofauna, which are biotic communities of tiny organisms such as copepods that live in the sand. These organisms play a central role in the marine food chain. Nancy Mercado Salas has been the head of the Department of Crustacea at the Center of Natural History (CeNak) at Universität Hamburg since 1 February 2020.
The international IceAGE program (Icelandic Marine Animals: Genetics and Ecology) researches maritime zones in the North Atlantic. With water depths of 300 to 3,000 meters and a large temperature range from –0.9°C to14°C, this region is particularly sensitive to climate changes. “Studying and observing life in climate-sensitive areas such as the deep sea near Iceland helps us to understand how marine communities respond to climate change,” says Nancy Mercado Salas.
During the one-month expedition on the Sonne, she and her team collected sediment samples so that they could analyze the morphological and genetic features of the crustaceans living in the sediment. In addition, some of the samples will be analyzed using state-of-the-art molecular methods such as metabarcoading. Such methods allow biological diversity to be assessed and monitored much more quickly than with traditional methods. Many samples can be examined and prepared directly on board in the well-equipped microscopy and bio lab before they are transferred to the CeNak collection. At CeNak, they will be further analyzed and together with objects from previous IceAGE expeditions will serve as an important reference archive for the comparison of new species. Nancy Mercado Salas says, “Our collection is a treasure that helps us tremendously to get an overview of deep sea life in the North Atlantic.”
Quarantine before start of expedition
Many things are going differently than planned in times of the corona crisis. After 2 weeks in quarantine, Nancy Mercado Salas had to go into isolation for 4 days before the start of the expedition. She wasn’t allowed to leave her hotel room or have contact with anyone. The researchers were allowed on board only after they received a negative coronavirus test. Their expedition ship turned out not to be the Meteor as originally planned, but the larger and more spacious Sonne. It started from a German port—and not, as usual, from the port closest to the research site. Stopovers with visits onshore were also prohibited. Nancy Mercado Salas says, “We mostly stay in our rooms. Many things will be different, but I look forward to research on-site and to the fauna in the sea.”
A fascination for copepods and their relationships have shaped the research career of the native Mexican: “I adore these little animals. They’re amazing!” They form the basis of life in the deep sea—if something changes for them, it has a direct influence on other marine animals.
Tiny animals with a great impact
Research into the smallest animals allows scientists to draw conclusions about the lives of others. Nancy Mercado Salas has long concentrated on these tiny creatures that don’t even measure a single millimeter. They represent the majority of marine plankton and the biotic communities of tiny invertebrates (meiobenthos) on the seabed and play an important role in biochemical processes.
Given her knowledge of the species and her experience in biomonitoring, Nancy Mercado Salas is regularly asked to take stock and assess the situation in international waters, for example, in the Pacific between Mexico and Hawaii. This means that she conducts an analysis of life in the depths of the ocean—and of deep-sea mining. The economic goal is to transport valuable mineral resources such as polymetallic nodules to the surface. Together with geologists and other biologists, Nancy Mercado Salas examines the seabed and assesses the biodiversity there. “Species-rich areas should be excluded from drilling,” she explains. “Marine life is affected not only by the removal and compacting of seabed by deep sea mining vehicles, but also by oil contamination, noise, and heat. This is very complex. We need to think holistically and include both direct and indirect factors that affect the closely interwoven life of the species there.”
Since we can only protect what we know, Nancy Mercado Salas puts a lot of energy into identifying and describing species: “We probably know about only 10 to 20 percent of the meiofauna species in the deep sea. But thanks to the collections—including those at CeNak—we can continually expand our knowledge.”
CeNak’s Crustacea Collection currently includes about 850,000 objects that represent 7,188 species of marine crustaceans from around the world. This makes the collection one of the largest and—with the type specimens of 1,736 species and important historical treasures—also one of the most important collections of crustaceans in Germany. The collection is therefore used by many international researchers, who also rely on the increasing amount of data online (to date, 50 percent of the catalog numbers have been digitized).
Dr. Nancy Mercado Salas
Head of the Department of Crustacea
Center of Natural History (CeNak)
Tel: +49 40 42838-2278