Surveying and Dredging: Day 5

Benthic Ecology: Andreia, Ana, and Liza

Researchers Liza Akoulina and Andreia Henriques consult with Yersin Captain Jean Dumarais

Benthic Ecology is the study of organisms that live close to or at the bottom of the sea, and have a close relationship to the sea floor. The team studies their diversity, habitat, habitat preferences, and integrity of the habitat, abundance, they map the habitats and study the impacts on the ecosystem.

A Van Veen Grab sampler is used to collect samples of the bottom – this specific dredge is used to collect sedimentary samples.

The team takes samples from several depths to understand more about the species and ecosystems. For example; why a species may live at 10 meters and 40 meters but not in between.

After collecting the samples, they bring them back to the lab on Yersin to sort, catalogue, process and preserve. They count the animals, weigh the sediment, measure the abundance, and preserve the samples for multiple studies.

After finishing their work with Monaco Explorations aboard the Yersin, the team will return to their lab to continue analysis of the more than 200 samples they collected.

Seabird Ecology: Jose, Paulo, Inês, João, and Luis

Together, through Project OceanWebs, this team is studying seabird colonies in the region of the Island of Madeira, in particular on the Desertas and the Selvagens Islands. This area is particular because it is very large and the sea here is very deep.  Compared to coastal waters that have flow from other water sources and are nutrient rich, deep-sea areas are less productive, forcing the seabirds to travel long distances to feed.

The deep sea is one of the most difficult places to study due to the cost and conditions necessary for research. Because of this, we do not know a lot about the deep sea. Sea birds can give us a glimpse into deep-sea conditions through analysis of what the seabirds feed on from deep-sea waters.

This team’s research includes tagging the seabirds with GPS trackers while they are nesting, to learn where they go to feed, and analyzing the GPS trackers and contents of their stomachs when they return to the colony. They can also analyze droppings, feathers, blood and shells.

Through this data collection, researchers have learned, among other topics, that the seabirds are feeding on species that are known to live at 500 plus meters, which shows that these deep-sea species are being driven toward the ocean’s surface. This poses some questions:

  • Is there a direct relationship between deep-sea predators and aerial predators?
  • Are they sharing prey and what species of prey?
  • Are they working together to feed?
  • Does this occur in multiple locations around the world?

While on board the Yersin, this team is observing the areas where the seabirds are known to feed, in hopes of catching the interaction between the deep-sea animals and the seabirds. They are collecting plankton samples after dark to analyze the species and abundance of the plankton. The team will preserve these samples and take them back to their lab to study.