In early August, a team of researchers with the multi-year, multi-institutional BIOS-SCOPE (Bermuda Institute of Ocean Sciences – Simons Collaboration on Ocean Processes and Ecology) program completed their seventh research cruise aboard the BIOS-operated research vessel Atlantic Explorer. For four days, 13 scientists from eight institutions came together to study the unique microbial communities that develop in the Sargasso Sea during the summer, as well as the dissolved organic matter (DOM) they produce, consume, and redistribute throughout the water column.

BIOS acquired three new instruments this spring to enrich investigations into the roles and interactions between microbial communities and migrating zooplankton in the Sargasso Sea.

Scientists estimate there are more than a million times more viruses in the ocean than stars in the universe. While wildly abundant, their tiny sizes present a big a hurdle to fully understanding their function in ocean ecosystems. If a cell were the size of a baseball stadium, a virus would be roughly the size of a baseball, so not only are viruses difficult to see under the microscope, but even gathering enough of their genetic material to analyze can be tricky.

Sampling offshore Bermuda this July, the BIOS-SCOPE (Bermuda Institute of Ocean Sciences – Simons Collaboration on Ocean Processes and Ecology) program completed its first full year of study to learn how marine microbes produce, transform, and leave behind dissolved organic matter as the seasons progress, and microbial communities wax and wane.

At midnight on a warm night off Bermuda in July, research technician Joe Cope and a small team of crew members prepared to deploy a net system stretching nearly the length of a city bus from the stern of the research vessel Atlantic Explorer. Though it’s not unusual for oceanographers to work around the clock during a research cruise, the timing of this particular cast was important. Every night, under cover of darkness, the marine animals they hoped to capture—some a few inches in length, others the size of a sand grain—come to the surface to feed on phytoplankton, after spending the daylight hours far below the surface, hiding from predators.

After a year of shark attacks, leaking instruments, and a hiatus resulting from the global COVID-19 pandemic, BIOS’s gliders are back to work in the waters offshore Bermuda.

In mid-November, the BIOS-operated research vessel Atlantic Explorer headed into the Sargasso Sea for the eighth research cruise as part of the multi-year, multi-institutional BIOS-SCOPE (Bermuda Institute of Ocean Sciences – Simons Collaboration on Ocean Processes and Ecology) project. Since 2015, scientists from Bermuda, Germany, the United Kingdom, and the United States have converged at BIOS to investigate the microbial ecology of the Sargasso Sea and understand how organic matter (carbon) cycles within the marine environment.

St. George’s, Bermuda –– An anonymous donor has awarded BIOS $6 million to support collaborative research on the distinctive microbial communities of the Sargasso Sea over the next five years. The research will leverage ocean measurements and ongoing research at the Bermuda Atlantic Time-series Study (BATS) site, bringing new collaborations and technologies to study the ocean’s smallest life forms.

Earlier this year, BIOS associate scientist and zooplankton ecologist Leocadio Blanco-Bercial published a paper in the scientific journal Frontiers in Marine Science that sheds light on zooplankton communities in the Sargasso Sea, where zooplankton diversity is among the highest in the world’s ocean.

For nearly a hundred years, scientists have known that plankton—the microscopic organisms that drift and float in the ocean, also known as marine microbes—form the basis of the ocean’s food web. Phytoplankton (literally “plant wanderers”) are photosynthetic, like their terrestrial counterparts, and convert sunlight into energy. Phytoplankton, in turn, are consumed by zooplankton (literally “animal wanderers”), as well as a host of larger marine organisms, including juvenile fish, shellfish, birds, and even whales. However, scientists are now learning that plankton play an even larger role in earth’s complex biogeochemical systems.