Within the waters off New England, considered one of Earth’s rarest mammals swims slowly, mouth agape. The North Atlantic proper whale filters clouds of tiny reddish zooplankton — referred to as Calanus finmarchicus — from the ocean. These zooplankton, no larger than grains of rice, are the whale’s lifeline. Solely about 370 of those huge creatures stay.
For many years, monitoring the tiny plankton meant sending analysis vessels out within the ocean, towing nets and counting samples by hand. Now, scientists are wanting from above as a substitute.
Utilizing NASA satellite tv for pc information, researchers discovered a solution to detect Calanus swarms on the ocean floor within the Gulf of Maine, selecting up on the animals’ pure purple pigment. This early-stage method, described in a new study, might assist researchers higher estimate the place the copepods collect, and the place whales may comply with.
Monitoring the zooplankton from house may support each the whales and maritime industries. By predicting the place these mammals are prone to feed, researchers and marine useful resource managers hope to scale back lethal vessel strikes and fishing gear entanglements — two main threats to the species. Realizing the feeding patterns may additionally assist transport and fishing industries function extra effectively.
“NASA invests in this type of analysis as a result of it connects space-based commentary with real-world challenges,” stated Cynthia Corridor, a assist scientist at NASA headquarters in Washington. She works with the Early Profession Analysis Program, which partly funded the work. “It’s yet one more a solution to put NASA satellite tv for pc information to work for science, communities, and ecosystems.”
Revealing the Ocean’s Hidden Patterns
The brand new method makes use of information from the Average Decision Imaging Spectroradiometer (MODIS) aboard NASA’s Aqua satellite tv for pc. The MODIS instrument doesn’t straight see the copepods themselves. As an alternative, it reads how the spectrum of daylight mirrored from the ocean floor adjustments in response to what’s within the water.
When massive numbers of the zooplankton rise to the floor, their reddish pigment — astaxanthin, the identical compound that offers salmon its pink coloration — subtly alters how photons, or particles of sunshine, from the solar are absorbed or scattered within the water. The destiny of those photons within the ocean depends upon the combo of residing and non-living matter in seawater, making a slight shift in coloration that MODIS can detect.
“We didn’t know to search for Calanus earlier than on this approach,” stated Catherine Mitchell, a satellite tv for pc oceanographer at Bigelow Laboratory for Ocean Sciences in East Boothbay, Maine. “Distant sensing has sometimes centered on smaller issues like phytoplankton. However current analysis instructed that bigger, millimeter-sized organisms like zooplankton may also affect ocean coloration.”
Just a few years in the past, researchers piloted a satellite tv for pc technique for detecting copepods in Norwegian waters. Now, a few of those self same scientists — together with Mitchell’s staff — have refined the method and utilized it to the Gulf of Maine, a vital feeding floor for proper whales throughout their northern migration. By combining satellite tv for pc information, a mannequin, and discipline measurements, they produced enhanced photos that exposed Calanus swarms on the sea floor, and have been capable of estimate numbers of the tiny animals.
“We all know the proper whales are utilizing habitats we don’t totally perceive,” stated Rebekah Shunmugapandi, additionally a satellite tv for pc oceanographer at Bigelow and the research’s lead creator. “This satellite-based Calanus data may ultimately assist establish unknown feeding grounds or higher anticipate the place whales may journey.”
Monitoring Elusive Giants
Regardless of many years of research, North Atlantic right whales stay remarkably enigmatic to scientists. As soon as pretty predictable of their actions alongside the Japanese Seaboard of North America, these huge mammals started abandoning some conventional feeding grounds in 2010-2011. Their sudden shift to surprising areas just like the Gulf of Saint Lawrence caught individuals off guard, with lethal penalties.
“We’ve had whales getting hit by ships and whales getting caught in fishing gear,” stated Laura Ganley, a analysis scientist within the Anderson Cabot Heart for Ocean Life on the New England Aquarium in Boston, which conducts aerial and boat surveys of the whales.
In 2017, the Nationwide Oceanic and Atmospheric Administration designated the scenario as an “uncommon mortality occasion” in an effort to deal with the whales’ decline. Since then, 80 North Atlantic proper whales have been killed or sustained severe accidents, in line with NOAA.
Within the Gulf of Maine, there’s much less transport exercise, however there generally is a complicated patchwork of lobster fishing gear, stated Sarah Leiter, a scientist with the Maine Division of Marine Sources. “Every fisherman has 800 traps or so,” Leiter defined. “If a bigger variety of whales reveals up abruptly, like they only did in January 2025, it’s difficult. Fishermen want time and good climate to regulate that gear.”
What excites Leiter probably the most concerning the satellite tv for pc information is the potential to make use of it in a forecasting device to assist predict the place the whales may go. “That will be extremely helpful in giving us that essential lead time,” she stated.
PACE: The Subsequent Technology of Ocean Observer
For now, the Calanus-tracking technique has limitations. As a result of MODIS detects the copepods’ purple pigment, not the animals themselves, meaning different small, reddish organisms will be mistaken for the zooplankton. And cloud cowl, tough seas, or deeper swarms all restrict what satellites can spot.
MODIS can also be nearing the top of its operational life. However NASA’s next-generation PACE (Plankton, Aerosol, Cloud, ocean Ecosystem) satellite tv for pc — launched in 2024 — is poised to make dramatic enhancements within the detection of zooplankton and phytoplankton.
“The PACE satellite tv for pc will certainly be capable to do that, and perhaps even one thing higher,” stated Bridget Seegers, an oceanographer and mission scientist with the PACE staff at NASA’s Goddard House Flight Heart in Greenbelt, Maryland.
The PACE mission contains the Ocean Color Instrument, which detects greater than 280 wavelengths of sunshine. That’s an enormous leap from the ten wavelengths seen by MODIS. Extra wavelengths imply finer element and higher insights into ocean coloration and the kind of plankton that the satellite tv for pc can spot.
Native data of seasonal plankton patterns will nonetheless be important to interpret the info accurately. However the objective isn’t excellent detection, the scientists say, however quite to offer one other device to tell decision-making, particularly when time or sources are restricted.
By Emily DeMarco
NASA Headquarters