NASA Scientists Zoomed in on the Ocean and Uncovered a Tiny Red Organism That Keeps Whales Alive

Far offshore in the North Atlantic, one of the most endangered species on the planet continues to shift its migratory patterns in search of food. The North Atlantic right whale, with fewer than 370 individuals remaining, has become increasingly difficult to track, and even harder to protect. Vessel strikes and fishing gear entanglements remain persistent threats, but efforts to prevent these incidents depend heavily on knowing where the whales will appear next.

What drives those movements is not always visible. Unlike the whales themselves, their primary food source is microscopic, scattered across vast areas, and until recently, largely undetectable in real time. For decades, scientists have used physical sampling to study zooplankton distributions, but the method is inherently constrained by geography and time. Entire feeding grounds could shift or collapse before they are fully measured.

A growing body of satellite-based research now suggests this may be changing. New techniques allow researchers to detect not the whales, but the red-hued plankton they feed on, from hundreds of kilometres above the ocean surface. The result is a new way to monitor critical food supplies for marine megafauna, with broad implications for conservation and maritime policy.

At the centre of this development is Calanus finmarchicus, a small red copepod that carries more ecological weight than its size implies. The ability to track this organism from orbit may offer a strategic advantage in managing risks to both whales and the broader marine food web.

High-Density Zooplankton Swarms Detected From Orbit

A team led by oceanographer Rebekah Shunmugapandi at the Bigelow Laboratory for Ocean Sciences has demonstrated that satellites equipped with optical sensors can identify surface aggregations of Calanus finmarchicus by analysing ocean colour anomalies. These zooplankton contain astaxanthin, a red pigment that alters how light is reflected at the ocean surface. When present in high concentrations, their collective signature becomes measurable from space.

The researchers used data from NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS) aboard the Aqua satellite to process enhanced RGB (red-green-blue) images of the Gulf of Maine. By comparing these images with in situ plankton data collected by the Continuous Plankton Recorder (CPR), the team confirmed that red-hued anomalies in satellite imagery aligned with high plankton concentrations at sea level. One observed patch contained an estimated 150,000 individuals per cubic metre.

These findings build on prior work in the Norwegian Sea, where similar methods detected large-scale Calanus swarms over areas exceeding 1,000 square kilometres. In both cases, the satellite-derived imagery matched known biological data. Researchers concluded that large zooplankton blooms can significantly influence surface reflectance patterns, opening new possibilities for satellite-based ecological monitoring.

Implications for Right Whale Protection and Risk Forecasting

For the North Atlantic right whale, the distribution of Calanus finmarchicus is more than a matter of nutrition. The species relies almost exclusively on dense copepod patches to build fat reserves essential for reproduction and migration. When these patches shift, the whales often leave established feeding areas and travel into zones of high maritime activity.

Researchers noted that tracking Calanus via satellite may enable early detection of these shifts, allowing resource managers to implement temporary vessel speed restrictions, route diversions, or fishery closures. Data published by Earth.com indicated that satellite imagery could be integrated with live whale sightings to inform policy decisions on short notice.

The technique also aligns with thresholds identified in ecological studies. A 2023 analysis in Marine Ecology Progress Series found that right whale presence closely correlates with Calanus densities above 10,000 individuals per cubic metre. The satellite-derived data not only exceeds this benchmark but does so over wide geographic areas, extending the observational range beyond the limits of traditional ship-based surveys.

Method Limitations and Species Misidentification

While the use of astaxanthin as a spectral marker for Calanus is promising, the pigment is not unique to the species. Other copepods, such as Centropages, and several phytoplankton species, including Tripos muelleri, also contain red or red-brown pigments that affect surface reflectance.

In two case studies described in the peer-reviewed Frontiers in Marine Science journal, researchers tested the detection system’s specificity. In one, satellite data indicated unusually high Calanus abundance during late autumn, a time when the species typically enters a dormant state below the surface. In another, a bloom of Tripos muelleri triggered false positives in the anomaly detection model. Although the algorithm reduced spectral mismatches by incorporating Calanus into the analysis, the residual signal suggested a misclassification.

The authors concluded that, in the absence of local species distribution data and species-specific absorption profiles, the system functions primarily as a general astaxanthin detection tool. Precise species identification would require supplementary biological information or concurrent field sampling.