"We can then ask, out of all these combinations of potential options of species, which ones could we select and how much of each, in a way that would provide us with sufficient nutrition to meet a person’s diet [needs] with the lowest amount of fish biomass," Heilpern explained. The results were telling. The model consistently showed that the most efficient way to nourish a person was not to focus on a single "superfood" fish, but to utilize the specific strengths of a biodiverse catch.
One of the most significant revelations of the model was the type of species that emerged as "optimal" for both nutrition and sustainability. When fisheries are managed with biodiversity in mind, the diet that requires the least amount of fish tends to lean heavily toward species with specific biological traits. These traits—such as being smaller in size and sitting lower on the food chain—make these species remarkably resilient to the "anthropogenic pressures" that currently threaten global fish stocks, including overexploitation and the shifting temperatures caused by climate change.
Small species, such as sardines, anchovies, and various types of herring, are often more ecologically resilient than the large, predatory fish that are highly prized in many Western markets. Because these smaller fish grow at much faster rates and reach maturity more quickly than larger species like tuna or swordfish, their populations can bounce back more rapidly from fishing pressure. Furthermore, the study found that these optimal species are often better able to tolerate wider temperature ranges. This thermal flexibility is a critical asset in a warming world, making these species less susceptible to the sudden "climate shocks" that can cause more sensitive fish populations to collapse.
The study also highlighted a "substitution" effect inherent in biodiverse systems. In a fishery with a high variety of species, if one small, nutrient-dense species declines due to environmental changes, there are often several other species with similar nutrient profiles and ecological roles that can take its place. This redundancy provides a safety net for human food security that simply does not exist when a diet or an industry is reliant on only one or two major species.
The geographic distribution of this "nutritional biodiversity" is not uniform across the globe. The investigation showed that tropical coastal countries currently possess the most biodiverse fisheries, positioning them as critical hubs for future food security. Regions such as the Coral Triangle in the Pacific Ocean—which encompasses waters around Indonesia, Malaysia, the Philippines, Papua New Guinea, Timor-Leste, and the Solomon Islands—are among the most species-rich environments on the planet. Other biodiversity hotspots identified in the study include the coastal waters of Australia and India, as well as the vast, intricate river systems of the Amazon basin.
