From Surface Encounters to Deep-Sea Knowledge: Sustainable Tourism in the Azores

The Azores archipelago occupies a rare position at the intersection of oceanography, biodiversity, and sustainable tourism. Rising from a geologically complex seafloor at the convergence of major North Atlantic currents, the region supports one of the world’s most reliable assemblages of cetaceans. Over the past three decades, whale watching has become a cornerstone of the Azorean economy. Between 2020 and 2024, the MONICEPH project demonstrated that this same industry can also function as a powerful scientific platform– one capable of revealing new dimensions of deep-ocean ecology.

Monitoring Cephalopods during Whale Watching Activity (MONICEPH) was designed to address a persistent gap in marine science: the scarcity of data on deep-sea cephalopods. These organisms play a central role in pelagic ecosystems, transferring energy from midwater prey to apex predators, such as sperm whales, while contributing to nutrient cycling and long-term carbon sequestration through daily vertical migration. Yet their distribution and population dynamics remain poorly understood, largely because direct sampling of the deep sea is technologically demanding, costly, and environmentally intrusive.

The Azores provide an ideal natural laboratory for indirect deep-sea observation. The archipelago’s steep island slopes, seamounts, abyssal plains, and volcanic structures create habitats that support cephalopods across mesopelagic and bathypelagic depths. Nutrient enrichment driven by the interaction of the Gulf Stream, Canary Current, and Azores Current sustains high biological productivity, which in turn attracts teuthophagous cetaceans year-round.

When whales feed at depth, cephalopod remains are occasionally transported to the surface. These events, linked to incomplete consumption, regurgitation, or social feeding behavior, offer rare, non-invasive opportunities to document deep-sea species. MONICEPH formalized this process by training whale-watching guides and onboard biologists to collect, document, and preserve such remains during routine excursions.

The project represents a methodological innovation: the integration of opportunistic biological sampling into a commercial tourism framework. Thirteen whale-watching companies across four Azorean islands participated, collecting standardized data on location, timing, cetacean presence, and observed behavior. Samples were later identified using a combination of morphological analysis and DNA barcoding, incurring taxonomic accuracy even when specimens were fragmented.

This approach yielded 182 cephalopod records representing sixteen species, including one not previously documented in the region. Crucially, these data were gathered without deploying dedicated research vessels or increasing offshore effort. Whale-watching boats effectively functioned as distributed research platforms, expanding spatial and temporal coverage while minimizing cost and environmental impact.

Beyond species documentation, the dataset provides rare behavioral insights into predator-prey dynamics, particularly involving sperm whales and their calves. More than half of the cephalopod occurrences were associated with sperm whale sightings, and a substantial proportion suggested that adult whales deliberately brought large cephalopods to the surface in proximity to juveniles.

These events support emerging hypotheses that certain feeding behaviors may serve social or educational functions rather than purely nutritional ones. Large, gelatinous cephalopods– frequently recorded in the dataset– may be especially suited to such interactions, as they are easier to manipulate and detect acoustically. This aligns with broader evidence that sperm whales engage in culturally transmitted behaviors, including prey handling and echolocation strategies. MONICEPH thus contributes empirical observations to a growing body of research on social learning in marine mammals.

From an economic perspective, MONICEPH illustrates how nature-based tourism can generate value beyond direct revenue. The project transformed routine commercial activity into a source of high-quality ecological data, effectively lowering the marginal cost of scientific observation. This has implications for regions where research funding is limited but tourism infrastructure is well developed.

The model also strengthens the credibility of the Azores within the blue economy framework. Whale watching becomes not only a low-impact alternative to historical extractive practices, but a contributor to global biodiversity knowledge. Participation in open-access data networks further amplifies this value, positioning the region as both a conservation leader and a producer of marine intelligence.

MONICEPH demonstrates that the boundaries between science, conservation, and tourism are more permeable than traditionally assumed. By aligning economic activity with ecological monitoring, the project offers a scalable, replicable approach to studying the deep ocean. In the Azores, whale watching no longer ends at the surface. It extends downward, revealing ecological processes unfolding thousands of meters below, and offering a model of how sustainable economies can also be knowledge-generating systems.

MONICEPH project: Monitoring cephalopods during whale watching activity in the Azores (2020-2024)