Mapping Critical Habitats of Threatened Shark Species Along the Algarve Coast
- FAM Foundation
- Mar 17
- 4 min read
The Mapping Sharks project, supported by the FAM Foundation, was designed to address this gap by investigating the movement patterns and habitat use of juvenile smooth hammerhead (Sphyrna zygaena) and blue sharks (Prionace glauca) along the Algarve coast, with particular focus on the Sagres region, where shark aggregations have been reported.
Hosted by CCMAR, led by David Abecasis, project focuses on the spatial ecology of smooth hammerheads and blue sharks along the Algarve coast. Using telemetry techniques, it seeks to identify and protect essential fish habitats under pressure from fishing and coastal development. The project supports SDG 14 by promoting science-based conservation strategies and public awareness initiatives.
Addressing a Critical Knowledge Gap in Shark Conservation Impact
Sharks are among the most threatened marine vertebrates globally, facing increasing pressure from overfishing, habitat degradation, and climate change. Their low reproductive rates and late maturity make them particularly vulnerable to population collapse. Yet effective conservation remains constrained by limited knowledge of their spatial ecology, especially in coastal areas where anthropogenic pressures are highest .
A Complementary Monitoring Strategy: Acoustic and Satellite Telemetry
To better understand shark movement patterns, the project implemented a dual biotelemetry strategy combining acoustic transmitters and satellite tags. Acoustic telemetry enables long-term monitoring — potentially up to ten years — through receiver arrays strategically placed along the coast. Satellite pop-up archival tags, although shorter-term, provide valuable information on vertical habitat use, depth profiles, and environmental conditions .
This complementary framework allows researchers to capture both fine-scale coastal habitat use and broader offshore movements. While acoustic telemetry identifies repeated use of coastal zones and potential nursery areas, satellite tags contribute vertical and offshore movement data, generating a multi-scale understanding of juvenile shark ecology.
Establishing Long-Term Monitoring Infrastructure
Although field opportunities were limited due to environmental conditions, the project successfully demonstrated the feasibility of safely capturing and tagging juvenile pelagic sharks. A juvenile female blue shark (152 cm) was successfully tagged with an acoustic transmitter offshore Sagres, validating field protocols and providing proof of concept for future deployments .
Beyond individual tagging efforts, one of the most important achievements was the strengthening of the existing acoustic receiver network along the Algarve coast. Additional receivers were deployed in deeper offshore areas (60–200 m depth), and institutional partnerships were reinforced, including collaboration with the Ocean Tracking Network (OTN) and Instituto Hidrográfico .
This expanded monitoring infrastructure significantly increases the probability of detecting tagged sharks and enhances the long-term scientific value of the regional telemetry array. Data downloads planned for 2026 are expected to generate the first detailed insights into shark movements within and beyond the Algarve region.
Large-Scale Shark Sightings Dataset
Recognising the inherent challenges of working with highly mobile species, the project complemented telemetry efforts with the compilation and analysis of shark sightings data collected between 2006 and 2025 .
The final dataset integrated 1,526 shark sighting records, making it the most comprehensive dataset currently available for southern Portugal. Blue sharks represented approximately two-thirds of observations, followed by hammerhead sharks, with additional records of basking sharks and shortfin makos .
Spatial analyses revealed clear hotspots along the central Algarve shelf for blue sharks and a pronounced concentration of hammerhead shark sightings around Sagres. Seasonal patterns were also identified, with peak occurrences during late spring and summer, coinciding with warmer sea surface temperatures and increased biological productivity .
Effort-aware statistical models were developed to account for uneven sampling intensity. These models identified environmental conditions associated with higher encounter probabilities and provided decision-support tools to guide future tagging campaigns and conservation prioritization.
Innovative Monitoring Tools: Drone-Based Surveys
The project also tested drone-based surveys as a cost-effective monitoring tool for coastal shark detection. Although no sharks were observed during the trial flights around Sagres, the exercise demonstrated the operational feasibility and high potential of drone-based monitoring for repeated coastal surveys .
Drone imagery successfully captured pelagic fish schools and habitat features, confirming its value for future monitoring integration. This innovation broadens the methodological toolbox available for shark conservation in dynamic coastal environments.
Analytical Workflows and Digital Communication
In parallel with fieldwork, the project developed analytical workflows designed to reconstruct movement paths and habitat use once telemetry data accumulate. These frameworks ensure that future detections can be rapidly translated into conservation-relevant insights .
The project also placed strong emphasis on outreach and science communication. A dedicated webpage was created to showcase digital tools, and multimedia materials were developed to support public awareness, stakeholder engagement, and educational activities. Scientific publications based on the sightings dataset are currently in preparation, with further outputs expected as telemetry data become available .
Capacity Building and International Engagement
Beyond scientific outputs, the project strengthened institutional partnerships and provided hands-on training opportunities for MSc students. The team will present results at the Sharks International Conference and the European Tracking Network Symposium in 2026, reinforcing international collaboration and knowledge exchange .
Strategic Outcomes and Conservation Impact
Although telemetry data are still accumulating, the project has already delivered three strategic outcomes. First, it strengthened long-term shark monitoring infrastructure through expanded acoustic telemetry capacity and international network integration. Second, it produced the most comprehensive shark sightings analysis for the Algarve coast, identifying key spatial and seasonal hotspots. Third, it established a scientifically robust framework ready to scale through future tagging and conservation initiatives .
The funding provided by the FAM Foundation supported essential equipment acquisition, including satellite transmitters and acoustic receivers, field campaign logistics, and human resources necessary to implement the project . This investment created durable infrastructure whose ecological returns will extend well beyond the formal project timeline.
Building the Foundations for Long-Term Shark Conservation
The Mapping Sharks project represents a critical first step toward understanding the spatial ecology of threatened juvenile sharks along the Algarve coast. By combining telemetry, long-term observation data, drone innovation, and science communication, the initiative laid the methodological and institutional foundations for sustained shark conservation efforts in southern Portugal.
Aligned with SDG 14 — Life Below Water — the project demonstrates how targeted philanthropic support can catalyse long-term conservation impact, even in the early phases of research on highly mobile and ecologically complex marine predators.
Please find more information on the report above.
FAM Foundation is committed with the sustainable development goals, Blue Carbon in Algarve project impact the following SGD's.
The Sustainable Development Goals (SDGs), also known as the Global Goals, were adopted by the United Nations in 2015 as a universal call to action to end poverty, protect the planet, and ensure that by 2030 all people enjoy peace and prosperity.
