The urgency of the problem is grounded in a shifting hazard landscape. Climate change is intensifying climate-driven natural hazards, and these events increasingly strike simultaneously, in quick succession, or trigger one another in cascading chains. Recent studies cited by the authors show that multi-hazard events are becoming more frequent across Europe and globally. The United Nations Office for Disaster Risk Reduction defines multi-hazards as the selection of multiple major hazards a country faces, considering the specific contexts where hazardous events may occur simultaneously, cascadingly or cumulatively over time, taking into account their potential interrelated effects. In response, risk research has been shifting from single-hazard to multi-hazard thinking, yet most large-scale assessments remain dominated by quantitative methods such as machine learning, and data gaps often force studies into narrow approaches that exclude low- and middle-income countries.

The difficulty, the authors argue, is that multi-hazard risk assessment is inherently complex. It demands data, a deep understanding of how risks interact across space and time, and awareness of the local context in which disasters actually unfold. Decision makers face competing adaptation priorities and potential conflicts between measures designed for different hazard types. Moreover, the effectiveness of any disaster risk reduction strategy depends on how communities perceive and respond to risk, a dimension that standardized quantitative methods aimed at larger scales routinely miss. Risk perception, the essay notes, does not always align with modelled risk. A study in Bangladesh combining media narratives, interviews and field observations found that risk perception is often ignored in local adaptation planning, while research on coastal property markets in the United States shows that despite growing hazards, coastal properties continue to rise in value.

The temporal dynamics of perception are equally striking. Immediately after a flood event, property prices in inundated areas drop by an average of 24.9 percent compared to non-flooded properties, yet that discount loses statistical significance within five years. In multi-hazard contexts there is a further complication: focusing on one hazard can decrease people’s attention to the risk posed by another. To structure their investigation of these dynamics, the researchers anchored their survey work in Protection Motivation Theory, a psychological framework with two key components. Threat appraisal addresses how likely people believe an event is and how severely they expect to be hit, while coping appraisal probes whether people believe anything can be done, whether it is affordable, and whether government adaptation measures would actually work.

Mixed-methods research, defined as projects that bring together qualitative approaches such as interviews with quantitative techniques such as risk modelling and survey analysis, is not new. Greene and colleagues laid the terminological foundations in 1989, reviewing studies that already combined methodologies, and interest has grown notably over the past decade, particularly in the social sciences. The main designs include convergent parallel, explanatory sequential and exploratory sequential approaches. What García Álvarez and de Ruiter propose is a simultaneous, iterative process in which quantitative and qualitative strands inform each other continuously. A qualitative interview can improve the interpretation of structured survey data or reshape the survey itself for later stages, as stakeholders identify problems the researchers had not anticipated. Quantitative results, in turn, can guide which questions matter most in interviews and which adaptation solutions to model.

The framework was tested during a ten-day fieldwork trip to Tenerife in March 2025, an island the authors describe as a complex multi-hazard environment exposed to volcanic eruptions, coastal hazards, wildfires and landslides. Recent events, including the devastating 2023 wildfires and the 2021 eruption on the neighboring island of La Palma, have highlighted gaps in preparedness. The team applied a sequential design in which quantitative methods influenced qualitative instruments and vice versa: GIS-based observations and survey results shaped interview questions, while exploratory interviews determined which key questions to address quantitatively and which adaptation solutions to model. A total of 174 respondents completed a 25-question survey, administered in person and online in Spanish and English versions, coded in KoboToolbox and analyzed in Python to test Protection Motivation Theory hypotheses. Five semi-structured interviews targeted three key economic sectors highly exposed to climate risk: agriculture, tourism and critical infrastructure, with thematic analysis covering risk perception, adaptation levels and trust in authorities.

The complementarity of the methods surfaced repeatedly. Desktop analysis and GIS-based exposure mapping provided an initial understanding of each region and identified locations to verify in the field, where observations revealed missing infrastructure, unregistered buildings and local bottlenecks. Several regions of the island contained buildings absent from Google Maps that would have been neglected in modelling otherwise. Questionnaire results showed that respondents were unaware of any emergency plan for most climate hazards despite recent wildfires and coastal storms, yet residents knew volcanic eruption procedures because drills had been conducted by some municipalities after the La Palma eruption. That contrast, the authors suggest, could directly shape future emergency communication plans. In the northern town of Tegueste, nestled in a valley between forested mountains and exposed to wildfires and flooding from steep ravines called barrancos, field observations confirmed residential areas and infrastructure inside high-risk zones, along with accumulated vegetation and debris that could block water flows.

Interviews then revealed opportunities invisible to any dataset. Conversations with locals and field observations uncovered large areas of abandoned agricultural terraces near Taganana, offering low-conflict sites for reforestation, since converting productive farmland to nature-based solutions would require compensating farmers. For Tegueste specifically, the survey confirmed that locals ranked wildfires as the top perceived hazard following the nearby 2023 blaze, and econometric analysis showed that residents with prior hazard experience were more likely to have taken adaptive measures. Yet overall worry levels were low, a contrast between perceived and modelled risk that the authors say reveals communication and awareness gaps pure modelling would overlook. The final recommendations combined these strands: clearing vegetation at barranco bottlenecks, installing five small retention basins to slow runoff, and introducing grazing herbivores to manage vegetation regrowth.

The approach carries particular weight for nature-based solutions, defined by the European Commission as solutions inspired and supported by nature that are cost-effective while providing environmental, social and economic benefits. Their feasibility depends on community acceptance and perceived co-benefits, dimensions that are difficult to quantify but critical for uptake, and the lack of standardized indicators has limited both the evidence base and private investment. Mixed-methods can monetize non-market co-benefits through tools such as choice experiments and contingent valuation, feeding into cost-benefit analysis, while also exposing inequities, since nature-based solutions can raise property prices and displace lower-income residents. In one Dutch study cited by the authors, conversations with waterboard members revealed land-use conflicts that led researchers to add agricultural land conversion as a survey attribute, uncovering a significant decline in respondent utility as more farmland was converted, an insight that would otherwise have been missed. The framework also aligns with the IUCN Global Standard for Nature-based Solutions, addressing criteria on societal challenges, local context, economic viability, inclusive governance and trade-offs.

The authors are candid about the costs and pitfalls. Fieldwork is resource-intensive and time-bounded; access to key locations was sometimes blocked by private property, forcing contingency plans. Time constraints limited questionnaire numbers and raised sampling bias risks, since environmentally engaged residents were more willing to participate, and any mid-fieldwork survey revision cost a full day of data. Language barriers complicated interviews with stakeholders uncomfortable speaking English, and technical terms such as multi-hazards and nature-based solutions required clarification. Integrating diverse data types, from ecological measurements to soil stability and tourism impacts, into a coherent framework risks inconsistencies, and local results resist generalization. Their research agenda responds with concrete prescriptions: interdisciplinary teams familiar with the region, standardized mixed-methods protocols for local multi-hazard risk, pre-testing surveys before fieldwork begins, preliminary analysis during the trip to catch data problems while they can still be fixed, and genuine incorporation of local knowledge. Done well, they conclude, the iterative integration of methods bridges the gap between scientific modelling and community realities, producing adaptation strategies that are simultaneously evidence-based, socially equitable and, crucially, accepted by the people they are meant to protect.

Subject of Research: Mixed-methods approaches to local multi-hazard climate risk assessment and nature-based solutions in Tenerife

Article Title: Breaking the methodological silos: Integrating Mixed-Methods in Multi-Hazard Risk Assessment Lessons learnt from fieldwork in Tenerife

Article References: García Álvarez, G., & de Ruiter, M. C. (2026). Breaking the methodological silos: Integrating Mixed-Methods in Multi-Hazard Risk Assessment Lessons learnt from fieldwork in Tenerife. PLOS Climate, 5(10), e0001070. https://doi.org/10.1371/journal.pclm.0001070

Image Credits: AI Generated

DOI: 10.1371/journal.pclm.0001070

Keywords: multi-hazard risk, mixed methods, Tenerife, nature-based solutions, climate adaptation, risk perception, disaster risk reduction, fieldwork, stakeholder interviews, GIS mapping, PLOS Climate, Canary Islands

Mesophotic ecosystems occupy the dimly lit zone of the ocean, roughly between 30 and 150 meters in many subtropical regions, where light is too scarce for most photosynthetic reef builders but where life still flourishes in remarkable abundance. In many oceanic archipelagos, these communities are dominated by black corals of the order Antipatharia, a group of more than 300 species characterized by proteinaceous skeletons, an almost universal lack of symbiotic algae, slow growth and long lifespans. Whip black corals are a distinctive form within this group: they grow as a single unbranched stem that can extend several meters in length, spiraling and swaying in areas of strong current. Where they aggregate in high densities, they form what ecologists call Marine Animal Forests, three-dimensional structures built by suspension-feeding animals that alter water flow, trap sediments, generate shade and create an architectural complexity comparable to that of terrestrial forests.

These animal forests are far more than scenic curiosities. Scientists regard them as biodiversity hotspots, nursery grounds and refugia for a vast array of associated species, from crustaceans to fish, and as key regulators of biogeochemical cycling in the sediments beneath their canopies. Yet because mesophotic depths require expensive equipment to explore, black coral forests remain among the least studied and least protected ecosystems on the planet. The new research, conducted as part of the Ocean Citizen project, a marine restoration initiative funded through Horizon Europe, set out to map benthic habitats along a stretch of Tenerife’s rocky coastline between La Arena and the southern end of San Juan Beach, and in doing so captured an unexpected ecological relationship on camera.

Between June 16 and 25, 2024, the research team, which included scientists from the University of Salento in Italy and the non-profit organization Oceana, deployed a remotely operated vehicle to survey the seabed. The vehicle, a Sibiu Pro model from Nido Robotics rated to 300 meters, was equipped with 4K cameras, LED lights and eight thrusters. It crawled along the bottom at an average speed of just 0.2 to 0.3 knots, its camera field of view spanning roughly 185 centimeters. Of 61 planned dives, 55 were completed, covering a total surveyed area of 31,217 square meters at depths ranging from 7 to 157 meters. The resulting footage was cut into 1,502 one-minute sample units, yielding 26 hours of analyzable video from which the team identified 169 distinct taxa.

The statistical analysis revealed a striking pattern. The bearded fireworm co-occurred with whip coral forests in 40 percent of the transects, appearing in the algae at the base of the black corals or in their immediate vicinity. Peak abundances of both the fireworm and the two whip coral species studied, Stichopathes gracilis and Stichopathes setacea, fell between 80 and 120 meters depth. Pearson correlation analysis confirmed that the association was not coincidental: the relationship between fireworm occurrence and S. gracilis produced a correlation coefficient of 0.895 with a p-value of 0.0027, a strong and statistically significant positive association, while the relationship with S. setacea yielded a coefficient of 0.715 with a p-value of 0.0464, also significant. All three species showed unimodal distributions across depth, peaking in the 80 to 100 meter range, with polynomial trendlines suggesting a partial overlap of their ecological niches.

Understanding why a fireworm would seek out a black coral forest requires appreciating the peculiar biology of both partners. Hermodice carunculata is a large amphinomid polychaete armed with brittle, venom-filled bristles that deliver painful stings to anything that handles it. It is an omnivorous, opportunistic feeder and scavenger, consuming decaying organic matter, and preying on corals, sea urchins, sponges and ascidians. It can also act as a reservoir for coral pathogens. Crucially, it is thermophilic and highly tolerant of environmental variation, coping with swings in temperature, salinity and oxygen. As ocean waters warm, the species has been expanding northward through the Atlantic and the Mediterranean, attacking fish caught in nets, degrading catch quality and injuring fishers, swimmers and divers. In shallow water it favors structurally complex habitats, hiding in rock cavities and algal canopies to evade predators and reduce exposure to current and light.

The whip corals, meanwhile, are ecosystem engineers of a very particular kind. Antipatharians require strong currents to feed, extending their polyp-covered stems into the flow to capture passing particles. Those same currents that sustain the forest also create a hostile hydrodynamic environment for a soft-bodied worm. The study’s authors propose a dual function for the forest: the whip corals are a product of strong currents, yet their dense stems and algal understory simultaneously provide shelter from the current’s sheer force. At the base of the corals, accumulated algae offer both refuge and a foraging ground rich in decaying organic matter, precisely the kind of organically enriched, microbially active habitat to which fireworms are known to be attracted. In essence, the fireworm appears to exploit a contradiction engineered by the corals themselves, benefiting from the very conditions that made the forest possible while escaping the conditions that make it formidable.

Perhaps the most consequential observation is what the researchers did not see. In all the analyzed video, fireworms were detected only at the base of the coral colonies, never climbing the stems. No feeding or predation behavior against the whip corals was recorded, and the coral populations appeared healthy, with no signs of damage or necrosis, despite their high density throughout the study area. This stands in contrast to recent reports of fireworms actively feeding on branching black coral colonies, concentrating on the colony tips. The evidence from Tenerife instead suggests a commensal or opportunistic relationship, in which the fireworm uses the forest as shelter and a feeding ground on associated algae and detritus rather than as prey, although the authors caution that the possibility of occasional coral consumption cannot be ruled out without further observation.

The finding carries implications well beyond the natural history of a single worm. The detection of H. carunculata at mesophotic depths extends its known vertical distribution, echoing a similar recent discovery in the same study area in which the green alga Caulerpa prolifera was recorded down to 80 meters, far deeper than previously acknowledged. As climate change pushes thermophilic, adaptable species into new depths and latitudes, understanding which habitats will harbor them, and whether vulnerable ecosystem engineers such as black corals will face new pressures, becomes a matter of urgency. Black corals are already listed in Appendix II of CITES, which regulates their international trade, and are used as indicator species for ecosystem vulnerability by regional fishery management organizations.

The authors argue that expanding knowledge of these deep, dim ecosystems is essential for conservation and for effective monitoring guidelines. Marine Animal Forests are among the most extensively distributed ecosystems on Earth, spanning from shallow mussel beds to deep cold-water coral habitats in both tropical and polar seas, yet the mesophotic black coral forests remain largely unmapped and unprotected. Determining the foraging advantages, potential risks and patterns of association between vagile species like the fireworm and the ecosystem engineers that structure these communities is, the study concludes, a necessary step toward safeguarding them. For now, the image of a venomous worm coiled in the algal shadows at the foot of a swaying black coral whip serves as a reminder that the ocean’s twilight zone is neither empty nor simple, and that its most surprising residents are only now coming into view.

Subject of Research: Co-occurrence of the bearded fireworm Hermodice carunculata with whip black coral forests in mesophotic ecosystems off Tenerife, Spain

Article Title: Co-occurrence of Hermodice carunculata (Polychaeta, Annelida) and Stichopathes spp. (Hexacorallia, Cnidaria) off Punta Blanca (SW Tenerife, Spain)

Article References: Fraissinet, S., Aguilar, R., Blanco, J., Arduini, D., Anglano, M., & Rossi, S. (2026). Co-occurrence of Hermodice carunculata (Polychaeta, Annelida) and Stichopathes spp. (Hexacorallia, Cnidaria) off Punta Blanca (SW Tenerife, Spain). Discover Conservation, 3(1), Article 23. https://doi.org/10.1007/s44353-026-00092-0

Image Credits: AI Generated

DOI: 10.1007/s44353-026-00092-0

Keywords: Hermodice carunculata, bearded fireworm, Stichopathes, black corals, mesophotic ecosystems, Marine Animal Forests, Tenerife, Canary Islands, ROV survey, biodiversity hotspots, ecosystem engineers, climate change