Coastal Islands of Santa Catarina in the Context of the Climate Crisis
Master's Project - PPGOceano/UFSC | 2026
Student: Ronan Armando Caetano
To investigate how environmental and geomorphological variables influence the diversity and distribution of marine macrophytes across three coastal islands of Santa Catarina, focusing on spatial mapping and habitat suitability modeling.
There is still a lack of detailed and comparable maps showing where marine macrophytes occur on the coastal islands of Santa Catarina and how they respond to environmental changes. Without this foundation, it becomes harder to prioritize monitoring and plan conservation actions.
The team records species, abundance, and environmental conditions on the three islands using a standardized methodology to enable fair comparison.
Field data are integrated into maps and models to indicate the most favorable areas for macrophytes and priority areas for monitoring.
The project generates scientific and technical products that can be used by research, environmental management, and coastal monitoring planning.
Three coastal islands of Santa Catarina with a gradient of size, isolation, and anthropogenic pressure.
Centroid: 27Β°13'33"S, 48Β°21'56"W
Area: 17,131.72 ha
Status: Federal Conservation Unit
Distance from shore: ~15 km
Study depth range: 0β15 m
Centroid: 27Β°41'48"S, 48Β°27'55"W
Area: 76.19 ha
Status: Archaeological/Scenic Heritage
Distance from shore: ~1.5 km
Study depth range: 0β15 m
Centroid: 27Β°36'36"S, 48Β°23'11"W
Area: 16.98 ha
Status: No specific protection
Distance from shore: ~8 km
Study depth range: 0β15 m
| Criterion | Arvoredo | Campeche | Xavier |
|---|---|---|---|
| Area (ha) | 17,131.72 | 76.19 | 16.98 |
| Relative size | ~1,000x larger than Xavier | Intermediate | Smallest in the gradient |
| Distance from shore | ~15 km | ~1.5 km | ~8 km |
| Protection status | Federal Conservation Unit (REBIO) | Archaeological/Scenic Heritage | No specific protection |
| Anthropogenic pressure | Low (regulated) | High | Moderate |
| Tourist pressure | Controlled | Intense in summer | Lower than Campeche |
| Logistical accessibility | More complex (vessel and weather window) | Simpler and faster | Intermediate |
| Degree of isolation | High | Low | Intermediate |
| Habitat complexity | High (multiple microenvironments) | Medium (contrasting sectors) | Medium/high at small scale |
| Dominant substrate | Rocky shores with high-energy zones | Rocky and sandy mosaic | Rocky shores and islets |
| Relevance for modeling | Reference for more preserved conditions | Reference for high anthropogenic influence | Reference for a small, understudied area |
| Role in study gradient | Extreme of largest area/isolation | Extreme of greatest human use/proximity | Intermediate connectivity point |
The selection of Arvoredo, Campeche, and Xavier was made to represent a realistic and comparable ecological gradient at a regional scale, enabling robust tests on macrophyte distribution and habitat suitability.
The maps below show the spatial basis used to compare Arvoredo, Campeche, and Xavier. These are the cartographic products providing the territorial context of the study.
How to use the interactive map: click the button below to open a dynamic view of the three study areas. On the map, you can switch basemaps, check the legend and cartographic metadata, use both the graphic and numeric scales, and zoom in/out to explore spatial details of each island.
Open interactive map of study areas
Reference map of the three island study areas.
Spatial comparison of REBIO Arvoredo, Campeche, and Xavier.
To assess the diversity and spatial distribution of marine macrophyte communities in Ilha do Campeche, Ilha Xavier, and REBIO Marinha do Arvoredo, correlating biological patterns with environmental and geomorphological variables to generate habitat suitability models.
Conduct an inventory of macrophytes in the 0β15 m depth range.
Map spatial distribution and relative abundance using geoprocessing.
Generate orthophotos and surface models to refine habitat mapping.
Characterize rocky substrate and local variables such as water transparency.
Build a habitat suitability index (HSI) and SDMs to estimate occurrence patterns (i.e., where species tend to be found).
Consolidate a reference collection (herbarium) for long-term monitoring.
The study logic is straightforward: measure macrophytes in the field, record environmental conditions, and then transform that into maps and models to understand where each species is most likely to occur.
Connected visual summary: from field collection through to final conservation products.
Points, transects, and logistics.
Freediving/SCUBA, presence, abundance (DAFOR), and rocky shore collection.
Depth, transparency, and substrate.
Orthophoto and DSM with RGB/multispectral.
Spatial data integration.
Suitability and distribution modeling.
Field checks and performance metrics.
Maps and synthesis for monitoring.
Study type: comparison between three islands (Arvoredo, Campeche, and Xavier).
Depth range: 0 to 15 m.
Strategy: apply the same method across all three areas to allow fair comparisons.
| Step | What Will Be Done | Expected Outcome |
|---|---|---|
| Step 1 | Define sampling points, transects, and operational windows (tide/weather) for each island | Standardized fieldwork plan |
| Step 2 | Conduct underwater sampling by freediving (shallow sectors) and SCUBA diving (deeper sectors), with safety protocols and buddy system | Standardized coverage of the 0β15 m range under different depth conditions |
| Step 3 | Record macrophyte presence and abundance (DAFOR), with georeferenced photos per point/transect | Species list and occurrence intensity per point and per island |
| Step 4 | Collect material on rocky shores (samples/vouchers) with labeling, storage, and traceability | Reference material for taxonomic confirmation and herbarium |
| Step 5 | Collect environmental variables at the same point (e.g., transparency, depth, substrate type, geomorphology) | Environmental data linked to biological records |
| Step 6 | Georeference all data in GIS and integrate field data, drone data, and environmental layers | Organized, auditable, and campaign-comparable spatial database |
| Step 7 | Calculate HSI, run SDMs, and validate results with independent field data | Suitability and potential distribution maps with quality-controlled outputs |
| Step 8 | Check final consistency, generate thematic maps, and consolidate products for dissertation and management | Technical and scientific products ready for use and communication |
Drone photogrammetry transforms multiple aerial photos into detailed, measurable maps of the coastal area.
In summary: the drone improves the cartographic foundation of the study and increases confidence in habitat models.
To strengthen the methodology, a comparative test will be conducted between an RGB camera and a multispectral camera in the same area and under similar tidal and lighting conditions.
| Test Stage | How It Will Be Executed | Product/Indicator |
|---|---|---|
| 1. Flight planning | Same area, equal altitude and overlap for both sensors | Fair comparison between RGB and multispectral |
| 2. Data acquisition | Short flight window to reduce variation in light, wind, and sea conditions | Paired image dataset |
| 3. Photogrammetric processing | Orthomosaic and DSM generation for both sensors | Comparable orthophotos and surface models |
| 4. Spectral products | In multispectral, calculate indices (e.g., NDVI/GNDVI/NDRE or coastal equivalent) | Layers to discriminate cover type and vegetation vigor |
| 5. Resolution metrics | Compare GSD, visual sharpness, and geometric error (RMSE of checkpoints) | Objective spatial performance by sensor |
| 6. Ecological validation | Check maps against field points (presence/absence and DAFOR) | Thematic accuracy for habitat/macrophytes |
| 7. Final synthesis | Compare sensor advantages and recommend standalone or combined use | Optimized protocol for future campaigns |
| Indicator | Ideal Target | Acceptable Range | How to Verify | Corrective Action |
|---|---|---|---|---|
| GSD (ground resolution) | 2β5 cm/pixel | up to 7 cm/pixel | Photogrammetric processing report | Adjust flight altitude and/or focal length |
| Front overlap | 80% | 75β85% | Flight plan + drone log | Recalculate flight lines and speed |
| Side overlap | 70% | 65β75% | Flight plan + orthomosaic inspection | Reduce spacing between flight strips |
| Flight altitude | 60β100 m (sensor dependent) | up to 120 m (current regulation) | Drone telemetry and field notebook | Standardize altitude per campaign and sensor |
| Flight speed | 3β6 m/s | up to 8 m/s | Mission log | Reduce speed in rough sea/wind conditions |
| Acquisition time | 10amβ2pm, low cloud cover | 9amβ3pm | Field record and EXIF metadata | Reschedule flight to reduce shadow and glare |
| Sea/wind conditions | Calm sea and low wind | wind up to ~20 km/h | Weather bulletin + local observation | Suspend flight in critical conditions |
| Geometric RMSE | < 10 cm | 10β15 cm | Independent checkpoints/GCPs | Redo block adjustment and review GCPs |
| GCP/Checkpoint density | Distributed across entire mosaic | minimum 5 well-distributed points | Control point map | Add points at edges and center |
| Radiometric quality (multispectral) | Calibration panel before/after flight | At least 1 calibration per mission | Metadata and panel images | Recalibrate and repeat acquisition if needed |
| Thematic validation | Overall accuracy > 85% and Kappa > 0.75 | Accuracy > 80% and Kappa > 0.65 | Confusion matrix with field points | Revise classes, training, and sampling |
| Cross-campaign reproducibility | Same protocol and key settings | Documented and justified differences | Standardization checklist per campaign | Update protocol and record deviations |
| Source/Tool | When to Consult | Purpose | Practical Criterion (go/no-go) |
|---|---|---|---|
| INMET (forecast and alerts) | 24β48 h before and on the morning of the flight | Check wind trend, rain, and official alerts | No-go: active alert for strong wind, heavy rain, or storm |
| CPTEC/INPE (models) | 24 h before + day-of review | Compare wind/cloud scenarios to reduce uncertainty in the mission window | No-go: high model divergence and instability risk during planned time |
| Navy (DHN/CHM: tide and sea state) | 24 h before and immediately before departure | Assess navigation safety, swell, and coastal conditions | No-go: rough sea/swell for safe vessel access and drone launch |
| METAR/TAF (REDEMET/nearest airport) | 2β6 h before the mission | Confirm real-time observed conditions and very short-term trend | No-go: low visibility, strong gusts, or approaching rain cells |
| Windy/Meteoblue (visual support) | Initial planning and final adjustment | Visualize wind by altitude and clouds; logistical decision support | Use only as support; final decision must follow official sources + local observation |
| Local field observation | Immediately before launch | Validate actual wind, water glare, low cloud, and operational safety | No-go: gusts above drone limit, rain, poor visibility, or excessive glare |
| Drone type/scenario | Recommended flight planning software | Project strength | Operational note |
|---|---|---|---|
| DJI Enterprise (Mavic 3E, Matrice) | DJI Pilot 2 | Stable and fast automated mapping mission in the field | Standardize altitude, overlap, and speed between campaigns |
| DJI with iPad workflow | DJI GS Pro | Simple interface for photogrammetric grid | Check model compatibility before the campaign |
| Campaigns focused on academic photogrammetry | Pix4Dcapture Pro | Good mission standardization and processing integration | Keep fixed parameters for temporal comparison |
| Multi-area operation with cloud management | DroneDeploy | Agile field workflow and mission centralization | Review costs/licensing for continuous use |
| Complex missions and high customization | UgCS | Advanced planning for coastal scenarios | Steeper learning curve, but greater operational control |
| ArduPilot/PX4 platforms | QGroundControl or Mission Planner | High flexibility for technical parameterization | Check telemetry, failsafe, and logs before each mission |
Operational recommendation for this project: flight decision based on official sources (INMET + Navy + METAR), validated by local observation at the launch point, and use of a standardized flight plan per sensor to ensure comparability between campaigns.
Integrated, replicable, decision-oriented methodology connecting field observation, geotechnologies, and ecological modeling to support the monitoring and management of marine macrophyte habitats.
The products of this research were designed to transform field data into evidence useful for science and coastal management. Each deliverable answers a stage of the project's central question: where are the macrophytes, what conditions favor their occurrence, and how to prioritize monitoring.
In addition to scientific output, results will be delivered in an applicable format with clear documentation and standardized organization. This facilitates reuse by research teams, environmental agencies, and island habitat monitoring initiatives.
Key terms used in this presentation, explained in plain language. The goal is to make reading accessible to non-specialists without sacrificing technical accuracy.
Large plants and algae that live in the sea and help maintain ecological balance.
A place with the necessary conditions for a species to live (light, substrate, temperature, etc.).
The level of "favorability" of a location for the occurrence of a species.
A coastal area of exposed rocks with many crevices and microenvironments.
The surface on which organisms settle, such as rock, sand, or sediment.
The physical shape of the environment (walls, slabs, boulders, crevices), important for biodiversity.
Impact caused by human activities (tourism, pollution, construction, boat traffic).
Degree of connection between areas; influences species dispersal and recolonization.
Diving without a tank, used in shallow areas with fast operations.
Self-Contained Underwater Breathing Apparatus, used in deeper areas.
A sampling line placed in the field to standardize observations between areas.
A defined location for collecting biological and environmental data.
Abundance scale: Dominant, Abundant, Frequent, Occasional, and Rare.
A physical sample collected for identification confirmation and storage in a scientific collection.
An organized collection of plant specimens used as a scientific reference.
The ability to link each data point to its location, date, method, and collector.
A verification list to ensure safety, standardization, and completeness of the survey.
Associating data with exact geographic coordinates.
A technique that transforms multiple photos into maps and models with real-world measurements.
A corrected aerial image β like a "photo-map" without significant distortion.
A 3D model of the surface, including terrain and above-ground elements.
Pixel size on the ground. A smaller pixel means greater detail.
Percentage of repetition between photos to ensure stable 3D reconstruction.
Standard camera (red, green, blue) with excellent visual resolution.
A camera that records bands beyond the visible spectrum, useful for separating cover types.
Vegetation indices calculated from light reflectance data.
Photo metadata (date, time, coordinates, and camera settings).
Flight data recorded by the drone (altitude, speed, position, battery).
Ground control points used to adjust and validate mapping accuracy.
Root Mean Square Error β a positioning error indicator; the lower, the better.
A tool for combining maps, tables, and analyses in a single environment.
An index that summarizes whether a location is more or less favorable for a species.
A model that predicts where a species may occur based on environmental conditions.
A documentation standard that helps explain and reproduce ecological models.
Total percentage of correct classifications in a map or model.
An agreement metric that discounts chance-level matches.
A table comparing predicted class with the class observed in the field.
A testing stage to verify whether the result is reliable.
The ability to repeat the method and obtain comparable results.
A projection of future conditions used to assess possible shifts in species distribution.
A period with adequate conditions to safely conduct fieldwork and drone flights.
Decision to proceed or cancel a mission based on prior safety and quality criteria.
Official weather forecast used to plan and adjust field activities.
Airport weather messages useful for observed conditions and very short-term forecasts.
Wave and water agitation conditions, essential for safety in coastal areas.
The drone's safety mode triggered in case of signal loss or critical problems.
Using the same parameters across surveys to allow fair comparisons over time.
An alternative plan for unexpected events (strong winds, rain, rough seas, technical failure).
Planned start: March 2026
Main duration: 22 months + post-defense stage
The timeline was structured to maintain a continuous flow between planning, fieldwork, analysis, and writing, reducing workload toward the end of the program and ensuring time for result validation.
| Phase | Period | Central Objective |
|---|---|---|
| Phase 1 | M1βM5 | Theoretical foundation, sampling design, and operational preparation |
| Phase 2 | M6βM10 | First fieldwork campaign and initial data consolidation |
| Phase 3 | M11βM15 | Second campaign, final integration, and ecological modeling |
| Phase 4 | M16βM22 | Scientific synthesis, qualification, defense, and publication |
| Period | Main Activities | Planned Deliverables |
|---|---|---|
| M1βM2 | Literature immersion, methodological alignment, and final sampling design definition. | Consolidated methodological protocol and work plan validated with supervisor. |
| M3βM5 | Permits, field logistics, form standardization, and collection training. | Complete operational checklist and finalized field schedule. |
| M6βM8 | 1st campaign: inventory, DAFOR, environmental variables, and georeferenced records. | Primary field data (biological + environmental + spatial) organized. |
| M9βM10 | Data cleaning, GIS organization, and preliminary descriptive analysis. | Initial occurrence maps and partial technical report for campaign 1. |
| M11βM13 | 2nd campaign for sampling reinforcement, pattern validation, and gap filling. | Integrated data from both campaigns and final geospatial working database. |
| M14βM15 | HSI calculation, SDM execution, and model performance assessment. | Suitability and potential distribution maps with statistical validation. |
| M16βM18 | Ecological interpretation of results and writing of qualification Stage 1. | Partial chapters and intermediate qualification presentation (M18). |
| M19βM21 | Final dissertation writing, technical review, and figure/table adjustments. | Complete dissertation version ready for the examination board. |
| M22 | Public defense and incorporation of examination board recommendations. | Defended dissertation and final version for institutional deposit. |
| Post-defense (Jan/2028) | Conversion of results into a scientific manuscript for a journal. | Article submitted. |
The project is feasible given the alignment between the topic and the supervisor's research line, the availability of laboratory infrastructure at UFSC, and a fieldwork plan compatible with the master's program timeline.