Queen Conch (Aliger gigas) · Nassau Grouper (Epinephelus striatus) Project Objectives, Overview & Preliminary Data
Presented by Dr. Héctor Ruiz, Principal Investigator
Multi-year habitat vulnerability assessment of two highly valued, federally protected species — integrating scientific surveys, long-term temperature monitoring, and Traditional Knowledge from local fishers — to inform management measures and recovery plans across the U.S. Caribbean.
Describe the state of submerged aquatic vegetation (SAV) juvenile habitat and areas of reproductive activity; assess vulnerability via traditional ecological knowledge TEK.
3
Temperature & reproductive cycle
Characterize the relationship between seawater temperature at the seafloor and reproductive phenology of both species.
2
Juvenile abundance
Document juvenile A. gigas and E. striatus abundance, benthic composition, and environmental conditions as well as sargassum inundation events (SIE).
4 Communication
Integrate the perspectives of local project partners (fishers) and asses the knowledge of local coastal communities regarding the impacts to these habitats.
1 · Literature & TEK
Review of peer-reviewed and grey literature; consultations with fishers; structured workshops to elicit traditional ecological knowledge on phenology, tolerance, and habitat use.
2 · Habitat Surveys
Photoquadrats, in-situ water quality measurements, long-term temperature loggers, and standardized juvenile/adult abundance surveys.
3 · Analysis & Synthesis
Trends in data collected crossreferenced with TEK; outputs feed CFMC ecosystem vulnerability assessment.
· Evidence base for climate-ready fisheries management of two ESA-Threatened species
Mariana C. León-Pérez, Ph.D. · Mar Caribe Consulting LLC
Sentinel-2 MSI
Level-1C top-of-atmosphere reflectance, 13 spectral bands, 5day revisit
34 months analyzed
May–April years for 2018, 2022, 2023 — covering peak and recent sargassum seasons
6 regions of interest
7 detection indices
True color, Highlight Natural
Color, 3 false-color composites, NDCI, NDWI
Expert digitization
Manual digitization at 1:7,000 in ArcGIS Pro; ≥4 of 7 indices required to confirm Sbt
S. Cabo Rojo · W. La Parguera · E.
La Parguera · Guánica · Bosque
Seco · Guayanilla
3 frequency classes
Natural breaks: low (1–8 obs), medium (9–14 obs), high (15–25 obs)
Findings · Sbt is Persistent Across SW Puerto Rico
79% of months analyzed had Sbt (27 of 34 cloud-free months)
75% of the three-year study period showed active Sbt
What this means
Sbt is not an episodic phenomenon — it is a nearconstant condition along the southwest coast. Data unavailable for only 2 months (Sept 2018 and Sept 2022) due to cloud cover. Of the remaining 34 months, Sbt was confirmed in 27.
Implication: A. gigas and E. striatus juvenile habitats in the corridor are exposed to chronic, not acute, Sbt stress.
Conch with a flared lip by size class.
Surveys from May 20 to November 12, 2025
Fishers don't just report 'less fish'.
They describe structural habitat transitions, altered sediment regimes, recruitment pulse variability, microclimate gradients, and reduced nursery capacity.
Lived language → ecological concept
“The grass is gone.”
Potential loss of critical habitat 'nursery' function
“The sediment doesn't settle.”
Water quality declines & sediment covers food
“It's hotter inside the bay.”
Potential thermal intolerance of juveniles
“You can't even work there.”
Reduction in fishing areas
Field operations since 20 May 2025.
44
Data collection trips Surface YSI environmental data
354 Juveniles quantified Queen conch & Nassau grouper
610 Repeated measurements 2 depths · 14 sites · weekly
71 Abundance surveys completed Cabo Rojo → Guánica
18 Radial surveys
Targeting adult queen conch
6 Participant meetings Protocols, logistics, results
Work conducted in partnership with local fishers trained in standardized data collection methods
Caribbean Fishery Management Council
NOAA Fisheries · IRA Priorities 1 & 3
Species Conservation Branch (Southeast Region)
Protected Resources Division (Southeast Region)
USVI and Puerto Rico fishing communities
Questions and feedback welcome.
CONTACT INFORMATION
Dr. Héctor Ruiz
Principal Investigator · CFMC IRA Project
reefscaping@gmail.com
Michelle Sharer PhD, Richard Appeldoorn PhD, Emmanuel Maldonado, Andrés Maldonado, Roberto Gutierrez