DESCRIPTION OF REEF FISH SPAWNING AGGREGATIONS AT MONA ISLAND PUERTO RICO Michelle Schärer, Michael Nemeth, Alfonso Aguilar, Richard Appeldoorn Department of Marine Sciences, University of Puerto Rico, Lajas PR 00667-908
SCIENTIFIC RECOMMENDATIONS (based on ecological & socio-economic data) MANAGEMENT STRATEGY (driven by goals & objectives) MPA APPLIED RESEARCH (baseline & monitoring) MANAGEMENT QUESTIONS
Principles of Conservation POPULATIONS Genetic diversity Reproductive potential CRITICAL HABITATS Juvenile nursery area Nesting or aggregation sites Foraging areas CONNECTIVITY Between critical habitats Between distant
Fish spawning aggregations (FSA) are defined as any temporary aggregations formed by fishes that have migrated for the specific purpose of spawning According to Domeier and Colin (1997) there are 2 types of FSAs Based on: Frequency of FSA Longevity of FSA Distance traveled to FSA (Claydon, 2004) Transient aggregations often involve long-distance migrations and a short reproductive season. Resident aggregations may form frequently, often over an extended period and occur close to, or even within, the areas of participating fish.
Aims of this study Gather local knowledge on the occurrence of FSA at Mona Island Document the existence of FSA Identify the location(s) of FSA Provide a basis for the monitoring of FSA
Study Site
Fisher Interviews Fishing Experience FSA Location FSA Timing Season (months) Moon phase Time of day Species Status (present, absent) Landings Fishing Gears METHODOLOGY Preliminary Data Collection based on Colin et al. 2003 and Heyman et al. 200
RESULTS Interviews 10 Fishers with +30 yrs experience FSAs form in winter (Dec. to March), before & after full moon days Locations: 5m patch reef to 30m shelf edge Species forming FSA: Groupers (Epinephelus striatus, E. guttatus, Mycteroperca venenosa, M. tigris) Snappers (Lutjanus jocu) Confirmation: 3 fishers witnessed aggregations of grouper and 1 witnessed snappers Status: Disappeared Landings: 500-1,500 lbs. per 5-7 day trip (~167 lbs/day) Fishing Gears: Spearfishing (no SCUBA, later hookah), traps, hook & line Due to diminishing catches, fishers modified to deep water snappers
RESULTS Interviews We asked each fisher to place a round sticker on each site where he had observed or fished an aggregation at Mona Island Site information was mapped in GIS to determine where field surveys should be focused
Field Methods Field surveys during winter full moon periods Visual Surveys Time at start, end & each grouper sighting Species and abundance Estimated size (Fork Length cm) Depth at each sighting Habitat (Substratum & dominant sessile org.) GPS Tracking each dive Convert tracks to GIS features Incorporate sighting data into points Create a map with the distribution of sightings by species
RESULTS Fieldwork 42 Transects (Dives) Mean transect length 757m (range 214-1723m) Depths 10-30 m Area Covered ~0.33km 2 111 Grouper observations 1 Spawning Event Observed
Distribution of grouper observations
Mycteroperca venenosa Yellowfin grouper Lutjanus jocu Dog snapper Epinephelus striatus Nassau grouper Mycteroperca interstitialis Yellowmouth grouper
Epinephelus adscensionis Rock Hind Mycteroperca tigris Tiger grouper Epinephelus guttatus Red Hind
Grouper Species Proportions M. venenosa 16% E. adsenscionis 15% M. tigris 7% M. interstitialis 10% E. striatus 6% E. guttatus 46%
Multi Species Aggregation Site GROUPERS Epinephelus guttatus (red hind) Mycteroperca venenosa (yellowfin grouper) Mycteroperca tigris (tiger grouper)
Multi species aggregation site 2 Randall Sparisoma rubripinne (yellowtail parrotfish) Randall Acanthurus coerulus (blue tang)
ACKNOWLEDGEMENTS: NOAA-Coral Reef Ecosystem Studies Department of Natural and Environmental Resources of Puerto Rico Department of Marine Sciences, UPR-M Crews of PEZMAR, RORQUAL & ORCA TOO F I N Volunteer Divers: Francisco Pagan Bjorn Bowmeister Anthony Marshak Ron Hill (Video Cam) Kimberly Ferran Ivonne Bejarano Katie Flynn Kassandra Cerveny