Improving catch quality and lowering coral reef habitat damage: Anthony R. Marshak 1, Ronald L. Hill 2, and Richard S. Appeldoorn 3 Modifying the fishing strategy for Antillean traps in Puerto Rico 1 University of South Alabama/Dauphin Island Sea Lab 2 NOAA Fisheries Galveston Laboratory 3 University of Puerto Rico – Recinto de Mayagüez

Five Year Broad Study Objectives Monitor shelf-wide distribution of Antillean fish traps ( ) Informs about degree of fishing effort for the region and per habitat Examine benthic impacts of trap fishing in coralline habitats Quantify and monitor damage and recovery of sessile invertebrates For this component, the major objective was to examine catch trends as related to fished habitat and habitat damage potential

Antillean fish traps Commonly used in Caribbean artisanal fisheries Wood or steel-rebar frame with galvanized wire mesh Highly effective at capturing reef fishes and spiny lobster Non-selective passive gear that may be deployed in massive quantities

Heavy use of traps, and their non- selectivity, have contributed to overfished Caribbean waters

 Recent focus upon habitat degradation Damage to sessile benthic fauna/flora during placement, fishing, and hauling

Geography of the Caribbean

Current study Monitored shelf-wide distribution of traps off La Parguera, PR – Evaluate benthic impacts of trap fishing within coralline habitats – Focus upon relation of trap non-selectivity and fished habitat Map of the Puerto Rico Archipelago and insular platform, with La Parguera study area highlighted

Compare observed trap contents in areas of high/med/low relief and corresponding habitat damage potential Provide commentary upon how to improve current trap fishing strategy Current study Colonized Hardbottom (Intermediate Damage Probability) Hard Coral Reef (High Damage Probability) Vegetated/Sand/Mud (Low Damage Probability)

Methods Monitored seasonal trap distribution 3-4 times per yr ( )

Divers recorded: – Habitat outside a 5 m radius of the trap – Trap construction and configuration – # individuals per fish/mobile invertebrate sp. within each trap Total Length (mm) Actual trap soak time and final catch were unknown Methods

From : – 1438 traps surveyed in La Parguera – 161 diver-assessed traps – 39% observed traps were empty at the time of inspection Results

Results: Inspected Trap Habitat

Results: Inspected Trap Depth

Results: Catch per Unit Effort

Results: Catch Composition (Fishes)

Results: Catch Composition (Species)

Majority of surveyed/inspected traps in colonized hardbottom (12-18 m) – Large number of traps also in deeper offshore algal sand – Previous studies have highlighted the significance of these regions – Further movement offshore due to inshore depletion/degradation Majority of inspected trap contents were reef fishes – Predominantly herbivorous fishes – Low numbers of snappers/groupers P. argus remains the most frequently captured/targeted trap sp. – Although decreased trap landings over time – Increased SCUBA and gill net fishing for lobster Summary

Trap Associated Habitat Damage Potential for habitat damage in colonized hardbottom is high – Little topographic relief to protect sessile inverts from traps – Variation in water clarity and unknown habitat delineations

Higher probability for catches in colonized hardbottom, but greater associated bycatch, and intermediate habitat damage Algal Sand/Mud Contents Summary: – Grunts, trunkfishes, and snappers proportionally higher – P. argus most frequently encountered species – Lower bycatch in lowest relief habitats Moving traps into lowest relief habitats could benefit fishermen and ecosystem – Higher CPUE of commercially important species in lower relief habitats – Maintain reef structure and decrease bycatch Changing Fishing Strategy

Recently observed decreased densities of Antillean traps in Puerto Rico – Traps being phased out due to recovery cost > catch value Increased observations of buoyed gill nets in trap habitats – Causes increased by-catch and fishing pressure – May lead to further depletion of fish communities Propose more favorable ecological/economical strategy: – Move traps away from reefs – Lower fishing intensity in colonized hardbottom – Prevent shifts to less selective fishing gears – Can lead to increases in first-class species captures and minimized degradation Shifts in Puerto Rico Fishing Strategy

Observed coincident presence of spiny lobster, and greater proportion of commercially important reef fishes in low-relief habitats. Increased numbers of low value herbivorous fishes in higher relief habitats. Suggests that there may be economic incentive to persuade fishers to decrease fishing intensity in areas more prone to habitat damage. May work to prevent shifts to increased use of even less selective gear, and maintain habitat integrity. Conclusions

Acknowledgements NOAA Coral Reef Conservation – Funded project: “Distribution of trap fishing and effects on habitats in coral reef ecosystems” Department of Marine Sciences, University of Puerto Rico – Mr. Marcos Rosado – Michelle Scharer – Michael Nemeth – Martha Prada – Sylvia Rodriguez – Idelfonzo Ruiz – Wessley Merten *The views contained in this presentation do not necessarily reflect the views of NOAA – Alfonso Aguilar-Perera – Ivonne Bejarano – Bjorn Bouwmeester – Kassandra Cerveny – Cecile Jadot