Puerto Rico Sea Grant Progress Report Submitted: November 20, 2019 -Title: Ciguatoxin detection and model predictions for use in fisheries management in Puerto Rico -Name and affiliation of researchers: Joseph J. Luczkovich AFFILIATION: Department of Biology, East Carolina University, Greenville, NC, 27858 luczkovichj@ecu.edu 252-328-9402 Cynthia Grace-McCaskey AFFILIATION: Department of Anthropology, East Carolina University, Greenville, NC, 27858 gracemccaskeyc15@ecu.edu David Griffith AFFILIATION: Department of Anthropology, East Carolina University, Greenville, NC, 27858 griffithd@ecu.edu Miguel Del Pozo AFFILIATION: University of Puerto Rico - Ponce, Miguel.delpozo@gmail.com
Results and findings Interviews with fishers Using open format interviews with fishers, ciguatoxin (CTX) “hotspots” were identified via TEK (Traditional Ecological Knowledge) on Puerto Rico (south coast of Puerto Rico from Ponce east to Maunabo, south coast of Vieques, east coast of Vieques, south coast of St. Thomas). We are in the process of confirming these “hotspots” in two ways: 1) with CTX toxicity measurements (these samples are being processed now with the mouse neuroblastoma N2A bioassay) of fish tissues that we collected in March - June 2019 and October 2019; and, 2) with Gambierdiscus sp. collections taken with screen rig collectors at the “hotspots” and “cold spots” (October 2019). We interviewed fishers at fish houses and marinas in Fajardo, Naguabo, Maunabo, Guayama, and Ponce on Puerto Rico and Charlotte Amalie on St. Thomas USVI. A summary of these interviews indicated that most CTX “hotspots” and ciguatera fish poisoning cases were on the southern side of the islands of Puerto Rico, Vieques, and St. Thomas, USVI. The fish species with ciguatera named by fishers are in the families Carangidae (jacks), Sphyraenidae (barracuda), Lutjanidae (snappers), Labridae (wrasses, including hogfish), Serranidae, and Epinephelidae (groupers).
CTX testing in fish tissues We have now collected fish tissues from these species and others at several trophic levels, both from samples obtained at the fish houses and from fishes speared or caught hook and line at “hotspot” and “coldspot” areas identified in the TEK interviews. We have fish tissue samples from 110 individual fish, with various tissue samples were taken from each fish including epaxial muscle, liver, gonads, and stomach contents taken. These fishes are all from Puerto Rico in TEK-reported “hotspots” and other “cold spots” (places where fishers have harvested and sold fish in the past without any ciguatoxin or fish poisoning reports). Hogfish and great barracuda tissues were obtained at both “hotspot” and “coldspot” ciguatoxin areas. Preliminary data from N2A mouse neuroblastoma assays conducted at the ECU Brody Medical School to date indicate that hogfish and barracuda were toxic at the hotspot areas only (fish obtained directly from fishers in Guayama, PR on the south coast); most neuroblastoma cells exposed to these fish tissue extracts were killed. Hogfish were obtained from fish houses in