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Tlusty, M. F.

Publications and source records attributed to Tlusty, M. F..

2 recordsLinked to original sources

Evaluating Species at Risk in Data-Limited Fisheries: A Comprehensive Productivity-Susceptibility Analysis of the Most Traded Marine Aquarium Fish

The marine aquarium trade is a significant global industry harvesting millions of live coral reef fishes annually. Wild-caught fish dominate public and private aquaria markets in the USA and Europe, supporting fisher livelihoods in the Indo-Pacific. This diverse and species-rich trade is considered data-limited, creating barriers to quantify the sustainability of this fishery to the net benefit of the coral reef socio-ecological system. We present a revised and expanded productivity-susceptibility analysis (PSA) framework to assess the vulnerability to overharvesting of the top 258 traded species, an estimated 92.5% of all import volume into the USA in 2011. Vulnerability was calculated based on various productivity and susceptibility factors, tailored to the unique life-history and fishery selectivity characteristics of the marine aquarium trade. We present novel factors that improve model accuracy, methods to overcome missing data for individual factors, and apply an improved Gaussian mixture model clustering algorithm to objectively classify species as least, moderately, or most vulnerable. Our results show that an overwhelming 85% of species evaluated fall into the least or moderately vulnerable classification, with the remaining species designated as high priority for localized assessment and management initiatives. A comparative case study between our PSA and the popular FishBase Vulnerability assessment illustrates how it is ill-suited to handle data limitations of non-food fishes. The results of our PSA, at a species and family level, provide useful information to stakeholders and serves as a robust and accessible risk assessment tool to prioritize species for management based on their vulnerability scores.

ecology↗

Where does it go? The fate of thiocyanate in the aquarium water and blood plasma of Amphiprion clarkii after exposure to cyanide.

The illegal practice of cyanide fishing continues to damage coral reef ecosystems throughout the Indo-Pacific. To combat this destructive fishing method, a simple, reliable test to detect whether or not a fish has been captured using cyanide (CN) is needed. This study analyzed the toxicokinetics of acute, pulsed CN exposure as well as chronic exposure to thiocyanate (SCN), the major metabolite of CN, in the clownfish species, Amphiprion clarkii. Fish were pulse exposed to 50 ppm CN for 20 or 45 seconds or chronically exposed to 100 ppm SCN for 12 days. Blood plasma levels of SCN were measured following derivatization to SCN-bimane using an Acquity UPLC I-Class and Q-Exactive hybrid Quadrupole-Orbitrap HRAM mass spectrometer or directly by HPLC-UV. After exposure to CN, depending on the duration of exposure, SCN plasma levels reached a maximum concentration (300-470 ppb) 0.13-0.17 days after exposure, had a 0.1 to 1.2 day half-life, and often did not return to baseline levels. The half-life of plasma SCN after direct exposure to SCN was found to be 0.13 days, similar to the CN exposure, and that SCN in the holding water would often drop below detection. Finally, we observed that when a fish, never exposed to SCN, was placed in aquarium water spiked with SCN, there was a steady decrease in aqueous SCN concentration over 24 hours until it could no longer be detected. This pattern was repeated with a second sequential dose. These results demonstrate that A. clarkii do not excrete SCN after CN exposure, but in fact can absorb low concentrations of SCN from water, refuting several publications. It appears that A. clarkii exhibit a classic two compartment model where SCN is rapidly eliminated from the blood plasma and is distributed throughout the tissue but not excreted in their urine. This study demonstrates that SCN may be used as a marker of CN exposure only if fish are tested shortly after exposure. There is species specific variability in response to CN, and studies of other taxa need to be performed before this test can be deployed in the field.

pharmacology and toxicology↗