Understanding dive behavior of artisanal fishermen divers of the Yucatán Peninsula

Abstract

Introduction/Background: Artisanal fishermen dive for sustenance. The lifetime prevalence of decompression sickness (DCS) in this population is alarmingly high. We wanted to understand the level of decompression stress fishermen in this region of the Yucatán experience in their daily fishing effort. We used a mathematical model to quantify nitrogen-loading in a nine-tissue compartment model. Materials and methods: Approved by the UCLA IRB 2#13-000532, this study was conducted during fishing seasons 2012 through 2017. Diving fishermen were instructed to attach dive recorders to their waists every fishing day during the study period. Sensus Ultra dive recorders (ReefNet Inc.), with an accuracy of ± 1 foot of ;seawater (fsw), 0.304 meters, and an activation depth of 10 fsw, 3.04 meters, were used to record dive parameters. Sampling interval was set to 10 seconds. A program in RStudio was created to extract the dive profiles of each fishing day and curtail into single-line outputs: pressure, time, date, start of dive and end of dive. An exponential decay formula was used to calculate the nitrogen-loading pressures for nine theoretical tissue compartments. Final nitrogen pressure, controlling compartments, decompression stop and time at stop were calculated. Results: Fishermen completed 4,961 dives over 1,758 diving days during the study period. The 40-minute compartment controlled most of the dives. The 80-minute compartment controlled 5%-20% of dives two through five. Decompression stop times for the last dive ranged from one minute to 190 minutes. Most of the required stop time observed was seen at depths of 1-15 fsw.

Sustainability of the hookah diving fishery in Turkey

“…Hookah systems consist of an average 5 -6 horsepower gasoline engine, a single-stage air compressor that can compress air, an air tank with sufficient volume and pressure for the diver to dive to depths of 20-30 meters, a hose group and a regulator (Aydın et al 2016). The whole system is mounted on wooden planks on the deck of the fishing boat (Figure 5a; Chin et al 2015). Equipment problems, exhaustion of air/breathing gas, poisoning, entanglement, and on-board fire are the leading known causes of death in hookah diving (Smart 2010; US Navy 2016; Acencio-Lane et al 2019;Buonfiglio and Lovatelli 2023).…”