To investigate the tolerance limit and critical thermal maximum (CTM), behavioral responses of wild goldeye rockfish Sebastes thompsoni according to exposure to high water temperature were observed using a continuous behavior tracking system. As a result, behavioral index (BI) of S. thompsoni in each temperature (20.0, 25.0, and 30.0°C) showed a significant difference (p<0.05) when compared with the value measured in a stable condition of 15.0°C. The activity level of S. thompsoni exposed to 25.0°C decreased sharply after 20 hours. Their rest time at the bottom of experiment chamber increased, and their normal swimming and metabolic activities were disturbed. In addition, at a high water temperature of 30.0°C, S. thompsoni reached the limit of resistance and showed a sub-lethal reaction of swimming behavior, with energy consumption in the body increased and all test organisms died. In conclusion, the eco-physiological response of S. thompsoni to water temperature varied greatly depending on the fluctuation range of the exposed temperature and the exposure time. In addition, the tolerance limit of S. thompsoni to high water temperature was predicted to be 25.0- 30.0°C. The maximum critical thermal that had a great influence on the survival of this species was found to be around 30.0°C.

This study introduces the Three-Memory-Model (Cherry, 2019) in education into Maritime Simulator- based training in Sri Lanka and conducts empirical research. In simulator-based education what is disseminated as knowledge during the Briefing, Scenario and Debriefing phases must be transferred from short-term, across working memory to long-term-memory. Working memory gained during the scenario phase, could be encoded into long-term-memory through rehearsal probes. But the number of probes which could be tolerated by the participants of simulator-based training has not undergone empirical investigation. Thus, selecting the Open Sea scenario phase as its setting the research questions aim to identify tolerance limits in the participants for the number of freezes and the number of probes introduced during each freeze. The methodology selects a population of seafarers (n = 60). Through stratified random sampling this population was subdivided based on experience at sea as Group A (n = 30): Mean of 2 years and Group B (n = 30): Mean of 13.6 years of sea experience. The duration of the open sea scenario phase is 35 minutes with freezes at 10-minute intervals. The number of probes were given a range of 7 to. Data analysis utilized SPSS. The highest percentage mean value was obtained for three freezes for the Open Sea scenario phase while two freezes had the next highest percentage mean value. The mean value of the tolerance limits for questions during one freeze is approximately 9 and 6 probes for Group A and B respectively. Citing prior research on working memory, visuo-spatial vs. verbal working memory, reaction time and age this study raises a counter argument against the findings: the self-declared tolerance limits of the number of questions the participants feel comfortable to answer during each freeze. The findings of this research are valuable to maritime Simulator-based instructional designers outside and within Sri Lanka.

In this study, using a continuous behavior measurement technique, the short-term behavioral responses and tolerance limits of red seabream Pagrus major fingerlings to sudden exposure to low salinity in a controlled environment were observed. The activity of the fingerlings suddenly exposed to 21.4, 17.3, and 9.8 psu increased temporarily at the initial exposure to show irregular swimming behavior, but then recovered a stable activity pattern through rapid salinity adaptation. However, the organisms suddenly exposed to 7.3 and 4.3 psu could not withstand the salinity stress, and their swimming behavior was severely disturbed and all individuals died within 48 hours. The findings suggest that red seabream underwent a temporary salinity stress process at the beginning of the exposure to concentrations of 10.0 psu or higher. At these concentrations, osmotic control was possible within at least 11 hours, so stable metabolic activity was also possible. However, organisms suddenly exposed to concentrations below 5.0 psu exceeded the tolerance to low salinity and the sublethal limit. In red seabream exposed to this concentration range, severe behavioral and metabolic disturbances were observed, and death was observed due to osmotic control failure. In conclusion, a salinity range of 5.0 to 10.0 psu can be predicted to correspond to a concentration range in which the osmotic control ability of the red seabream fingerlings is lost, and sub-lethal reactions occur.