Murray–Darling Basin Authority Native Fish Strategy Strategies to improve post release survival of hatchery-reared threatened fish species Michael Hutchison, Danielle Stewart, Keith Chilcott, Adam Butcher, Angela Henderson
Download 3.02 Mb.
|
- Navigate this page:
- Treatment Replicates Mean
Figure 30: Use of tank cells by groups of eight freshwater catfish fingerlings before (control only) and after (all treatment groups) introduction of a predator (Murray cod) to the predator cell. The maximum possible count in any cell is 480. Number of replicates is eight. Bars show mean values. Error bars show one standard error of the mean. Figure 30 suggests a trend for fewer 48 and 72 hour trained fish in the predator cell compared to control fish after introduction of a predator, but this was not statistically significant at the 5% level. There were no significant differences between treatments in the central cell after introduction of a predator. Table 5: Pairwise differences in percentage use of the far cell by freshwater catfish fingerlings post introduction of a predator. Means with the same subscript are not significantly different at the P=0.05 level
Table 6: Pairwise differences in percentage use of the near cell by freshwater catfish fingerlings post introduction of a predator. Means with the same subscript are not significantly different at the P=0.05 level
Figure 31: Catfish trained for 72 hours showed a tendency to use far cells. Figures 32 and 33 show changes in use of the far and predator cells respectively by catfish fingerlings before and after the introduction of a predator. A general increase in use of the far cell with time after introduction of the predator can be seen across all treatment groups. The upward trend is steeper in the trained fish compared to the control fish (Figure 32). The use of the predator cell declines across all groups after introduction of the predator. Mean use of the predator cell declines to close to zero in 48 hour and 72 hour trained fingerlings within 10 minutes of introduction of a predator (Figure 33). 
Figure 32: Mean numbers of freshwater catfish (control, 24 hr trained, 48 hr trained and 72 hr trained) recorded in the far cell for five minutes before introduction of a predator and for 10 minutes after. The predator was introduced at time 0 denoted by the dashed line. Counts of catfish were recorded every 15 seconds. The maximum possible count at any one time is eight fish. Number of replicates for each treatment is eight. Error bars have been excluded for clarity of reading the graph 
Directory: sites -> default -> files -> pubs files -> Northern England’s set-jetting locations files -> Nstructions for Acquiring Excess Equipment online, through the 1033 Program files -> Occupational health and safety files -> The Black Panther Party’s Ten Point Program files -> International programs roel profile files -> Fermi Questions a guide for Teachers, Students, and Event Supervisors Lloyd Abrams, Ph. D. DuPont Company, cr&D/ccas experimental Station Wilmington, de 19880 files -> Personal Information Name: Maha Al-Ammari Nationality: Saudi Relationship Status pubs -> Aboriginal Partnerships Action Plan Download 3.02 Mb. Share with your friends:
|