Trans RINA, Vol 154, Part B2, Intl J Small Craft Tech, Jul-Dec 2014 4.
SOUTH-EASTERN SHARK AND SCALEFISH FISHERY
The AFMA-managed south-eastern shark and scalefish fishery (SESSF) is undertaken in Tasmanian waters. The main target species are various species of deep-water fin fish such as blue grenadier and pink ling. The target catch is landed using demersal long lines, Danish-siene trawling or bottom trawling. The number of vessels and catch landed for previous fishing years is summarised in Table 7.
Table 7: Number of Vessels Participating in the South- Eastern Shark and Scalefish and total catch landed by these vessels [10]
Fishing Year
Number of Long line
Vessels
2008 14 2009 20 2010 20
Total Catch Landed By Long Line
Vessels (tons)
1048 53 845 896
53 51
4.1. VESSEL EFFICIENCY From the data
Number of
Trawlers
Total Catch Landed By
Trawlers (tons)
12249 11440 12114
From Figure 5 it can be seen that the relationship
between fuel consumed and the catch landed varies throughout the calendar year because operators have been unable to locate areas of concentrated fish during these periods. The main difference between Vessels A and B and Vessel C is the fishing techniques used to land their target catch.
Vessels A and B use the same
Mustad® automated long-line systems to land the target catch, while Vessel C uses bottom trawling. The difference in efficiency between Vessel A and Vessel B could be due to Vessel A being able to spend 100 more days at sea per year due to Vessel A having larger length, beam and draft, and more horsepower. Also, when discussing the fuel use with the
operators, they
mentioned that these vessels tend to have very consistent fishing operations.
4.2 FLEET FUEL USE ESTIMATION
By taking the data presented in Figure 5 and placing it into groups of 0.5 kg/L as shown in Figure 6, it can be seen that majority of the vessel efficiencies lie between 1.0 and 1.5 kg/L.
gathered the efficiency of a vessel
operating in the south-eastern shark and scalefish fishery was determined using the same measure as for the southern rock-lobster vessels and is shown in Figure 5.
0.00 0.15 0.30 0.45 0.60 0.75 0.90 1.05 1.20 1.35 1.50 1.65 1.80 1.95
We assumed that data gathered from the questionnaires for the long-line vessels follows a normal distribution. The mean amount of diesel consumed per kilogram of catch landed was calculated using Equation (1) from the data gathered in Figure 5 for long-line vessels, with a sample size of 22, giving a sample mean of
x 1.19 .
10.00 12.00 14.00 16.00 18.00 20.00
0.00 2.00 4.00 6.00 8.00
0‐0.5 0.5‐1.0 1.0‐1.5 Vessel Efficiencies (kg/L) Figure 6: Surveyed Vessel Efficiencies Month Vessel A Vessel B Vessel C
Figure 5: Fuel consumed per litre of catch landed for SESSF vessels surveyed
To check that this sample mean is accurate, a one-sided mean test was conducted. Using a confidence interval of 95%, an appropriate hypothesis is
H 0:1.0 vs :1.0 H a 1.5‐2.0
B-62
©2014: The Royal Institution of Naval Architects
January February March April May June July August September October November December
Vessel Efficiencies (kg/L)
Number
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