Trans RINA, Vol 154, Part B2, Intl J Small Craft Tech, Jul-Dec 2014 1.1 TASMANIAN WATERS DEFINITION
For this research the vessels surveyed were only vessels based in Tasmania and operating within the area shown in Figure 1.
2. RESEARCH METHODOLOGY
In order to determine the fuel use of vessels operating in these fisheries, a decision was made to use the energy- audit methodology as opposed to life-cycle assessment. This methodology was used, since it is comparable with previous research vessels and due
undertaken on Australian fishing to the expected
difficulties in
determining the energy consumed in construction of vessels as the yards which constructed some of these vessels are no longer around. To determine the data required for this project, the methodology for a Level 1/Level 2 energy audit in accordance with the Australian standard AS/NZS 3598:2000 was used as a guide. Using this standard the following types of data about fishing operations were gathered:
Figure 1: Southern Rock-Lobster Fishery Australian Fisheries Management Authority [9]
Currently in the area defined in Figure 1 there are the State-government-managed and Commonwealth- managed fisheries. The fisheries are managed by either the Tasmanian government
through Department or by
through the Australian Fisheries Management Authority (AFMA).
These fisheries either
the Commonwealth use
“passive” of
Primary Industries, Parks, Water and Environment (DPIPWE)
government or
“active” fishing methods to land the target species catch [8]. Passive fishing methods rely on the target species of fish to interact with the fishing gear, while active fishing methods rely on the movement of the fishing gear to interact with the target species. The different active and passive fishing methods are shown in Table 1.
Table 1: Active and Passive Fishing Method Examples Active Fishing Methods Passive Fishing Methods Demersal Trawling, Pelagic Trawling, Purse- Seine Net, Scallop Dredge, Abalone Diving
Baited Traps, Demersal Long line, Pelagic Long line, Handlines, Drop Lines, Demersal Gill Net
By reviewing the fisheries reports on these different fisheries, the decision was made to primarily focus on the fuel consumption of vessels operating in the southern rock-lobster fishery (a high catch value fishery) and, where possible, compare them to vessels that operate in the AFMA-managed south-eastern shark and scalefish fishery (a low catch value fishery).
Zone,
different engine loads; engine load duration; estimated annual fuel consumption; estimated annual fuel cost; estimated annual catch landed; typical trip duration; and vessel specifications.
This data was gathered using a questionnaire that the vessel operators would be able to answer themselves due to time constraints. The questionnaire covered the areas of catch landed, fuel consumed, trip duration, days spent at sea per year, and vessel specifications. Since this research project
involved social and ethical
data gathering process was undertaken in accordance with the University of Tasmania’s Social Science HREC minimal risk guidelines. To mitigate the risk, all information identifiers, such as vessel names, fishing locations and home port locations, have been removed.
In order to analyse the data and calculate the estimated fuel consumed, some formulae are needed.
We assumed that data gathered from the questionnaires for the vessels follows a normal distribution. The mean amount of diesel consumed per kilogram of catch landed x was calculated using Equation (1):
xx n
1 n i i 1
where n is the sample size and x is the amount of diesel consumed per kilogram of catch landed.
To check that this sample mean is accurate, a one-sided t- test was conducted. The t-test was used to compare the sample means since they are independent. Using a confidence interval of 95%, a hypothesis of
0 hypothesis) vs H (alternative hypothesis), and assuming a
that the variance is unknown, the test statistic t was calculated using Equation (2):
(1)
issues, the
H (null
B-58
©2014: The Royal Institution of Naval Architects
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