Demersal Fishery Resourceshttp://hdl.handle.net/20.500.12067/2252024-03-29T05:47:17Z2024-03-29T05:47:17ZReport of In-house Workshop on Benthic Habitat Mapping on Board M.V. SEAFDEC 2Southeast Asian Fisheries Development Center, Training Departmenthttp://hdl.handle.net/20.500.12067/6282023-04-20T03:50:48Z2012-09-01T00:00:00ZReport of In-house Workshop on Benthic Habitat Mapping on Board M.V. SEAFDEC 2
Southeast Asian Fisheries Development Center, Training Department
Referring to the recommendations made at the “Expert Meeting on DeepSea
Fishing and
Its Impact on Ecosystem1” that SEAFDEC is requested to find best practice of the sampling gears
for deep‐sea fisheries resources. Over the years, SEAFDEC/TD has explored ways to utilize the
deep‐sea fisheries resources in Southeast Asian Region through improvement of so‐called
“environmental friendly sampling gears”, including mid‐water trawl, gillnet, and bottom vertical
longline. It was also suggested through the series of activities related to deep‐sea fisheries
resources exploration in the Southeast Asian Region that technical information/knowledge and
experience on bathygraphic mapping (fisheries resources mapping) should be transferred to
the Member Countries in order to provide an alternative source of fisheries resources from the
deep‐sea waters of the Member Countries with science‐based information, particularly on the
vulnerable marine ecosystem of their respective waters. In respond to this, SEAFDEC TD has
developed a set of equipment ready to be put into the trial before transferring such knowledge
and technology to the Member Countries. Subsequently, SEAFDEC/TD plans to organize
“Regional training workshop on benthic habitat mapping” scheduled in the third quarter of
2012, of which the tools2 for resources mapping are needed to be trailed.
2012-09-01T00:00:00ZPreliminary Report Demersal Resources on the Un-trawlable Grounds in the South China Sea and Andaman SeaYasook, NakaretSiriraksophon, Somboonhttp://hdl.handle.net/20.500.12067/6132023-04-20T03:50:47Z2007-01-01T00:00:00ZPreliminary Report Demersal Resources on the Un-trawlable Grounds in the South China Sea and Andaman Sea
Yasook, Nakaret; Siriraksophon, Somboon
The demersal fishery resources surveys on the continental slopes particularly in the un-trawlable grounds of South China Sea and the Andaman Sea have been conducting by SEAFDEC using the specific fishing gear such as bottom vertical longline or/and trap. The aim is to investigate the potential demersal resources existing on the continental slopes in the Southeast Asia waters through the actual fishing trails and data/information collection onboard the research vessels. This project is a part of ASEAN-SEAFDEC program on the "Sustainable Utilization of Potential Fisheries Resources and Reduction of Post-harvest Losses". A series of field surveys were carried out with collaboration to SEAFDEC member countries.
2007-01-01T00:00:00ZSurvey Report on Demersal Fishery Resources Living in Un-trawlable Area in Rakhine fishing Ground of Myanmar Using Bottom Vertical LonglingSoutheast Asian Fisheries Development Center, Training Departmenthttp://hdl.handle.net/20.500.12067/3812023-04-20T03:50:46Z2009-01-01T00:00:00ZSurvey Report on Demersal Fishery Resources Living in Un-trawlable Area in Rakhine fishing Ground of Myanmar Using Bottom Vertical Longling
Southeast Asian Fisheries Development Center, Training Department
Since 2006, SEAFDEC had conducted Demersal Fishery Resources Living in Untrawlable
Fishing Grounds in Southeast Asian Waters using MV.SEAFDEC2 and using other
research vessels in collaboration with the Member Countries. This aims to evaluate on the
potential resources of economically important species in the un‐trawl able areas. The survey
areas will be focused in the EEZ of member countries and/or trans‐bordering areas
particularly in the un‐trawlable fishing grounds.
Rakhine fishing ground of Myanmar is one of the target survey areas where still
lacking information considering an un‐trawlable fishing area. It characteristic is a narrow
continental shelf with the rocky area. It is therefore not suitable for trawling but there is still
a possibility for other fishing gear such as bottom vertical longline. It is envisaged that the
survey result will be analyzed together with the data collected from other un‐trawlable
areas in the region.
2009-01-01T00:00:00ZAn Analysis of Catch Curve Using Length Composition Data With Applications to the Lizard Fish (Saurida elongata) in the Gulf of ThailandSommani, Pricharhttp://hdl.handle.net/20.500.12067/2372023-04-20T03:50:45Z1987-04-01T00:00:00ZAn Analysis of Catch Curve Using Length Composition Data With Applications to the Lizard Fish (Saurida elongata) in the Gulf of Thailand
Sommani, Prichar
Since the beginning of this century a catch curve, which represents the relationship between the size or age of the fish and the logarithms of the frequency of the occurrence of the fish in catches, has long been recognized as a convenient method of representing the catches graphically and as a useful method of estimating the mortality rate Ricker (1958) . At that time, the method was mostly applied to estimate the mortality rate under the constant mortality with age condition . Not until the middle of the 1960’s was the method developed independently, to make is possible to estimate the mortality rate by iterative method when the fishing mortality varies with age, by Murphy (1965, 1966) for the North Pacific fish and by Gulland (1965, See also his manual published in 1980) for the North Atlantic fish . The common features of these methods are that they require the catches in numbers of various age groups, the natural mortality usually assumed to be constant and the fishing mortality of the older age group. The method has not been widely used, however, because it is tedious and time consuming especially when worked by hand . Pope (1972) developed an ingenious technique which approximates Gulland’s method and this has fish stocks when the fishing and natural mortality rates are less than 1.2 and 0.3 respectively.
The technique, however, relies to a large extent on age information for the catches. This makes it difficult or even impossible to apply to tropical fishes for whom age determination is not as easy as for temperate species and the results of age determination are often unreliable. However recently, Jones (1981)
Made some modifications to Pope’s (1972) technique so that it could be used to estimate the mortality rate based on the length composition data of the catches. This modification has proved to be very useful in working with tropical fishes . But there still exist some weak points which underly Pope’s (1972) approximation i.e. , the fishing mortality and natural mortality rates must be lower than 1.2 and 0.3 respectively.
I have attempted to modify the Gulland-Murphy technique and combine it with the method of estimating the fishing mortality rate from the exploitation and natural mortality rates by iterative method described by Sommani (1972), so that it can be used to estimate the mortality rate from the length composition of the catches . Although the technique is tedious and time consuming, it is my view that at the present time, it is not impossible to carry on the iteration by using a small personal computer or even a small electronic calculator with an algebraic memory mode.
1987-04-01T00:00:00Z