48 research outputs found
Fishing capacity management
Excess fishing capacity has been identified as one of the most pernicious problems affecting long-term sustainability and biodiversity of fishery resources and economic viability of fishing operations. Significant economic gains could be achieved by eliminating excess capacity, in addition to attaining objectives of resource sustainability. In this paper, approaches to fishing capacity management are reviewed in the context of Indian fisheries. A rights based regulated access system under a co-management regime based on a strong inclusive cooperative movement of stakeholders with built-in transferable quota system and buy-back or rotational right of entry schemes seems to hold potential for capacity management in the shelf fisheries of Indian states, which need to be implemented in collaboration with the Union Government and the neighboring states with confluent ecosystems and shared fishing grounds. A key advantage of the use of rights based approaches for managing fishing capacity is that they provide a mechanism through which stakeholders can more easily and actively participate in the management process
Gross energy requirement in fishing operations
Energy is a key input into the fish harvesting process. Efficient use of energy helps in reducing operational costs and environmental impact, while
increasing profits. Energy optimisation is an important aspect of responsible fishing as enunciated in the Code of Conduct for Responsible Fisheries.
Gross Energy Requirement (GER) is the sum of all non-renewable energy resources consumed in making available a product or service and is expressed in energy units per physical unit of product or service delivered. GER is a measure of intensity of non-renewable resource use and it reflects the amount of depletion of earth’s inherited store of non-renewable energy in order to create and make available a product or service. In this study, GER in
fish harvesting up to the point of landing is estimated in selected fish harvesting systems in the small-mechanised sectors of Indian fisheries and
compared with reported results from selected non mechanised and motorised fishing systems to reflect the situation during 1997-1998. Among the fish
harvesting systems studied, GER t fish-1 ranged from 5.54 and 5.91 GJ, respectively, for wooden and steel purse seiners powered by 156 hp engines; 6.40 GJ for wooden purse seiner with 235 hp engine; 25.18 GJ for mechanised gillnet/line fishing vessel with 89 hp engines; to 31.40 and 36.97 GJ, respectively, for wooden and steel trawlers powered by 99-106 hp engines
Performance of 25m large mesh demersal trawl off Veraval, north west coast of India
Performance of a 25m large mesh demersal trawl, with 150mm mesh size in the fore parts of the trawl was evaluated in comparison with one boat high opening trawl of the Bay of Bengal Programme (BOBP) with 360 meshes of 160mm mesh size and 25.6m head rope length. An 8.2% increase in catch was obtained by 25m large mesh demersal trawl. The gear is comparatively cheaper, lighter in construction and offered better horizontal spread with significantly lower towing resistance. Commercial suitability of the gear for efficient harvesting of demersal fish resources of the region is discussed
Studies on the suitability of HDPE material for gill nets
The suitability of HDPE yarn and HDPE twine in place of nylon for gill nets has been studied. As regards total catch nylon gill net is found to be better than HDPE
nets. However, statistical analysis of the catch in respect of quality fishes shows that HDPE yarn nets are equally efficient as nylon nets
A new high opening trawl for Veraval waters
The newly developed 25m high opening trawl possesses the properties of a high rising bottom trawl and a semi-pelagic trawl. The new gear is effective for the capture of demersal and semi-pelagic fishes. The net offered more horizontal opening and less resistance with significantly high catch of ribbon fish when compared with bulged belly trawl
On the comparative efficiency of "V" shaped and rectangular flat otter boards for trawling off Veraval, north west coast of India
V shaped all steel boards, with their inherent stability to tide over obstacles and mud, interchangeability of starboard and portside boards are found to be superior to conventional flat rectangular boards for bottom trawling. These are cheaper in construction, offer less resistance and give longer service. Comparative trials with the two types of boards showed significant difference in tension between the boards but not in catch or horizontal opening
Effect of sailkite in improving trawl gear performance
Effectiveness of sailkite has been evaluated in two trawl designs, namely, a 25m high opening trawl and a 32m large mesh demersal trawl, rigged with sailkite through full scale comparative field trials. A 25m high opening trawl showed significant increase in total catch by 54.4% ribbon fish (Trichiurus spp.) alone by 138.3% with a reduction in miscellaneous catch, comprising mostly small sciaenids and juvenile fish, by 13.2% while 32m large mesh demersal trawl showed an improvement in total catch by 9%, ribbon fish by 17.2% and miscellaneous catch by 7.7%. The difference in fishing performance between the two gear arrangements has been attributed to changed net mouth configuration because of higher head line lift and also the possible herding effect on the fish in the vicinity of trawl mouth, due to addition of sailkite
Waste minimisation in fishing operations
Sources of wastes in fishing operations mainly
include bycatch discards; processing wastes where
catch is processed onboard; plastic wastes due to
abandoned, lost and discarded fishing gear; bilges
and other wastes from the vessel operations. Fishing
systems in general have an associated catch of nontargeted
organisms known as bycatch. Non-selective
fishing gear that is not modified or equipped to
exclude non-targeted organisms, may take a significant
quantity of bycatch of non-targeted finfish,
juvenile fish, benthic animals, marine mammals,
marine birds and vulnerable or endangered species
that are often discarded. Average annual global
discards, has been estimated to be 7.3 million t,
based on a weighted discard rate of 8%, during
1992-2001 period. Trawl fisheries for shrimp and
demersal finfish account for over 50% of the total
estimated global discards. Plastic materials are
extensively used in fisheries, owing to their durability
and other desirable properties, contributing to
the efficiency and catchability of the fishing gear.
However, plastics biodegrade at an extremely slow
rate compared to other organic materials. Abandoned,
lost or otherwise discarded fishing gear
(ALDFG) and related marine debris have been
recognized as a critical problem in the marine
environment and for living marine resources.
Prevention of excess fishing capacity by appropriate
management measures could lead to enormous
savings in terms of fuel consumption, emissions and
bycatch discards from the excess fishing fleet, capital
and operational investments and labour deployment
in capture fisheries, with significant economic gains.
In this paper, wastes originating from fishing
operations are reviewed, along with their environmental
impacts and possible mitigation measure
Studies on the effect of colour of webbing on the efficiency of gill nets for hilsa and pomfret off Veraval
Influence of colour of webbing on the catch of gill nets for commercially important hilsa (Hilsa toli and Hilsa ilisha) and pomfret (Pampus argenteus and Parastromateus niger) has been studied in the coastal waters off Veraval. Among the colours tested yellow and white are recommended for hilsa and pomfret gear. Influence of fishing depth, surface water temperature and turbidity on catch are also discussed
Energy analysis of the ring seine operations, off Cochin, Kerala
Ring seines are lightly constructed purse seines
adapted for operation in the traditional sector. Fish
production and energy requirement in the ring seine
operations, off Cochin, Kerala, India are discussed
in this paper, based on data collected during 1997-
1998. The results reflect the Gross Energy Requirement
(GER) situation that existed during 1997-1998.
Mean catch per ring seiner per year worked out to
be 211.9 t of which sardines (Sardinella spp.)
constituted 44.3%, followed by Indian mackerel
(Rastrelliger kanagurta) 29.7%, carangids 11.4%,
penaeid prawns 2.2%, pomfrets 1.1% and miscellaneous
fish 11.3%. Total energy inputs into the ring
seine operations were estimated to be 1300.8 GJ.
Output by way of fish production was determined
to be 931.85 GJ. GER is the sum of all non-renewable
energy resources consumed in making available a
product or service and is a measure of intensity of
non-renewable resource use. GER per tonne of fish
landed by ring seiners was estimated to be 6.14.
Among the operational inputs, kerosene constituted
73.4% of the GER, followed by petrol (12.7%), diesel
(6.7%) and lubricating oil (2.4%). Fishing gear
contributed 3.8%, engine 0.8% and fishing craft
0.3% of the GER. Energy ratio for ring seining was
0.72 and energy intensity 1.40
