Troll Line Research Articles

The Small-Scale Tuna Fishery in Leyte, Philippines: Fishing Gears, Practices, Catch Rate and Composition

The Philippines is a significant tuna producer globally and ranks among the major tuna-fishing nations. One of the various areas where tuna fishery occurs in the country is the province of Leyte in Eastern Visayas. However, available information on the fishery in the province is limited. Thus, this study aimed to provide comprehensive information on the current status of small-scale tuna fishery in selected municipalities in Leyte, particularly on the types of fishing gears used, practices employed by fishers, and the catch rate and composition of the gears. This study used a purposive sampling method, and data were gathered through face-to-face interviews with a total of 68 small-scale tuna fishers, and actual catch sampling. The respondents’ involvement in tuna fishing ranged from 3 to 60 years with a mean of 26±13 years. A total of three different types of hook and line gear used in the fishery were recorded, namely: 1) paired troll line, 2) single troll line, and 3) single hook and line with float. The paired troll line is the most commonly used gear among tuna fishers. The mean catch per unit effort varies depending on the fishing gear type. The catch composition of the three gears based on the actual catch sampling was comprised of four tuna species including longtail tuna Thunnus tonggol (50.48%), big-eye tuna T. obesus (21.90%), eastern little tuna Euthynnus affinis (18.10%), frigate tuna Auxis thazard (3.81%), and two other species including Megalapis cordyla (3.81%) and Scomberomorus commerson (1.90%). The current major issues in the fishery include catch seasonality, illegal fishing, and border restriction.

Kajian tentang jenis umpan buatan pancing tonda terhadap hasil tangkapan

The aim of this research is to determine the differences between two types of artificial bait on troll line on catches and to identify the composition of catch types based on bait type. This research was carried out in Tanawangko waters and was carried out from February to March 2023 using the experimental fishing method, where two pancing tonda each using silk fiber and chicken feather bait were operated simultaneously in one boat for 5 trips which were then analyzed using the t test. The catch during the research was 24 individuals with 3 species, namely with silk fiber bait, 20 individuals were caught consisting of 3 species and using chicken feather bait, 4 individuals were caught consisting of 2 species. The analysis results show that tcount = 1.684 < t table = 2.776; so it accepts H0 and rejects H1. This explains that the use of chicken feather bait is not significantly different from silk fiber as trolling bait for catch results. The conclusion of this research is that using silk fiber bait resulted in more catches than chicken feather bait, but the results of the t test analysis showed that the two were not significantly different and the three species of fish caught were 15 skipjack tuna (Katsuonus pelamis), 7 baby tuna (Thunnus sp.), and 2 lemadang (Coryphaena hippurus).

Influence of Colors on the Catching Performance of Artificial Lures of Multiple Troll Line in Bongao Waters, Tawi-Tawi, Philippines

Improving the efficiency of fishing gears to catch species and sizes selectively and to catch more fish with less fishing efforts are essential objectives in fisheries research. This study utilized a small-scale multiple troll line, using two different artificial lures, i.e., green and blue, to determine the color lure preference of fish catch, catch composition, relative abundance, and catch per unit effort. In addition, the length-weight relationships of the caught species were also investigated. The study was conducted in the Bongao waters, Tawi-Tawi, Philippines, through fishing samplings using two separate motorized boats with two gears. A total of 1,032 fishes were caught by multiple troll line, which identified nine species with relative abundance: frigate tuna juvenile Auxis thazard (37.11%), bullet tuna Auxis rochei (24.90%), eastern little tuna Euthynnus affinis (15.99%), bigeye scad Selar crumenopthalmus (15.21%), yellowfin tuna Thunnus albacares (3.01%), common dolphin fish Coryphaena hippurus (1.75%), double-lined mackerel Grammatorcynus bilineatus (1.16%), shortfin scad Decapterus macrosoma (0.58%), and skipjack tuna Katsuwonus pelamis (0.29%). There were 677 fishes (65.89%) and 355 fishes (34.41%) lured by green and blue artificial lures, respectively. Most of the caught species had a size distribution ranging from 21.5 cm to 30.5 cm for both lure colors. The slopes (b) of the length-weight relationships of the caught fishes ranged between 1.5473 (skipjack tuna) and 3.305 (bullet tuna). In terms of catch per unit effort (CPUE) for all the species caught, the multiple troll line with the green lure had the highest mean CPUE with 0.63±0.12 kg/hr, while the blue lure had a mean CPUE of 0.35±0.7 kg/hr, although there was no significant difference (p > 0.05). This study suggests that multiple troll lines with either green or blue lures are effective small-scale fishing gear to catch small tunas and tuna-like, especially frigate tuna, bullet tuna, and eastern little tuna.

The Tuna Handline fishing fleet of Infanta, Pangasinan, Philippines: An assessment

The study was conducted to provide baseline information that could be used by authorities to further support this sector in the municipality of Infanta, Pangasinan. Purposive sampling was employed and data was generated through face-to-face interviews aided by a structured questionnaire. Results revealed that the fishing fleet is mainly operated by boat captains at the age of 36-41 years old (32.56%), high school graduates (46.51%), members of fishing organization (67.44%), and with no other sources of income aside from fishing (90.70%). Most boat units are within the size of 9.1-12.0 GT (48.84%), with 90.1-130.0 metric HP engines (44.19%) and manned by 10-12 (41.86%) regular and seasonal fishing crews. Four (4) line gears are primarily used in catching tuna which include simple handline (surrate), multiple hook and line (sibid-sibid), troll line (bira-bira) and bottom set long line (kitang). These gears are fabricated using monofilament nylon lines and “J” type hooks with varying sizes. Majority are fishing off the coast of Zambales (45.51%) and Pangasinan (44.19%) with effort days of 4-6 (65.12%). There are several problems encountered by the fishing fleet at present and increasing cost of fishing supplies (fuel, gear materials, etc.) is considered a major constraint for sustainable operation.

Satisfaction of the Fisheries Troll Line Service Section of the Port Authority at Bungus PPS, West Sumatra

The purpose of this research is to improve and revise the service quality performance that is given to fishermen. The method used in this research is to use a survey method with direct interviews using questionnaires at the research location. Respondents in this research were addressed to Troll Line Fishermen. The analysis used is the validity and reliability test obtained from the questionnaire results, the Customer Satisfaction Index (CSI) is used to determine the level of satisfaction of fishermen, and Importance and Performance Analysis (IPA) is used to find out the things that are priority improvements to the attributes that affect consumer satisfaction level. Based on the Customer Satisfaction Index (CSI) method, the results obtained 95.082%, which indicates that the level of service provided by the porter's party where it can be seen that the service users have a high level of satisfaction with the harbormaster's service

Time Efficiency of Filling Supplies at Marine Supplies Tonda Fishing Ship in PPS Bungus, West Sumatra Province

When filling supplies at sea, it is not only troll line fishing vessels that fill up supplies at PPS Bungus but also other fishing vessels. The large number of fishing fleets filling up fishing supplies causes queues that can affect the cost of mooring ships. To find out how efficiency the time of filling supplies at sea troll line fishing vessels is and the factors that influence it, this study was conducted. The method used is a survey method of 20 sample ships that carry out fishing activities. From the results of the study, it was found that the efficiency level of filling time for troll line fishing boats ranged from 74.22% to 89.01% with an average of 82.31%, which means efficiency. The size of the efficiency level when filling fishing supplies is very dependent on the length of the effective time used. The amount of effective time is influenced by the number of supplies of clean water (x1), fuel (x2), ice cubes (x3), and the number of actors filling fishing supplies (x4), in the form of multiple regression equation Y = 58,5700 + 0.0363x1 + 0 .0488x2 + 0.1652x3 – 9.5800x4. The efficiency level of filling time for fishing supplies can still be improved by reducing wasted time

Growth patterns of skipjack tuna (Katsuwonus pelamis, linnaeus 1758) caught by troll line in Prigi waters, Trenggalek East Java Indonesia

Skipjack tuna (Katsuwonus pelamis) is an important pelagic fish species caught in tropical and subtropical waters of the Pacific, Atlantic, and Indian oceans. Skipjack tuna (K. pelamis) is also a high economic fisheries resource in Prigi waters which is caught by troll line. High market demand results in high levels of exploitation. This study aimed to identify the length-weight relationship and biological reproduction of skipjack tuna in the Prigi waters. The research was conducted in the sampling period between December 2019 - April 2020 with total samples obtained as much as 1642 fish and was analyzed using linear regression. The results informed that the length-weight relationship of skipjack tuna was positive allometric with equation W=0.007FL3.223 which means that the fish has a fat body. The sex ratio between male and female fish is 1:1. While gonad maturity level obtained in this study is mostly in GML 1 and GML 2 which indicates that the catches were dominated by immature fish, so it is necessary to limit fishing effort so that sustainability of the skipjack tuna (K. pelamis) resource can be managed.

The Biological Aspects of the Main Targets of Troll Line at Palabuhanratu Fishing Port, Indonesia

The biological aspect is a piece of basic information that is commonly presented in assessing the level of environmental friendliness of fishing gear or fishing vessel. This study was conducted to analyze the biological aspects of the main catch of the troll line at the Palabuhanratu Fishing Port, Sukabumi, Indonesia. The biological aspects analyzed consisted of length frequency distribution, length-weight relationship, to the average feasibility status of the caught target fish. There were three main target commodities for fishing from the troll line that was identified during the research activity, namely yellowfin tuna (Thunnus albacares), skipjack tuna (Katsuwonus pelamis), and frigate tuna (Auxis thazard). A total of 14 troll line fleets were obtained as a source of research data based on the accidental sampling method. The total number of 1404 fish consisting of 480 yellowfin tuna, 475 skipjack tuna, and 449 frigate tuna were obtained as research data objects. The stratified random sampling method was used in determining the observed sample fish data. Yellowfin tuna were distributed at size 29 – 148 cm, skipjack tuna at size 29 – 88 cm, and frigate tuna at size 23 – 82 cm. Analysis of the length-weight relationship showed a negative allometric growth pattern in the three main fishing target commodities. The analysis of the feasibility of the average fish caught based on compared of L50% to ½ L∞ shows that the average size of tuna and frigate tuna caught is undersize for catching, while the average skipjack caught has reached a legal size. The results of this study indicate that there is a need for a review of the use of fishing hooks in the fishing activity of the troll line fishing fleet. Increasing the hook size can be used to avoid catching fish that are at a size that is not suitable for catching.

Management policy of small-scale tuna fisheries based on island cluster in Maluku

Tuna is one of essential economic fish commodities in Maluku which mostly caught by handline and trolling line small scale fishery with fishing vessel capacity under 5 GT. The fishing vessel numbers and fish production of this fishery are declining recently, and the catching was predominantly by small size. The highest yellowfin tuna production was found in Island Cluster 7 amounted to 9,107 tones or 31% of total yellowfin tuna production in Maluku by 2019. This study was aimed to analyze the condition of yellowfin tuna in Maluku and to propose a management policy for small-scale tuna fishery base on Island Cluster. Result shows that the production between 2013-2019 was stagnant with a declining tendency. The implementation of island cluster approach in small-scale tuna fishery management will increase the efficiency, productivity, and competitiveness on it, especially at the potential island clusters 7, 5, and 4. Of all-island clusters found, island cluster 7 having the highest performance indicator for small-scale tuna fishery.

Small scale fisheries performance: comparative analysis before and during the Covid-19 pandemic in Indonesia

The incidence of the Covid-19 pandemic indirectly affects the decline in the activity of the processing industry and fish consumption by the community. In the short term, there is also a decline in fish prices. This study examines whether the decline in economic activity in the fisheries sector causes changes in the performance of small-scale fisheries, both before and during the Covid-19 pandemic in Tolitoli Regency, Central Sulawesi Province. The target of the research object is fishers who use trolling lines, handline, and beach seine. The analytical method used is Exponential Comparison Method. The results showed that capture fisheries belonging to SSF, which had high performance before covid-19, were fishing gear, and the lowest performance was Surrounding net. On the other hand, the surrounding net has a higher performance during the pandemic than the other three fishing gears, and the lowest is Trolling lines. However, there has been a significant decline in prices and market affordability, the economic contribution of small-scale fishing businesses from before and during the COVID-19 pandemic. For this reason, a policy to open up an export-oriented fish catch market and a wider market reach is required.

KELAYAKAN USAHA NELAYAN PANCING TUNA DI JAZIRAH LEIHITU

Tuna fishing activities using troll line tool is an optional activity that has been occupied by the community in Peninsula Leihitu. The activities have been occupied since hereditary and their life depends on fishery resources. In reality, most of coastal communities are still living below the poverty line. The aim of this research is (1) to analyze the thecnical, economic, social and institutional condition of tuna fishing fisherman, (2) to analyze the income level and the feasibility of fishing business in Ureng, Assilulu and Larike (Dusun Lai) of Central Maluku Regency. The used research methods include statistical descriptive analysis, income analysis, investment criteria analysis. The study was conducted for 6 months from October 2017-March 2018. Data required in the study consists of primary data and secondary data. Sampling is done purposively of 55 fishermen (30%) from total population of tuna fishermen line which is still active doing fishing activity. Based on the results of research income analysis of this business make a profit. The result of analysis calculation of investment criteria obtained value NPV>1, Net B/C>1 and IRR> discount rate, indicating that tuna business in Ureng, Assilulu and larike (Dusun Lai) is a well run.

Efektifitas Umpan Tiruan yang Berbeda Warna Terhadap Hasil Tangkap Ikan tongkol (Euthynnus sp) di Perairan Tenggara Karangsem Bali

Catching Tuna Fish (Euthynnus sp.) in territorial waters of Southeast Karangasem, Antiga Kelod Village using trolling is very influenced by the type of baited. In a manner line, there are two type of baited that used for trolling, fishworm and lure. The objective of this research is to determine the effectiveness and the effect of lure on tuna fish catch (Euthynnus sp.) In territorial waters of Southeast Karangasem, Antiga Kelod Village. All of three baits are made about the size of the baits and have the same color, there are blue-white, red-white, and green-white, and it’s operated simultaneously on one unit trolling line for 12 times . This research using descriptive comparative analysis and complete randomized design statistic analysis (RAL). The results of this research obtain, the blue-wait color of the bait can produce 146 tuna fish (Euthynnus sp.) with an effectiveness value 34.27%, with average value of results catch is 12 tails on once trip. While for red-white color, produce 220 tuna fish with an effectiveness value 51.64%, and the average value of results catch is 18 tails on once trip, and the produce of green-white color is 60 tuna fish with effectiveness value 14.08%, the average outcome catch 5 tails on once trip. Based on the results of the research The red-white bait was a bait with the highest catch and the highest effectiveness value.

BIOLOGICAL ASPECTS, CATCHING ASPECTS AND FISHING GROUND OF EASTERN LITTLE TUNA OR KAWAKAWA(Euthynnusaffinis (Cantor, 1849)) BASED ON THE FISHING GEAR AT WPP 572

Eastern little tuna ( Euthynnus affinis ) is the main catch in WPP572. The caught E. affinis are still in their infancy. This research aims is to know the biological aspects, the fishing aspects and the distribution of the fishing gear per fishing gear, as a consideration for sustainable fisheries management. The research was carried out during the years 2019-2020. Taking samples for gonad observation was carried out by direct survey to the location in February, May, July and October 2019. The measurement of fish length was carried out in stratified random. Catching data were retrieved by requesting secondary data and interviews with related parties. The distribution of fishing grounds is mapped using the QGIS 3.4, the spatial distribution of catches is mapped. This study showed the size structure of E. affinis on purse seine, troll line and encircling gill netfishing gear from 16-55 cm FL, while on the boat/raft lift net it was 21-50 cmFL. These fish growth's is positive allometric on purse seine and encircling gillnet fishing gear, negative allometric on boat/raft lift net fishing gear, and isomeric on troll line. The sex ratio is in the ratio 1: 1.15 and balanced. Based on the maturity level, the gonads were mature in July and October and immature in February and May. Gonads ripened for the first time at a size of 42.032 cmFL. The distribution of the purse seine catchment areas at 3°-6°N and 93°-96°E, and 3°-6°S and 94°-95°E. Boat/raft lift net at 0°-3°S and 95° -101°E. Troll line 4°-6°N and 94°-95 E. Encircling gillnet 0°-2°S and 99°-101°E.

Length – Weight Relationships of 12 Commercial Fish Species Caught with Static Fishing Gear in the N. Ionian Sea (Greece)

This study presents the length-weight relationships (LWR) for 12 commercial fish species from coastal waters off South Corfu Island (N. Ionian Sea, Greece). All fish originated from the catches made by a single artisanal fisherman during April – September 2009. Multiple types of predominantly static fishing gear were used, mainly gillnets (mesh size: 28 mm) operated at depths of 10–40 m and trammel nets (mesh sizes: 22, 24, 28, 32, 34, 36, 40 mm) operated at depths of 7–70 m. Moreover, bottom longlines and trolling lines were occasionally used, at depths of 20–50 m and 35 m, respectively. Length (TL) in cm and weight in g of all the individuals in the catches were measured in the laboratory. Estimates of the b parameter ranged between species from 2.652 to 3.593. For none of the fish species examined in the present paper has LWR information been published before for the N. Ionian Sea, and for six of them (i.e. for Epinephelus costae, Labrus viridis, Oblada melanura, Sarda sarda, Scomber colias and Scorpaena porcus) there is no LWR information for the Ionian Sea as a whole. The results of this study may thus contribute in fisheries management and marine conservation in the Ionian Sea by providing baseline LWR information for several commercial fish species based on samples of local populations. Moreover, this study contributes in complementing the few LWR datasets that exist in the international literature for E. costae and L. viridis.

Short Communication: The species and body size composition of pelagic fishes that caught by troll line in the fish landing of Sendang Biru, East Java, Indonesia

Abstract. Hidayati D, Oclandhi B, Maulidinia N, Sa’adah NN, Nurhayati APD. 2019. Short Communication: The species and body size composition of pelagic fishes that caught by troll line in the fish landing of Sendang Biru, East Java, Indonesia. Biodiversitas 20: 1764-1769. Troll line is the most used pelagic fishing gear for fishermen in Sendang Biru, the part of Indian ocean at East Java, which have an impact on the catch composition. The study was aimed to obtain data on species composition and size of pelagic fish caught in troll line in Sendang Biru, East Java, Indonesia. Fish samples were collected from nine different vessels landed in Sendang Biru for three days in April 2018. The composition of fish species was measured based on relative abundance. The fish size composition was obtained by measuring fork length which is also used to determine the stage of development of juvenile (Jv) or adult (Ad) fish. The results of the research showed there were four pelagic fish species which dominated by Katsuwonus pelamis or skipjack tuna (50.05%) and Thunnus albacares or yellowfin tuna (47.95%) and a small amount of Coryphaena hippurus and Makaira mazara. According to the body size, the fish caught by troll line in Sendang Biru is dominated by adult skipjack tuna (41-60 cm) and juvenile yellowfin tuna (21-78 cm).

After the Trolls: Patent Litigation As Ex-Post Market Making

Recent patent policy emphasizes the superiority of ex ante licensing over ex post patent assertion. Ex ante means before costs are sunk by a patent defendant, so licensing at this stage avoids the leveraging of a defendant’s investments in product design which is a presumptive aspect of litigation in the ex post period. Contrary to the dominant narrative (ex ante good, ex post bad) this Article defends patent litigation as a reasonable way to award compensation in the ex post (i.e., after product development) period. The literature on strategic delay, together with the sometimes heavy costs of negotiating patent licenses during an intensive product development project (including opportunity costs), point to a productive role for patent litigation: ex post market-making. Patent litigation determines which patented inventions contributed to product success during the all-out scramble for successful product development and market entry. But it does so after development is complete and the product market is established. This temporal decoupling – separating intensive development competition from a careful assessment of the contributions of individual patented technologies – is a rational way to appropriately compensate the various contributors to a new product in fast-moving, technology-intensive markets. The last part of the Article reviews the many ways that litigation has been reformed in recent years in response to the problem of rent-seeking litigation, i.e., patent trolls. Many patent doctrines have been adjusted to better police the “troll line”: the line separating socially worthless troll patents from value-adding patents that are worth enforcing. Because of these reforms, we can be confident that patent litigation primarily serves the positive function of rewarding (ex post) the actual contributors to a new product.

POLA BAGI HASIL PADA PERIKANAN TANGKAP DI KELURAHAN TANJUNG LAUT INDAH KOTA BONTANG

This research aims to analyze the business and the profit sharing pattern of fisheries fishermen in Tanjung Laut Indah Village. The research used the survey method and applied purposive sampling that selected 45 respondents based on 3 types of fishing gear. The respondents composed by 15 owners and 30 crews of capture fisheries business. The method of data analysis using qualitative and quantitative analysis. The results of this research indicated that the average income of gill net fishermen in Tanjung Laut Indah Village was Rp 15.314.800/month/respondent in the harvest season and Rp 4.634.800/month/respondent in the non harvest season. The average profit of troll line fisherman was Rp. 12.742.033,33/month/respondent in the harvest season and Rp. 9.432.033,33/month/respondent in the non harvest season. The average profit for barrier trap fisherman in Tanjung Laut Indah Village was Rp. 9.619.800/month / respondent in the harvest season and Rp. 3.379.800/ month / respondent in the non harvest season. The profit sharing pattern of catch fisheries business in Tanjung Laut Indah Village that used gill nets, troll line, and barrier trap swhowed the same pattern, that were 50% of profit shared for the owner and 50% for the fishermen crews.

해양안전심판원의 재결에 나타난어로종사선의 범위

The term 'vessel engaged in fishing' means any vessel fishing with nets, lines, trawls or other fishing apparatus which restrict manoeuvrability, but does not include a vessel fishing with trolling lines or other fishing apparatus which do not restrict manoeuvrability. But in the Korean Maritime Safety Tribunal(hereafter “KMST”), there have been some disputes whether the legal position of “vessel engaged in fishing” is granted for the vessel which is in fishing or navigating for fishing. The study and research on these disputes have been carried out by KMST for long time, and the conclusion was established through the judgements of the cases concerned. Therefore the a standard of judgment for the points of issue could be ascertained by analyzing the judgements of KMST for the cases concerned. One important subject of the disputes is defining the “fishing apparatus which restrict manoeuvrability”. Generally “fishing apparatus which restrict manoeuvrability” means ① altering course or reducing speed is difficult due to the water-resistance by fishing apparatus, ② when if altering course or reducing speed, there could be damage to the fishing apparatus or to the vessel. And when is the time which vessel is presumed engaged in fishing is another subject of the disputes. Not only casting or drawing-in the nets or lines. but also conducting other work, navigating for the fishing or casting/drawing-in sea-anchor is in the process of fishing, is presumed “engaged in fishing” and if that work or navigating restrict vessel’s manoeuvrability, the vessel is presumed “vessel engaged in fishing”. And, although a fishing vessel is in fishing and there is a little restriction on the vessel’s manoeuvrability, if the vessel could keep out of the way of another vessel, that vessel is not presumed “the vessel engaged in fishing”.

Flume tank and in situ trials for verification of static and dynamic methods for gear depth and underwater behavior of hairtail trolling lines

We investigated the underwater shapes of trolling lines for the improvement of hairtail fishing efficiency. Two sets of experiments were carried out, one on a small scale, where flume tank tests of four models were scaled down by a ratio of 1:10 and trolled at different speeds, and another at full scale, comprising a survey on board a commercial fleet. In situ trials were conducted off the coast of Jeju Island, South Korea, at 33°27′57.528″N, 126°55′48.846″E, a potential fishing ground for hairtail fishing. The full-scale gear was set by altering sinker weights whilst changing the length of the warp line at different towing speeds. A dynamic method using a mass-spring technique and full-scale gear was developed. External and internal forces that govern the motion of the gear were considered. A non-linear differential equation of motion was developed, solved by a fourth-order Runge–Kutta method at a time step of 5 × 10−4 s for each trial. A static method was also developed using full-scale gear to predict the equilibrium gear configuration under all fishing conditions. The dynamic method better predicts the actual underwater performance of trolling line gear in real time.

A study on the change of the depth and catch of hairtail trolling lines

A study on the change of the depth and catch of hairtail trolling lines