Using underwater video to directly estimate gear selectivity: the retention probability for walleye (Sander vitreus) in gill nets

2004 ◽  
Vol 61 (2) ◽  
pp. 168-174 ◽  
Author(s):  
Gerold C Grant ◽  
Paul Radomski ◽  
Charles S Anderson
Keyword(s):  
Video Camera ◽  
Fishing Gear ◽  
Sander Vitreus ◽  
Underwater Video ◽  
Retention Curve ◽  
Gill Nets ◽  
Gill Net ◽  
Gear Selectivity ◽  
Absolute Probability ◽  
Selection Parameters

We developed a new approach for directly quantifying selection parameters for fishing gear using a dual underwater video camera apparatus and employed the method to estimate gill net retention probability for walleye (Sander vitreus). The method allows observation of fish behavior around fishing gear and estimation of the absolute probability of fish encountering, contacting, or being retained by the gear. We demonstrated the applicability of this method by quantifying the probability that walleye were retained in multifilament nylon gill nets after contacting the nets. Walleye with total lengths 2.49 times the perimeter of the mesh were most likely to be retained, and retention probability peaked at 0.60 (95% confidence interval 0.41–0.90), meaning 40% of walleye that were the ideal size for a given mesh escaped after contacting the net. Our empirically derived retention curve exhibited a steep ascending limb and strong positive skew because of walleye morphology and the tendency for larger walleye to be captured by tangling. Most walleye that avoided capture did not fully enter the mesh or backed out of the mesh after they became temporarily wedged or tangled.

scholarly journals Construction of Gill Net 2 and 3 Inches in The Village Kampung Nelayan of Regency Tanjung Jabung Barat

2019 ◽  
Vol 10 (1) ◽  
pp. 15-23
Author(s):  
Nelwida Nelwida ◽  
Lisna Lisna ◽  
Ren Fitriadi
Keyword(s):  
Statistical Analysis ◽  
Survey Method ◽  
Fishing Gear ◽  
Environmental Friendliness ◽  
Gill Nets ◽  
A Value ◽  
Gill Net ◽  
Dimension Analysis ◽  
The Village ◽  
Descriptive Statistical Analysis

Gill nets is the most dominant fishing gear used by fishermen in Kampung Nelayan Village. Gill nets 2 and 3 inches are widely used by traditional fishermen and modern fishermen because this tool is very practical to catch fish also friendly to the environment. This study aims to determine the construction and friendliness of fishing gear gill nets 2 and 3 inches which include the length of the net, the width of the net, shortening, buoyancy and sinking power. This research was carried out in the Village of Kampung Nelayan, Tungkal Ilir Subdistrict, Tanjung Jabung Barat District in February 2018. The method used in this research was survey method. The data obtained were analyzed using net dimension analysis and descriptive statistical analysis. Based on the results of research on the construction of 2 and 3 inches gill nets consisting of nylon monofilament made from transparent colors. The knot used by the English knot. Top rope, float, and float buoy made from polyethylene (PE) rope and ballast rope made from polypropylene (PP). The sinker made from tin and gill net 3 inch weight based on bracelet-shaped wire.Net shortening value of 2 inch is 51.75% and has a buoyancy of 3.05 kgf and a sinking power of 9.97 kgf. As well as the value of gill shortening 3 inch 50.62% and the buoyancy generated 6.22 kgf and the sinking power of 365.4 kgf. The value of environmental friendliness of 2 and 3 inch nets has a value of 31.25 and 30.75 and is classified as environmentally friendly fishing gear.

scholarly journals Catching Technology of Fish Maw Snapper’s: Case Study of the KMN Nur Aqila07 Fishing Boat in Kumbe Village, Malind District, Merauke Regency, Papua

2021 ◽  
Vol 328 ◽  
pp. 08011
Author(s):  
Sajriawati Sajriawati
Keyword(s):  
Data Collection ◽  
Mesh Size ◽  
Fishing Gear ◽  
The Sun ◽  
Running Water ◽  
Gill Nets ◽  
Weight Range ◽  
Fishing Boat ◽  
Gill Net

The purpose of this study was to determine the fishing technology used by fishermen in Merauke to catch snapper and post-harvest handling of fish maw snapper. This research was conducted in January 2021 in Kumbe Village, Malind District. Data collection was carried out by interviewing fishermen on the fishing boat KMN Nur Aqila07. The results showed that the fishing boat KMN Nur Aqila07 has a weight specification of 30 GT. The main fishing gear is a drift gill net with a length of 50 meters with a width of 2 meters with a mesh size of 7.5 inches. The pulley machine is used to help pull the gill nets when they want to pull fishing gear (hauling). Fish maw of snapper is removed manually using a knife, then cleaned with running water and then dried in the sun to dry. Fish maw is sold dry. The highest price for fish maw is in the weight range of 150 grams which can reach Rp. 22,500,000 per kg, while the lowest price is in the weight range of less than 50 grams, which is Rp. 4,500,000 per kg.

scholarly journals Assessment of a small-scale fishery: Lane Snapper (Lutjanus synagris) using a length metric method

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0233479
Author(s):  
Liliana Sierra Castillo ◽  
Masami Fujiwara
Keyword(s):  
Small Scale ◽  
Fishing Gear ◽  
Optimal Length ◽  
Gill Nets ◽  
Limited Availability ◽  
Small Scale Fisheries ◽  
Catch Data ◽  
Gear Selectivity ◽  
Fishing Gear Selectivity ◽  
High Level

Small-scale fisheries are hard to assess because of the limited availability of data. Therefore, a method requiring easy-to-obtain catch-data is important for the assessment and management of small-scale fisheries. The objective of this study was to assess the effect of fishing gear selectivity on a length-based metric method proposed by Froese by estimating three indicators using catch-data from Lane Snapper (Lutjanus synagris) collected in Honduras. These indicators are (1) the percentage of mature individuals in the catch, (2) the percentage of fish within the range of estimated optimal lengths to be captured, and (3) the percentage of fish larger than the optimal length. These indicators determine the level of overfishing. The indicators were estimated separately for catch-data corresponding to gill nets, and each indicator was estimated with and without selectivity correction. Selectivity and mesh sizes of the fishing gear had a major impact on the estimation of indicators 1 and 2. As for indicator 3, it consistently showed a high level of exploitation. The three estimated indicators suggested that the Lane Snapper fishery in Honduras is experiencing overfishing. Overall, the method appears to be promising for the assessment of small-scale fisheries, but it should be used cautiously.

scholarly journals PENERAPAN PERUBAHAN UKURAN MATA JARING DALAM PENANGKAPAN IKAN TERBANG SECARA BERKELANJUTAN DI KECAMATAN SENDANA KABUPATEN MAJENE

2018 ◽  
Vol 1 (1) ◽  
pp. 17-27
Author(s):  
Najamuddin Najamuddin ◽  
Andi Assir ◽  
Mahfud Palo ◽  
Andi Asni Najamuddin
Keyword(s):  
Mesh Size ◽  
Community Empowerment ◽  
Fishing Gear ◽  
Young Fish ◽  
Gill Nets ◽  
Group Management ◽  
Gill Net ◽  
Large Numbers ◽  
Flying Fish ◽  
The Government

Catching flying fish in Sendana Majene Subdistrict is carried out continuously with gill nets 1-1.5 inches. The catch of flying fish is mostly still young fish (not yet worth catching). The demand for flying fish is quite high due to the existence of special stalls of smoke fly fish around fishing settlements. Apart from smoke flying fish, dried flying fish are also sold as souvenirs. Therefore, fishermen will continue to increase production. Various results of research and field observations show that gill net is able to catch flying fish well but the size of fish caught is dominated by young fish. The effort to increase the net mesh size to 1.5 inches resulted in the diminishing number of young flying fish. Catching flying fish in Majene waters is generally carried out with drifting gill nets with mesh sizes of 1 and 1.25 inches which are very intensive every fishing season while L50 (11.92 cm) and Lm (13.59 cm) for 1 inch more net mesh size were smaller compared to the length of the first gonad maturity, in this case most of the catch is still classified as young fish (Palo, 2009). Partners are a group of flying fish fishermen. Partner problems, flying fish production is getting smaller, group capacity is not strong and group management is still weak. Partners have not been able to obtain assistance facilities from various community empowerment programs carried out by the government. The approach to be used in this service includes: identification, observation, counseling, demonstration, construction, application, assistance, field observation and evaluation monitoring. Indicators of the success of activities are measured based on the results of the application of technology compared to the results of fishing gear commonly used by fishermen. Implementation of service includes counseling, construction of fishing gear, fishing operations and assistance has been going well. The size of 1.5-inch mesh is only able to catch flying fish in a limited amount, while the size of the 1.25-inch mesh can catch flying fish in relatively large numbers. Flying fish caught with 1.25-inch mesh size has passed the size of the first gonad mature so that it supports sustainable fisheries.

scholarly journals Pengaruh Perbedaan Ukuran Jaring Insang Terhadap Hasil Tangkapan Ikan Tongkol Euthynnus sp. di Perairan Tenggara Kabupaten Karangasem

2021 ◽  
Vol 4 (2) ◽  
pp. 16
Author(s):  
Dwi Nindra Saputra ◽  
I Wayan Gede Astawa Karang ◽  
Ni Luh Putu Ria Puspitha
Keyword(s):  
Pelagic Fish ◽  
Fishing Gear ◽  
F Test ◽  
Tuna Fish ◽  
Anova Test ◽  
Gill Nets ◽  
Gill Net ◽  
Sphyraena Barracuda ◽  
The Difference

Tuna is one of the main catching commodities in the waters of Southeast Karangasem. Fishers in the Southeast waters of Karangasem used drift gillnet operations to find pelagic fish such as mackerel. This study aims to determine the composition of fish catches using different net sizes and determine the effect of different gill nets on the catch of tuna fish in the southeast waters of the Karangasem Regency. The study was conducted for one month from mid-October to mid-November 2017 by following fishers' fishing trips. The fishing gear used was gill nets with differences, namely 2' 2.5 and 3 inches. The data was taken directly by operating the gill net, which has three different mesh sizes then the data was analyzed by ANOVA. Based on the research found four types of fish, namely Tuna (Euthynnus sp.), ikan kembung (Restrelliger kanagurta), barracuda (Sphyraena barracuda), and Manta sp. with details on 2.5 sized nets, three species (cobs, mackerel, barracuda), while sediment nets with a size of 2 (tuna and mackerel), and 3 (tuna and manta rays). Each gets two types of fish. Based on the ANOVA test, the calculated F results in this study are (7.7608) and F table (3.4668). The difference in the size of the gill nets significantly affects the catch of tongkol fish. The F test value shows that the F count was greater than the F table.

scholarly journals Pengaruh ekstrak minyak cumi pada umpan bubu terhadap hasil tangkapan kepiting bakau dan rajungan di Perairan Malise Kecamatan Tabukan Tengah

2016 ◽  
Vol 2 (3) ◽  
Author(s):  
Maichel Arvan Pananggung ◽  
Ivor L. Labaro ◽  
Emil Reppie
Keyword(s):  
Coastal Waters ◽  
Scylla Serrata ◽  
Fishing Gear ◽  
Swimming Crab ◽  
Portunus Pelagicus ◽  
Mangrove Crab ◽  
Gill Net ◽  
Oil Extract ◽  
Mangrove Crabs ◽  
By Catch

ABSTRACT Mangrove crab (Scylla serrata) and swimming crab (Portunus pelagicus) are economically important marine commodities produced from the coastal waters of Sangihe Islands Regency. But those marine commodity products are usually only caught accidentally with a bottom gill net. There has been a special trap fishing gear for that resources, but not known well by local fishermen. Addition of squid oil extraction baits could increase the fishing power of mangrove crab and swimming crab traps. This research aims to study the effect of squid oil extract on traps bait to catch mangrove crab and swimming crab; and identify the types of biota captured. This research was done in coastal waters of Malise village, Tabukan Tengah District of Sangihe Islands Regency for 2 weeks September 2015; based on experimental method. Six unit traps were operated ten trips where three units of them used scad mackerel bait that injected with squid oil extract, and tree other units just used scad mackerel bait without extract; and the capture data were analyzed using t test. The catch was 142 individuals (135 mangrove crabs and 7 swimming crab); where 86 crabs was caught by scad mackerel bait with squid oil extract, and 56 crabs caught with bait without squid oil extract. The analysis showed that the use of squid oil extracts on trap baits increased the catch. Keywords: mangrove crab, swimming crab,trap baits, squid oil extract, Sangihe   ABSTRAK[1] Kepiting bakau (Scylla serrata) dan rajungan (Portunus pelagicus) merupakan komoditi hasil laut ekonomis penting yang dihasilkan dari perairan pantai Kabupaten Kepulauan Sangihe. Tetapi komoditi hasil laut tersebut biasanya hanya tertangkap tanpa sengaja (by catch) dengan jaring insang dasar. Sebenarnya telah ada alat tangkap bubu khusus untuk kepiting bakau dan rajungan, tetapi belum dikenal oleh nelayan lokal. Pemberian ekstrak minyak cumi pada umpan, diduga dapat meningkatkan kemampuan tangkap dari bubu kepiting bakau dan rajungan. Penelitian ini bertujuan untuk mempelajari pengaruh ekstrak minyak cumi pada umpan bubu terhadap hasil tangkapan kepiting bakau dan rajungan, dan mengidentifikasi jenis-jenis biota yang tertangkap. Penelitian ini dilakukan di perairan Malise Kecamatan Tabukan Tengah, Kabupaten Kepulauan Sangihe; selama 2 minggu pada bulan September 2015; yang didasarkan pada metode eksperimental. Enam unit bubu dioperasikan selama sepuluh trip untuk mengumpulkan data; di mana tiga unit menggunakan umpan ikan layang yang disuntikan ekstrak minyak cumi, dan tiga unit lainnya hanya menggunakan umpan ikan laying tanpa ekstrak; dan data dianalisis dengan uji t. Tangkapan total berjumlah 142 ekor (135 ekor kepiting bakau dan 7 ekor rajungan); di mana 86 ekor tertangkap dengan umpan layang yang diberi ekstrak minyak cumi, dan 56 ekor tertangkap dengan umpan tanpa ekstrak. Hasil analisis menunjukkan bahwa penggunaan ekstrak minyak cumi pada umpan bubu, memberikan hasil tangkapan yang sangat berbeda dibandingkan dengan umpan tanpa ekstrak minyak cumi. Kata-kata kunci: kepiting bakau, rajungan, umpan bubu, ekstrak minyak cumi, Sangihe  

Overwintering habitat use of shortnose sturgeon (Acipenser brevirostrum): defining critical habitat using a novel underwater video survey and modeling approach

2007 ◽  
Vol 64 (9) ◽  
pp. 1248-1257 ◽  
Author(s):  
Xinhai Li ◽  
Matthew K Litvak ◽  
John E. Hughes Clarke
Keyword(s):  
Habitat Use ◽  
Linear Models ◽  
Video Camera ◽  
Sampling Procedure ◽  
Shortnose Sturgeon ◽  
Underwater Video ◽  
Camera System ◽  
Critical Habitat ◽  
Acipenser Brevirostrum ◽  
Modeling Approach

The overwintering habitat use of shortnose sturgeon (Acipenser brevirostrum) was investigated from January to March 2005 in the upper Kennebecasis River, New Brunswick, Canada, using a novel underwater video camera system and modeling approach. Following a random sampling procedure, 187 holes were drilled into the ice, and 234 sturgeon were counted and video-recorded. We found that sturgeon concentrated in a 2 ha area at the confluence of the Kennebecasis and Hammond rivers on a flat sandy substrate at a depth of 3.1–6.9 m. Generalized linear models were developed to describe the relationship of shortnose sturgeon density and habitat variables. The model indicated that the shortnose sturgeon had significant preference to deeper areas within this region. The total abundance of shortnose sturgeon in the area was estimated to be 4836 ± 69 (mean ± standard error) using the ordinary kriging method to interpolate sturgeon density at unsampled sites. This overwintering habitat of shortnose sturgeon can be defined as critical habitat following the identification policies of the Canadian Species at Risk Act (SARA).

PEMANFAATAN ALAT BANTU RUMPON ELEKTRONIK TERHADAP PENINGKATAN HASIL TANGKAPAN PADA ALAT TANGKAP GILL NET DI WILAYAH PESISIR KAB. BULUKUMBA

2021 ◽  
Vol 4 (1) ◽  
pp. 91-104
Author(s):  
Rahmat Bin Aburaera Sileh ◽  
Danial Sultan ◽  
Ihsan Ihsan
Keyword(s):  
Data Collection ◽  
Deep Sea ◽  
Sustainable Management ◽  
Management Strategy ◽  
Fishing Gear ◽  
Total Catch ◽  
Community Based ◽  
Shallow Marine ◽  
Fishing Trip ◽  
Gill Net

The purpose of this study was to determine the yield and type of catch, the comparison of the number of catches and the efforts to manage electronic FADs on Gill Net fishing gear. This research was conducted in Bulukumba waters from February to March 2017. Data collection was carried out by direct observation of fishermen in Bulukumba waters. The samples used in this study were FADs installed by fishermen in the waters of Bulukumba as many as 20 locations. Based on the research results, fish catches with electronic FADs ranged from 98 to 131 fish per fishing trip with a total catch of 2,324 fish. Meanwhile, the usual FAD catches ranged from 51 to 84 fish per fishing trip with a total catch of 1,313 fish and the highest type of fish was selar, followed by male mackerel, Selar bentong, white Kuwe, Layang, Barracuda, selangat and Mata goyang. The ratio between the catch and the use of electronic FADs was 64%, while the regular FADs were 36%. Considering that FADs are an effective tool in collecting fish, a sustainable management strategy is needed, including by (1) community based management, (2) limiting fishing efforts, (3) stopping the addition of shallow marine FADs. , (4) use of fishing gear with large mesh sizes and (5) prioritize the use of deep sea FADs.

scholarly journals Fishers' ecological knowledge of smalleye hammerhead, Sphyrna tudes , in a tropical estuary

2016 ◽  
Vol 14 (2) ◽  
Author(s):  
Vinicius J. Giglio ◽  
Hugo Bornatowski
Keyword(s):  
Marine Protected Area ◽  
Local Population ◽  
Austral Summer ◽  
Biological Data ◽  
Reproductive Season ◽  
Ecological Knowledge ◽  
Fishing Gear ◽  
Gill Nets ◽  
Biological Aspects ◽  
Trawl Fisheries

ABSTRACT Coastal hammerheads have suffered from overexploitation and environmental degradation. We interviewed 79 artisanal fishers to verify fishery aspects, temporal changes in catches and biological aspects of the smalleye hammerhead, Sphyrna tudes , in a marine protected area on Abrolhos Bank, Brazil. Data were compared between three generations of fishers: young, middle-aged and old. Fishers' age varied between 17 and 88 years. We verified significant reductions in the weight of individuals caught by younger fishers. The main types of fishing gear used to catch S. tudes were gill nets and longlines. Overfishing through gill nets and trawl fisheries were mentioned as the cause of S. tudes population collapse in the region. The shark's diet as reported by fishers consisted of fish, crab and shrimp; austral summer was the reproductive season. A strong similarity was verified between fishers' knowledge and biological data. We suggest as plausible strategies to conserve the local population of S. tudes the reduction of net fisheries impact through zoning and establishment of no take areas. These steps can help to initiate the recovery of this depleted species.

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