scholarly journals Application of Métier-Based Approaches for Spatial Planning and Management: A Case Study on a Mixed Trawl Fishery in Taiwan

2021 ◽  
Vol 9 (5) ◽  
pp. 480
Author(s):  
Yi-Jou Lee ◽  
Nan-Jay Su ◽  
Hung-Tai Lee ◽  
William Wei-Yuan Hsu ◽  
Cheng-Hsin Liao
Keyword(s):  
Spatial Planning ◽  
Clustering Algorithm ◽  
Fishing Gear ◽  
Target Species ◽  
Trawl Fishery ◽  
Fishery Resources ◽  
Planning And Management ◽  
Catch Composition ◽  
Fleet Dynamics

Mixed fisheries refer to fishing activities that catch more than one species simultaneously, and a species may be fished using different gear. A trawl fishery shares these features to exploit multiple species simultaneously, with diverse fishing gear and strategies. The situation becomes more complex when interactions among fleet dynamics, fishing activities, and fishery resources are involved and influence each other. Information regarding the operational patterns may be hidden in a set of long-term big data. This study aims to investigate the fishery structure and fleet dynamics of trawl fisheries in Taiwan for spatial planning and management, based on a long-term dataset from a management system that collects information by using voyage data recorders (VDR) and dockside observers. We applied a two-step data mining process with a clustering algorithm to classify the main groups of fishery resources and then identified 18 catch métiers based on catch composition. The target species, operation pattern, and fishing season were determined for each métier, and associated with the relevant fishery resources and the fishing gear used. Additionally, fishing effects on target species were estimated using information on fishing grounds and trajectories from VDR. The métier-based approach was successfully applied to define the six major fishery resources targeted by trawlers. We examined the key features of fishing activity associated with catch composition and spatial-temporal fishing metrics, which could be used to provide suggestions for the spatial planning and management of the mixed trawl fishery in the offshore waters of Taiwan.

Bycatch of chondrichthyans in a coastal trawl fishery on Chubut province coast and adjacent waters, Argentina

2016 ◽  
Vol 98 (3) ◽  
pp. 605-616 ◽  
Author(s):  
J. Ruibal Núñez ◽  
N. D. Bovcon ◽  
P. D. Cochia ◽  
M. E. Góngora
Keyword(s):  
Single Species ◽  
Ecosystem Approach ◽  
Squalus Acanthias ◽  
Fishing Gear ◽  
Target Species ◽  
Trawl Fishery ◽  
Merluccius Hubbsi ◽  
By Products ◽  
Discopyge Tschudii ◽  
Mustelus Schmitti

Chondrichthyans are usually caught incidentally in fisheries for species of high commercial value and then discarded on board or landed as by-products. On the coast of Chubut province and adjacent waters (43°00′S–44°56′S) a bottom trawl fishery has developed targeted at the Patagonian shrimp (Pleoticus muelleri) and common hake (Merluccius hubbsi). Since 2005, this fishery has been monitored by the On-board Observers Program of Chubut province (POBCh). With the aim of advancing towards an ecosystem approach, POBCh not only collects information about target species but also about all the species caught by the trawl nets of the province fisheries. From the information collected by this programme it was possible to identify and record the chondrichthyan species vulnerable to the fishing gear used by the coastal fleet that operates from Puerto Rawson. The composition of the fleet catch was characterized according to the target species during the 2005–2014 period. In the analysis of 3786 hauls, 23 species of chondrichthyans (seven species of sharks, 15 species of batoids and a single species of Holocephali) were identified. Seven species showed a frequency of occurrence greater than 10% (Callorhinchus callorynchus, Discopyge tschudii, Mustelus schmitti, Sympterygia bonapartii, Psammobatis normani, Squalus acanthias and Zearaja chilensis). Species spatial distribution was evaluated and five areas of species assemblages were established. Besides the aspects related to bycatch, these analyses have contributed to the knowledge of the chondrichthyan biodiversity in the provincial coast where the fleet operates, a region with incomplete and mostly dispersed and outdated information.

scholarly journals KOMPOSISI JENIS IKAN HASIL TANGKAPAN SAMPINGAN (BYCATCH) PUKAT DORONG DI TAMBAK LOROK, SEMARANG

2018 ◽  
Vol 7 (3) ◽  
pp. 288-297
Author(s):  
Laeli Luthfiani ◽  
Abdul Ghofar ◽  
Frida Purwanti
Keyword(s):  
Size Distribution ◽  
Research Method ◽  
Sampling Method ◽  
Survey Method ◽  
Fishing Gear ◽  
Target Species ◽  
Purposive Sampling ◽  
Type Composition ◽  
Trichiurus Lepturus ◽  
Catch Composition

Kegiatan perikanan tangkap di Tambak Lorok dilakukan menggunakan berbagai alat tangkap, salah satunya adalah pukat dorong / sodo. Penggunaan pukat dorong menghasilkan tangkapan sampingan (bycatch). Penelitian dilaksanakan pada Desember 2017 - Maret 2018 di Tambak Lorok, Semarang. Penelitian bertujuan untuk mengetahui cara pengoperasian pukat dorong, komposisi hasil tangkapan, komposisi jenis, dan distribusi ukuran hasil tangkapan sampingan pukat dorong di Tambak Lorok, Semarang. Metode penelitian yang digunakan adalah metode survey, sedangkan pengambilan sampel dilakukan dengan metode purposive sampling. Sampling dilakukan sebanyak 5 kali dengan mendata hasil tangkapan kapal pukat dorong di dermaga dan 1 kali mengikuti kegiatan nelayan dalam operasi penangkapan ikan. Pengoperasian pukat dorong meliputi proses setting, pushing, dan hauling selama 6 jam pada kedalaman 5-12 meter sekitar 2 mil dari bibir pantai dengan nilai B/C Ratio yaitu 1,63 yang berarti usaha tersebut menghasilkan keuntungan sehingga layak untuk dijalankan. Komposisi hasil tangkapan pukat dorong berdasarkan berat tangkapan yaitu 39,84% tangkapan utama dan 60,16% tangkapan sampingan. Hasil tangkapan sampingan pukat dorong yang sering ditemukan adalah Ikan Layur (Trichiurus lepturus), Ikan Kempar (Secutor ruconius), Ikan Kembung (Rastrelliger sp.), dan Ikan Tunul (Sphyraena jello). Distribusi ukuran beberapa jenis tangkapan sampingan merupakan ukuran yang belum layak tangkap karena < Lm dan nilai L50% < ½ L∞.  Capture fisheries in the Tambak Lorok use a variety of fishing gear; one of which is pushnet / sodo. The use of pushnet produces bycatch. The research was conducted in December 2017 - March 2018 aiming to find out the way of pushnet operation, catch composition, bycatch type composition, and bycatch size distribution of pushnet in the Tambak Lorok, Semarang. The research method used survey method, while sampling done by purposive sampling method. Operation of pushnet includes the process of setting, pushing, and hauling for 6 hours at a depth of 5-12 meters about 2 miles away from the shore. The value of B/C Ratio is 1.63 which means the business is feasible. Catches composition by weight is 39,84% target species and 60,16% bycatch. Composition type of bycatch was dominated by Ribbonfish (Trichiurus lepturus), Ponyfish (Secutor ruconius), Mackerel (Rastrelliger sp.), and Barracuda (Sphyraena jello). The size distribution of some bycatch were included the size of uncatchable fish because < Lm and L50% < ½ L∞. 

Fishers' description of changes in fishing gear and fishing practices in the Australian South East Trawl Fishery

2001 ◽  
Vol 52 (4) ◽  
pp. 411 ◽  
Author(s):  
Pascale Baelde
Keyword(s):  
Stock Assessment ◽  
Single Species ◽  
Fishing Gear ◽  
Qualitative Synthesis ◽  
Quota System ◽  
Fish Stocks ◽  
Trawl Fishery ◽  
Individual Transferable Quota ◽  
Catch Composition ◽  
Fishing Practices

Between the mid 1980s and early 1990s, the concurrence of three major events significantly altered the structure and dynamics of the demersal trawl sector in the Australian South-East Fishery (SEF). These events included marked technological improvement, severe decline of major fish stocks and introduction of an Individual Transferable Quota system. They have led to a switch from maximizing catch volume to maximizing catch composition and quotas, with important associated changes in fishing practices and catches. To better understand these changes and their effect on stock assessment and management, an industry survey asked SEF trawl fishers to describe their fishing gear and fishing practices in detail. This paper is a qualitative synthesis of current trends in fishing that most significantly affect the single-species, logbook-dependent assessment and management of the fishery. It demonstrates how effective collaboration between scientists and fishers can benefit fisheries research and management, by helping scientists make more informed analysis and interpretations of fisheries data.

scholarly journals Towards sustainable demersal fisheries: NepCon image acquisition system for automatic Nephrops norvegicus detection

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0252824
Author(s):  
Maria Sokolova ◽  
Fletcher Thompson ◽  
Patrizio Mariani ◽  
Ludvig Ahm Krag
Keyword(s):  
Learning Algorithm ◽  
Image Acquisition ◽  
Automatic Detection ◽  
Observation System ◽  
Fishing Gear ◽  
Learning Approaches ◽  
Nephrops Norvegicus ◽  
Trawl Fishery ◽  
Perception System ◽  
Catch Composition

Underwater video monitoring systems are being widely used in fisheries to investigate fish behavior in relation to fishing gear and fishing gear performance during fishing. Such systems can be useful to evaluate the catch composition as well. In demersal trawl fisheries, however, their applicability can be challenged by low light conditions, mobilized sediment and scattering in murky waters. In this study, we introduce a novel observation system (called NepCon) which aims at reducing current limitations by combining an optimized image acquisition setup and tailored image analyses software. The NepCon system includes a high-contrast background to enhance the visibility of the target objects, a compact camera and an artificial light source. The image analysis software includes a machine learning algorithm which is evaluated here to test automatic detection and count of Norway lobster (Nephrops norvegicus). NepCon is specifically designed for applications in demersal trawls and this first phase aims at increasing the accuracy of N. norvegicus detection at the data acquisition level. To find the best contrasting background for the purpose we compared the output of four image segmentation methods applied to static images of N. norvegicus fixed in front of four test background colors. The background color with the best performance was then used to evaluate computer vision and deep learning approaches for automatic detection, tracking and counting of N. norvegicus in the videos. In this initial phase we tested the system in an experimental setting to understand the feasibility of the system for future implementation in real demersal fishing conditions. The N. norvegicus directed trawl fishery typically has no assistance from underwater observation technology and therefore are largely conducted blindly. The demonstrated perception system achieves 76% accuracy (F-score) in automatic detection and count of N. norvegicus, which provides a significant elevation of the current benchmark.

scholarly journals Effective Implementation of Urban Agendas through Urban Action Structures (UAS): The Case of the Basque Country

2021 ◽  
Vol 13 (11) ◽  
pp. 6059
Author(s):  
Irati Otamendi-Irizar ◽  
Olatz Grijalba ◽  
Alba Arias ◽  
Claudia Pennese ◽  
Rufino Hernández
Keyword(s):  
Spatial Planning ◽  
Social Inequalities ◽  
Basque Country ◽  
Social Structures ◽  
Prospective Analysis ◽  
Sustainable Cities ◽  
Urban Policies ◽  
Effective Implementation ◽  
Catalytic Capacity

Cities are the main contributors to pollution, resource consumption and social inequalities. Therefore, they should play a key role in the path towards a more sustainable scenario in line with SDGs and different Urban Agendas. However, there are still difficulties in their implementation and citizen can play a central role. This paper presents the Urban Action Structures (UAS), understood as entities with a catalytic capacity with respect to innovative urban policies. Methodologically, firstly, a prospective analysis from regional to international level has been developed, making it possible to identify innovative lines of action in the field of sustainable cities. Secondly, the study has focused on identifying and studying UAS that can make it possible to implement the lines of action previously identified. This paper has shown that there are already social structures that can be understood as UAS, since they implement actions aligned with the priorities of the Urban Agenda for the Basque Country and, therefore, of the SDGs. The research concludes that UAS can play a key role in facilitating the implementation of Urban Agendas. Hence, urban policies should favor the generation of UAS, in order to promote long-term urban development and to foster a more sustainable spatial planning.

Fish and invertebrate by-catch in the crab pot fishery in the Isle of Man, Irish Sea

2017 ◽  
Vol 98 (8) ◽  
pp. 2099-2111
Author(s):  
Fikret Öndes ◽  
Michel J. Kaiser ◽  
Lee G. Murray
Keyword(s):  
Irish Sea ◽  
Target Species ◽  
Catch Per Unit Effort ◽  
Isle Of Man ◽  
Ecosystem Effects ◽  
By Catch ◽  
Catch Rates ◽  
Taxonomic Groups ◽  
Catch Composition ◽  
Autumn And Winter

Baited trap or pot fisheries are considered to have relatively few wider ecosystem effects on the marine environment, particularly when compared with towed mobile fishing gear. However, this assumption is rarely tested in the field. This study aimed to determine the composition of non-target species that occur in crustacean pots and to assess spatial and temporal differences in catches in the waters around the Isle of Man, Irish Sea. The data were collected using fishery independent surveys and a questionnaire study. Based on fishery independent surveys, a total of five taxonomic groups and 43 species occurred as by-catch. The dominant by-catch species was velvet crab Necora puber. The by-catch per unit effort (BPUE) for all of the non-target species was low particularly in comparison to towed bottom gear fisheries around the Isle of Man. BPUE of species composition varied considerably between different locations around the Isle of Man. The results of both the fishery independent and questionnaire data suggested that the by-catch rates varied with season with peak BPUE occurring in spring which then declined into autumn and winter. By-catch composition did not decrease significantly with an increasing target species catch. Overall, by-catch was low relative to target species catch which may be partially attributable to the use of escape panels in pot fisheries in the Isle of Man.

scholarly journals Studi pengaruh perbedaan warna umpan buatan pancing gurita terhadap hasil tangkapan

2019 ◽  
Vol 4 (2) ◽  
pp. 69
Author(s):  
Kholid Kurniawan ◽  
Lefrand Manoppo ◽  
Fanny Silooy ◽  
Alfret Luasunaung ◽  
Meta Sonya Sompie
Keyword(s):  
Coral Reef ◽  
Experimental Method ◽  
T Test ◽  
Fishing Gear ◽  
Fishery Resources ◽  
Large Potential ◽  
Color Differences

The western part of North Minahasa waters is mainly covers by coral reef with relatively large potential of fishery resources including Octopus.  Fishermen of Budo village catches the Octopus by fishing gear known as sihoru or gara – gara boboca in local name with classified as trowling.  The goals of this study are to analyze the influence of using different colors of typical bait released to fishing catch and to identity the catches species.  Experimental method and T-Test wore using to analyze the data.  The result indicated that the color differences not influence to the number of catches, which the analysis probability of brown and black colors is 0.6041, the brown and red is 0.4762, the black and red is 0.8455 which all of these numbers or higher than α0.05 = 2.2281.  Based on this identification, Octopus cyanea is mainly catches.ABSTRAK        Perairan Minahasa Utara bagian Barat pada umumnya merupakan hamparan batu karang yang memiliki potensi sumber daya perikanan yang relatif melimpah salah satunya adalah gurita (Octopus).  Dalam memanfaatkan sumber daya ini masyarakat nelayan Desa Budo menangkap gurita menggunakan alat tangkap pancing yang disebut sihoru atau gara–gara boboca, alat tangkap ini adalah alat tangkap pancing jenis tonda. Tujuan dalam penelitian ini adalah menganalisis pengaruh penggunaan warna umpan terhadap jumlah hasil Tangkapan dan mengetahui spesies octopus hasil tangkapan.  Metode yang digunakan dalam penelitan adalah eksperimental dan dianalisis menggunakan metode statistik Uji T.  Dari penelitian ini diperoleh hasil  nilai analisis P coklat hitam dan sebesar 0.6041, coklat dan merah sebesar 0.4762, hitam dan merah sebesar 0.8455 yang semua nilainya berada diatas α0.05 = 2.2281 dan dapat disimpulkan bahwa perlakuan warna umpan tidak berpengaruh terhadap hasil tangkapan.  Berdasarkan hasil identifikasi gurita yang tertangkap adalah Octopus cyanea.

scholarly journals PENDEKATAN BIONOMI PADA PELUANG PENGEMBANGAN PERIKANAN TANGKAP DI KABUPATEN KEPULAUAN TALAUD

2012 ◽  
Vol 1 (2) ◽  
pp. 57
Author(s):  
Jeti Pulu ◽  
Mulyono S. Baskoro ◽  
Daniel R. Monintja ◽  
Budhi H. Iskandar ◽  
Akhmad Fauzi
Keyword(s):  
Open Access ◽  
Economic Value ◽  
Secondary Data ◽  
Primary Data ◽  
Fishing Gear ◽  
Fish Production ◽  
Resource Rent ◽  
Illegal Fishing ◽  
Fishing Gears ◽  
Catch Composition

The research is aimed to reveal opportunity development of the capture fisheries in Talaud Islands Regency by using bionomy approach with Gordon-Schaefer model (Fauzy, 2005) con-cerning the dominant of illegal fishing activities around the area. The research was started by co-llected some secondary data on fish production and number of fishing units. Primary data were collected on catch composition and types of fishing gear. Gordon-Schaefer methods was applied to evaluate the tuna and skipjack resources in the area. The troll and pole and line are indicated as the dominant fishing gears used to catch the skipjack and tuna. In case of open access condition, the production will end up to 25,09 tons, while the resource rent will be end up to zero. For the development, simulations were exercised in 3 scenarios: 1) scenario of enhancing domestic fleet, 2) scenario of illegal fishing, and 3) scenario of net surplus. With those scenarios, if the illegal fishing could be eliminated, the capture fisheries in this regency could render economic value to 10 billion rupiah.

scholarly journals Evaluating deepwater fisheries management strategies using a mixed-fisheries and spatially explicit modelling framework

2013 ◽  
Vol 70 (4) ◽  
pp. 768-781 ◽  
Author(s):  
Paul Marchal ◽  
Youen Vermard
Keyword(s):  
Fisheries Management ◽  
Management Strategies ◽  
Spatially Explicit ◽  
Catch Per Unit Effort ◽  
Modelling Framework ◽  
Control Rules ◽  
Bioeconomic Modelling ◽  
Stock Assessments ◽  
Fleet Dynamics

Abstract Marchal, P., and Vermard, Y. 2013. Evaluating deepwater fisheries management strategies using a mixed-fisheries and spatially explicit modelling framework. – ICES Journal of Marine Science, 70: 768–781. We have used in this study a spatially explicit bioeconomic modelling framework to evaluate management strategies, building in both data-rich and data-limited harvest control rules (HCRs), for a mix of deepwater fleets and species, on which information is variable. The main focus was on blue ling (Molva dypterygia). For that species, both data-rich and data-limited HCRs were tested, while catch per unit effort (CPUE) was used either to tune stock assessments, or to directly trigger management action. There were only limited differences between the performances of both HCRs when blue ling biomass was initialized at the current level, but blue ling recovered more quickly with the data-rich HCR when its initial biomass was severely depleted. Both types of HCR lead, on average, to a long-term recovery of both blue ling and saithe (Pollachius virens) stocks, and some increase in overall profit. However, that improvement is not sufficient to guarantee sustainable exploitation with a high probability. Blue ling CPUE did not always adequately reflect trends in biomass, which mainly resulted from fleet dynamics, possibly in combination with density-dependence. The stock dynamics of roundnose grenadier (Coryphaenoides rupestris), black scabbardfish (Aphanopus carbo) and deepwater sharks (Centrophorus squamosus and Centroscymnus coelolepis) were little affected by the type of HCR chosen to manage blue ling.

Sign in / Sign up

Export Citation Format

Share Document