scholarly journals Fishing for euros: how mapping applications can assist in maintaining revenues under the Landing Obligation

2020 ◽  
Author(s):  
Julia Calderwood ◽  
Kristian Schreiber Plet-Hansen ◽  
Clara Ulrich ◽  
David G Reid
Keyword(s):  
Temporal Dynamics ◽  
Species Distributions ◽  
Fishing Effort ◽  
Fishing Industry ◽  
Fishing Activity ◽  
Spatio Temporal ◽  
Catch Rates ◽  
Demersal Species ◽  
High Catch

Abstract With the introduction of the Landing Obligation (LO) in EU fisheries, there is an increasing need for fishers to avoid unwanted catches while maximizing revenues. Improving understanding of the spatio-temporal dynamics of unwanted catches could assist the fishing industry optimize catches by altering where they fish. How following such advice relates to revenues and fishery dynamics requires more consideration. We take an existing hotspot mapping methodology and examine how it could be used to identify fishing opportunities under the LO in Irish (Celtic Sea) and Danish (North Sea and Skagerrak) demersal fisheries. We consider if fishing effort can be relocated to avoid unwanted catches while maintaining revenues. The value per unit effort of fishing activity in both areas was often linked to high catch rates of key demersal species (cod, haddock, hake, and whiting). Our analyses indicated, however, that there are options to fish in areas that could provide higher revenues while avoiding below minimum conservation reference size catches and choke species. This was evident across both case study areas demonstrating that hotspot mapping tools could have wide applicability. There does, however, remain a need to explore how the displacement of vessels may further alter species distributions and fleet economics.

scholarly journals Bycatch: complementary information for understanding fish behaviour. Namibian Cape hake (M. capensis and M. paradoxus) as a case study

2006 ◽  
Vol 63 (8) ◽  
pp. 1513-1519 ◽  
Author(s):  
Ana Gordoa ◽  
Heinrich Lesch ◽  
Silvia Rodergas
Keyword(s):  
Negative Relationship ◽  
Temporal Distribution ◽  
Horse Mackerel ◽  
Sample Data ◽  
Strong Negative Relationship ◽  
Different Depths ◽  
Spatio Temporal ◽  
Catch Rates ◽  
Informative Component

Abstract To identify spatio-temporal distribution in Namibian Cape hake (M. paradoxus and M. capensis), incidental hake catch by the horse mackerel fleet and targeted catch by the hake fleet were analysed for the period 1999–2004. The targeted catch, 45 955 fishing days, came from hake fishery logbooks and the incidental catch, 24 689 trawls, from observers' sample data collected aboard vessels of the horse mackerel fleet. A strong negative relationship between monthly catch rates (cpue) and bycatch was observed, confirming that the seasonal change in catchability is caused by differences in hake vertical dispersion. The October trends were an exception: both cpue and bycatch were negative. A drop in catchability at different depths of the fishing grounds indicates that M. capensis migrates to shallower water (<200 m) at the peak of spawning. Although there was no significant relationship between annual catch rates and bycatch, probably because of the short length of the time-series, annual bycatch should not be discarded as an indicator of hake recruitment. The results highlight the potential informative component of bycatch in identifying population patterns that cannot be extracted from the targeted catch.

scholarly journals Scottish Inshore Fisheries Integrated Data System (SIFIDS): work package (2) final report WP2A: development and pilot deployment of a prototypic autonomous fisheries data harvesting system, and WP2B: investigation into the availability and adaptability of novel technological approaches to data collection

2019 ◽  
Author(s):  
R. Ayers ◽  
G.P. Course ◽  
G.R. Pasco
Keyword(s):  
Data Collection ◽  
Economic Value ◽  
Fishing Effort ◽  
Final Report ◽  
Executive Summary ◽  
Fishing Activity ◽  
Business Decisions ◽  
Fishing Vessels ◽  
Spatio Temporal ◽  
Data Deficient

[Extract from Executive Summary] To enhance sustainability and foster resilience within Scotland’s inshore fishing communities an effective system of collecting and sharing relevant data is required. To support business decisions made by vessel owners as well as informing fisheries managers and those involved in marine planning it will be vital to collect a range of information which will provide a robust understanding of fishing activity, the economic value of the sector and its importance within local communities. The SIFIDS Project was conceived to assist in attaining these goals by working alongside fishers to develop and test technology to automatically collect and collate data on board vessels, thereby reducing the reporting burden on fishers. The project built upon previous research funded through the European Fisheries Fund (EFF) and was designed to deliver a step change in the way that inshore fisheries in Scotland could be managed in cooperation with the industry. The project focussed on inshore fishing vessels around Scotland, where spatio-temporal information on the distribution of vessels and associated fishing effort is data deficient. The whole project was broken down into 12 highly integrated work packages. This is the integrated report for work packages 2A and 2B, entitled’ Development and Pilot Deployment of a Prototypic Autonomous Fisheries Data Harvesting System’ (2A) and ‘Investigation into the Availability and Adaptability of Novel Technological Approaches to Data Collection’ (2B).

scholarly journals POTENTIAL FISHING GROUND MAPPING BASED ON GIS HOTSPOT MODEL AND TIME SERIES ANALYSIS: A CASE STUDY ON LIFT NET FISHERIES IN SERIBU ISLAND

2017 ◽  
Vol 9 (1) ◽  
pp. 337-356
Author(s):  
Andi Alamsyah Rivai ◽  
Vincentius P. Siregar ◽  
Syamsul B. Agus ◽  
Hiroki Yasuma
Keyword(s):  
Time Series ◽  
Fisheries Management ◽  
Fishing Ground ◽  
Effective Management ◽  
Target Species ◽  
Fishing Activity ◽  
Fishing Season ◽  
Spatio Temporal ◽  
West Monsoon

Information on the spatial and temporal of fishing activity can optimize a fisheries management and increase their economical and biological benefit. For effective management and good understanding of fishing activities, information about fishing ground is crucial. In this study, we aimed to analyze the spatio-temporal of lift net fisheries in Kepulauan Seribu by analyzing their fishing season, investigating their hotspot of fishing ground using GIS-based hotspot model, and mapping the potential fishing ground of each target species. We found that anchovy and scad could be caught throughtout the year, while sardine and squid had high fishing season in west monsoon. Hotspot of fishing ground of lift net fisheries in Kepulauan Seribu waters generally was concentrated around Lancang Island and in southern part of Kotok Island. Potential fishing ground for sardines was located in around Lancang Island on west monsoon. Squids were highly distributed around Lancang Island in December to January and around Lancang and Rambut Islands in November. Anchovy and scad had more potential fishing ground in around Kepulauan Seribu waters.  Keywords: fishing ground, lift net, hotspot, fishing season 

scholarly journals Estimating Fishing Effort and Spatio-Temporal Distribution of Longline Vessels in the Indian Ocean

2021 ◽  
Vol 8 ◽  
Author(s):  
Febrianto W. Utama ◽  
Xavier Hoenner ◽  
Britta Denise Hardesty ◽  
David Peel ◽  
Jessica H. Ford ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Temporal Distribution ◽  
Fishing Effort ◽  
Fishing Activity ◽  
Widespread Occurrence ◽  
Fisheries Resources ◽  
Spatial Shift ◽  
Landing Sites ◽  
The Indian Ocean ◽  
Spatio Temporal

Protein from fish is essential for feeding the world’s population and is increasingly recognized as critical for food security. To ensure that fisheries resources can be sustainably maintained, fisheries management must be appropriately implemented. When logbook and landing records data are not complete or are incorrect, it is challenging to have an accurate understanding of catch volume. Focusing on Indonesian longline vessels operating in the Indian Ocean from 2012–2019 (n = 1124 vessels), our aims were to (1) assess compliance through identification of landing sites and potentially illicit behavior inferred by interruptions in VMS transmission, and (2) understand how the fishery operates along with quantifying the spatio-temporal distribution of fishing intensity by applying a Hidden Markov Model, which automatically classified each VMS position as fishing, steaming and anchoring. We found vessel compliance gaps in 90% of vessels in the dataset. Compliance was questionable due both to the widespread occurrence of long intermissions in relaying VMS positions (mean = 17.8 h, n = 973 vessels) and the use of unauthorized landing sites. We also observed substantial changes in fishing effort locations among years. The introduction of regulatory measures during the study period banning transshipment and foreign vessels may be responsible for the spatial shift in fishing activity we observed, from encompassing nearly the whole Indian Ocean to more recent intense efforts off western Sumatra and northern Australia.

scholarly journals Using Red List species in designating protection status to forest areas: a case study on the problem of spatio-temporal dynamics

2020 ◽  
Vol 29 (11-12) ◽  
pp. 3429-3443
Author(s):  
Lise Tingstad ◽  
John-Arvid Grytnes ◽  
Magne Sætersdal ◽  
Ivar Gjerde
Keyword(s):  
Temporal Dynamics ◽  
Rank Order ◽  
Common Species ◽  
Red List ◽  
Red List Species ◽  
Polypore Fungi ◽  
Temporal Turnover ◽  
Spatio Temporal ◽  
Selection Of

Abstract Red-listed species are often used as target species in selection of sites for conservation. However, limitations to their use have been pointed out, and here we address the problem of expected high spatio-temporal dynamics of red-listed species. We used species data (vascular plants, bryophytes, macrolichens and polypore fungi) from two inventories 17 years apart to estimate temporal turnover of red-listed and non-red-listed species in two forest areas (147 and 195 ha) and of plots (0.25 ha) within each area. Furthermore, we investigated how turnover of species affected the rank order of plots regarding richness of red-listed species, using two different national Red List issues (1998 and 2015). In both study areas, temporal turnover was substantial, despite minor changes in the overall number of species. At plot level, temporal turnover in red-listed species was higher than in non-red-listed species, but similar to non-red-listed species of the same frequency of occurrence. Adding the effect of changing identities of species red-listed according to the two Red List issues, further increased the estimated spatio-temporal dynamics. Recorded spatio-temporal turnover also resulted in substantial changes in the rank order of plots regarding richness of red-listed species. Using rare red-listed species for site selection may therefore be accompanied by a higher loss of conservation effectiveness over time than for more common species, and particularly at finer scales.

Evaluating spatio-temporal dynamics of multiple fisheries-targeted populations simultaneously: A case study of the Bohai Sea ecosystem in China

2020 ◽  
Vol 422 ◽  
pp. 108987
Author(s):  
Lisha Guan ◽  
Xiujuan Shan ◽  
Xianshi Jin ◽  
Harry Gorfine ◽  
Tao Yang ◽  
...  
Keyword(s):  
Bohai Sea ◽  
Temporal Dynamics ◽  
The Bohai Sea ◽  
Spatio Temporal

scholarly journals Structure and spatio-temporal dynamics of artisanal fisheries around a Mediterranean marine protected area

2009 ◽  
Vol 67 (2) ◽  
pp. 191-203 ◽  
Author(s):  
Aitor Forcada ◽  
Carlos Valle ◽  
José L. Sánchez-Lizaso ◽  
Just T. Bayle-Sempere ◽  
Fabio Corsi
Keyword(s):  
Protected Area ◽  
Marine Protected Area ◽  
Temporal Dynamics ◽  
Marine Reserve ◽  
Fishing Effort ◽  
Western Mediterranean ◽  
Artisanal Fisheries ◽  
Time Data ◽  
Western Mediterranean Sea ◽  
Spatio Temporal

Abstract Forcada, A., Valle, C., Sánchez-Lizaso, J. L., Bayle-Sempere, J. T., and Corsi, F. 2010. Structure and spatio-temporal dynamics of artisanal fisheries around a Mediterranean marine protected area. – ICES Journal of Marine Science, 67: 191–203. Marine protected areas (MPAs) have been proposed and established throughout the world, but few studies have adequately assessed the spatial adaptations of fishers to the limitations imposed by their placement. The main objectives of this work were to identify and describe the characteristics of the artisanal fisheries around Tabarca Marine Reserve (western Mediterranean Sea) and to define their activity in space and time. Data were collected through questionnaires to fishers and onboard sampling. The artisanal fisheries were complex owing to the multispecific nature of the landings, the variety of gears involved, and their marked seasonality. All boats of the three harbours around the MPA were assessed, for a total of 32 boats. The fishers exploit 18 fishing grounds with eight gear types, for a total of 17 métiers. Mullus trammelnet, Sepia trammelnet, and sparid longline are the most frequently used métiers. The main factors determining the spatial distribution of the fishing effort are proximity to home harbour, habitat heterogeneity, and closeness to the MPA. Total fishing effort appeared slightly concentrated around the MPA, but each métier showed different patterns of effort distribution. Although the sparid gillnet and the sparid longline concentrated along MPA boundaries, the Sepia trammelnet and the Mullus trammelnet did not.

Spatio-temporal distribution of longline catch per unit effort, sea surface temperature and Atlantic marlin

2003 ◽  
Vol 54 (4) ◽  
pp. 409 ◽  
Author(s):  
C. Phillip Goodyear
Keyword(s):  
Temporal Distribution ◽  
Fishing Effort ◽  
Sea Surface ◽  
Sea Surface Temperatures ◽  
Fishing Mortality ◽  
Catch Per Unit Effort ◽  
Surface Temperatures ◽  
Unit Effort ◽  
Spatio Temporal ◽  
Catch Rates

Atlantic blue and white marlin are currently overfished, primarily as a result of bycatch in pelagic longlines directed at other species. One possible management measure to reduce fishing mortality on these species would be to restrict fishing effort in times and places with exceptionally high marlin catch per unit effort (CPUE). The International Commission for the Conservation of Atlantic Tunas maintains a database of catch and catch-effort statistics of participating nations. These data were analysed to determine whether the distribution of CPUE is sufficiently heterogeneous in time and space that such measures might provide meaningful management alternatives. The resulting distributions of catch rates were also contrasted with monthly average sea surface temperatures to examine the possible association between temperature and CPUE. The results show spatio-temporal heterogeneity in catch rates that may be partly explained by seasonal changes in sea surface temperatures. The time–area concentrations of high CPUE differ between the species. This observed heterogeneity might be exploited to develop alternatives for reducing fishing mortality for future management of the fisheries, but additional research is needed to refine the spatial scale of the analysis and to more fully understand the factors contributing to the observed distribution.

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