Can vessel monitoring system data also be used to study trawling intensity and population depletion? The example of Australia's northern prawn fishery

Deng, Roy A.; Dichmont, Cathy; Milton, David A.; Haywood, M. D. E.; Vance, D.J.; Hall, Natasha; Die, David J.

doi:10.1139/f04-219

Cited by 98 publications

(69 citation statements)

References 9 publications

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“…Most analyses are based on satellite-based VMS where records are transmitted on long time intervals, with the risk that records classified as fishing would be incorrectly classified. Moreover, Deng et al (2005) assessed that, in bottom trawl fisheries, the biases increases with time interval and the loss of precision is quite marked with polling interval longer than 30 min. Transmission data from the vessel to the land station via satellite is quite expensive, consequently data are generally transmitted much less frequently, often every 1-2 h.…”

Section: Discussionmentioning

confidence: 99%

The Spanish blackspot seabream (Pagellus bogaraveo) fishery in the Strait of Gibraltar: spatial distribution and fishing effort derived from a small-scale GPRS/GSM based fisheries vessel monitoring system

Burgos

Gil

Olmo

2013

Aquat. Living Resour.

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-This paper aims to investigate the potential interest of using a Vessel Monitoring System (VMS) based on GPRS/GSM (Global System for Mobile Communications) technology to obtain a better estimation of fishing activity and distribution of a small-scale artisanal fleet, for which the European satellite-based system is not available. Since the early 1980s, the artisanal fishery targeting blackspot seabream (Pagellus bogaraveo), commonly known as "voraz", has been developing along the Strait of Gibraltar area. Up to now the fishing effort was estimated using the number of sales, a proxy for the number of fishing days. This measure does not, however, capture the "missing effort", i.e., fishing days resulting in no catch or not enough catch to be sold at public auction. The European satellite-based VMS provides information about the dynamics of different fishing fleets, but is not installed on small vessels (<15 m), such as those used by the artisanal "voracera" fleet targeting blackspot seabream in the Strait of Gibraltar. The Andalucía Regional Government installed its own vessel monitoring system on several artisanal fleets using GPRS/GSM cellular network technology that sends data on vessel positions and speed every three minutes. Data collected from 2009 to 2011 using this system were filtered and analysed to estimate fishing effort, catch rates and the spatial distribution of the blackspot seabream fishery. The estimates obtained seem to provide a good representation of fishery reality. As expected, the missing effort increases as the resource levels decrease. Additionally, expert knowledge of the fishery allowed application of an algorithm for splitting these daily trips into estimated fishing hauls. Afterwards the spatial distribution of catches and Catch per Unit Effort (CPUE) could be obtained linking VMS locations with landings information. This study provides a considerably finer spatial scale view of the fishery than data available in the past.

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Section: Discussionmentioning

confidence: 99%

The Spanish blackspot seabream (Pagellus bogaraveo) fishery in the Strait of Gibraltar: spatial distribution and fishing effort derived from a small-scale GPRS/GSM based fisheries vessel monitoring system

Burgos

Gil

Olmo

2013

Aquat. Living Resour.

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“…departure locations, destinations or travel routes) to develop a representative boating network (Sidman & Fik, 2005). Alternatively, map-based and electronic GPS tracking have been used successfully to collect data on the distribution of boating activities (Deng et al, 2005 andPelot andWu, 2007).…”

Section: Introductionmentioning

confidence: 99%

An analysis of visitor movement patterns using travel networks in a large marine park, north-western Australia

2011

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“…European states fit registered fishing vessels with vessel monitoring systems (VMS), which regularly declare their position via satellite (Deng et al 2005). The activities of vessels not fitted with VMS are harder to ascertain, particularly offshore.…”

Section: Applicability For Management and Monitoringmentioning

confidence: 99%

Use of machine-learning algorithms for the automated detection of cold-water coral habitats: a pilot study

Purser¹,

Bergmann²,

Lundälv³

et al. 2009

Mar. Ecol. Prog. Ser.

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Cold-water coral reefs are recognised as important biodiversity hotspots on the continental margin. The location of terrain features likely to be associated with living reef has been made easier by recent developments in acoustic sensing technology. For accurate assessment and finescale mapping of these newly identified coral habitats, analysis of video data is still required. In the present study we explore the potential of manual and automatic abundance estimation of cold-water corals and sponges from still image frames extracted from video footage from Tisler Reef (Skagerrak, Norway). The results and processing times from 3 standard visual assessment methods (15-point quadrat, 100-point quadrat and frame mapping) are compared with those produced by a new computer vision system. This system uses machine-learning algorithms to detect species within frames automatically. Cold-water coral density estimates obtained from the automated method were similar to those gained by the other methods. The automated method slightly underestimated (by 10 to 20%) coral coverage in frames which lacked a uniform seabed illumination. However, it did much better in the detection of small live coral fragments than the 15-point method. For assessing sponge coverage, the automated system did not perform as satisfactorily. It mistook a percentage of the seabed for sponge (0.1 to 2% of most frames) and underestimated sponge coverage in frames that contained many sponges. Results indicate that the machine-learning approach is appropriate for estimating live cold-water coral density, but further work is required before the system can be applied to sponges within the reef environment.

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Can vessel monitoring system data also be used to study trawling intensity and population depletion? The example of Australia's northern prawn fishery

Cited by 98 publications

References 9 publications

The Spanish blackspot seabream (Pagellus bogaraveo) fishery in the Strait of Gibraltar: spatial distribution and fishing effort derived from a small-scale GPRS/GSM based fisheries vessel monitoring system

The Spanish blackspot seabream (Pagellus bogaraveo) fishery in the Strait of Gibraltar: spatial distribution and fishing effort derived from a small-scale GPRS/GSM based fisheries vessel monitoring system

An analysis of visitor movement patterns using travel networks in a large marine park, north-western Australia

Use of machine-learning algorithms for the automated detection of cold-water coral habitats: a pilot study

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