Fishing vessels as scientific platforms: An introduction

Melvin, Gary D.; Gerlotto, François; Lang, Carolina; Trillo, Pedro

doi:10.1016/j.fishres.2016.02.022

Cited by 8 publications

(2 citation statements)

References 8 publications

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“…Despite the promising results from bi-or multi-frequency methods, many existing datasets have been collected in the past using only one frequency, and therefore those methods cannot be applied. The same situation holds for data recently collected by fishing vessels that have been implemented as scientific platforms (Fässler et al, 2016;Melvin et al, 2016). Mexico's National Fisheries Institute (INAPESCA) has conducted a series of acoustic surveys to assess the biomass of Pacific sardine in the Gulf of California, and from 2008 to 2011, before another frequency was incorporated (120 kHz), only data collected at 38 kHz are available.…”

Section: Introductionmentioning

confidence: 80%

A probabilistic procedure for estimating an optimal echo-integration threshold using the Expectation-Maximisation algorithm

López-Serrano

Ortíz

Nevárez-Martı́nez

2018

Aquat. Living Resour.

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To obtain reliable fish biomass estimates by acoustic methods, it is essential to filter out the signals from unwanted scatterers (e.g. zooplankton). When acoustic data are collected at more than one frequency, methods that exploit the differences in reflectivity of scatterers can be used to achieve the separation of targets. These methods cannot be applied with historical data nor recent data collected on board fishing vessels employed as scientific platforms, where only one transducer is available. Instead, a volume backscattering strength (Sv) threshold is set to separate fish from plankton, both for echogram visualisation or, more importantly, during echo-integration. While empirical methods exist for selecting a threshold, it often depends on the subjective decision of the user. A−47 dB threshold was empirically established in 2008 at the beginning of a series of surveys conducted by Mexico's National Fisheries Institute to assess the biomass of Pacific sardine in the Gulf of California. Until 2012, when a 120 kHz transducer was installed, only data collected at 38 kHz are available. Here, we propose a probabilistic procedure to estimate an optimal Sv threshold using the Expectation-Maximisation algorithm for fitting a mixture of Gaussian distributions to Sv data sampled from schools associated with small pelagic fish and their surrounding echoes. The optimal threshold is given by the Bayes decision function for classifying an Sv value in one of the two groups. The procedure was implemented in the R language environment. The optimal threshold found for 38 kHz data was −59.4 dB, more than 12 dB lower than the currently used value. This difference prompts the need to revise the acoustic biomass estimates of small pelagics in the Gulf of California.

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Section: Introductionmentioning

confidence: 80%

A probabilistic procedure for estimating an optimal echo-integration threshold using the Expectation-Maximisation algorithm

López-Serrano

Ortíz

Nevárez-Martı́nez

2018

Aquat. Living Resour.

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“…Ships of opportunity provide another means to improve coverage of ocean observations. Bucklin et al (2001) and Melvin et al (2016) highlighted the potential for the use of fishing vessels to undertake biological and environmental sampling. Commercial ships have a presence on the high seas second to none and offer society a feasible and cost-effective opportunity to contribute to solving observational deficiencies (SCOR, 2011).…”

Section: Other Considerations In Stakeholder Engagement Using Communimentioning

confidence: 99%

The Role of Stakeholders in Creating Societal Value From Coastal and Ocean Observations

et al. 2019

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The importance of stakeholder engagement in ocean observation and in particular the realization of economic and societal benefits is discussed, introducing a number of overarching principles such as the convergence on common goals, effective communication, co-production of information and knowledge and the need for innovation. A series of case studies examine the role of coordinating frameworks such as the United States' Interagency Ocean Observing System (IOOS R), and the European Ocean Observing System (EOOS), public-private partnerships such as Project Azul and the Coastal Data Information Program (CDIP) and finally the role of the "third" or voluntary sector. The paper explores the value that stakeholder engagement can bring as well as making recommendations for the future.

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Ontogenetic and temporal diet variation in adult Antarctic krill Euphausia superba at South Georgia during austral winter revealed by stable isotope analysis

et al. 2019

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Fishing vessels as scientific platforms: An introduction

Cited by 8 publications

References 8 publications

A probabilistic procedure for estimating an optimal echo-integration threshold using the Expectation-Maximisation algorithm

A probabilistic procedure for estimating an optimal echo-integration threshold using the Expectation-Maximisation algorithm

The Role of Stakeholders in Creating Societal Value From Coastal and Ocean Observations

Ontogenetic and temporal diet variation in adult Antarctic krill Euphausia superba at South Georgia during austral winter revealed by stable isotope analysis

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