Sampling Procedure for Establishing Criteria for Sea Urchin (Loxechinus albus) Proportion under the Legal Minimum Length of landings

Danilo Pereira,Javier E Contreras-Reyes,Marvin Querales,Carola Hernández-Santoro,Gustavo Di Giorgi

doi:10.3390/jmse8020102

Danilo Pereira, Javier E Contreras-Reyes + Show 3 more

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https://doi.org/10.3390/jmse8020102

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Abstract

Sea urchin (Loxechinus albus) is one of the most economically important species in the northeast of Chilean Patagonia, forming part of the highly diverse benthic community. This resource is being harvested under selective fishing pressure, which suppresses growth rates. In response, the National Standards Institute established Regulation 44 as a quality control measure, based on a sampling approach considering the percentage of sea urchin under the minimum legal size (UMLS) through an acceptance sampling plan. In 2019, the Chilean Undersecretary of Fisheries and Aquaculture (SUBPESCA), under Exempt Resolution No. 910, ruled that any vessel that landed 15% with sea urchin of 6.5 cm UMLS of the total catch weight will be sanctioned. In this paper, a sampling design is presented to establish criteria regarding compliance with this provision. The plan provides a statistical methodology for the evaluation of the percentage of UMLS sea urchin, which corroborates and certifies the current legislation that sanctions and fines the capture of sea urchin that does not comply with UMLS values outlined in Regulation 44. Assuming a systematic sampling plan and under assumed UMLS values of 6.0, 6.5, and 7.0 cm, it is determined that 15% of total landings (margin of tolerance) of sea urchin under 6.5 cm is the optimal level. Thus, a correct specification of the UMLS allows protecting the most vulnerable fraction of the population from overexploitation for growth.

Highlights

Sea urchin (Loxechinus albus, Molina 1782) is an economically crucial species for the northeast of Chilean Patagonia, belonging to the highly diverse benthic community [1]
The first was the level of quality desired by the customer (acceptable quality level (AQL)), where the producer’s risk (α) was the possibility that the sampling plan did not verify an acceptable quantity in the lot and that, was rejected: a “type I” error
In accordance with Regulation 44, with AQL = 10 and considering a Level II inspection, the data in Table 1 were obtained. This AQL value was considered because it was established in the regulation and because it remained below an RQL of 15

Summary

Introduction

Sea urchin (Loxechinus albus, Molina 1782) is an economically crucial species for the northeast of Chilean Patagonia, belonging to the highly diverse benthic community [1]. This species forms populations in areas of between 11,000 and 2,500,000 individuals, with densities of up to 11 individuals per square meter [2,3]. The fishing pressure led to a crisis in 2001, which led to the establishment of a management plan that took effect in 2005. Since 2007, the management plan has been a fixed annual catch policy, set at 18,000 tonnes and a minimum size of capture of 6.0 cm in diameter [5]. A global catch quota was first established in 2011 based on an stock assessment that considered catch and effort information obtained directly from the landings [3]

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