Artisanal shark fishing in Milne Bay Province, Papua New Guinea: biomass estimation from genetically identified shark and ray fins

S A Appleyard,S Vieira,B Sabub,W T White

doi:10.1038/s41598-018-25101-8

Abstract

Our study is the first detailed examination of species composition using DNA COI barcoding of elasmobranchs from an artisanal fishery of Papua New Guinea. The study is the first in the region to provide biomass estimates based on species confirmation following examination of dried fins. Over 20 species of elasmobranchs were identified from 623 fins from the artisanal fishery in Milne Bay Province of PNG, with Carcharhinus amblyrhynchos and Carcharhinus melanopterus the most abundant species in the catches. Of concern, 21% of fins examined were from IUCN listed threatened species (Vulnerable or Endangered) with 8% of fins from the Endangered scalloped hammerhead (Sphyrna lewini). Following species identifications and use of species-specific length and weight extrapolations, we estimated over 9 t of elasmobranchs contributed to the fin batch. Importantly, the vast majority of the elasmobranchs in this batch were from immature animals. Genetic identification has an important role to play in the ongoing sustainable management of elasmobranchs in artisanal fisheries in PNG and more widely. However in the absence of ongoing genetic testing, recording the species (if known) at the time of catch is more achievable and would provide more robust data for fisheries managers in PNG over the longer term.

Highlights

Our study is the first detailed examination of species composition using DNA c oxidase subunit I (COI) barcoding of elasmobranchs from an artisanal fishery of Papua New Guinea
In the Commonwealth Scientific and Industrial Research Organisation (CSIRO)/Australian Centre for International Agricultural Research (ACIAR)/Papua New Guinea (PNG) NFA research, we developed a barcode library for known elasmobranch species in the region
Out of the 623 individuals recorded in the artisanal sourced batch of fins from Asiapac, 557 fin samples were extracted and genetically analysed

Summary

Introduction

Genetic identification has an important role to play in the ongoing sustainable management of elasmobranchs in artisanal fisheries in PNG and more widely. As apex predators which serve important and unique roles in the marine ecosystem[1,2,3], many elasmobranch species (i.e. Class Chondrichthyes, sharks and rays) and populations are under significant pressure from fisheries-driven declines[4] Much of this decline is linked to the demand for shark fins[5,6,7,8,9,10]. In the west Pacific country of Papua New Guinea (PNG), limited government resourcing and relatively large fishing territories, coupled with lack of species identification tools for elasmobranchs makes it challenging to quantify shark landings and fin catches more explicitly[16]. There are currently no national management arrangements in place for the artisanal fishery[16]

Methods

Results

Conclusion