Near Disappearance of the Angelshark Squatina Squatina Over Half A Century of Observations

Peer reviewed: 
Yes, item is peer reviewed.
Scholarly level: 
Faculty/Staff
Final version published as: 

Hiddink JG, Shepperson J, Bater R, Goonesekera D, Dulvy NK. 2019. Near disappearance of the Angelshark Squatina squatina over half a century of observations.  Conservation Science and Practice. 

Keywords: 
Historical ecology
Reconstruction of changes in abundance
Local ecological knowledge
Elasmobranchii
Fisheries
Abstract: 

Marine extinctions are particularly difficult to detect and almost all have been discovered after the fact. Retrospective analyses are essential to avoid concluding no-extinction when one has occurred. We reconstruct the Angelshark population trajectory in a former hotspot (Wales), using interviews and opportunistic records. After correcting for observation effort and recall bias, we estimate a 70% (1.5% yr-1) decline in abundance over 46 years. While formerly widespread, Angelshark distribution contracted to a central core of Cardigan Bay. Angelshark declined almost unnoticed in one of the best-monitored and most intensively managed seas in the world. Bycatch may be minimised by limiting netting on shingle reefs in Cardigan Bay. We provide the first quantitative time series to reveal the timing and trajectory of decline of Angelshark in the coastal waters of Wales and uncover historical centres of abundance and remnant populations that provide the first opportunity for the focus of conservation. 

Description: 

The full text of this paper will be available in Aug 2020 due to the embargo policies of Conservation Science and Practice. Contact summit@sfu.ca to enquire if the full text of the accepted manuscript can be made available to you.

Language: 
English
Document type: 
Article
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