Mapping the distribution of scale-rayed wrasse Acantholabrus palloni in Swedish Skagerrak using angling records.

Joacim Näslund,Markus Lundgren

doi:10.7717/peerj.5900

Abstract

In this paper, we map the distribution of scale-rayed wrasse Acantholabrus palloni in eastern Skagerrak based on a combination of verified and personally communicated angling records. Long thought to be occasional vagrants outside its known range in the eastern Atlantic Ocean and Mediterranean Sea, we ask if this rare and understudied labrid has expanded its range and become established in Swedish waters. A recent surge in verified angling records in the Swedish Anglers Association’s specimen database Storfiskregistret provides information to suggest that this species should no longer be considered an occasional guest, but rather a species established in the Swedish parts of Skagerrak. These records are supported by additional personal communications with anglers. The species is currently well spread geographically along the Swedish Skagerrak coast, with many locations providing repeated captures of adult fish over multiple years. The typical Swedish catch sites are rocky reefs located between the general 40- and 80-m depth curves, likely influenced by currents bringing higher-salinity water from the North Sea. The present study show that angling records can provide an important, but underutilized, resource for mapping the distribution of data-deficient fish species.

Highlights

Records of rare species and their natural history can constitute important information for future research on these species and the ecosystems they occur in, for example, with respect to human impacts (Boero, 2013; Able, 2016)
Swedish non-angling records The occurrence of A. palloni in Swedish waters was rarely reported prior to 2010, with a first record of a juvenile specimen from year 1993 from somewhere between 50 and 115 m depth in the mouth of the Singlefjord, northeastern Skagerrak (Cedhagen & Hansson, 1995; Fig. 1, position 5)
The species has been previously reported from the Koster Fjord area around the Koster Islands, northeastern Skagerrak (Fig. 1, position 4; Hallberg, 2011), and six km west of Rörö Island (Fig. 1, position 6), southern Skagerrak in 2008

Summary

Introduction

Records of rare species and their natural history can constitute important information for future research on these species and the ecosystems they occur in, for example, with respect to human impacts (Boero, 2013; Able, 2016). Obtaining records of rare species is, time consuming and professional biologists are often active within projects limited in time and space, making alternative sources for information important (Devictor, Whittaker & Beltrame, 2010; Bradter et al, in press). This is true for records from aquatic environments, where the occurring species rarely can be observed directly, but rather have to be obtained by indiscriminate techniques such as trawls, nets, and dredges, which are limited in their areal coverage at any given point in time. The aim is to present a desktop study where citizen-generated data, in the form of private and publicly available angling records, are used to map out a tentative distribution map for a data-deficient species, the scale-rayed wrasse Acantholabrus palloni (Risso, 1810), in Swedish waters

Methods

Results

Conclusion