Publication Abstract

Geolocation of free-ranging fish on the European continental shelf as determined from environmental variables. II. Reconstruction of plaice ground-tracks

Geolocation of free-ranging fish on the European continental shelf as determined from environmental variables. II. Reconstruction of plaice ground-tracks

E. Hunter, J.D. Metcalfe, B.H. Holford & G.P. Arnold

Between December 1993 and February 1997, 302 electronic data storage tags (DST), programmed to record depth at 10 minute intervals and temperature daily were attached to mature female plaice, Pleuronectes platessa, and released in the Southern North Sea. Fifty tags were returned, 38 of which functioned fully and recorded 2955 days of data. Twenty-seven tags recorded data over the full period at liberty, and 34 geographical ground-tracks were reconstructed. Reconstruction was performed using a 2-dimensional tidal stream simulation model that translated vertical movement of fish, recorded by DSTs, into horizontal movement assuming an initial down-tide swimming speed of 0.6 BLs-1. Geographical accuracy of reconstructed tracks was assessed based on closeness of fit between (i) reconstruction endpoint and reported recapture position; (ii) reconstructed locations and corresponding locations based on tidal data recorded by DSTs using Tidal Location Method (TLM; location of areas with similar tidal range and time of high water); and (iii) DST temperature records and corresponding averaged sea surface temperature data records for corresponding locations. The results demonstrate that the assumptions of the tidal stream simulation model were sufficient to reconstruct geographically accurate representations of the migrations of individual plaice, which have in turn provided new information on the extent, duration and directionality of movement. Our study demonstrates how DSTs can provide fishery-independent data with direct management applications in behaviourally-driven, individual-based predictive models of fish migration.

Reference:

E. Hunter, J.D. Metcalfe, B.H. Holford & G.P. Arnold. 2003. Geolocation of free-ranging fish on the European continental shelf as determined from environmental variables. II. Reconstruction of plaice ground-tracks. Marine Biology, 144: 787-798

E. Hunter*, J.D. Metcalfe*, B.H. Holford & G.P. Arnold

Marine Biology, 144: 787-798