Preliminary evaluation of a large‐scale American eel conservation stocking experiment

Published source details Pratt T.C. & Threader R.W. (2011) Preliminary evaluation of a large‐scale American eel conservation stocking experiment. North American Journal of Fisheries Management, 31, 619-628.
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This study is summarised as evidence for the following.

	Action	Category
	Translocate wild eels to re-establish or boost native populations (‘stocking’ or ‘restocking’) Action Link

Translocate wild eels to re-establish or boost native populations (‘stocking’ or ‘restocking’)

A study in 2009 in a lake and adjoining river in Ontario, Canada (Pratt & Threader 2011) reported that translocated wild American eels Anguilla rostrata dispersed and increased in length and weight. Results are not based on tests of statistical significance. Translocated eels were recaptured or observed at six locations within the lake (40–300 km from release sites, total 253 eels) and at one location in the river (30 km downstream of release sites, total 88 eels). The average length and weight of translocated eels increased between spring and autumn in both the lake (spring: 131 mm, 3 g; autumn: 147 mm, 6 g) and river (spring: 172 mm, 12 g; autumn: 291 mm, 53 g). Wild American eels were translocated to five sites in a lake (1.3 million glass eels in 2008–2009) and five sites in an adjoining river (167,000 elvers in 2006, 2.6 million glass eels in 2007–2009). Eels were obtained from a commercial fishery, and were quarantined and marked before release. In spring and autumn 2009, boat electrofishing was carried out at night along transects (100-m long, 2.5-m wide) in the lake (28–33 transects) and river (42–44 transects). Captured eels (lake: 144 eels, river: 28 eels) were measured and weighed. Size was estimated for eels observed from the boat (lake: 109 eels, river: 60 eels).

(Summarised by: Anna Berthinussen)