Change type of recreational fishing gear (e.g. hook type, bait, lure size)

Supporting evidence from individual studies

1. A replicated, controlled study in 2014 in a lake in Hordaland, Norway (Weltersbach et al. 2018) found that using small hooks for recreational fishing of European eels Anguilla anguilla led to higher hook-shedding rates compared to large hooks, but survival rates were similar for eels caught on small and large hooks with and without barbs. Seven of 17 captured eels (41%) shed small hooks after release, whereas none of 15 eels (0%) shed large hooks. After five months, the percentage of released eels that survived did not differ significantly between those caught on large barbed (5 of 10 eels, 50%), large barbless (3 of 5 eels, 60%), small barbed (8 of 11 eels, 73%) or small barbless hooks (3 of 6 eels, 50%). In May 2014, thirty-two European eels (31–50 cm long) were caught by rod and line from a lake shoreline at night. Large (10-mm gap width) and small hooks (6.8-mm gap width) with and without barbs were attached to 7-kg monofilament line and baited with 1–2 live earthworms Eisenia hortensis. All captured eels were hooked beyond the mouth cavity (‘deep-hooked’), and the line cut as close to the mouth as possible. Eels were transported to a research facility where they were anaesthetized, measured, tagged and x-rayed before being transferred to a holding tank. Eels were fed and checked daily for 23 weeks, and x-rayed 1, 3, 10, 24, 54, 115 and 163 days after capture. 

   Study and other actions tested

   Referenced paper

   Weltersbach M.S., Ferter K., Sambraus F. & Strehlow H.V. (2016) Hook shedding and post-release fate of deep-hooked European eel. Biological Conservation, 199, 16-24.

2. A replicated, controlled study in 2015 in two ponds in Germany (Weltersbach et al. 2018) reported that using small J-hooks for recreational fishing led to fewer deaths of European eel Anguilla anguilla after catch and release than large J-hooks. Unless stated, Results are not based on tests of statistical significance. Up to 65 days after release, 21 of 53 eels (40%) died after fishing with a small J-hook, compared to 31 of 57 (54%) with a large J-hook. Meanwhile, 12 of 38 eels (32%) died after being caught in a fyke net. Fishers caught significantly more eels with small J-hooks (242 eels, 0.17 eels/hour) than large J-hooks (150 eels, 0.1 eels/hour). In May–June 2015, two drainable fishing ponds (roughly 41 x 9 x 1.5 m) were each stocked with 153 wild yellow eels (36–63 cm length) caught from nearby lakes. In June–July 2015, eels were fished from the shoreline of each pond at night on 16 occasions. Small (34.6 x 11.4 mm) and large J-hooks (20.8 x 7.0 mm) were attached to a 50 cm line and baited with 1–3 live earthworms Eisenia hortensis or Lumbricus terrestris. As a comparison, eels were simultaneously caught in one fyke net/pond. After catching, hooks were removed or the line cut as close to the mouth as possible. Eels were held in rectangular nets for 72 h, and then monitored daily in a holding pond for 43–65 days, after which the pond was drained and searched. Eels not recovered from the ponds were assumed to have died. Eel catch rates with small and large J-hooks were assessed by 67 fishers in a citizen science project in June–October 2015.

   Study and other actions tested

   Referenced paper

   Weltersbach M.S., Strehlow H.V., Ferter K., Klefoth T., De Graaf M. & Dorow M. (2018) Estimating and mitigating post-release mortality of European eel by combining citizen science with a catch-and-release angling experiment. Fisheries Research, 201, 98-108.