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1- Impacts on reproduction Mature (C,R) and pre-spawning (R) fish capture |
Stock depletion |
Fishing closures in mangrove and shallow waters areas, mainly in spring and summer, can help to protect maturing and spawning individuals. Van Overzee and Rijnsdorp (2014)VAN OVERZEE, H.M.J. and RIJNSDORP, A.D., 2014. Effects of fishing during the spawning period: implications for sustainable management. Reviews in Fish Biology and Fisheries, vol. 25, no. 1, pp. 65-83. http://dx.doi.org/10.1007/s11160-014-9370-x.
http://dx.doi.org/10.1007/s11160-014-937...
add that such action may reduce risk of over-exploitation in species forming large spawning aggregations and effects on spawning habitats, as noise and chemical pollution, which affect egg survival and newborns welfare. |
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2- Removal of strategic fish sizes Capture of individuals with higher fecundity (C,R) |
Stock depletion |
No-retention of small fish is usual in fishing routines, and law enforcement acts in this sense. However, in 2012 a new Brazilian policy was adopted, which aimed to protect the best reproducers. Moreover, research on strategic sizes to be released after catching is stimulated. |
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3- ALDFGs Gillnets (P); hooks, weights, floaters, luminous baits (R) |
Water pollution; stock depletion |
Educational campaigns are efficient in reducing abandonment and discards of fishing gears. Recreational fishermen must be persuaded to avoid rocky zones, and commercial fishermen, to keep derelict gears in appropriate dispensers. Scheld et al. (2016)SCHELD, A.M., BILKOVIC, D.M. and HAVENS, K.H., 2016. The dilemma of derelict gear. Scientific Reports, vol. 6, no. 1, pp. 19671. http://dx.doi.org/10.1038/srep19671. PMid:26790394.
http://dx.doi.org/10.1038/srep19671...
recommend a combination of preventative and mitigating measures; mitigating measures include removal of derelict gear programs. |
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4- Natural baits Shrimp extraction (C); crustacean extraction from sandy beach; non native species introduction (R) |
Genotype introduction; stock depletion |
Artificial baits are more expensive than natural ones, but their use may reduce beach fauna extraction and use of vannamei. Additionally, artificial baits are recognized by fish during catch-and-release, and their rejection increases fish survival (Bartholomew and Bohnsack, 2005BARTHOLOMEW, A. and BOHNSACK, J.A., 2005. A review of catch-and-release angling mortality with implications for no-take reserves. Reviews in Fish Biology and Fisheries, vol. 15, no. 1-2, pp. 129-154. http://dx.doi.org/10.1007/s11160-005-2175-1.
http://dx.doi.org/10.1007/s11160-005-217...
; Chaves and Freire, 2012CHAVES, P.T.C. and FREIRE, K.M.F., 2012. A pesca esportiva e o pesque-e-solte: pesquisas recentes e recomendações para estudos no Brasil. Bioikos, vol. 26, no. 1, pp. 29-34.). |
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5- Bycatch Rays, turtles, non- target finfish (C); rays and small, non-edible fish (R) |
Stock depletion |
Apart from spatial and temporal fishing closures, solutions include the development of more selective nets and fishing practices that minimize the capture and mortality of non-target species and undersized individuals of the target ones. Discard levels may be lower and subsequent mortalities of fish may also be reduced because of the decreased soak times. Based on gillnet fisheries in Australian estuaries (Gray et al., 2003GRAY, C.A., JOHNSON, D.D., YOUNG, D.J. and BROADHURST, M.K., 2003. Bycatch assessment of the estuarine commercial gill net fishery in NSW. Cronulla: NSW Fisheries, 58 p. NSW Fisheries Final Report Series, no. 55.), larger mesh sizes can result in fewer bycatch. |
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6- Post-discard or post-release mortalities Undersized fish and protected fauna (C,R), fish with no commercial value (C) |
Stock depletion |
Action must be taken to increase survival of animals discarded/released. Examples are decline in the time taken by anglers to place fish into bucket, use of barbless hooks (Hickley, 1998HICKLEY, P., 1998. Fish, sustainability and development. In: P. HICKLEY and H. TOMPKINS, eds. Recreational fisheries: social, economic and management aspects. Oxford: Blackwell Science, pp. 137-157.), and avoid of C&R during reproductive period (FAO, 2012FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS – FAO, 2012. Technical guidelines for responsible fisheries. Rome: FAO. FAO Technical Guidelines for Responsible Fisheries, no. 13.). For tournaments, Mannheim et al. (2018)MANNHEIM, S.L., CHILDS, A.-R., BUTLER, E.C., WINKLER, A.C., PARKINSON, M.C., FARTHING, M.W., ZWEIG, T., MCCORD, M., DROBNIEWSKA, N. and POTTS, W.M., 2018. Working with, not against recreational anglers: evaluating a proenvironmental behavioural strategy for improving catch-and-release behaviour. Fisheries Research, vol. 206, pp. 44-56. http://dx.doi.org/10.1016/j.fishres.2018.04.016.
http://dx.doi.org/10.1016/j.fishres.2018...
suggest improving angler knowledge, behavioral modelling, rewards and penalties. Delimitation of exclusive areas for recreational fisheries can improve survival rates post-releasing, avoiding fish exposure to commercial, intensive effort (Bartholomew and Bohnsack, 2005BARTHOLOMEW, A. and BOHNSACK, J.A., 2005. A review of catch-and-release angling mortality with implications for no-take reserves. Reviews in Fish Biology and Fisheries, vol. 15, no. 1-2, pp. 129-154. http://dx.doi.org/10.1007/s11160-005-2175-1.
http://dx.doi.org/10.1007/s11160-005-217...
). In commercial fisheries, reduction of the permitted maximum setting time (overnight) of gillnets can increase survival rates of bycatch post-discarding (Gray et al., 2003GRAY, C.A., JOHNSON, D.D., YOUNG, D.J. and BROADHURST, M.K., 2003. Bycatch assessment of the estuarine commercial gill net fishery in NSW. Cronulla: NSW Fisheries, 58 p. NSW Fisheries Final Report Series, no. 55.). |
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