Anti-trawling devices are a specific kind of artificial reef. Trawling is a controversial fishing practice which has attracted environmental, legal, and political objections. Anti-trawling devices have been invented, manufactured, and deployed to damage trawlers' nets and thus slow them down, force them to stop operating, or force them elsewhere. They are usually large concrete blocks with metal hooks or blades embedded in their tops. Anti-trawling devices are being used by environmental groups, fishermen, and sometimes even by governments.[1][2][3][4][5][6][7][8][9][10][11][12]
As with artificial reefs in general,[13][14][15] the actual effectiveness of anti-trawling reefs is understudied.[14][15] An Australian Government analysis anticipates very high costs and difficulty if they are removed.[16] If they are removed, however, they expect:[16]
- Increased fish abundance rather than decreased, because typically fishing increases around such devices to greater degree than the actual biological productivity does;
- Return and resurgence of finfish and other mobile organisms;
- Stabilization of prey numbers due to restored ecological balance due to the return of larger predators;
- Return of predators preventing "spill over" of predators and grazers into other areas;
- Restoration of appropriate movement and migration patterns.
They recommend changing permitting processes to account for the cost, and for whether removal is even feasible.[16]
References
edit- ^ "Creation of the Artificial Shellfish Reefs and Anti Trawling Devices". Marine Conservation Cambodia - Volunteer Internship in Marine Conservation and Research. 2016-10-14. Archived from the original on 2021-01-17. Retrieved 2021-01-17.
- ^ Tessier, A; Verdoit-Jarraya, M; Blouet, S; Dalias, N; Lenfant, P (2014-05-07). "A case study of artificial reefs as a potential tool for maintaining artisanal fisheries in the French Mediterranean Sea". Aquatic Biology. 20 (3). Inter-Research Science Center: 255–272. doi:10.3354/ab00563. ISSN 1864-7782.
- ^ Iannibelli, M.; Musmarra, D. (2008). "Effects of anti-trawling artificial reefs on fish assemblages: The case of Salerno Bay (Mediterranean Sea)". Italian Journal of Zoology. 75 (4). Informa: 385–394. doi:10.1080/11250000802365290. ISSN 1125-0003. S2CID 84091089.
- ^ Juan J. Muñoz-Pérez; Jose M. Gutiérrez Mas; Jose M. Naranjo; Enrique Torres; Lorenzo Fages (September 2000). "Position and monitoring of anti-trawling reefs in the Cape of Trafalgar (Gulf of Cadiz, SW Spain)". Bulletin of Marine Science. 67 (2): 761–77.
- ^ Serrano, Alberto; Rodríguez-Cabello, Cristina; Sánchez, Francisco; Velasco, Francisco; Olaso, Ignacio; Punzón, Antonio (2010-06-02). "Effects of anti-trawling artificial reefs on ecological indicators of inner shelf fish and invertebrate communities in the Cantabrian Sea (southern Bay of Biscay)". Journal of the Marine Biological Association of the United Kingdom. 91 (3). Cambridge University Press (CUP): 623–633. doi:10.1017/s0025315410000329. ISSN 0025-3154. S2CID 86041772.
- ^ Ramos-EsplÁ, Alfonso A.; GuillÉn, Juan E.; Bayle, Just T.; SÁnchez-JÉrez, Pablo (2000). "Artificial Anti-trawling Reefs off Alicante, South-Eastern Iberian Peninsula: Evolution of Reef Block and Set Designs". Artificial Reefs in European Seas. Dordrecht: Springer Netherlands. pp. 195–218. doi:10.1007/978-94-011-4215-1_12. ISBN 978-0-7923-6144-2.
- ^ "Anti-trawling block "NETTUNO"". Acquatecno. 2016-07-26. Retrieved 2021-01-17.
- ^ "Subtidal Benthic Invertebrate Conservation: Global Evidence for the Effects of Interventions".
- ^ "Install physical barriers to prevent trawling". Conservation Evidence. Retrieved 2021-01-17.
- ^ "Spain investigating claims that Gibraltar has further blocked bay". El País. 2013-08-23. Retrieved 2021-01-17.
- ^ "Fishing Protection - OPEC Egypt". 2017-07-17. Retrieved 2021-01-17.
- ^ "Gibraltar Dispute: Spanish Fishermen in Reef Protest - Other Media news". Tasnim News Agency. 2013-08-19. Retrieved 2021-01-17.
- ^ Macura, Biljana; Byström, Pär; Airoldi, Laura; Eriksson, Britas Klemens; Rudstam, Lars; Støttrup, Josianne G. (2019-03-12). "Impact of structural habitat modifications in coastal temperate systems on fish recruitment: a systematic review". Environmental Evidence. 8 (1). Collaboration for Environmental Evidence (BMC): 14. Bibcode:2019EnvEv...8...14M. doi:10.1186/s13750-019-0157-3. hdl:11577/3401331. ISSN 2047-2382. S2CID 84831487.
Conclusions: This review revealed a very limited evidence base for how structural modifications and marine urban sprawl can affect fish recruitment. Thus, there is a substantial mismatch between stakeholder needs and research evidence. Further, the impact and ecological performance of artificial structures depend both on context and species. Clearly, there is a need for more research on the subject, especially on long-term consequences at larger spatial scales.
- ^ a b Baine, Mark (2001). "Artificial reefs: a review of their design, application, management and performance". Ocean & Coastal Management. 44 (3–4). Elsevier: 241–259. Bibcode:2001OCM....44..241B. doi:10.1016/s0964-5691(01)00048-5. ISSN 0964-5691.
Their use as a tool in coastal management has many general purposes including ... the prevention of trawling in Europe [4]. Artificial reef reviews do exist [5] although varying in their focus and objectivity. ... Number of papers ... Anti-trawling ... 5 ... These respective case studies refer to the use of vessels and concrete modules for the prevention of illegal trawling in the Mediterranean Sea ...
- ^ a b Airoldi, Laura; Beck, Michael W.; Firth, Louise B.; Bugnot, Ana B.; Steinberg, Peter D.; Dafforn, Katherine A. (2021-01-03). "Emerging Solutions to Return Nature to the Urban Ocean". Annual Review of Marine Science. 13 (1). Annual Reviews: 445–477. Bibcode:2021ARMS...13..445A. doi:10.1146/annurev-marine-032020-020015. hdl:10026.1/16842. ISSN 1941-1405. PMID 32867567. S2CID 221402720.
4.1.1.1. Artificial reefs. Artificial reefs are one of the earliest approaches to greening gray infrastructure ... providing multiple additional benefits. These benefits include blocking ... the use of trawling nets ... (Baine 2001). ... The effectiveness of artificial reefs is debated (Macura et al. 2019), and even when their stated primary objectives have been achieved, they come with negative impacts: They are expensive (Pioch & Doumenge 2010), and distortions or abuses of the concept have offered pretext for ocean dumping or for uncritical equation of any artificial structure to a reef (Macdonald 1994). However, the lessons learned have laid the foundations for new adaptive and biomimetic design concepts (Airoldi et al. 2005, Dafforn et al. 2015a, O'Shaughnessy et al. 2020), which aim to integrate some of the scopes of artificial reef design into structures built for other primary functions (Firth et al. 2014, Perkol-Finkel et al. 2012).
- ^ a b c Pears, R.; Williams, D. (2005). Potential effects of artificial reefs on the Great Barrier Reef: background paper. Townsville, Qld, Australia: Australian Government Cooperative Research Centres Program CRC Reef Research Centre. pp. 1–33. ISBN 1-876054-54-9.