Action: Use a different type of anchor
Key messagesRead our guidance on Key messages before continuing
- We found no studies that evaluated the effects of using a different type of anchor on subtidal benthic invertebrate populations.
‘We found no studies’ means that we have not yet found any studies that have directly evaluated this intervention during our systematic journal and report searches. Therefore, we have no evidence to indicate whether or not the intervention has any desirable or harmful effects.
Anchors are designed to dig into or hook onto the seabed to secure a vessel’s position and prevent it from drifting with the winds or currents. Anchoring can impact subtidal benthic invertebrates through physical damage, disturbance to and penetration in the seabed (Griffiths et al. 2017). Because anchor size, weight and design affect the level of impact caused (Liley et al. 2012), a different type of anchors, such as sacrificial anchors, could be used to reduce the level of impact caused. For recreational boats, the use of a particular type of anchor has been shown to be effective in reducing impact in seagrass beds (Milazzo et al. 2004). Evidence for other interventions related to anchoring are summarised under “Threat: Transportation and service corridors – Provide additional moorings to reduce anchoring”, and “Set limits or reduce the area where ships/boats/vessels can anchor”.
Griffiths C.A., Langmead O.A., Readman J.A.J. & Tillin H.M. (2017) Anchoring and Mooring Impacts in English and Welsh Marine Protected Areas: Reviewing sensitivity, activity, risk and management. A report to Defra Impacts Evidence Group.
Liley D., Morris R.K.A., Cruickshanks K., Macleod C., Underhill-Day J., Brereton T. & Mitchell J., (2012) Identifying best practice in management of activities on Marine Protected Areas. Footprint Ecology/Bright Angel Consultants/MARINElife. Natural England Commissioned Reports, Number 108.
Milazzo M., Badalamenti F., Ceccherelli G. & Chemello R. (2004) Boat anchoring on Posidonia oceanica beds in a marine protected area (Italy, western Mediterranean): effect of anchor types in different anchoring stages. Journal of Experimental Marine Biology and Ecology, 299, 51–62.