Nine To Noon Seabed mapping reveals ongoing damage caused by anchors
Mar 17, 2026
Dr Marta Ribot, AUT senior lecturer and marine researcher specialising in seabed mapping and human impacts, discusses mapping that reveals anchor scars lasting decades. She talks about how anchoring can damage seafloor habitats similar to trawling. Mapping shows scars spreading beyond designated anchoring zones. Practical steps and management goals to let damaged areas recover are explored.
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Anchor Scars Can Persist For Around 15 Years
- Wellington Harbour mapping indicates anchor scars can persist for around 15 years.
- Long preservation of scars means cumulative anchoring causes lasting habitat disruption over decades.
Anchors Produce Deep Long Lasting Seabed Scars
- Anchoring creates two distinct seabed scars: linear scours and broomstick-like abrasion zones.
- These features can reach over 400 metres long and 40–80 centimetres deep, showing anchor impact comparable to bottom trawling.
Allocated Anchor Sites Become Growing Damage Zones
- Disturbed seabed is usually centred on allocated anchoring sites but the impacted zone grows over time.
- In Wellington repeated anchoring has enlarged impacted areas rather than staying confined to the single point.