Marine debris impacts to a tidal fringing-marsh in North Carolina

  • Published source details Uhrin A.V. & Schellinger J. (2011) Marine debris impacts to a tidal fringing-marsh in North Carolina. Marine Pollution Bulletin, 62, 2605-2610.


This study is summarised as evidence for the following.

Action Category

Remove debris from brackish/salt marshes

Action Link
Marsh and Swamp Conservation
  1. Remove debris from brackish/salt marshes

    A replicated, before-and-after, site comparison study in 2008–2009 in a coastal salt marsh in North Carolina, USA (Uhrin & Schellinger 2011) found that following removal of crab pots and tyres from the marsh, smooth cordgrass Spartina alterniflora height and density typically recovered to undisturbed levels within a year. Immediately before intervention, impacted patches contained fewer cordgrass stems (120–133 stems/m2) than undisturbed marsh (300–370 stems/m2). There was a similar trend (not statistically significant) for the maximum height of cordgrass (impacted: 34–62 cm; undisturbed: 72–80 cm). Patches cleared of crab pots consistently had similar cordgrass height to undisturbed marsh from 22 weeks after clearance (cleared: 25–81 cm; undisturbed: 30–87 cm) and statistically similar cordgrass density to undisturbed marsh from 42 weeks (cleared: 167–229 stems/m2; undisturbed: 302–414 stems/m2). Patches cleared of tyres consistently had similar cordgrass height to undisturbed marsh from 45 weeks (cleared: 50–85 cm; undisturbed: 53–87 cm). However, cordgrass densities remained significantly lower in cleared than undisturbed marsh over the whole study year (33 of 35 comparisons; cleared: 84–273 stems/m2; undisturbed: 287–538 stems/m2). Methods: In August or September 2008, seven wire crab pots and seven vehicle tyres were removed from a salt marsh. Vegetation was surveyed under the debris before removal, then regularly after removal until September 2009. In each survey, live cordgrass stems were counted and measured in 1–2 quadrats covering the footprint of each pot or tyre (including stems growing through the centre of tyres) and seven quadrats in undisturbed patches of the marsh.

    (Summarised by: Nigel Taylor)

Output references
What Works 2021 cover

What Works in Conservation

What Works in Conservation provides expert assessments of the effectiveness of actions, based on summarised evidence, in synopses. Subjects covered so far include amphibians, birds, mammals, forests, peatland and control of freshwater invasive species. More are in progress.

More about What Works in Conservation

Download free PDF or purchase
The Conservation Evidence Journal

The Conservation Evidence Journal

An online, free to publish in, open-access journal publishing results from research and projects that test the effectiveness of conservation actions.

Read the latest volume: Volume 20

Go to the CE Journal

Discover more on our blog

Our blog contains the latest news and updates from the Conservation Evidence team, the Conservation Evidence Journal, and our global partners in evidence-based conservation.

Who uses Conservation Evidence?

Meet some of the evidence champions

Endangered Landscape Programme Red List Champion - Arc Kent Wildlife Trust The Rufford Foundation Save the Frogs - Ghana Bern wood Supporting Conservation Leaders National Biodiversity Network Sustainability Dashboard Frog Life The international journey of Conservation - Oryx British trust for ornithology Cool Farm Alliance UNEP AWFA Bat Conservation InternationalPeople trust for endangered speciesVincet Wildlife Trust