Coastal Sediment Elevation Change Following Anthropogenic Mangrove Clearing

Authors

Heather Lyn Hayden, Portland State University
Elise F. Granek, Portland State UniversityFollow

Document Type

Post-Print

Publication Date

9-2015

Subjects

Mangrove conservation -- Caribbean Area, Mangrove ecology -- Caribbean Area -- Effects of anthropogenic activity on

Abstract

Coastal mangrove forests along tropical shorelines serve as an important interface between land and sea. They provide a physical buffer protecting the coastline from erosion and act as sediment “traps” catching terrestrial sediment, thus preventing smothering of subtidal coral reefs. Coastal development that removes mangrove habitat may impact adjacent nearshore coral reefs through sedimentation and nutrient loading. We examined differences in sediment elevation change between patches of open-coast intact and anthropogenically cleared red mangroves (Rhizophora mangle) on the east side of Turneffe Atoll, Belize, to quantify changes following mangrove clearing. Samples were collected over a 24 month period at five study sites, each containing paired intact (+mangrove) and cleared (-mangrove) plots. Five sediment elevation pins were deployed in each plot: behind areas cleared of mangroves (-mangrove) and behind adjacent intact mangroves (+mangrove). Sediment elevation increased at intact mangrove sites (M= +3.83 mm, SE=0.95) whereas cleared mangrove areas suffered elevation loss (M= -7.30 mm, SE=3.38). Mangroves inshore of partial or continuous gaps in the adjacent fringing reefs had higher rates of elevation loss (M=-15.05mm) than mangroves inshore of continuous fringing reefs (M=-1.90mm). Our findings provide information on potential effects of mangrove clearing and the role of offshore habitat characteristics on coastal sediment trapping and maintenance of sediment elevation by mangroves. With implications for coastline capacity to adjust to sea level rise, these findings are relevant to management of coastal fringing mangrove forests across the Caribbean.

Rights

Copyright 2015. This manuscript version is made available after a publisher embargo period under the CC-BY-NC-ND 4.0 license

Description

The definitive version published by Elsevier can be found at: http://dx.doi.org/10.1016/j.ecss.2015.09.004

DOI

10.1016/j.ecss.2015.09.004

Persistent Identifier

http://archives.pdx.edu/ds/psu/15919

Citation Details

Hayden, H.L., Granek, E.F., COASTAL sediment elevation change following anthropogenic mangrove clearing, Estuarine, Coastal and Shelf Science (2015), doi: 10.1016/ j.ecss.2015.09.004.