Salt Marsh Monitoring in Jamaica Bay, New York from 2003 to 2013: A Decade of Change from Restoration to Hurricane Sandy

Anthony Campbell,Yeqiao Wang,Sara Stevens,Mark Christiano

doi:10.3390/rs9020131

Abstract

This study used Quickbird-2 and Worldview-2, high resolution satellite imagery, in a multi-temporal salt marsh mapping and change analysis of Jamaica Bay, New York. An object-based image analysis methodology was employed. The study seeks to understand both natural and anthropogenic changes caused by Hurricane Sandy and salt marsh restoration, respectively. The objectives of this study were to: (1) document salt marsh change in Jamaica Bay from 2003 to 2013; (2) determine the impact of Hurricane Sandy on salt marshes within Jamaica Bay; (3) evaluate this long term monitoring methodology; and (4) evaluate the use of multiple sensor derived classifications to conduct change analysis. The study determined changes from 2003 to 2008, 2008 to 2012 and 2012 to 2013 to better understand the impact of restoration and natural disturbances. The study found that 21 ha of salt marsh vegetation was lost from 2003 to 2013. From 2012 to 2013, restoration efforts resulted in an increase of 10.6 ha of salt marsh. Hurricane Sandy breached West Pond, a freshwater environment, causing 3.1 ha of freshwater wetland loss. The natural salt marsh showed a decreasing trend in loss. Larger salt marshes in 2012 tended to add vegetation in 2012–2013 (F4,6 = 13.93, p = 0.0357 and R2 = 0.90). The study provides important information for the resource management of Jamaica Bay.

Highlights

Jamaica Bay, an estuary within the New York City (NYC) limits, is heavily influenced by urbanization
The 2003 data had an adequate overall accuracy of 85.6%, with vegetation classes exhibiting the lowest accuracies (Table 2). This led to a focus on comparing vegetated salt marsh and non-vegetated areas as most of the error was between the multiple classes of salt marsh
This study reiterates the importance of continuing salt marsh monitoring with high spatial resolution satellite data within Jamaica Bay

Summary

Introduction

Jamaica Bay, an estuary within the New York City (NYC) limits, is heavily influenced by urbanization. The salt marshes serve as an interface between the Bay and surrounding urban areas. Salt marshes provide numerous ecological benefits such as high biodiversity, improved water quality, flood reduction, and carbon sequestration [1]. The wetland ecosystems of New York State, including salt marshes, were reduced by 60% from 1780 to 1980 [2]. Salt marshes have been under particular stress with increasing rates of loss from 2004 to 2009 caused in part by coastal storms [3]. In the past, these trends were exacerbated in the urban-impacted Jamaica Bay

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Discussion

Conclusion