Welcome to PAP/RAC Mediterranean Coastal Alert! This newsletter is regularly updated monthly. It contains abstracts of selected current articles and archives on various environmental themes, in particular those dealing with all aspects of coastal issues. The selection is made from the articles published in the leading international scientific journals. This newsletter is an excellent way of keeping you updated with coastal studies and processes.

In this issue Issue No. 70, 2014-08-01

Managing urban coastal areas through landscape metrics: An assessment of Mumbai's mangrove system
(Abstract...)

Shoreline Change on the East Coast of Florida
(Abstract...)

Resident and tourist preferences for stormwater management strategies in Oahu, Hawaii
(Abstract...)

Long-term variability of sea surface temperature in Taiwan Strait
(Abstract...)

Abstract

Managing urban coastal areas through landscape metrics: An assessment of Mumbai's mangrove system

The loss of coastal landscapes resulting from urban sprawl has become a growing concern that is difficult to manage. The consequences of sprawl are often lasting, leading to the irreversible loss of vulnerable and valuable natural landscapes in favour of urban land. In this paper I analyse the spatiotemporal differences of the urban footprint in Mumbai, India, and compare these changes to the existent mangrove systems in the coastal stretches of metropolitan Mumbai. Based on the extracted urban footprint of the coastal mangrove regions, landscape metrics are performed to understand the impacts of urbanisation on the relative increase and decrease of mangrove systems. Of the entire mangrove system in the Mumbai Metropolitan Area, 36% has been lost to urban land since 1973. Over the four time periods studied, an area of urban sprawl comprises the southeastern border of Mumbai, where, since 2000, pressure on the wetlands has been largely aggravated. The high correlation of coastal stretches and urbanisation is one of the main reasons for the current fragile state of Mumbai's mangroves. A combination of a decrease and an increase in mangrove sites suggests that certain urban typologies, such as denser urban areas and older urban regions, are more prone to mangrove recovery, whereas unplanned urban settlements and highly fragmented urban areas lead to a less favourable mangrove landscape. A spatial accounting of the distribution of landscape metrics is proposed in this paper to understand land use transitions where (1) a significant increase of dense urban areas along Mumbai's fragile coastal stretches is reported; (2) this loss of mangroves is underpinned by urban typology over time; and (3) a combination of metrics vis-à-vis zones where mangroves increase and decrease are spatially and temporally addressed. With the increase in economic development that Mumbai has exhibited in recent decades, it is important to monitor the impacts on natural regions. This is a challenging task where spatial metrics combined with urban footprints may lead to a better understanding of the environmental impacts on coastal stretches. The current planning policies suggest that attention has been given to the mangrove systems of the MMR, equating to beneficial results if economic prosperity and preservation measures in Mumbai continue to take place.

Keywords: Urban coastal areas; Coastal landscapes; Mumbai mangrove system.

Source: E. Vaz (2014); “Managing urban coastal areas through landscape metrics: An assessment of Mumbai's mangrove system”, Ocean & Coastal Management, Volume 98, September 2014, Pages 27 - 37; DOI: 10.1016/j.ocecoaman.2014.05.020

Contact: evaz@ryerson.ca

Link: Science Direct

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Shoreline Change on the East Coast of Florida

A shoreline change data base for Florida dating back to the mid-1800s is unique in the United States, and perhaps the world, with thousands of shoreline change measurements at a nominal spacing of 300 m. Moreover, data are available on factors contributing to shoreline change, including beach nourishment, disposal of dredged sand outside the littoral zone, cutting of new inlets and subsequent growth of ebb shoals, and longshore sediment transport into and along the east coast of Florida. Effects of relative sea level rise can be estimated using the Bruun Rule. These factors should have caused significant shoreline recession since the mid-1800s, but instead, the east coast of Florida has experienced significant average shoreline advance. The formation of carbonate sand is shown not to account for this difference. Onshore transport of sand from beyond closure depth, probably during episodic storm events, is the only possible source of the large quantity of sand that has advanced on average the shoreline of Florida's east coast. For shorelines with significant offshore deposits of sand, it is possible that sea level rise in conjunction with wave action contributes to onshore transport and shoreline accretion.

Keywords: Coastal erosion; Coastal accretion; Sea level rise.

Source: J.R. Houston and R.G. Dean (2014); “Shoreline Change on the East Coast of Florida”, Journal of Coastal Research: Volume 30, Issue 4: pp. 647 – 660; Received: 10 February 2014; Accepted: 13 March 2014; Published Online: 7 May 2014.

Contact: james.r.houston@usace.army.mil

Link: JCR

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Resident and tourist preferences for stormwater management strategies in Oahu, Hawaii

Hawaii's economy relies on its global reputation of its coastal marine environments. This paper studies residents' and tourists' preferences for stormwater quality management strategies related to recreational beaches in Oahu, Hawaii. Using a Choice Experiment approach, we consider Willingness to pay for augmented efforts for Non-Structural and Structural Best Management Practices, Warning and Advisory systems, Testing methods, and Educational efforts. Our results show that Rapid testing and educational efforts are most favored by both residents and tourists. There are few differences in Willingness to Pay for the stormwater strategies among residents and tourists, such that meeting both groups' preferences is possible. Further, based on experts' information on the strategies' proposed costs, all strategies should be pursued by Hawaii's policymakers.

Keywords: Coastal marine environments; Tourists' preferences; Beaches, Hawaii.

Source: J. Penn, W. Hu, L. Cox and L. Kozloff (2014); “Resident and tourist preferences for stormwater management strategies in Oahu, Hawaii”, Ocean & Coastal Management, Volume 98, September 2014, Pages 79 - 85; DOI: 10.1016/j.ocecoaman.2014.06.002

Contact: jerrod.penn@uky.edu

Link: Science Direct

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Long-term variability of sea surface temperature in Taiwan Strait

Long-term variability of sea surface temperature (SST) in the Taiwan Strait was studied from the U.K. Met Office Hadley Centre climatological data set HadISST1. In 1957–2011, three epochs were identified. The first epoch of cooling SST lasted through 1976. The regime shift of 1976–1977 led to an extremely rapid warming of 2.1 °C in 22 years. Another regime shift occurred in 1998–1999, resulting in a 1.0 °C cooling by 2011. The cross-frontal gradient between the China Coastal Current and offshore Taiwan Strait waters has abruptly decreased in 1992 and remained low through 2011. The long-term warming of SST increased towards the East China Sea, where the SST warming in 1957–2011 was about three times that in the South China Sea. The long-term warming was strongly enhanced in winter, with the maximum warming of 3.8 °C in February. The wintertime amplification of long-term warming has resulted in a decrease of the north–south SST range from 5 to 4 °C and a decrease in the amplitude of seasonal cycle of SST from 11 to 8 °C.

Keywords: Variability; Sea surface temperature (SST); Taiwan Strait.

Source: I. M. Belkin and Ming-An Lee (2014); “Long-term variability of sea surface temperature in Taiwan Strait”, Climatic Change; Received: 20 September 2013; Accepted: 26 March 2014; Published Online: 15 April 2014; DOI: 10.1007/s10584-014-1121-4

Contact: igormbelkin@gmail.com

Link: Climatic Change

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