Challenges in Estuarine and Coastal Science

Estuarine and coastal waters are acknowledged centres for anthropogenic impacts. Superimposed on the complex natural interactions between land, rivers and sea are the myriad consequences of human activity – a spectrum ranging from locally polluting effluents to some of the severest consequences of global climate change. For practitioners, academics and students in the field of coastal science and policy, this book examines and exemplifies current and future challenges: from upper estuaries to open coasts and adjacent seas; from tropical to temperate latitudes; from Europe to Australia. This authoritative volume marks the 50th anniversary of the Estuarine and Coastal Sciences Association, and contains a prologue by founding member Professor Richard Barnes and a short history of the Association. Individual chapters then address coastal erosion and deposition; open shores to estuaries and deltas; marine plastics; coastal squeeze and habitat loss; tidal freshwaters – saline incursion and estuarine squeeze; restoration management using remote data collection; carbon storage; species distribution and non-natives; shorebirds; Modelling environmental change; physical processes such as sediments and modelling; sea level rise and estuarine tidal dynamics; estuaries as fish nurseries; policy versus reality in coastal conservation; developments in Estuarine, coastal and marine management.

Salt marsh width positively affects the occurrence of Least and Pectoral Sandpipers in the St. Lawrence River Estuary during fall migration

Salt marshes are vulnerable to climate change-associated sea-level rise and storm-induced surges. Their degradation will likely affect shorebirds relying on this ecosystem. Least Sandpiper (Calidris minutilla) and Pectoral Sandpiper (Calidris melanotos) migrating along coastline habitats typically use salt marshes to rest and replenish their body reserves. Our objective was to test if width of the different vegetation zones within salt marshes affects the occurrence of Least and Pectoral Sandpipers stopping along the St. Lawrence River Estuary, Quebec, Canada, during fall migration. We established 26 survey sites, each 600 m in length, along the shoreline. Shorebird surveys were conducted in 2011 and 2012. We characterized salt marshes by measuring the width of each vegetation zone (lower marsh and upper marsh). We analyzed shorebird presence/not detected data with generalized estimating equations to test the predictions that occurrence of Least Sandpipers and Pectoral Sandpipers increases with width of both the lower and upper marsh. Upper marsh width was positively associated with probability of occurrence in each species. Our results highlight the importance of protecting the integrity of salt marshes for these two species. In the St. Lawrence River Estuary, where landward migration of salt marshes is no longer possible (coastal squeeze), effective management of shorelines is much needed. Otherwise, salt marshes and these two species could be locally jeopardized.

Towards co-creation: A design-led study of ecological shifts in the tidal margin.

<p><b>The ecological resilience of the intertidal margins of many cities is increasingly under pressure due to climatic shifts and urbanisation. As rising sea levels push the high-water mark landward, many coastal species are prevented from migrating inland due to natural or man-made barriers. This results in a phenomena known as ‘coastal squeeze’. </b></p> <p>Pauatahanui Inlet, Porirua supports a diverse ecosystem of aqua-fauna, micro invertebrates and wading birds that rely on the shallow saltmarsh habitat within the estuary. However, with sedimentation from the surrounding catchments slowly filling up the inlet along with and predicted tidal inundation from sea level rise, the future of this coastline is uncertain. </p> <p>Rather than attempting to solve or secure a fixed future for the coastline, as is the prevailing anthropocentric response, this design led research seeks to respond to these human induced pressures by working with the cyclical phenological processes and ecological interactions occurring within the harbour. The research ambition is to co-create a shared public tidal realm. </p> <p>This objective is tested through the design of a coastal boardwalk for the Pauatahanui Inlet. Unlike human-focused boardwalks, this infrastructure is designed with the capacity to adapt as the tidal edge shifts, in either direction, while facilitating movement for all forms of life to traverse the harbour. The research attempts to surpass perceived barriers between nature and culture with an emergent inquiry into the poetic nature of the site itself. Here landscape design practice is developed towards the creation of social capital as occurring between species, while ensuring the natural ecosystem (and the life it supports) has the capacity to adapt to potential climate related changes.</p>

Towards co-creation: A design-led study of ecological shifts in the tidal margin.

<p><b>The ecological resilience of the intertidal margins of many cities is increasingly under pressure due to climatic shifts and urbanisation. As rising sea levels push the high-water mark landward, many coastal species are prevented from migrating inland due to natural or man-made barriers. This results in a phenomena known as ‘coastal squeeze’. </b></p> <p>Pauatahanui Inlet, Porirua supports a diverse ecosystem of aqua-fauna, micro invertebrates and wading birds that rely on the shallow saltmarsh habitat within the estuary. However, with sedimentation from the surrounding catchments slowly filling up the inlet along with and predicted tidal inundation from sea level rise, the future of this coastline is uncertain. </p> <p>Rather than attempting to solve or secure a fixed future for the coastline, as is the prevailing anthropocentric response, this design led research seeks to respond to these human induced pressures by working with the cyclical phenological processes and ecological interactions occurring within the harbour. The research ambition is to co-create a shared public tidal realm. </p> <p>This objective is tested through the design of a coastal boardwalk for the Pauatahanui Inlet. Unlike human-focused boardwalks, this infrastructure is designed with the capacity to adapt as the tidal edge shifts, in either direction, while facilitating movement for all forms of life to traverse the harbour. The research attempts to surpass perceived barriers between nature and culture with an emergent inquiry into the poetic nature of the site itself. Here landscape design practice is developed towards the creation of social capital as occurring between species, while ensuring the natural ecosystem (and the life it supports) has the capacity to adapt to potential climate related changes.</p>

Interaction between Tourism Carrying Capacity and Coastal Squeeze in Mazatlan, Mexico

While many coastal areas are affected by coastal squeeze, quantitative estimations of this phenomenon are still limited. Ambiguity concerning the degree of coastal squeeze, combined with a lack of knowledge on its interaction with human activities may lead to inadequate and unsuccessful management responses. The objective of the present research was to quantify the degree of coastal squeeze on the highly urbanized coast of Mazatlan, Mexico, and to investigate the relationship between the development of tourism and coastal squeeze from various time perspectives. The Drivers, Exchanges, States of the environment, Consequences, and Responses (DESCR) framework was applied to identify the chronic, negative consequences of dense tourism in the area, together with the assessment of coastal squeeze. A Tourism Load Capacity (TLC) estimation was made and correlated with the DESCR results, showing that coastal squeeze is inversely correlated with tourism load in Mazatlan. The medium-intensity coastal squeeze currently experienced in Mazatlan requires interventions to avoid severe degradation of the ecosystem on which the local tourism industry relies, for which immediate, long-term, and administrative recommendations are given.

An Overview on Railway Impacts on Coastal Environment and Beach Tourism in Sicily (Italy)

The main aim of this paper is to analyze the development of the railway network in Sicily (Italy), where it runs close to the sea on two of the three sides of the island, and give an overview of the related impacts on coastal environment and tourism. In order to achieve such an objective, the impacts of the railway network were analyzed according to coastal typology (distinguishing between rocky and sandy coastal sectors) and distance from the shoreline (dividing distance values in concrete intervals). Rails were mostly emplaced in flat coastal areas due to the island’s rugged terrain: out of 1592 km of railway, ca. 350 km is located less than 1000 m from the shoreline (123 km on rocky sectors and 227 km on beaches and coastal plains). On sandy beaches and low sandy coastal sectors, approximately 6 km of track is within 25 m from the shoreline, a value rising to 16 km if a 50 m distance is considered, 48 km at 100 m and 103 km at 200 m distance. In correspondence of rocky platforms and high cliffed sectors, data reported for short distances between the rail and the shore are similar to ones observed along sandy coastal sectors, but differ when distance increases, i.e., there is only 32 and 47 km of railway respectively within 100 and 200 m from the shoreline. The emplacement of the railway embankment on beaches and dunes favored coastal squeeze and enhanced coastal erosion due to wave reflection on the embankment, which had to be protected by hard structures. Impacts on rocky sectors, with respect to beach and dune systems, are generally low because such sectors are usually stable (they do not need to be protected), less attractive to tourists and present small urban development. Tourism was affected by reducing landscape quality, beach access and width. More detailed studies and monitoring programs are necessary to locally assess the detailed impacts of the railway network, with this study constituting a preliminary but useful approximation to determine which coastal sectors are potentially the most affected. Results obtained in this paper can stimulate similar researches in other countries to prevent or decrease railway impacts on “Sun, Sea and Sand” tourism and, in general, on the coastal environment.

Coastal green infrastructure to mitigate coastal squeeze

Infrastructure is necessary to protect and provide the goods and services required by humans. As coastal green infrastructure (CGI) aims to respect and work with natural processes, it is a feasible response to mitigate or avoid the consequences of coastal squeeze. The concept of CGI is receiving increased attention of late due to the challenges facing us, such as climate change, population growth and the overexploitation of natural resources on the coast. Terms which may be applied to encourage the construction of infrastructure, or to minimize the responsibility for poorly made decisions, often induce misunderstanding. In this paper, the concept of CGI and its use in solving coastal problems is reordered. Four categories are proposed, according to the degree of naturalness of the project: Nature reclamation, Engineered ecosystems, Ecologically enhanced engineering, and De-engineering/Relocation. Existing coastal risk evaluation frameworks can be used to design many types of CGI. Key concepts, challenges and good practices for the holistic management of coastal squeeze are presented from the analysis of successful and unsuccessful CGI projects worldwide.