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Ecological Indicators 104 (2019) 172–183 Contents lists available at ScienceDirect Ecological Indicators journal homepage: www.elsevier.com/locate/ecolind Original Articles Assessing risk of collapse of Lake Burullus Ramsar site in Egypt using IUCN Red List of Ecosystems T ⁎ Somaya Magdy M. Ghoraba3, Marwa Waseem A. Halmy1,3, , Boshra B. Salem, Nadia Badr E. Badr2 Department of Environmental Sciences, Faculty of Science, Alexandria University, Alexandria, Egypt ARTICLE INFO ABSTRACT Keywords: The IUCN Red List of Ecosystems (RLE) assessment is a new powerful scheme that identifies ecosystems that are Ecosystem assessment at risk of collapse due to global environmental changes, which can help any mitigation actions aimed at con- Nile Delta coastal lakes serving and rescuing these natural ecosystems. The current study applied RLE assessment protocol on Lake Wetlands Burullus ecosystem, a highly productive wetland ecosystem, Ramsar site and International Bird Area (IBA) of Ecological services Egypt. A conceptual model of the key ecosystem processes for Burullus wetland was constructed. The application Anthropogenic impacts of RLE followed the standard protocol for the first four criteria; (A) declines in distribution, (B) restricted dis- tribution, (C) degradation of the abiotic components, and (D) regarding the assessment of the disruption of biotic processes and interactions. However, data were insufficient for assessing Criterion (E) that entails conducting quantitative estimates of the risk of collapse. Multi-date satellite images were obtained and processed to estimate the changes in the spatial distribution under criteria (A) and (B) of the study area. For evaluating Criteria (C) and (D), long-term data were collected from literature and previous works to cover the time frame of the assessment as much as possible. The results from the RLE assessment revealed that the status of the ecosystem is Critically Endangered (CR), which was attributed to various types of threats that caused degradation of the natural quality and integrity of the ecosystem. Although the RLE assessment provides a coherent approach for identifying ecosystems vulnerable to human-induced changes; data insufficiency can be an impediment for the efficient application of the RLE assessment. Remotely-sensed data can help in derivation of suitable spectral indicators of the status of the ecosystems structure and functioning that might overcome some of the challenges of data adequacy and relevance to the RLE assessment especially for the understudied and data-deficient ecosystems. 1. Introduction The RLE protocol rely on the evaluation of the status of the ecological processes and native biota using standard criteria for assessing risks of Humans are fully dependent on Earth’s ecosystems and ecological ecosystems collapse (Mahoney and Bishop, 2017; Rodriguez et al., services they provide for their well-being as these services participate in 2012; Marshall et al., 2018). The state of ecosystem collapse is defined the economic activities and processes (MA, 2005). However, human according to the RLE as the endpoint of ecosystem decline, which oc- activities have altered natural ecosystems and disturb biological life all curs when the ecosystems lose their characteristic biotic and abiotic over the world (Rodriguez et al., 2015). Therefore, controllable actions features in a way that irreparably changed their identity (Rodriguez to manage ecosystems sustainably are a priority to prevent reaching to et al., 2015; Bland et al., 2016; Marshall et al., 2018). The RLE out- high levels of degradation or state of collapse (MA, 2005). The IUCN comes indicate whether ecosystems have reached the final stage of Red List of Ecosystems (RLE) assessment protocol was formulated as a degradation, i.e. state of collapse, or they can be considered as Critically tool to support conservationist and natural resources managers to Endangered, Endangered, Vulnerable levels, or Least Concern. An identify and characterize ecosystems at high risk of degradation and ecosystem can be considered as Least Concern, if it doesn't face any deterioration (Bland et al., 2017; Keith et al., 2015; Keith et al., 2013a). prevailing significant risks (Keith et al., 2013a). ⁎ Corresponding author at: Department of Environmental Sciences, Faculty of Science, Moharm Bek P.O. Box: 21511, Alexandria, Egypt. E-mail address: [email protected] (M.W.A. Halmy). 1 ORCID ID: https://orcid.org/0000-0002-4183-973X. 2 ORCID ID https://orcid.org/0000-0002-4434-7538. 3 These authors contributed equally to the development of this manuscript. https://doi.org/10.1016/j.ecolind.2019.04.075 Received 11 October 2018; Received in revised form 19 April 2019; Accepted 25 April 2019 1470-160X/ © 2019 Elsevier Ltd. All rights reserved. S.M.M. Ghoraba, et al. Ecological Indicators 104 (2019) 172–183 Fig. 1. True colour composite subset of Landsat 8 scene acquired in 2016, showing location of Burullus Wetland ecosystem at the northern Mediterranean coast of Egypt. The RLE assessment is conducted according to five standard criteria. 2. Methodology The assessment of each of the five RLE criteria depends on assuming a threshold of collapse. The first two criteria A and B assess spatial or A crucial step prior to conducting the assessment is to define and distributional symptoms of collapse; where Criterion A assess the rate of describe the study area (unit of assessment) that will be evaluated. change in geographic distribution, which may influence the ecosystems’ Moreover, a conceptual model that depicts the key ecosystem processes, carrying capacity for the dependent biotic components; and Criterion B interactions and threats need to be formulated (Bland et al., 2017). assess the status of the restricted distribution, which make the eco- system susceptible to spatially specific threats. The threshold of collapse 2.1. Ecosystem description defined for spatial extent criteria (A & B), is generally set as the level at which the ecosystem distribution declines to zero. However, it is worth The ecosystem description of Lake Burullus was compiled from mentioning that some ecosystems may collapse before their mapped published data and literature to fulfil the standard elements of the as- distribution declines to zero. Therefore, threshold of collapse will de- sessment. The information and data collected were used to identify the pend on maps and variables used for the assessment. Both criteria C and key ecosystem components and important threats, and were employed D assess functional symptoms of ecosystem collapse of abiotic compo- in constructing conceptual model (Fig. 2) for the ecosystem. Lake nents and disturbance of biotic processes respectively (Bland et al., Burullus is the main component of Burullus Protected Area (BPA) which 2017; Keith et al., 2013a). The last Criterion E provides quantitative is located on the Mediterranean coast of the northern Delta of Egypt, in estimates of the risk of ecosystem collapse using simulation model that a central position between the two branches of the River Nile (Khalil, rely on multiple mechanisms of interactions between two or more of the 2013). The Lake covers an area of about 410 km2 with a maximum previously mentioned criteria (Bland et al., 2017). length of about 47 km and an average width of 14 km (Tharwat and The current study attempted to assess the status of Lake Burullus Hamied, 2000; Khalil, 2013). According to the IUCN (2012) habitats (Fig. 1) at north of the Nile Delta of Egypt. The wetland is one of five classification scheme (Version 3.1) the site is classified as (13. Marine/ coastal lakes in Egypt that was included among the internationally 13.4 coastal brackish/ saline lagoons, marine lakes). important wetlands of the world in accordance with the Ramsar Con- vention in 1988. The entire area of the lake and most of its surrounding 2.1.1. Abiotic environment wetland area has been declared as a protected area in 1998 (Galal, Lake Burullus is a shallow basin, its depth varies between 40 cm ’ et al., 2012). Burullus is also considered as one of the world s Important near the shores and 200 cm near the Sea outlet and the depth increases Bird Area (IBA) in 1999 (Khalil, 2013). in east–west direction. The lake belongs to the arid region which is ’ The current study sought to consider the applicability of the IUCN s characterized by warm temperatures in summer ranging from 20 to RLE risk assessment protocol criteria to Burullus wetland. The study 30 °C and mild temperatures in winter ranging from 10 to 20 °C examined the common causes of decline in the ecosystem of Lake (Shaltout and Khalil, 2005). There is variation in sources of water that Burullus and tested a set of proposed indicators to be used as predictors enter the lake. The western section receives freshwater from the Nile of the state of the ecosystem by natural resources managers and con- through Brimbal Canal that branches directly from Rosetta branch of servationists. The application of RLE protocol to evaluate the state of the Nile; however, the eastern side receives saline water directly from Lake Burullus will aid in prioritizing conservation measures and sus- the Mediterranean Sea through El-Boughaz opening (Younis and Nafea, tainable management of the region. 2012)(Fig. 1). This variation resulted in salinity gradient pattern from 173 S.M.M. Ghoraba, et al. Ecological Indicators 104 (2019) 172–183 Fig. 2. Cause-effect conceptual model of the main ecological processes relevant to Lake Burullus ecosystem risk assessment. east to west (El-Reefy et al., 2006; Emara et al., 2016). Average salinity Keddy, 2005). Rotifers are the dominant group followed by copepods, levels of Lake Burullus decreased dramatically from 14‰ in 1966 to while cladocerans are the least abundant group and dominated mostly 3‰ in 2015 due to discharge of agricultural drainage into the lake by freshwater species (Shaltout and Khalil, 2005). The changes in the (Khalil, 2016; Negm et al., 2019). Currently, Lake Burullus receives lake’s salinity towards being more fresh water due to discharge of drainage waters from neighbouring areas through nine main drains (Ali agriculture waste in the lake over the last two decades have changed and Khairy, 2012).

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