Science of the Total Environment 505 (2015) 269–281

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Science of the Total Environment journal homepage: www.elsevier.com/locate/scitotenv

An integrated environmental risk assessment and management framework for enhancing the sustainability of marine protected areas: The Cape d'Aguilar Marine Reserve case study in Hong Kong Elvis G.B. Xu a,b, Kenneth M.Y. Leung a,b,⁎, Brian Morton a,b, Joseph H.W. Lee c a b c

The Swire Institute of Marine Science, The University of Hong Kong, Pokfulam, Hong Kong, China School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong, China Department of Civil and Environmental Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China

H I G H L I G H T S • • • • •

A scheme is designed to assess environment risks in marine protected areas (MPAs). It can systematically evaluate the elements that affect the sustainability of MPAs. Cape d'Aguilar Marine Reserve of Hong Kong is employed to illustrate the method. Most significant components are identified for protecting the integrity of the MPA. The results can improve decision-making and conservation of marine biodiversity.

a r t i c l e

i n f o

Article history: Received 14 July 2014 Received in revised form 26 September 2014 Accepted 26 September 2014 Available online xxxx Editor: D. Barcelo Keywords: Marine protected areas Environmental risk assessment DPSIR (Driver–Pressure–State–Impact– Response) model Integrated environmental risk assessment and management (IERAM) Marine pollution Cape d'Aguilar Marine Reserve

a b s t r a c t Marine protected areas (MPAs), such as marine parks and reserves, contain natural resources of immense value to the environment and mankind. Since MPAs may be situated in close proximity to urbanized areas and influenced by anthropogenic activities (e.g. continuous discharges of contaminated waters), the marine organisms contained in such waters are probably at risk. This study aimed at developing an integrated environmental risk assessment and management (IERAM) framework for enhancing the sustainability of such MPAs. The IERAM framework integrates conventional environmental risk assessment methods with a multi-layer-DPSIR (Driver– Pressure–State–Impact–Response) conceptual approach, which can simplify the complex issues embraced by environmental management strategies and provide logical and concise management information. The IERAM process can generate a useful database, offer timely update on the status of MPAs, and assist in the prioritization of management options. We use the Cape d'Aguilar Marine Reserve in Hong Kong as an example to illustrate the IERAM framework. A comprehensive set of indicators were selected, aggregated and analyzed using this framework. Effects of management practices and programs were also assessed by comparing the temporal distributions of these indicators over a certain timeframe. Based on the obtained results, we have identified the most significant components for safeguarding the integrity of the marine reserve, and indicated the existing information gaps concerned with the management of the reserve. Apart from assessing the MPA's present condition, a successful implementation of the IERAM framework as evocated here would also facilitate better-informed decision-making and, hence, indirectly enhance the protection and conservation of the MPA's marine biodiversity. © 2014 Elsevier B.V. All rights reserved.

1. Introduction Anthropogenic activities can result in a broad range of adverse impacts upon coastal marine environments and thereby cause a degradation of the ecosystem services that it provides (Halpern et al., 2008). ⁎ Corresponding author at: School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong, China. Tel.: +852 22990607; fax: +852 25176082. E-mail address: [email protected] (K.M.Y. Leung).

http://dx.doi.org/10.1016/j.scitotenv.2014.09.088 0048-9697/© 2014 Elsevier B.V. All rights reserved.

Marine protected areas (MPAs) are increasingly being established to conserve marine ecosystems, through protecting habitats, facilitating the recovery of over-exploited stocks and degraded areas, and resolving user conflicts (Toropova et al., 2010). Since the First World Conference on National Parks (1962), the number of MPAs around the world has increased substantially to more than 5850 in 2010. In 2010, MPA coverage has reached over 1% of the total global sea area, of which only 0.01% are marine reserves (i.e., no-take areas) (Wood et al., 2008; Toropova et al., 2010).

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Although MPAs are universally supported as an important tool for the conservation of marine ecosystems and biodiversity (at all levels), their effectiveness and sustainability remain controversial (Boersma and Parrish, 1999). The achievement goals for MPAs are determined by many factors, including management plans, legislative requirements, enforcement, research and education. In practice, MPAs shield marine organisms within their boundaries but do not guarantee protection from threats to the marine environmental quality (Mwangi et al., 1998). For example, it has been demonstrated that even no-take areas can be threatened by the contamination of various toxic chemicals such as persistent organic pollutants (POPs) and trace metals (Campanella et al., 2001; Terlizzi et al., 2004), which originate from surface runoff, partially treated effluents, freshwater discharges from polluted rivers and/or contaminated atmospheric depositions. Given that some MPAs are situated in close proximity to urbanized areas and influenced continuously by anthropogenic activities such as untreated and partially treated wastewater discharges (Siracusa et al., 2001), marine organisms inhabiting such MPAs are, as a consequence, at risk. An effective and pragmatic environmental risk assessment (ERA) and management framework is, therefore, deemed necessary for the sustainability of such MPAs. Both chemical and non-chemical stressors should be addressed during a comprehensive environmental risk assessment (ERA). By definition, an ERA is a process that combines risks from multiple sources, stressors, and routes of exposure for humans, biota and ecological resources in one assessment (USEPA, 2002). The ERA process was established originally to assess the risks of chemical contaminants to human health and the environment. In the United States of America in the 1980s, ERAs mainly targeted the toxicities of single chemicals to human health (USNRC, 1983) and was modified subsequently to evaluate the impact of chemical contaminants on ecosystems (Suter, 1993; USEPA, 1998). Given their history, the most previously conducted ERAs mainly dealt with the environmental risks associated with single, multiple or groups of chemicals, but seldom considered the coexistence of other non-chemical stressors (Landis, 2003). In contrast, the European Union's Environment and Health Strategy adopts a broader approach that integrates information obtained from scientific research, environmental health, the environmental effects and fate of pollutants, and seeks views from different stakeholders prior to policy making (CEC, 2003), although there has been little elaboration of how ecological and economic risk estimates can be either considered or weighted during the decision making process (Thomas et al., 2012). There is, hence, a challenging demand to extend chemical-oriented ERA to embrace non-chemical stressors and link their risks with ecological, social and economic factors. A comprehensive evaluation of multi-sectoral risks facing MPAs is important and should integrate socio-economic dimensions into ecological research for MPA management (Thomas et al., 2012). As a multi-sectoral approach, the DPSIR (Driver–Pressure–State–Impact–Response) framework, based on the concept of a “chain of causation”, considers both environmental and socio-economic impacts on the marine environment (Ojeda-Martinez et al., 2009). This heuristic methodology is being employed increasingly among researchers and policy-makers for structuring and communicating environmental policies because it is highly flexible and suitable for projects of different natures such as fisheries management (Mangi et al., 2007), a feasibility study on offshore wind power facilities (Elliott, 2002) and the integrated coastal zone management of multiple beneficial uses (Pastres and Solidoro, 2012). The DPSIR model for assessing either water quality or the effectiveness of MPAs has been a common tool in the management of MPAs (Ojeda-Martinez et al., 2009; Beliaeff and Pelletier, 2011). They provide, however, insights only into the development of indicators and cause–effect relationships, but not explicit ecological risk assessment methods or applications of the developed indicators. In this sense, a vigorous, yet practical, integrated environmental risk assessment and management (IERAM) framework is still lacking for MPAs.

In this study, we develop an IERAM framework for MPAs by integrating a newly-constructed multi-layer DPSIR model with the conventional ERA approach. Our proposed IERAM framework includes screening mechanisms for various stressors to MPAs, the objective identification of stressors with unacceptable risks, and formulation and prioritization of management options with consideration of both ecological and socio-economic dimensions. To illustrate the IERAM framework, the Cape d'Aguilar Marine Reserve of Hong Kong, China is used as a case study. The marine environmental problems described in this case study would be similar to those encountered by other coastal metropolises where MPAs are located in proximity to urbanized areas. This case study will, thus, generate essential information for future deployment of IERAM frameworks in the management of coastal marine environments and MPAs. 2. Description of the case study site Cape d'Aguilar is situated on the southeastern tip of Hong Kong Island in the Hong Kong Special Administrative Region (SAR) of China. In 1995, the Hong Kong Government, recognizing the importance and urgency of protecting the geomorphological and ecological environment of Cape d'Aguilar, designated this area as the first and, to date, only marine reserve in Hong Kong (Fig. 1). Morton and Harper (1995) published a holistic seminal introduction to the Cape d'Aguilar Marine Reserve, providing important information on the geology, coastal geomorphology and broad ecological significance of the multiple habitats encompassed by the borders of this tiny reserve. The marine reserve has a rich marine biodiversity, with numerous habitats such as intertidal sea arches and subtidal caves (zawns), hermatypic and ahermatypic coral reefs, exposed and sheltered rocky beaches, cobble beaches, intertidal pools of varying dimensions and elevations, and protected underboulder landscapes (Morton and Harper, 1995). This reserve is considered to be of immense scientific and environmental significance for Hong Kong, which enables it to be managed as a single ecological unit under the protection of the Hong Kong Marine Park's and Reserves Ordinance 1995 (Cap. 476). Due, however, to its small size (0.2 km2) and location in close proximity to sources of human activities, the management for protection and conservation of this reserve may not be effective without a dedicated survey and assessment of the impacts of such human-derived perturbations. 3. Methodological approaches Fig. 2 outlines “A multi-level assessment approach” within a framework that combines qualitative and quantitative approaches to the different steps of the assessment process. Such a preliminary approach was developed to obtain an overview of the risks involved and their prioritization for the further management of the Cape d'Aguilar Marine Reserve. 3.1. First step: identification of potential threats — linking MPAs to broader coastal areas MPAs can be affected profoundly by human activities that lie outside their boundaries, ranging from marine transportation and fishing to land-based marine pollution. MPAs are often designed and managed without recognition of the larger marine system within which they are located. A variety of economic and social activities taking place outside a MPA need to be identified and geographically mapped, therefore, for further risk assessment of the MPA. Activities that threaten the sustainable uses of the marine environment and effectiveness of the Cape d'Aguilar Marine Reserve include (Fig. 1): • Contamination from land-based activities, such as inputs of chemical and bacteria through sewage treatment plants, which can pollute the MPA;

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Fig. 1. Potential threats to the Hong Kong marine environment and the location of the Cape d'Aguilar Marine Reserve (in box); STP: sewage treatment plant.

• Illegal fishing either nearby or inside the MPA which can directly degrade its function of marine conservation by destroying natural food webs; • Marine transportation and port activities often involve the dumping of waste at sea, and the release of antifouling paints, which create negative impacts on the health of marine species and communities; • Mariculture activities in coastal areas nearby the MPA which can lead to the degradation of water quality by the release of nutrients (uneaten food and feces) and antibiotics; and

• Coastal landfills of waste nearby the MPA which can result in the leaching of toxins, and destroy benthic communities through the build-up of contaminated sediments. 3.2. Data collection A prerequisite for reporting upon the state of the marine environment and the MPA as affected by human activities is the collection of adequate sets of environmental and socio-economic indicators that are

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Identify potential

Potential Threats Mapping Process (see Fig. 1)

threats at broader scale

Basic Rule for Indicators Collection (based on OECD 1998) 1.

Policy relevant and useful

2.

Related to changes in the marine environment

3.

Able to show trends over time and to establish comparisons among regions

Collect systematic 4.

Simple and easy to interpret

5.

Related to the different stakeholders perspectives

6.

Easily available

information

DPSIR Categories (refer to 149 indicators by Ojeda -Martinez et al. 2008) Drivers : Socio-economic and socio-cultural forces driving human

Group indicators into

activities, which increase pressures on the environment (e.g.

DPSIR categories

population) Pressures: Stresses that human activities place on the environment (e.g. wastewater) States : The condition of the environment (e.g. water quality) Impacts : Effects of environmental degradation (e.g. loss value of fishery) Responses: Responses by society to the environmental situation (e.g. regulation)

Prioritize / Estimate rank

Seven Rapid Ranking Criteria

Low / Medium High Qualitative assessment

1.

Damaging MPA’s potential benefits

2.

Frequency of occurrence

3.

Estimated severity of consequence (ecological / economic)

4.

Existing management measures

5.

Operability analysis / possible remedy measures

6.

Estimated scale of hazard (temporal / spatial)

7.

Existing peer-reviewed evidence on damage

Low Quantitative assessment Compar ison against criteria and benchmarks from literatures Low

No further action

Mediu m / High

Detailed analysis

Fig. 2. A multi-level assessment process (see details of the seven Rapid Ranking Criteria in Table S1 in Appendix A).

linked to the potential threats listed above. Following the Principle of Strengthening Linkages between MPAs and the Wider Coastal/Marine Area proposed by Cicin-Sain and Belfiore (2005), the collection of indicators herein described and to be discussed were based on the best available knowledge and existing databases. Much of this information was relevant to and drawn from the basis of broader marine area management of Hong Kong's waters. The chosen databases, their sources and time periods considered are summarized in Table 1. 3.3. Data classification Given the complex interactions among different agents (e.g. environmental stressors, impact receptors, social responses) operating in the marine ecosystem, we have developed a multi-layer DPSIR framework to describe the cause–effect relationships of different ecological, economic and social indicators. Multiple datasets, mostly from local

authorities, i.e., different government departments in Hong Kong, were screened and classified according to the 149 DPSIR variables defined by Ojeda-Martinez et al. (2009). Based on the cause–effect relationships, databases were categorized into five sets within a DPSIR loop (Fig. 3). Such a framework is flexible enough to be used for the establishment of priorities for response actions by different stakeholders. For instance, if managers and scientists are concerned mostly with issues related to marine pollution, they would place the ‘marine pollution’ DPSIR cycle on the ‘top layer’ of the model as D1–P1–S1–I1–R1 (Fig. 3). In essence, ‘Dn–Pn–Sn–In–Rn’ can be applied to any sector of the marine environment and can be different in different geographical areas. For example, D2–P2–S2–I2–R2 can be the ‘Eutrophication’ DPSIR cycle, and D3–P3–S3–I3–R3 can refer to ‘Dredging activities’ DPSIR cycle. In this study, the issue of marine pollution in MPAs is of major concern, and is placed on the top layer of the multi-dimensional model (Fig. 4). It should also be noted that each DPSIR cycle is driven by both endogenic

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Table 1 The indicators of IERAM developed for safeguarding the marine environment of Hong Kong, with the original data sources provided. DPSIR indicator

Type Description

Driver

GDP

SC

Population

SC

Number of visitors to beach Number of fishing vessels Total engine power of fishing vessels Tropical cyclones, wind and rainstorm Total water consumption Total amount of sewage Amounts of municipal solid wastes

Pressure

State

Impact

No. of ships on the register Total gross tonnage in maritime transport Production value of fishing catch per unit of effort (CPUE) Seawater quality Sediment quality Oil pollution Refuse collected from vessels Red tides occurrence

Quality of swimming beach Environmental expenditures Response Sewage Treatment Plans Marine Protected Areas Environmental Laws and Legislations Scientific support

Prioritya Assessment Data sourceb QL

CSD (1967–2010)

QL

CSD (1967–2010)

SC

A measure of the total value of production of all resident producing units of a territory NA in a specified period. The number of Hong Kong permanent and non-permanent Residents and visitors H who are in Hong Kong at the reference time-point. Number of visitors to a beach during bathing season M

SC

Number of local fishing boats.

M

QL

CSD (1960–2010)

SC

Total power of the fishing boats that fish in the MPA, in its boundaries or close to it.

M

QL

CSD (1985–2008)

EC

Number of cases and magnitude of tropical cyclones and rainstorm; speed and direction of wind Total volume of water used for household-drinking, communal water, and industrial uses in a year. Total volume of sewage from domestic and non-domestic sources in a year.

M

QL

HKO (2005–2009)

L

QL

CSD (2001–2010)

H

QL

CSD (2001–2010)

M

QL

CSD (1991–2009)

SC

Total volume of municipal solid wastes includes domestic, commercial and industrial waste excluding construction and demolition waste and recovered municipal solid waste. Number of ships registered in a year.

L

QL

CSD (1990–2009)

SC

Total gross tonnage in maritime transport in a year

L

QL

MD (1990–2009)

SC

Total profit produced by fishing activities in a year.

NA

QL

CSD (1965–2010)

SC

Catch Per Unit Effort (CPUE).

NA

QL

CSD (1965–2010)

EC EC SC SC

Changes in water composition and/or quality. Changes in sediment composition and/or quality. Alleged oil pollution incidents, reported (case) Refuse collected from vessels (tons) yearly.

H H M M

QT QT QL QL

AFCD (2005–2010) EPD (2005–2009) MD (2003–2010) MD (2003–2010)

EC

M

QL

EPD (1980–2009)

NA

QL

CSD (1991–2009)

SC

Numbers of cases of red tides that occur in both polluted and unpolluted waters in a year. The geometric mean Escherichia coli count per 100 mL of sea water during bathing season, Budget invested in waste programs or actions

M

QL

CSD (1991–2009)

SC

Number, types, and locations of Sewage Treatment Plans

H

QL

DSD (2012)

SC SC

Surface, types, and locations of Marine Protected Area Changes in laws, normative, restrictions and/or limitations

H H

QL QL

AFCD (2012) DJ (2012)

SC

Number of publications related to the MPA.

M

QL

web search engine

SC SC SC

EC

QL

EPD (2007–2011)

Note: SC, social-economy; EC, ecology; QT, quantitative assessment; QL, qualitative assessment; AFCD: Agriculture, Fisheries and Conservation Department. CSD: Census and Statistics Department. DJ: Department of Justice. DSD: Drainage Services Department. EPD: Environmental Protection Department. MD: Marine Department. a An example of ecological risks associated with MPAs, and anticipated relative ranks are indicated with abbreviations H, high priority; M, medium priority; L, low priority; NA, not applicable. b Sources: GovHK bhttp://www.gov.hk/en/residents/N.

and exogenic forces. The former are manageable and come from within the system (e.g. population growth) whereas the latter are those that local management cannot address but have to deal with the consequences, such as climatological variability and natural disasters (Elliott, 2010). Both of the endogenic and exogenic drivers are included in the model (Fig. 4). Once the links between driving forces, pressures and impacts are clear and well-defined, managers can respond to them by reducing and mitigating the pollution-associated pressures and threats, and target policies can be formulated accordingly. 3.4. Indicator screening and prioritization The objective of this step was to identify and prioritize/rank indicators by taking into account the likelihood of occurrence of the environmental threats as well as their consequences. The estimated priority of each DPSIR indicator (e.g. pollution, fishing) was assessed based on the existing measurement of each indicator and the principle of qualitative weight-of-evidence by a group of experts (Weed, 2005). Each indicator was assigned a qualitative score of low, medium or high based on the “Seven Rapid Ranking Criteria” for MPA management (Fig. 2). The

numbers of high, medium and low scores for each measurement endpoint were counted and the indicator assigned an overall rank of priority (i.e., low, medium or high; see example in Table S1 in Appendix A). Subsequently, the anticipated priority of an indicator determines whether a qualitative or quantitative ERA approach is warranted. 3.5. Assessment approaches To deal with the complexity of marine environmental problems and lack of quantifiable data, we firstly decided to prioritize risk management measures using a qualitative assessment. The qualitative approach was based on the categorizations of putative diagnostic characteristics of possible threats to the marine environment, with all available relevant information and weight-of-evidence judgments being undertaken by experts (Read and West, 2010), as exemplified in Table S1 (Appendix A). In contrast to the qualitative approach, quantitative methods require extra technical inputs from experts in mathematical modeling and statistical computation. Detailed protocols of this quantitative approach can be found in Brown (1985). In this study, since there is an urgent need to implement risk analysis associated with MPA pollution in

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measured environmental concentrations (MECs) with predicted noeffects concentrations (PNECs) to obtain the RQs (RQ = MEC / PNEC). When the RQ is b 1, it is presumed that the risk (likelihood of adverse effects) is low; when the RQ is either equal to or N1, the risk is high and the magnitude of adverse effects increase proportionally with RQ. Worst-case and average scenarios are expressed as RQMax and RQAve, respectively. RQMax is calculated by dividing the highest MEC by the PNEC and RQAve is obtained by dividing the arithmetic mean of MECs with the PNEC. The MEC data sources were obtained from Marine Water Quality documents in Hong Kong, that were produced by the Environmental Protection Department (EPD, 2005–2009) and Agriculture, Fisheries and Conservation Department (AFCD, 2005– 2010). PNECs included the Sea Water Quality Standard of China (GB 3097–1997), Water Quality Objectives for the marine waters of Hong Kong, and Lower Chemical Exceedance Level in Sediment Quality Criteria for the Classification of Sediments in Hong Kong (WBTC No. 34/ 2002). 4. Hong Kong's Cape d'Aguilar Marine Reserve case study 4.1. Endogenic driving forces Fig. 3. A multi-dimensional DPSIR model. D: driving forces. P: pressures. S: state of the environment. I: impacts. R: responses.

Hong Kong, simple and practical qualitative methods were used for most of the selected indicators, and quantitative methods were only applied for chemical indicators (Fig. 4). In this paper, the risk quotient (RQ) (USEPA, 1998) was applied as the quantitative ERA approach to determine if measured levels of chemicals in the target waters and sediments were likely to cause harms to local MPAs. This methodology is accomplished by comparing

4.1.1. Demographic and gross domestic product (GDP) increases Hong Kong is a harbor-based city with a land area of 1104 km2 and a population of over 7 million people. In the past 30 years, the population of Hong Kong has nearly doubled (Fig. S1 in Appendix A). Today, Hong Kong has become one of the most densely populated city-based entities in the world. Economic growth is linked closely to urbanization, as reflected by the 112-fold increase in GDP during the period of 1967– 2010 (Fig. S1 in Appendix A). The booming population (+ 0.7% per annum) combined with rapid economic growth has affected the marine

Fig. 4. Example of a DPSIR loop for marine pollution issues in the IERAM system.

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environment by changing land use, resource exploitation, mariculture and pollution.

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4.2.2. Tropical cyclones, rainstorm and wave In Hong Kong, tropical cyclones usually occur between April and December with an average number of 12.4 per year, and typhoons strike from June to October, that is, 0.4 times per year (information from Hong Kong Observatory). Although typhoons are most common in autumn, stronger summer typhoons (as sea temperatures rise) usually

result in more serious damage to marine organisms such as corals and sea cucumbers within the Cape d'Aguilar Marine Reserve. This is because the prevailing wind is from the south in summer which causes higher waves (Clark and Morton, 1999; Morton, 2002), and this combination of strong winds and high waves result in large numbers of the remains of marine organisms, e.g., snails, bivalves, sea cucumbers and corals, washing ashore within the marine reserve during typhoons. The Hong Kong Observatory has constructed a Warnings & Signals system for tropical cyclones, rainstorms and thunderstorms. Since the 1960s, 785 tropical cyclone warning signals have been recorded, and 394 rainstorm warnings were issued between 1998 and 2012. Heavy rainfall and typhoons can affect marine organisms in varying degrees depending on their intensity and duration. The damage to marine organisms living in the shallow waters of the Cape d'Aguilar Marine Reserve (less than 17 m in depth; see Fig. 1) could be heavier than that in deep water (Hughes and Connell, 1999). Few researches have investigated the impacts of rainfall and typhoons at the Cape d'Aguilar Marine Reserve. One study was conducted by Morton (2002), which illustrated changes in coral community structure probably due to hyposaline conditions resulting from the passage of typhoons. Morton (2005) also reported a significant increase in coral damages in the marine reserve after a series of typhoons in 2000 and 2001. Based on the records of seasonal patterns of wind, rainfall, salinity, reef topography and geographic location of the reserve, a typhoon-driven risk was considered to be relatively high between June and August compared to other months of the year, with high-speed southerly winds blowing directly over Cape d'Aguilar. Apart from typhoon-driven rainfall and hyposalinity, wave action can also adversely affect intertidal and shallow subtidal community structure and cause mortalities. In order to estimate the risk posed by wind, as described by Becerro et al. (2006), we initially categorized winds of N37 km/h from 225 to 270° as “risky” to the Cape d'Aguilar Marine Reserve. At this speed, wind can generate swells of 1.4 to 3.2 m (Anthoni, 2000), which are capable of disturbing the shallow waters of the entire marine reserve (with two bay areas N3 m deep, see Fig. 1). Marine organisms inhabiting the Cape d'Aguilar Marine Reserve are more susceptible to southerly winds and are more likely to be washed ashore to their death (Clark and Morton, 1999). The chances of such “risky” wind occurrence days are, however, low according to five-year wind records obtained from the Hong Kong Observatory (Fig. S2 in Appendix A). The wind and wave stresses to the Cape d'Aguilar Marine Reserve are, therefore, considered to constitute two potential, albeit natural, threats but are not of major concern. To refine the ERA of wind-driven damage, routine ecological surveys and weather monitoring should be implemented within the marine reserve especially in summer and autumn.

Fig. 5. Number of fishing vessels and total engine power of fishing vessels in Hong Kong. Data obtained from Agriculture Fisheries and Conservation Department.

4.2.3. Heat stress High temperature has been appreciated as a causal factor in the distribution and abundance of rocky shore organisms. ‘High shore kills’ refer to the severe heat stress in both sessile and mobile species caused by calm hot summer days on temperate and tropical rocky shores (Chan et al., 2006). Hong Kong shores experience a strongly seasonal climate, dictated by the local monsoons. Winter is cool and dry (mean air temperature 17 °C, mean rainfall 15 mm), whereas summer is hot and wet (mean air temperature 29 °C, mean rainfall 279 mm) (Table S3 in Appendix A). In summer, tides are lower than those in winter (by ~ 0.5 m, maximum tidal range ~ 2.5 m) and fall during the afternoon when rock temperatures can exceed 50 °C (Williams, 1994; Chan et al., 2006). In the Cape d'Aguilar Marine Reserve, this combination of factors results in extremely stressful conditions for intertidal organisms and mass mortalities can occur during calm, spring low tides (e.g. algae, Williams, 1993; barnacle and mussel, Liu and Morton, 1994; limpet, Williams et al., 2005; barnacle, Chan et al., 2006). Therefore, the risk driven by high temperature was considered high between June and September in the Cape d'Aguilar Marine Reserve, as hot temperature

4.1.2. Fishing Fishing is another major driver for marine environmental change and coastal management issues. The Hong Kong fishing industry has a long history and provides a large number of job opportunities and income. In 1960, the number of fishing vessels in Hong Kong was N10,000. After World War II, fishing efficiency was enhanced as modernized fishing technologies and mechanized vessels were introduced. The total number of fishing vessels has, however, gradually decreased to b4000 in 2010 (Fig. 5). Although there has been a large decrease in the numbers of fishing vessels, the total engine power of the fishing vessels has shown nearly 2-fold increase in just over the past 20 years, reflecting an increasing pressure on fish stocks, especially inshore and top-targeted species of Carangidae and Siganidae (information obtained from the Agriculture, Fisheries and Conservation Department). This pressure also keeps rising as a result of boosted local demand of seafood due to the human population increases. 4.2. Exogenic driving forces 4.2.1. Climatological characteristics Hong Kong has a sub-tropical climate with cold dry winters and hot wet summers due to the interplay of the north-east and southeast monsoons. Climate data vary greatly for different regions of Hong Kong. For example, the mean annual rainfall at Shek Kwu Chau is only half that at Tate's Cairn. In this study, regional climate data regarding the Cape d'Aguilar Peninsula rather than those related to the whole of Hong Kong were collected for assessment. Rainfall and climatological data from the Waglan Weather Station, which is closest to the Cape d'Aguilar Marine Reserve, were chosen for the analysis (Table S3 in Appendix A). Among all the climatic driving factors, rainfall, wind and temperature are the three most influential in relation to the Cape d'Aguilar Marine Reserve, as they are associated directly with hyposaline conditions, physical disturbance, and desiccation stress and they could indirectly lead to community declines of marine organisms (Morton, 2002; Williams et al., 2005).

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associated with the wet monsoon season will reduce the size of species population and thus influence the structure and functioning of the Cape d'Aguilar rocky shores. 4.3. Pressures 4.3.1. Potable water consumption and wastewater generation As a direct consequence of the extremely high population density and continuous growth of the urban environment in Hong Kong, freshwater and seawater consumption has increased 2 and 3 folds in the past 20 years (source: Water Supplies Department, the Government of the Hong Kong Special Administrative Region). All urban areas and 95% of Hong Kong households are provided with a sewer system to collect wastewater for treatment, and the majority of sewage is from domestic and restaurant uses (74%; Fig. S3 in Appendix A). There were gradual increases in both total amounts of sewage and domestic and restaurant consumption from 2001 to 2010 (Fig. S3). Before 1998, only 10% of sewage discharged into coastal waters received secondary treatment (biological), 25% received preliminary treatment (screening) and the remaining 65% comprising raw sewage was discharged into coastal waters without any treatment. In 2001, a major government infrastructure development – the Harbour Area Treatment Scheme (HATS) – was commissioned to combat water pollution caused by urban development around Victoria Harbour, improving water quality in the eastern and central parts of this water body. With HATS, over 75% of wastewater generated from the Victoria Harbour area is now treated at the Stonecutters Island Sewage Treatment Works using chemically enhanced primary treatment (Choi et al., 2009). 4.3.2. Solid waste loads Waste loads have been growing with the economic growth of Hong Kong. The total amounts of municipal solid wastes (including those from households, industries and commercial operations) increased from 2687 thousand tonnes in 1991 to 3271 thousand tonnes in 2009. Paper forms of waste are dominant (33%), followed by plastics (24%). Wastes have been managed through waste reduction programs, waste recycling and legislation (Waste Disposal Plan) implemented by the Environmental Protection Department. It has cost nearly HK$6 billion to build three strategic landfills, and their operating costs are around HK $400 million per annum. The challenge remains, however, that the existing limited landfill space will be filled up in the late 2010s, even if the rate of waste increase remains constant. Irrespective of what waste management measures will be taken, i.e., new landfill places or incineration, waste loads will still lead to environmental pressures in both ecological and economical spheres. 4.3.3. Maritime transport Maritime transport has always been a key factor in the economic and urban development of Hong Kong. The number of ships registered in Hong Kong doubled from 1990 to 2010, and the total gross tonnage increased six fold during the same period. More than 200,000 vessels arrive at Hong Kong harbors each year. Net registered tonnage of vessel arrivals, cargo throughput, and total passenger throughput for local and China-bound ferries have increased by 3.6%, 1.9%, and 2.9%, respectively in the past five years. Fully cellular container vessels and cruise ships/ferries together accounted for over 71% of the total number of ships on the local register. Irrespective of vessel type, maritime transport can be a major pressure, acting in different ways such as channel dredging, dumping of ballast water, spilling oil, and releasing toxic antifouling paints. 4.3.4. Production value of fishing and catch per unit of effect (CPUE) Mechanization and growth of local fishing vessels drove up the production of Hong Kong's fisheries and production value. The production value of fisheries dramatically increased from around HK$166 million in 1965 to HK$2320 million in 1993. Subsequently, the annual

production value decreased gradually by one third in 2007 (Fig. S4 in Appendix A). The Committee on Sustainable Fisheries in Hong Kong ascribes the downward trend in recent local production values to declining fisheries resources and competition from mainland fishermen. The total engine power of fishing vessels, however, has kept increasing despite the decreasing number of boats. As a consequence, the CPUE decreased from 483 kg/kW in 1985 to 205 kg/kW in 2008 (Fig. S4), reflecting a continual reduction in fishing efficiency. Such fishing operations pose a direct pressure on the marine environment. To alleviate the overfishing problem and allow the ecosystem recovery in Hong Kong waters, the Government of the Hong Kong Special Administrative Region has recently implemented territory-wide trawling ban since 31 December 2012 (Morton, 2011). 4.4. State 4.4.1. Water and sediment quality assessment Since 1986, the Environmental Protection Department (EPD) has implemented a marine monitoring program to appraise the Hong Kong Government of changes in Marine Water Quality. The two monitoring stations closest to the Cape d'Aguilar Marine Reserve — SM1/SS1 (22°12.738′N, 114°13.885′E) and EM3/ES2 (22°14.237′N, 114°16.144′E) (Fig. 1), were selected for evaluating the marine reserve's water quality. Eight water column parameters including dissolved oxygen (DO), total suspended solids (TSSs), biochemical oxygen demand (BOD), un-ionized ammonia nitrogen (UIA-N), total inorganic nitrogen (TIN), orthophosphate phosphorus (OP), chlorophyll a and Escherichia coli were investigated. Sediment sulfide, nine metals, polychlorinated biphenyls (PCBs) and aromatic hydrocarbons (PAHs) were also surveyed by the Environmental Protection Department. Copper concentration (38 mg/kg) at Station EM3 was found to pose a high risk in the worst case scenario (RQMax N 1). PCBs (at 18 μg/kg) presented high risk at both stations with an RQAve of 0.9 (Fig. 6). In general, sediment quality within the north-eastern waters of the reserve was worse than that in the south-west. Four parameters (TSS, BOD, TIN, and OP) showed high levels within the waters of the marine reserve. On average, seawater quality within the marine reserve was no better than in un-protected areas close to it (shown in terms of RQs in Fig. 7). 4.4.2. Oil pollution and marine debris Oil pollution, irrespective of its scale, is one of the most serious problems to navigation imposed on the marine ecosystem of Hong Kong (Spooner, 1977). The worst oil spill incident in Hong Kong's history occurred in 1973 when between 2000 and 4000 tonnes of oil leaked from Shell's oil storage installation on Ap Lei Chau. There were an average of 120 instances of oil spillage incidents each year reported between 2003 and 2010, creating an upward trend (Fig. S4 in Appendix A). In addition to oil pollution incidents, various types of vessels, most of them commercial cargo and fishery, use an inner route which abuts the Cape d'Aguilar Peninsula to the north for assess into eastern waters of Hong Kong for better protection from the weather and for shorter transit distances to local ports. The spills and discharges of oil from regular operations of these vessels is another threat to the Cape d'Aguilar Marine Reserve. Marine debris comes from boats and ships and is of less concern compared to other forms of toxic pollutants. According to prosecution statistics obtained from Hong Kong's Marine Department, between 2006 and 2010, the average number of marine littering convictions was 50 each year with an overall penalty of over HK$78,000. Refuse collected from vessels also showed an upward trend (Fig. S5 in Appendix A). In the Cape D'Aguilar Marine Reserve, over 100 kg of plastic litter can be gathered in any one month along only 300 m of coastline (unpublished data). The most frequently collected types of litter within the reserve are: plastic bottles, plastic bags, foam boxes, broken glass, metal cans, fishing buoys, fishing lines and nets. Plastics can pose severe problems for fish, seabirds and other marine life due to their properties

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Fig. 6. Risk quotients (RQs) for sediment quality parameters. SS1 and ES1 stand for two monitoring stations closest to the Cape d'Aguilar Marine Reserve.

(slow degradation, easy breakage into small pieces, release of toxic plasticizers and ease of being transported over large distances; Weisman, 2007). In short, coastal environments of the Cape d'Aguilar Marine Reserve suffer from many pollutants, from oil to marine debris, mainly derived from nearshore activities. 4.5. Impacts 4.5.1. Red tides Prior to 1970, red tides were rarely recorded in Hong Kong waters but, since the 1980s, they have been observed frequently. Between 1980 and 2009, 808 cases were recorded (information from the Agriculture, Fisheries and Conservation Department). Dinoflagellate species were the cause of 29% of overall reported red tides. Sixteen red tides led to the death of cultured fish and a direct economic loss amounting to HK$12.4 million from 1980 to 1997 (Environmental Protection Department, 2000). In order to minimize the damage caused by red tides and to reduce the monetary loss, the Environmental Protection

Department conducts long-term monitoring of phytoplankton at 25 stations within Hong Kong waters. From 1980 to 2009, 72% cases of red tides occurred in the eastern region, and 137 cases in the southern region. The Cape d'Aguilar Marine Reserve is located between these two high risk regions. Similar to the disaster in 1998, harmful algal blooms initiated in northeastern waters can be transported to southern waters with tidal currents (Lee and Qu, 2004) and constitute another threat to the marine reserve. The two closest phytoplankton monitoring stations to the reserve are, however, situated over 5 km. In practice, therefore, neither of them can reflect the actual algal conditions of the marine reserve, because there is usually large variance in the monitoring data between the two stations. To make a practical assessment of red tide risks, therefore, a real-time phytoplankton monitoring program should be implemented within the marine reserve. 4.5.2. Water quality of bathing beach One of the impacts generated from increasing coastal population and sewage is the change in water quality of bathing beaches. Between the

Fig. 7. Risk quotients (RQs) for water quality parameters. SS1 and EM3 stand for the two monitoring stations closest to the Cape d'Aguilar Marine Reserve.

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late 1980s and early 1990s, the water quality of beaches on the south of Hong Kong Island had been deteriorating due to sewage discharges from their hinterland. Remarkably, the three beaches closest to the Cape d'Aguilar Marine Reserve — Rocky Bay, Shek O and Big Wave Bay, showed the worst water qualities in terms of the concentration of E. coli. Rocky Bay beach has even been closed since 1989 until recently because of its poor water quality. In 1997, sewers were constructed in the Shek O hinterland to collect and convey sewage to the Shek O Sewage Treatment Plant for preliminary treatment and disposal via a submarine outfall. As a result, E. coli concentrations in Shek O beach declined from 400 counts/100 mL in 1997 to 13 counts/100 mL in 2009 (information from the Environmental Protection Department). In some enclosed water areas, however, such as the beaches in Tsuen Wan District, the concentrations of E. coli remain high, and more beach pollution controls should be implemented to deal with this pressure, such as visitor flow and entry time controls.

4.6.2. MPAs as a response To protect and conserve marine biodiversity for the purposes of conservation, research, education and recreation, the Hong Kong SAR Government has established four marine parks, and a marine reserve with differing ecological interests. Management works include planning for proper utilization of existing MPAs, monitoring the ecology, environment and activities within the MPAs, enforcing the Marine Parks Ordinance and the Marine Parks and Marine Reserve Regulations. The MPAs have been designated to date and include Hoi Ha Wan Marine Park, Yan Chau Tong Marine Park, Sha Chau and Lung Kwu Chau Marine Park, Tung Ping Chau Maine Park and the Cape d'Aguilar Marine Reserve. These five sites cover b1% of Hong Kong's marine sea area (Table S4 and Fig. S6 in Appendix A). Another four sites are under study and consideration as future MPA candidates. These are Southwest Lantau (6.57 km2), South Lamma Island, Shelter Island (10 km2) and the Soko Islands (12.72 km2) (Fig. S6).

4.5.3. Increasing environmental expenditures Environmental budgets reflect another significant type of impact in the DPSIR loop. The Hong Kong SAR Government has made big investments in environmental projects as a source of livelihood and improvements to the general quality of life. Such environmental projects cover four aspects: waste, sewage, noise and air. The total devoted expenditure increased from HK$1914 million in 1991 to HK$3272 million in 2009, and sewage-related projects accounted for 61% of this, on average, over the past two decades, followed by waste management with 35%. These budgets, with a concomitant increasing level of environmental support, recognize that more efforts and responses must be made by the government and that public environmental awareness needs to be enhanced to shift environmental impacts onto a sustainable path.

4.6.3. Laws and legislations Hong Kong possesses a wide variety of legislation associated with the marine environment and MPAs (Table S5 in Appendix A). The most significant governmental document regarding MPAs is the Marine Parks Ordinance. This Ordinance provides for designation, control and management of marine parks and the marine reserve. The Marine Parks and Marine Reserves Regulation enacted in July 1996 provides for the prohibition and control of certain activities in marine parks or marine reserve. The level of compliance with some of these regulations has, however, been low due to poor surveillance and a lack of enforcement. For instance, fishing is prohibited in the marine reserve, but fishing boats are actively operating within the reserve during the nighttime hours and at weekends when patrols are relatively weak (personal observation). Certain legislations are intrinsically inadequate to provide protection. One example, based on our observations, is the “boundary effect” to the MPA, e.g. fishing within the marine reserve is prohibited but fishing practices around the boundaries of the reserve are even more intense than in other unprotected areas. Furthermore, issues can arise during the execution of enforcement, e.g. the existing reporting system for detected illegal activities is problematic. When local residents observe a prohibited activity being carried out within the marine reserve, they are encouraged to take photographs, make notes, and call the marine park warden. On most occasions, however, no professional camera is at hand and an unawareness of proper recording actions jeopardizes the effectiveness of the reporting protocol. Even if marine park wardens are informed by telephone, by the time that an offender is spotted, damage may have already incurred, and poachers have often already left before the arrival of the authorities. In summary, Hong Kong has achieved some success in controlling different coastal activities by enacting corresponding regulations; nevertheless, there appears to be less than an integrated policy with regard to the, supposedly, protected areas of the marine environment.

4.6. Responses 4.6.1. Sewage treatment plants (STPs) In response to its changing marine environmental state, the Hong Kong SAR Government commenced the HATS project. Some 1.4 million tonnes of sewage is collected from sites along Victoria Harbour and treated at the chemically enhanced primary treatment plant on Stonecutters Island. As a result, water quality (e.g. DO level, ammonia level, E. coli level) in the Victoria Harbour has improved significantly since 2002. To date, 66 STPs have been built and managed by the Drainage Services Department all over Hong Kong, and secondary treatment works account for 56.06%, followed by preliminary treatment works with 33.33%. There are increasing improvements in water quality in North West Kowloon. There is, however, only one STP on the Cape d'Aguilar Peninsula and that is merely screening. The preliminary screening work is located at Shek O, 3 km away from the Cape d'Aguilar Peninsula in the northeast. Another STP close to the Cape d'Aguilar Marine Reserve is the Stanley STP, whose submarine outfall is located within 3 km of the western boundary of the marine reserve. Although population densities at Shek O and Stanley are much lower than those on the two sides of Victoria Harbour, the impacts from local domestic sewage should not be underestimated — as with Rocky Bay, the infamous case mentioned above. In addition to fecal pollution, environmental risks posed by toxic substances can also be high in areas near outfall discharges. Research on STPs in Hong Kong found that their discharges are the major pollution sources of most metals and several organic pollutants (Yang et al., 2006). We have also found that the two STPs close to the Cape d'Aguilar Marine Reserve are the primary sources of some endocrine disrupting chemicals such as nonylphenols and bisphenol A (Xu et al., 2014), and this calls for urgent and appropriate management actions to be taken with the STPs, such as upgrading the treatment facilities.

4.6.4. Scientific support and public involvement The Swire Institute of Marine Science (SWIMS) of the University of Hong Kong, is situated at the tip of the peninsula overlooking the Cape d'Aguilar Marine Reserve. It serves as a base for scientists to carry out research in different fields focusing on marine ecology. Because of studies carried out by the SWIMS researchers, since the establishment of the marine reserve in 1996, the scientific community has gained more insights into this area of ecological richness. The number of scientific publications related to this marine reserve has increased by over four times in the past 20 years (Fig. S7 in Appendix A). These research projects provide valuable baseline information on the ecological value of the area. The paradox is, however, that while scientists are mostly working on detailed and narrow aspects, the managers require a holistic framework which may not necessarily require high levels of detail.

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4.7. Summary of IERAM on the Cape D'Aguilar Marine Reserve To summarize our analysis conducted for the Cape d'Aguilar Marine Reserve at a broader marine environmental scale, a set of comprehensive indicators have been included into the ad-hoc DPSIR framework to create an integrated assessment (Table S6 in Appendix A). The indicator system encompassed 6 Drivers, 7 Pressure indicators, 25 State indicators (including 1 biological, 21 chemical and 3 physical parameters), 3 Impact indicators, and 4 Responses. The effects of MPA management and practices were evaluated by comparing the temporal distributions of these indicators over a certain time frame (Table S6). Each indicator was divided into two temporal groups, if applicable, by the time point of the designation of the Cape d'Aguilar Marine Reserve (i.e. 1996), and the comparison was then made between the two temporal groups of measurements of each indicator. The results showed that at the top of the system, anthropogenic driver forces at different levels (i.e., GDP, population, total engine power of fishing vessels) was still strengthening, which have triggered bigger pressures on the whole marine environment of Hong Kong. On the other hand, the intensities of natural drivers (e.g. tropical cyclones and rainstorms) showed no noticeable change over the past decades. The measurements of all indicators of pressure, e.g. seawater use and CPUE, significantly increased over time, causing more adverse effects on the changing state of the local marine environment. Little improvement in seawater and sediment quality around and within the Cape d'Aguilar Marine Reserve has been observed except for fewer amounts of metals (i.e., cadmium, mercury and aluminum). Copper and inorganic nutrients in waters and sediments pose high ecological risks to marine organisms indicated by their high RQ values. Changes in the state of the marine environment led to changes in the function of the local marine ecosystem and social economy. More capital expenditure was devoted to environmental projects to alleviate the problems of a deteriorating environment, and the improved water quality of swimming beaches was an example of reward. The responses expressed by the initiative feedbacks from the human society, included construction of sewage treatment plants, designation of MPAs, enforcement of environmental legislation, and inputs of science and technology. The larger the responses, the larger the enhancement effects upon the sustainability of marine conservation in the long term. 5. Discussion MPAs have been widely proposed as a tool to manage fisheries, protect marine biodiversity and provide multiple potential benefits, as elaborated above, but they are only complementary measures which should not be treated as management panaceas (Kaiser, 2005). Even the no-take MPAs, marine reserves, are insufficient protection for isolating ecosystems from all critical anthropogenic impacts (Allison et al, 1998). In fact, fewer than 10% of existing MPAs achieve their management goals (Pomeroy et al., 2004). Below we summarize five problems facing MPA management in Hong Kong that can lead to the failure of accomplishing the objectives assigned to the MPAs. Firstly, at the largest scale, global climate change can overwhelm communities within MPAs. This kind of adverse change, however, cannot be possibly counteracted by regional MPA management. Secondly, the spatial structure of an MPA is not good at addressing those threats which arise outside the protection boundaries, such as coastal development, pollution, navigation and fishing. MPAs may not be feasible without consideration being taken of surrounding areas. The most blatant example of this is chemical pollution. The existing legislation only deals with activities within an MPA, but land-originated pollutants may enter it through a variety of different channels. Marine species inside MPAs can be affected by the adjacent polluted water masses brought either into or through them by either winds or currents. Intensive fishing at the boundaries can also be a major factor contributing to the failure of the MPAs' initiative of species conservation as, whenever

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marine organisms recruit and spill over successfully, MPA edges actually act as magnets for fishing efforts, causing further conflicts (Christie et al., 2002). Thirdly, the MPAs in Hong Kong are small. For example, the small Anse Chastanet Reserve in St. Lucia does not benefit the species living within it (Roberts and Hawkins, 1997). Similarly, the Biosphere Reserve established in the northern Gulf of California, Mexico, also failed to protect the vaquita porpoises due to an insufficient protection area (Rojas-Bracho et al., 2006). Based on several examples from both temperate and tropical regions, McLeod et al. (2009) proposed that the minimum diameter of an MPA should be 10–20 km. Not one MPA in Hong Kong is even close to this proposed ideal size, with the largest (Sha Chau & Lung Kwu Chau Marine Park) one a mere 12 km2. Fourthly, it is crucial to ensure that in marine management planning, core areas, such as the entire marine reserve, is protected by sufficiently extensive buffer zones and this also applies to management for larger marine areas. Moreover, marine management can fail if it is fractured into too many different agencies with each tackling a single threat, because the uses managed by one agency, such as aquaculture by Agriculture Fisheries and Conservation Department, often end up as a threat to be managed by other agencies, such as water pollution from fish farms by Environmental Protection Department and Food and Environmental Hygiene Department. In other words, conservation efforts by one authority may be jeopardized if there is a lack of organizational integration among the government agencies responsible for different aspects of the marine environment. In Hong Kong, the work of the Country Parks and Marine Parks Divisions of Agriculture Fisheries and Conservation Department is isolated, but the boundaries of these areas are not clear-cut. Fifthly and last but not least, due to the lack of integrated long-term ecological and water quality monitoring programs (e.g. surveys on species abundance, diversity and composition, and monitoring on persistent organic pollutants and phytoplankton) within and around MPAs, it is accordingly difficult to establish baselines for assessing risks to them. Given these five complex and multidimensional problems of MPA management, an IERAM framework is needed to firstly identify all the potential threats to MPAs, analyze relationships among them, and prioritize management options. In this paper, we argue that applying an IERAM framework to MPA management in Hong Kong requires embracing more indicators, or variables, at broader geological and disciplinary scales that can be used to integrally describe the environmental phenomena and to provide managers with better understanding of the cause–effect relationships. Drivers can be divided into sub-drivers, taking into concern the scale of the study area. Fishing is a good example of one driving force. As illustrated above, the overall number of fishing vessels and their power parameters reflect the levels of fishing activities and account for the declining trend in fishery resources in the Hong Kong marine environment. The number of fishing vessels per year close to the MPA boundaries can be a good indicator of a sub-driver, because it reflects the direct pressure exerted upon the MPA. The biomass of catch from these boundary fishing vessels can, subsequently, be used as one indicator of pressure through the causal chain. The absence of sub-driver and sub-pressure indicators calls for more intense surveillance and monitoring actions. By assessing the risk posed by various pollutants, we acknowledge the impact on seawater and sediment quality within and close to the Cape d'Aguilar Marine Reserve, primarily produced by sewage and solid waste. In this part, due to the limited number of monitored chemical parameters, the level of authenticity and accuracy of the assessment is reduced to some degree. This is true for the data of trace toxic chemicals (e.g. POPs), which are not available in the case of the Cape d'Aguilar Marine Reserve. We also find existing gaps in the assessment of the effectiveness of MPAs. In this phase, there are few state indicators that are relevant to monitoring ecological changes in MPAs. At the Cape d'Aguilar Marine Reserve, fundamental information such as state changes in abundance, biomass, diversity of marine organisms, is still scarce after 15 years of

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designation. As defined by Ojeda-Martinez et al. (2009), other state indicators in MPAs involving dominance, community structure and trophic categories, should also be thought of as important assessment factors of the MPAs' functioning and policy decisions. In addition to intra-MPA state indicators, results from comparisons between protected and unprotected areas can indicate inter-state changes as well (Mangi et al., 2007). In short, most of the databases are currently available only at high levels of aggregation for administrative units, i.e. at the level of Hong Kong SAR Government departments, around and within MPAs, whereas regional data are required at finer levels of aggregation for more ecologically relevant assessment. Driving forces, pressures, state, impacts and response indicators for evaluating regional marine environments and MPAs are emphasized in this paper. These indicators have been adapted due to the necessities of integrated management, through identifying the different system components and processes affecting MPA's and their surrounding waters in Hong Kong. Interpretation of the relationships among the DPSIR indicators is not easy due to the complexity of feedbacks, the uncertainties involved and mismatched periods between different available databases (Degnbol, 2005). This causes difficulties for managers in developing policy and making management options, and for public understanding. Notwithstanding, great efforts have been expended to protect the marine environment of Hong Kong, including construction of STPs, allocating budgets for environmental projects, restriction and conservation by legislation, scientific support, and the establishment of MPAs. The responses of MPAs, interactions and causalities are worthy of deeper consideration, as their effectiveness is influenced directly by other responses. For example, poor enforcement or inappropriate implementation of the Marine Parks Ordinance can turn regulation to a mere scrap of paper. As illustrated above, the IERAM framework is not a single DPSIR causal cycle but is nested within multi-layer DPSIR pentagonal loops in three-dimensional spheres from different perspectives, as illustrated in Fig. 3, and encompasses many components of assessment interacting with each other. In essence, we focus on one particular issue (marine pollution) from the viewpoint of modeling linkages to MPAs through cause–effect connections, and place this layer of priority at the apex of the spheres because of the objective of safeguarding MPAs (Fig. 4). While one might attempt to model, for instance, mariculture management under the IERAM framework, visually, the Marine Pollution DPSIR cycle layer can be shifted down and still provide supplemental information for a new environmental assessment of mariculture and, hence, facilitate the work towards the necessary integrated perspective. Finally, based on the obtained results from IERAM, we have identified the most significant components for safeguarding the integrity of the marine protected areas (e.g., prevention of marine pollution and successful implementation of environmental legislation in Fig. 4 and Table S6). The control of external influences/threats is vital to reduce the ecological risks on the marine protected areas (Cicin-Sain and Belfiore, 2005). The recommended management options for õcontrolling the outside threats include: 1) a multiple-use zoning approach which can provide high levels of protection while allowing reasonable uses (Day, 2002); 2) regular monitoring which should be carried out in both sea and land areas linked to the protected area (e.g., pollution from land-based activities and destructive fishing in nearby seas); 3) new science and technologies, such as advanced oxidation technologies for wastewater treatment (Cui et al., 2009) and site-specific environmental quality standards (Kwok et al., 2008) which could be considered for better pollution prevention; and 4) coordinating committees between the protected area management authority (e.g., Agriculture, Fisheries and Conservation Department) and other authorities managing activities outside the protected area (e.g., Environmental Protection Department and Drainage Services Department) which should be established. Inside the protected areas, the following management measures are also recommended: 1) Long-term water quality

monitoring program needs to be in place, e.g., monitoring algal bloom associated parameters (e.g., chlorophyll a and inorganic nutrients) and trace toxic organic pollutants (e.g., EDCs); 2) continuous scientific studies are needed to establish a clear biodiversity and biomass database (Hilborn et al. 2004); and 3) new technologies, such as, unmanned aerial vehicles with inter-radar and night-vision camera, have the advantages of higher mobility and ability of investigation when and where patrols are lacking. It is, however, a complex task to accomplish the recommended MPA management options generated from the risk assessment (as described above), because the planning, investments and actions of the management options define the society's joint economic, social and environmental goals. Information exchange and view sharing among the public, stakeholders, scientists, management agencies and policy makers is a prerequisite for achieving these joint goals. Effective communication can enable consensus development, which is essential to the management of MPAs (Mascia, 2003). Strategic communication is also regarded as a core mechanism to support strategy processes for sustainable development, from setting communication objectives (e.g. the target beneficiaries and their locations), planning media production and education program, to evaluating the desired outcomes (OECD, 2000). Without effective communications, public participation and policy-making will become difficult to succeed because successful partnership and collaboration among key stakeholders highly depend on the information exchange and view sharing (GTZ, 2006). Thus, strategic communication should be fully implemented during the planning, investments and actions for any MPA management option. This calls for natural scientists and social scientists (e.g., communication professionals and media professionals) working together with various stakeholders, policymakers and environmental authorities to develop agreeable strategies and action plans for enhancing the sustainability of MPAs.

6. Conclusions Government and scientists have been developing new integrated management approaches for multiple and overlapping uses of marine resources. This paper proposes a conceptual IERAM framework for developing, integrating and analyzing a set of multi-disciplinary indicators for MPA management. A main advantage of this approach is the use of readily available governmental databases for evaluating MPA conditions and that of the broader marine environment on a continuous basis, thus providing timely information for MPA assessment and management. In addition, the conventional environmental risk assessment methods (both qualitative and quantitative) have been integrated into this framework. Further work is needed to improve data collection and elaboration, and to achieve an appropriate evaluation of problems in local MPA management. The next step, therefore, is to include more indicators as well as our own monitoring data associated with each element of the conceptual model, and its application to other MPAs and the entire MPA network.

Acknowledgments This work is jointly supported by the Area of Excellence (AoE) Scheme under the University Grants Committee of the Hong Kong Special Administration Region (HKSAR), China (Project No. AoE/P-04/ 2004), and by a research grant from the Swire Educational Trust (SWIRE-JHS-HKPHD-2010). Elvis Xu would also like to thank John Swire & Sons Limited and the Swire Educational Trust for providing him a James Henry Scott (Hong Kong) PhD Scholarship tenured at the Swire Institute of Marine Science. The authors also thank Dr. Stella Wong, Mr. Guihua Wang, Mr. Alex Yeung and Mr. Edward Law for their helpful comments on earlier drafts of this paper.

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