Coral reef health indicators: integrating ecological and perceptual assessments of anchor damage

Dinsdale, Elizabeth (2004) Coral reef health indicators: integrating ecological and perceptual assessments of anchor damage. PhD thesis, James Cook University.

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The ecosystem health concept is an integrative approach to environmental management and while conceptually logical, it is difficult to implement. The false dichotomy of nature and culture, and the way in which knowledge is constructed has led to many of these problems. To understand the relationship between knowledge systems, the ecosystem health concept is explored here by assessing the condition of coral reefs associated with different intensities of anchoring, using both an ecological and a social perspective. Specifically, the research aims to: 1) identify environmental indicators to evaluate management strategies; 2) identify perceptual meanings ascribed to coral reefs; 3) evaluate the relationship between perceptual meanings, health judgments and environmental indicators; and 4) use the ecosystem health indicators developed to assess a coral reef management strategy. Because environmental conservation can alienate scarce natural resources from competing uses, it is important to gain support for conservation programs by demonstrating that management actions have been effective in achieving their goals. One way to do this is to show that selected significant environmental variables (indicators) vary between managed and unmanaged areas, or change over time following implementation of a management regime. However, identifying indicators that reflect environmental conditions relevant to management practices has proven difficult. Initially this thesis focuses on developing a framework for choosing indicators in a coral reef habitat. To identify indicators suitable to measure the success of a management strategy to reduce anchor damage to a coral reef, twenty-four candidate variables were identified and evaluated at sites with different intensities of anchoring. In this study, measures which reflected injuries to coral colonies were generally more efficient than traditional measures of coral cover in describing the effects of anchoring. The number of overturned colonies was identified as the single most useful indicator of coral reef condition associated with anchoring intensities. The indicator selection framework developed has the advantages of being transparent, cost efficient, and is readily transferable to other types of human activities and management strategies. To further the development of collaborative management, an understanding of the meanings people hold for the environment is required. Therefore, community meanings for coral reefs were elicited by asking participants, with a range of experiences, to describe photographs of the coral reefs surveyed to identify the environmental indicators. Three important meanings ascribed to coral reefs were elicited. The most important meaning was “evaluation”, whether the scenes were perceived positively or negatively. The second meaning was “activity”, whether the scene depicted movement through the variation in numbers of fish and types of coral. The third meaning was “diversity”, describing highly diverse scenes compared to monocultures of coral. Participants with and without a working association with coral reefs all ascribed these meanings and had a remarkably consistent conceptualisation of coral reefs. Coral reefs with high levels of anchoring were associated with the constructs “unhealthy”, “boring”, “lacklustre” and “dead”, suggesting they had lost much of their value. A health judgement was added to the ecological and perceptual meanings of the coral reefs to identify the usefulness of the ecosystem health concept. The three assessments described changes to coral reef condition associated with anchoring. The ecological measures identified an increase in the number of overturned corals and a reduction in soft and branching corals, the perceptual meanings identified a loss of visual quality and the health judgements identified a reduction in health of the coral reef sites associated with high levels of anchoring. Comparing the three perceptual meanings with the health judgement showed that the evaluation dimension was highly correlated with coral reef health judgements, suggesting that when people enter an environment, the first and most important feature they identify is whether the environment is healthy. Health judgements were related to key ecological measures or environmental cues, the most important being the amount of damaged coral followed by amount of branching coral and perceived activity. The three ecological measures and normative health judgement were used as indicators to evaluate the effectiveness of the Reef Protection Program implemented to protect coral reefs from the effects of anchoring. To conduct the evaluation, three coral reef sites with high levels of boating, but a reduced number of anchor drops, because of the management strategy, were surveyed in addition to the six coral reef sites associated with low and high levels of anchoring intensity. The Reef Protection Program would be effective if the level of each of the indicators at the protected sites resembled that of the sites associated with low levels of anchoring. Two of the indicators, the number of overturned coral colonies and the judgement of health, showed that the condition of the protected coral reef sites were proceeding towards that of the coral reef sites with low levels of anchoring. However, the condition of the other two indicators, cover of soft corals and corals in the family Acroporidae, showed that the protected coral reefs sites were similar to the coral reef sites with high levels of anchoring intensity. Therefore, the Reef Protection Program is effective in reducing damage and improving the health of the coral reefs, but the reef condition had not yet returned fully to the condition described for the reefs associated with low levels of anchoring intensity. The coral reef case study showed that the ecosystem health concept, although contentious, is an appropriate concept for incorporating community and scientific information into environmental management decisions. People’s first assessment of coral reefs is a judgement of its health. The similarity in health judgements provided by the two groups of participants shows that health judgements are understood by a wide range of people and could be used to discuss concepts between various stakeholders. The health judgements were related to ecological measures and were useful in describing changes in condition associated with anchoring and a management strategy designed to protect coral reefs from the effects of anchoring. The evaluation of the Reef Protection Program showed that if the environment is managed to promote ecosystem health, humans can in some circumstances, change the way they are using the environment, to increase their use without causing detrimental effects to the environment.

Item ID: 67
Item Type: Thesis (PhD)
Keywords: ecosystem health concept, environmental management, coral reefs, anchor damage, Reef Protection Program
Date Deposited: 13 Jul 2010 01:03
FoR Codes: 05 ENVIRONMENTAL SCIENCES > 0502 Environmental Science and Management > 050205 Environmental Management @ 100%
SEO Codes: 96 ENVIRONMENT > 9605 Ecosystem Assessment and Management > 960506 Ecosystem Assessment and Management of Fresh, Ground and Surface Water Environments @ 100%
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