Human-related Disturbances Research Articles

An assessment of population structure and regeneration status of Magnolia punduana Hk. f. & Th. (Magnoliaceae) in fragmented forests of northeast India

The population structure and regeneration status of Magnolia punduana Hk. f. & Th., an endemic tree species of northeast India were investigated in fragmented forests in the Jarain Hills and in adjoining areas of Meghalaya state. The population structure was discontinuous in all the fragments with the absence of individuals in higher diameter classes. The number of individuals increased with the size of the fragment patches (p 105 ha). The number of seedlings and saplings were also higher in the larger fragments. Human-related disturbances had a negative impact on the species population (p < 0.002). Variation in the population density in different forest patches has been attributed to fragment size, site characteristics and ongoing human disturbances. The restricted distribution of the species coupled with exploitation and habitat destruction underlines the need for its conservation.

Detecting Vegetation Change in Response to Confining Elephants in Forests Using MODIS Time-Series and BFAST

Afromontane forests are biodiversity hotspots and provide essential ecosystem services. However, they are under pressure as a result of an expanding human population and the impact of climate change. In many instances electric fencing has become a necessary management strategy to protect forest integrity and reduce human-wildlife conflict. The impact of confining hitherto migratory elephant populations within forests remains unknown, and monitoring largely inaccessible areas is challenging. We explore the application of remote sensing to monitor the impact of confinement, employing the Breaks For Additive Season and Trend (BFAST) time-series decomposition method over a 15-year period on Moderate Resolution Imaging Spectroradiometer (MODIS) Enhanced Vegetation Index (EVI) (MOD13Q1) datasets for two Kenyan forests. Results indicated that BFAST was able to identify disturbances from anthropogenic, fire and elephant damage. Sequential monitoring enabled the detection of gradual changes in the forest canopy, with degradation and regeneration being observed in both sites. Annual rates of forest loss in both areas were significantly lower than reported in other studies on Afromontane forests, suggesting that installing fences has reduced land-use conversion from human-related disturbances. Negative changes in EVI were predominantly gradual degradation rather than large-scale, abrupt clearings of the forest. Results presented here demonstrate that BFAST can be used to monitor biotic and abiotic drivers of change in Afromontane forests.

Segregation, nestedness and homogenisation in plant communities dominated by native and alien species

ABSTRACTBackground: Highly modified landscapes offer the opportunity to assess how environmental factors influence the integration of alien plant species into native vegetation communities and determine the vulnerability of different communities to invasion.Aims: To examine the importance of biotic and abiotic drivers in determining whether alien plant species segregate spatially from native plant communities or become integrated and lead to biotic homogenisation.Methods: Ordination and classification of a floristic survey of over 1200 systematically located 6 m × 6 m plots were used to examine how plant community segregation, nestedness and homogenisation varied in relation to climate, environmental and human-related factors across Banks Peninsula, New Zealand.Results: The analyses of community structure indicated that native and alien plant communities were spatially and ecologically segregated due to different responses primarily to an anthropogenic impact gradient and secondly to environmental factors along an elevation gradient. Human-land use appeared most strongly linked to the distribution of alien species and was associated with increased vegetation homogenisation. However, despite spatial segregation of alien and native plant communities, biotic homogenisation not only occurred in highly managed grasslands but also in relatively less managed shrublands and forest.Conclusions: The role played by anthropogenic factors in shaping alien and native plant species community structure should not be ignored and, even along a marked environmental gradient, if the recipient sites have a long history of human-related disturbance, biotic homogenisation is often strong.

Uniquely regenerating frankincense tree populations in western Ethiopia

Dry tropical forests provide a wide range of forest products that directly support the livelihoods of people. These forests are the most threatened and least protected forests due to expansion of agriculture and pasture lands, unregulated grazing, forest fire, unregulated collection of wood and other forest products. Dry forests of Ethiopia are heavily affected by such human induced factors. The iconic Boswellia papyrifera (Del.) Hochst is a dominant tree species of this forest and the principal source of the globally traded frankincense. The species lacks regeneration in all forests evaluated so far. Frankincense forests in relatively wetter dry land areas with little or no human related disturbance are not evaluated so far. Here we quantified the regeneration status of the frankincense tree in such areas and evaluated these forests in comparison to non-regenerating frankincense forests elsewhere. We surveyed two-ha plots in each of five districts in Benishangul Gumuz Region, Western Ethiopia. The frankincense tree populations showed two different regeneration patterns: inverse J-shaped and bell-shaped pattern. The presence of regenerating populations in three of our study areas is in sharp contrast to all earlier studies on this species. The healthy regeneration might be related with the availability of more favourable conditions such as better precipitation, lower levels of anthropogenic disturbances and younger ages of the three woodlands. These unique, regenerating frankincense tree populations need recognition and should be delineated as priority areas for conservation, which includes their role as source of genetic material. Better attention of conservation practitioners, policy makers and frankincense companies may help this species to survive and therewith its emblematic frankincense.

Changes in behaviour and faecal glucocorticoid levels in response to increased human activities during weekends in the pin-tailed sandgrouse.

Human recreational activities are becoming increasingly widespread and frequent, a fact that may potentially exacerbate their effects on wildlife. These human-related disturbances on animals may induce behavioural and physiological changes that can ultimately affect their fitness, showing a similar anti-predator response that against natural predator or other threats. Here, we combine the use of behavioural and physiological approaches to assess the potential effect of winter human activities on a threatened farmland bird in Europe, the pin-tailed sandgrouse (Pterocles alchata). We compared before, during and after weekend variations in human activity rates, pin-tailed sandgrouse behaviour (flocking and flying behaviour, interspecific association in mixed flocks and habitat use) and faecal glucocorticoid metabolite concentrations. Human disturbances, in particular those associated with hunting activities, peaked during weekends. Sandgrouse showed significant behavioural changes (increased sandgrouse-only flock sizes, increased proportion of birds flying and changes in habitat use) during weekends and higher faecal glucocorticoid metabolite concentrations after the weekends compared with during or before weekends. Therefore, physiological stress levels could be modulated by behavioural adjustments such as increased flock sizes and changes in habitat use that may allow sandgrouse to cope with increased human disturbance rates during weekends. Nevertheless, temporal and spatial organization of hunting days among groups of estates might be good strategies to buffer these potential adverse effects on wintering pin-tailed sandgrouse and other steppe species of conservation concern, while preserving a socio-economically important activity such as hunting.

The Size of Winter-Flooded Paddy Fields No Longer Limits the Foraging Habitat Use of the Endangered Crested Ibis (Nipponia nippon) in Winter.

Paddy fields have traditionally been viewed as the key foraging habitats for the endangered crested ibis (Nipponia nippon). With the population of this species now increasing, its distribution has expanded to both lowland areas and outside the nature reserve. However, little is known about the current foraging habitat preferences of these birds, especially during winter. In this research, a total of 54 used sites and 50 unused sites were investigated during winter from December 2011 to January 2012. The results of logistic regression analysis indicate that soil softness, human disturbance, and distance to the nearest road were important factors. For the site plots of winter-flooded paddy fields, the birds prefer the paddy fields with higher coverage of vegetation, except softer foraging sites and lower human-related disturbance. In lowland areas, the size of winter-flooded paddy fields was not a limiting factor, due to the availability of other wetlands capable of providing abundant food. The micro-habitat characteristics were important indicators of foraging habitat quality rather than the size of winter-flooded paddy fields, and the food accessibility may play an important role in the process of foraging habitat use. We suggest the improvement of the foraging micro-habitat and environmental characteristics would be effective in ensuring the availability of food in the dispersed lowland areas. The local people still needed to be encouraged and compensated by their single-cropping cultivation, ploughed the paddy fields after harvesting and irrigated them with shallow water flooded in the original core areas of the nature reserve.

Characterization of Faidherbia albida (Del.) A. Chev. population in agroforestry parklands in the highlands of Northern Ethiopia: impact of conservation, environmental factors and human disturbances

Concerns about sustainable management and conservation of multipurpose trees in their habitat have led to increased number of studies on the ecological characterization of their population. Such knowledge on Faidherbia albida, the most used tree in agroforestry parklands in Ethiopia, is limited. F. albida population was characterized in and compared between two agroforests having different conservation status in Northern Ethiopia. Population structural parameters along with environmental factors and human activities were assessed in 42 randomly installed plots using a transect method. Size class distribution was used to describe and analyze the species long-term population dynamics. Adult density was almost three times higher in Zongi agroforest (19.9 ± 2.9 trees ha−1) where the species has been conserved and managed for longer time compared to Abraha-atsbeha agroforest (7.9 ± 2.5 trees ha−1). The same trend was observed for tree morphological parameters which were significantly higher at Zongi than Abraha-atsbeha. However, size class distributions coefficient of skewness and the median diameter indicated a declining and vulnerable population at Zongi and an increasing population at Abraha-atsbeha. Species population characteristics were influenced by environmental factors such as altitude, stone cover, erosion severity, slope, and human-related disturbances including land use, fodder harvesting, distance away from the center of the village and proximity of household to the plots. The study confirms the impact of conservation, environmental factors and human disturbances on shaping F. albida population and recommends the consideration of the trade-offs between them to design effective conservation and management strategies to sustain F. albida agroforests.

Effects of human-related disturbance on breeding success of urban and non-urban blue tits (Cyanistes caeruleus)

There is a need to study the effects of urbanization on wildlife in order to understand the ecological implications of increasing urbanization and find out how to reduce its threats to biodiversity. The blue tit evolved as a forest species and prefers deciduous and mixed forests, whereas its nesting in urban habitats is a more recent phenomenon. Our long-term study of blue tit populations has been conducted in two habitats: an urban parkland (frequently visited by people) and a deciduous forest outside of the city. Using linear mixed modeling, we revealed that a relationship of blue tit breeding success (and the number of fledglings) with thermal conditions in May differed between the urban parkland and the forest. While the relationship was positive in the forest, it was negative in the parkland. In addition, breeding success in the parkland increased with increasing number of rainy days in May. We argue that the main possible reason for such patterns is human activity in the parkland, which interferes with tit parental care, especially the regular feeding of nestlings, whereas it is evidently associated with weather conditions. Human disturbance in the forest is likely to be negligible.

Identifying critical areas to reduce bycatch of coastal common bottlenose dolphins Tursiops truncatus in artisanal fisheries of the subtropical western South Atlantic

Many anthropogenic actions have an impact on coastal dolphins, with bycatch being one of the main threats. We describe the distribution patterns of common bottlenose dolphins Tursiops truncatus and periods of higher entanglement risk by the artisanal gillnet fishery in the Patos Lagoon estuary and along the adjacent coast of southern Brazil. A total of 136 dolphin groups and 187 gillnets were encountered in 69 surveys conducted between September 2006 and July 2009. Data were analyzed in relation to environmental, spatial and temporal variables using generalized additive models and a spatially adaptive local smoothing algorithm for model selec- tion. In both areas, dolphin densities increased as distance to the estuary mouth decreased. For the estuary area, water salinity and temperature influenced dolphin distribution. Along the adjacent coast, dolphin densities were higher with distance to shore as well as in the north area during the warm period. Patterns of dolphin distribution were probably a response to the presence of pre- ferred prey or avoidance of human-related disturbance. Kernel density showed that fishing effort was distributed along the entire surveyed area inside the estuary, while along the adjacent coast it was higher in the south compared to the north area in the warm period. The overlap between gillnets and dolphins increased considerably from the cold (33.8%) to the warm (48.6%) period. Seasonal variation in fishing effort and distribution affect the overlap and the risk of dolphin entanglement. Based on the findings of this study, a fishing exclusion area aimed at reducing bycatch was established by the Brazilian Environmental Agency.

Range increase of a Neotropical orchid bee under future scenarios of climate change

Along with other human impacts, climate change is an important driver of biological changes worldwide and is expected to severely affect species distributions. Although dramatic range shifts and contractions are predicted for many taxa occurring at higher latitudes, including bumble bees, the response of widespread tropical species is less clear due in part to scarcity of reliable occurrence data. Newly mobilized specimen records and improved species distribution models facilitate more robust assessment of future climate effects under various scenarios. Here, we predict both current and future distribution of the orchid bee Eulaema nigrita Lepeletier, 1841 (Apidae: Euglossinae), a large-bodied species widely distributed in the Neotropics whose populations within the Amazon region are believed to be controlled by cleptoparasitic Euglossini bees, such as Exaerete smaragdina Guerin-Meneville, 1844 and Aglae caerulea Lepeletier and Serville, 1825. Under both current and future scenarios of climate change, El. nigrita is expected to persist in deforested areas including those that might suffer desertification. While under current climatic conditions this species is not expected to occur in central Amazonia where the forest is still conserved, its range is expected to increase under future scenarios of climate change, especially in areas corresponding to the arc of deforestation in eastern Amazonia. The increase of human-related disturbances in this biome, as well as changes in the relationship of El. nigrita–Ex. smaragdina and El. nigrita–A. caerulea may explain the potential range increase of El. nigrita under future scenarios of climate change.

Impact of Environmental and Disturbance Variables on Avian Community Structure along a Gradient of Urbanization in Jamshedpur, India.

Gradient pattern analysis was used to investigate the impact of environmental and disturbance variables on species richness, species diversity, abundance and seasonal variation of birds in and around Jamshedpur, which is one of the fastest growing cities of India. It was observed that avian community structure is highly influenced by the vegetation habitat variables, food availability and human-related disturbance variables. A total of 61 species belonging to 33 families were recorded from the suburban area. 55 species belonging to 32 families were observed in nearby wildland habitat consisting of natural vegetation whereas only 26 species belonging to 18 families were observed in urban area. Results indicated that the suburban habitat had more complex bird community structure in terms of higher species richness, higher species diversity and higher evenness in comparison to urban and wildland habitat. Bird species richness and diversity varied across seasons. Maximum species richness and diversity was observed during spring season in all type of habitat. Most of the birds observed in urban areas were found to belong to either rare or irregular category on the basis of their abundance. The observed pattern of avian community structure is due to combined effect of both environmental and human related disturbance variables.

No Evidence of Habitat Loss Affecting the Orchid Bees Eulaema nigrita Lepeletier and Eufriesea auriceps Friese (Apidae: Euglossini) in the Brazilian Cerrado Savanna.

Habitat loss, landscape fragmentation, and agriculture intensification constitute the main threats to bees. As the organisms responsible for almost one third of the food produced worldwide, there are growing concerns on bees' response to human-related disturbances. Among all bee groups, orchid bees (Apidae: Euglossini) compose an interesting group to test landscape-related hypotheses. In here, we tested the effect of landscape features (amount of anthropic areas and isolation) on the probability of occurrence and the abundances of both Eulaema nigrita Lepeletier and Eufriesea auriceps Friese in the Cerrado savanna. In general, we did not observe any effect of landscape features on the probability of occurrence and abundances of both species in our sampling sites. Given their potential high dispersal abilities, these bee species may be less sensitive to fragmented landscapes or even positively affected by the increase of anthropic habitats. Since we sampled many E. nigrita specimens in highly preserved Cerrado savanna areas, we believe that at least for this biome, this species may not be a good indicator of landscape disturbance.

A Temperate Ridge–Cliff–Talus System In An Urban Setting: Rock Rimmon In Manchester, New Hampshire

An unusual temperate ridge–cliff–talus system exists at Rock Rimmon in urban Manchester, New Hampshire. Recent surveys and historical data indicate that five natural communities occur within the system, of which three are critically imperiled in New Hampshire: Appalachian wooded talus, pitch pine–Appalachian oak–heath forest, and pitch pine rocky ridge. The remaining two natural communities are occasional in the state: Appalachian oak–pine rocky ridge and temperate acidic cliff. Seven plant taxa previously or currently recorded at Rock Rimmon are rare (SH, S1, or S2) in New Hampshire; four other taxa are uncommon (S3) in the state. We re-located two previously recorded rare taxa during our 2012 survey. Digitaria filiformis var. laeviglumis, a globally rare crabgrass, is endemic to this biodiversity hotspot, but was not re-located. In addition, four other rare plant taxa were not re-located, and all are likely extirpated as a result of the lengthy history of human-related disturbance at the site. The temperate ridge–cliff–talus system closely corresponds to NatureServe's central Appalachian pine–oak rocky woodland system, which is distributed from Maine to Virginia west to Kentucky and Ohio. Xerophytic oak and pine dominate across the range of this system type, although many canopy species differ along a latitudinal gradient.

Influence of Human Pressure on Forest Resources and Productivity at Stand and Tree Scales: The Case Study of Yunnan Pine in SW China.

This paper examines human impact on stands and individual trees of Pinus yunnanensis growing near the small mountain villages of Pianshui and Yangjuan in southwestern Sichuan Province, China. In an effort to assess whether use of these forests was sustainable, we examined the effects of human use in two ways. First, we directly measured the effect of cutting branches, for fuel and fodder, on tree growth. We hypothesized that branch cutting would negatively impact tree growth. We established 12 plots on four hills and compared 14 pairs of trees, one tree in each pair with an apparently full crown and the other with a considerable portion of the crown removed. Second, we assessed stand and tree properties over a 500 m elevation gradient above the villages where we hypothesized that as elevation increases, stand and tree properties should show fewer human impacts. Although extensive branch cutting reduced the live crown, tree height and diameter, compensatory processes likely enabled trees to recover and to add basal area increments (BAIs) similar to those added by trees with full crowns. Trees and stands close to villages showed less growth and lower basal areas, respectively, than stands and trees at intermediate or distant elevations from villages. Areas relatively close to the villages showed considerable effects of human-related disturbances such as branch cutting, grazing, tree and shrub removal, losses of litter, and human and animal trails. Such areas had increased soil erosion and often loss of the 'A' horizon. Stands close to villages had younger trees, lower stand basal areas, smaller basal area increments, and more stumps. Our results suggest an increasingly vulnerable interface between occupants of these two villages and their surrounding forests.

Land abandonment may reduce disturbance and affect the breeding sites of an Endangered amphibian in northern Italy

AbstractAlthough human-related disturbance is usually detrimental for biodiversity, in some instances it can simulate natural processes and benefit certain species. Changes in the disturbance regime, both natural and human-driven, can affect species that rely on it. The Apennine yellow-bellied toad Bombina variegata pachypus, an amphibian endemic to peninsular Italy, has declined throughout its range in the last 3 decades. We sought to identify the drivers of the decline in the region of Liguria, at the north-western limit of its distribution. In 2009 and 2010 we surveyed sites where the species occurred until 2005 and related the persistence of breeding activity to the characteristics of sites. Populations had disappeared from 50% of the sites between 2005 and 2009. Current breeding sites have less aquatic and bank vegetation, fewer predators and better insolation. Frequent disturbance events (desiccation and floods) were related to reduced vegetation, which in turn may decrease predator densities and increase insolation. In this region disturbance is provided by natural factors or, in the case of artificial water bodies, by regular maintenance carried out by landowners. The widespread land abandonment in Liguria can disrupt disturbance regimes, interrupting the removal of vegetation, and thus rapidly reduce the suitability of artificial sites. This was confirmed in our study, with most abandoned breeding sites occurring in formerly cultivated areas. Possible short-term conservation actions include creating new ponds, maintaining artificial water bodies and clearing vegetation. However, long-term conservation may be more problematic as the land abandonment process is unlikely to be reversed.

Climate change and elevational diversity capacity: do weedy species take up the slack?

Climate change leads to species range shifts and consequently to changes in diversity. For many systems, increases in diversity capacity have been forecast, with spare capacity to be taken up by a pool of weedy species moved around by humans. Few tests of this hypothesis have been undertaken, and in many temperate systems, climate change impacts may be confounded by simultaneous increases in human-related disturbance, which also promote weedy species. Areas to which weedy species are being introduced, but with little human disturbance, are therefore ideal for testing the idea. We make predictions about how such diversity capacity increases play out across elevational gradients in non-water-limited systems. Then, using modern and historical data on the elevational range of indigenous and naturalized alien vascular plant species from the relatively undisturbed sub-Antarctic Marion Island, we show that alien species have contributed significantly to filling available diversity capacity and that increases in energy availability rather than disturbance are the probable underlying cause.

Land use practices and their implications on soil macro-fauna in Maasai Mara ecosystem

The composition, abundance, diversity and species richness of soil macro-fauna communities were assessed in four major land use types present within protected and agricultural landscapes in Maasai Mara savannah ecosystem (MME), Kenya. The four land uses were: natural grassland; woodland, inside and outside protected area; maize mono-cropping and maize-bean intercropping systems in adjacent agricultural farms. Sampling of soil macro-fauna was carried out in November, 2009 (short rain), April 2010 (wet rainy season) and September 2010 (dry season). Hand sorting of soil taken from 25 × 25 × 30 cm monoliths was used to extract all soil macro fauna greater than 2 mm body length. A total of 3,658 individuals comprising of 128 species mainly belonging to Phylum Arthropoda distributed across 3 classes and 13 orders, and Phylum Annelida with one order were collected across the four different land use systems. Termites and ants, and to a lesser extent coleopteran and earthworms were the most abundant groups. Significant effects of land use on macro-fauna abundance and species richness in all cases (p 50% and eliminating some Orders/Species. Human related disturbances outside protected area network declined macro-fauna density in grassland and woodland in dry region (65.07 vs. 39.74%) but increased the density by 107 vs. 340% in wet region. The study highlights the important effect of agriculture on macro-fauna communities and the need for conservation alternatives in unprotected areas. This study supports conservation of biodiversity beyond protected area network. Key words: Macro-fauna, grassland, woodland, agriculture, Maasai Mara, land use.

Effect of land use system on Arbuscular Mycorrhiza fungi in Maasai Mara ecosystem, Kenya

Arbuscular mycorrhiza fungi (AMF) diversity and inoculums potential were assessed in different land use systems (protected and unprotected grassland and woodland, intensified monocropping systems and subsistence farming systems) in dry and wet region of Maasai Mara ecosystems (MME) during dry and wet season (November, 2009 and April, 2010). AMF spore were assessed in field and trap cultures (sorghum) using morphological tools. AMF inoculums potential were assessed using undisturbed soil cores planted with sorghum and cow pea. A total of 15 AMF species, dominated by species belonging to genus Acaulospora and Scutellospora were recorded across the MME. Wet region recorded high spore density and species richness in trap cultures. Human related disturbances caused by overgrazing and deforestation outside protected core altered AMF species composition in grassland, and negatively affected AMF species richness in woodland and grassland in the dry region. Similarly, intensified agriculture declined AMF diversity in dry region, but was unaffected in the wet region. Among different cropping systems, subsistence farming systems had higher AMF diversity and species numbers. This study demonstrates that human disturbances in natural ecosystems and intensified agricultural systems have adverse effects on AMF community especially in regions with semi-arid climatical conditions in Savannah ecosystems. Key words: Arbuscular mycorrhiza fungi, land use, grassland, woodland, monoculture, mixed cropping.

Functional traits of epiphytic lichens as potential indicators of environmental conditions in forest ecosystems

Several experimental studies support the effectiveness of lichen diversity as an indicator of environmental change. On the contrary, the potential of functional trait values of epiphytic lichens as indicators of environmental conditions is still poorly documented. Comparisons of lichen diversity across diverse regions may be problematic due to high levels of floristic variation related to differences in environmental conditions (e.g. climate and substrate availability and types). Species’ functional traits may prove to be a user-friendly tool for large-scale and long-term ecological monitoring. This paper explores the use of functional traits of epiphytic lichen species as indicators of environmental conditions: we tested the susceptibility of the three easily discernible functional traits (growth form, reproductive strategy, and photobiont type) to environmental factors related to climate, human disturbance, and stand structure. Lichen diversity and associated species traits were recorded in 14 plots within the Italian ForestBiota network representing the four main forest types of Italy. For each plot, several predictors of forest structure, climatic features, and human-related disturbances were recorded. A forward variable selection method, based on permutations and parametric tests, was used to evaluate the response of lichen diversity and functional traits. Of the three species traits, growth form was the most responsive and was a reliable indicator for evaluating and comparing the responses of epiphytic lichens to climate, human disturbance, and stand structure-related conditions in forest ecosystems across diverse regions. However, further research is needed to better clarify the potential of lichen traits in bioindication.

Using Coral Disease Prevalence to Assess the Effects of Concentrating Tourism Activities on Offshore Reefs in a Tropical Marine Park

Concentrating tourism activities can be an effective way to closely manage high-use parks and minimize the extent of the effects of visitors on plants and animals, although considerable investment in permanent tourism facilities may be required. On coral reefs, a variety of human-related disturbances have been associated with elevated levels of coral disease, but the effects of reef-based tourist facilities (e.g., permanent offshore visitor platforms) on coral health have not been assessed. In partnership with reef managers and the tourism industry, we tested the effectiveness of concentrating tourism activities as a strategy for managing tourism on coral reefs. We compared prevalence of brown band disease, white syndromes, black band disease, skeletal eroding band, and growth anomalies among reefs with and without permanent tourism platforms within the Great Barrier Reef Marine Park. Coral diseases were 15 times more prevalent at reefs with offshore tourism platforms than at nearby reefs without platforms. The maximum prevalence and maximum number of cases of each disease type were recorded at reefs with permanently moored tourism platforms. Diseases affected 10 coral genera from 7 families at reefs with platforms and 4 coral genera from 3 families at reefs without platforms. The greatest number of disease cases occurred within the spatially dominant acroporid corals, which exhibited 18-fold greater disease prevalence at reefs with platforms than at reefs without platforms. Neither the percent cover of acroporids nor overall coral cover differed significantly between reefs with and without platforms, which suggests that neither factor was responsible for the elevated levels of disease. Identifying how tourism activities and platforms facilitate coral disease in marine parks will help ensure ongoing conservation of coral assemblages and tourism.