Conservation management topics

Country codes: HO (Honduras), IN (Indonesia), MA (Madagascar), ME (Mexico), PE (Peru), SA (South Africa)

HO01 Structural complexity in tropical cloud forest ecosystems, Cusuco National Park, Honduras

The mountainous cloud forest of Cusuco National Park is a structurally diverse and complex ecosystem home to an abundance of species, a significant number of which are endemic and/or endangered. With its patchwork of forest types (broadleaf, pine, mixed), an elevation gradient of over 500m, and slopes varying from 10° to 50°, the Park contains a huge amount of structural complexity creating a vast array of microhabitats and niches for species to exploit. Compounding this complexity is the historic and ongoing human disturbance of the Park: deforestation for crop plantations, shade-grown coffee farms, and the legacy of logging conducted in the 1950s-60s have led to an additional gradient of human disturbance across the park. This project would make use of Opwall’s continuing forest structure surveys (collecting data on mature trees; understorey, canopy and soil variables; as well as elevation, aspect, and slope at over 100 plots across the Park) to relate structural variables of the forest and levels of human disturbance to ecological factors such as species richness, soil chemistry and microclimates.

Extended Project Summary

HO08 Prevalence of chytrid in amphibian populations within Cusuco

The effective conservation of Cusuco National Park is imperative for many endemic species, none more so than cloud forest amphibians. The spread of chytrid fungus has caused severe declines in many amphibian populations and is a major concern for global amphibian conservation. Chytrid is known to have been present within the amphibian populations of Cusuco for at least 15 years, but its prevalence within specific areas of the forest and the extent to which different species are affected are not well known. Amphibian species will be encountered during diurnal and nocturnal transects and swabbed for chytrid. Swabs will be taken back to the lab at base camp and tested for the presence of chytrid using polymerase chain reaction (PCR) and visualised using agarose gel electrophoresis. Individuals will also be assessed for visual signs of infection. Prevalence of chytrid will be mapped in the park using multiple years’ data to assess whether the disease is continuing to spread to previously uninfected areas to contribute to the investigation into the underlying mechanism of infectivity.

Extended Project Summary

HO12 Using camera traps to quantify human disturbance of large mammal species, Honduras

Large mammals, despite their size, are rarely observed in forest habitats and are often under-represented in biodiversity studies. By using indirect survey techniques to increase detectability, a total of 23 large mammal species have been recorded in Cusuco National Park using field signs such as footprints or droppings. These include the endangered Baird’s tapir and species which are commonly hunted for bushmeat such as red brocket deer and white collared peccaries. Camera traps are deployed throughout Cusuco National Park, placed either within 20m of the sample route network or up to 300m away from the sample routes. This enables us to examine the distribution of large mammals throughout the park with respect to distance from the park boundary, human habitation and nearby deforested patches and also distance from our transect network, focusing on the effect of human disturbance. For key target species for which there are >10 detections throughout the season, the Random Encounter Model (REM) may be employed to estimate probable abundance. Data from previous years will be available for comparison enabling temporal trends in detections to be assessed. NOTE: this project involves hiking the entire transect network and also considerable distances off transect. The park has an average slope of 30°. Thus, moderate to high levels of physical fitness are essential for students undertaking this project.

Extended Project Summary

HO14 Tracking the recovery of a keystone urchin species and its role in reef restoration

Under natural conditions, the sea urchin (Diadema antillarum) is the most important herbivore on Caribbean coral reefs, and is therefore considered a keystone species. However, a disease in the 1980s caused the death of an estimated 98% of individuals throughout the region. This mass mortality event had a devastating effect on reef health, driving subsequent phase shifts to algal dominated benthic communities. Recovery has been extremely limited, with populations on most reefs still severely depleted, and Utila Island is a classic example of this. Remarkably, the Banco Capiro reef system in Tela Bay has a population density of D. antillarum at astonishingly high levels. It also boasts extremely high benthic reef health, despite historical overfishing leading to a complete collapse of the fishery. Since its recent discovery, Operation Wallacea scientists began detailed population studies in 2013 and this project will continue to build on this. The primary objective is to quantify changes in the abundance, biomass and population structure of D. antillarum on the reefs of Utila and Banco Capiro. Further data will assess the potential roles of competition, predation and environmental factors in driving the recovery on Banco Capiro.

Extended Project Summary

HO15 Managing the Caribbean lionfish invasion

Lionfish are an invasive species in the Caribbean and are having a devastating impact on local fish communities throughout the region. Introduced in the 1980s, believed to be by accident, lionfish have spread extremely quickly and are now found as far as New York City and Brazil. Their success is down to a number of factors, including their high reproductive rate, generalism in terms of both diet and habitat, and a lack of natural predators. They are now considered to be one of the greatest threats to the future of Caribbean coral reefs and their fish communities. Management approaches to dealing with the lionfish invasion are limited, with one of the most common being direct removal via spear fishing. This relies on regular visitation to individual reef sites, as studies have shown full recovery of lionfish populations only five months after complete removal. Baseline data will be collected on population densities of lionfish at sites of varying intensities of culling. Lionfish will subsequently be removed and morphometric measurements taken along with dissections for physiological and gut content assessments, which can link fish assessments to gauge prey availability. In addition, lionfish behavioural responses to divers, such as Flight Initiation Distance (FID) and Alert Distance (AD)can be assessed, which could also be expanded to include commercially valuable fish such as grouper.

Extended Project Summary

IN24 The feeding behaviour of herbivorous fish and their role in maintaining reefs

Reef building corals are the foundations of coral reefs. They produce the physical structure and complexity that provide habitat for the many thousands of species. However their abundance is greatly threatened and as environmental conditions change we see other benthic taxa starting to outcompete corals and dominate which can lead to new less biodiverse alternative ecological states. Shifts from one dominate state to another are often termed phase shifts and knowledge of the key factors that increase and / or decrease the probability of such phase shifts occurring are desperately needed so that direct conservation action can intervene to prevent a net reduction in reef biodiversity. The shift from coral to algal dominance has been well documented in the Caribbean and appears commonplace. However, on the mega biodiverse reefs of the coral triangle there has been no such shift. One hypothesis is that the feeding rate and behaviour of herbivorous fish reduce the ability of algae to become dominant. There is thus an urgent need to quantify the amount of herbivory occurring on reefs of the Wakatobi using a combination of behavioural-based studies of specific key herbivores and assessment of actual grazing rates occurring per unit area of reef. Recent research has suggested that the presence of key predators of fish can influence herbivore-feeding behaviour. Therefore further studies could also examine how the presence of large predators such as large emperors, snappers and giant-and/or blue fin trevally influence the behaviour of herbivores. Other studies could use caging experiments to examine how the removal of herbivore pressure influences changes in algal biomass. This is an extremely important piece of research that will help identify the key issues facing the reefs of this biodiversity hotspot. Information gained will feed directly in to predictions of future health and help inform effective conservation strategies.

IN25 The prevalence of coral diseases and their impacts on reef biodiversity

Reef building corals are the key ecosystem architects that produce the complex physical structure that provides habitat for the many thousands of species inhabiting reefs. Like every other animal, corals are impacted by disease, caused by many different microbes. The extent of the threat caused by coral diseases to reef ecosystem health is largely dictated by environmental conditions both past and present. In the majority of reef systems, including those of the coral triangle, environmental quality is decreasing, resulting in corals being put under increasing pressure. The environmental conditions thought to increase disease include sedimentation and pollution. The vulnerability of corals to diseases is also increased when they are put under physiological stress. During 2016 the global thermal event, commonly termed the Godzilla El Niño, devastated the world’s reefs and although corals of the Wakatobi demonstrated remarkable resilience, the prolonged physiological stress caused by the El Niño could have increased long term vulnerability to disease. Therefore there is urgent need to understand the current prevalence of disease, the key diseases present in the Wakatobi, the species of corals affected and how diseases are spatially distributed across reefs of different environmental conditions. Data gained from this research are paramount for marine park managers and will greatly add conservation efforts. Research can also be compared to original data published over a decade ago to determine how diseases have changed over time.

IN33 Fisheries research in local communities

Opwall have been working with local fishing communities in the Wakatobi for almost 20 years, developing a deep understanding of the conservation issues associated with declining fish stocks and producing several award winning dissertations along the way. Opportunities exist for students to build on this extensive experience by completing dissertation projects focusing on artisanal fishing pressure by working alongside Opwall staff and local Indonesian partners in small fishing communities on and around Kaledupa island. To talk about this opportunity, and how it might be suitable for your undergraduate or masters dissertation research, please email Dr Dan Exton:

ME48 Large mammal abundance and distribution patterns in relation to habitat characteristics and hunting in the Mayan forest

Large mammal density at Calakmul Biosphere Reserve is very high and the forest is one of the last remaining strongholds of endangered mammals such as spider monkeys, jaguar and tapir. Although these species are not hunted, indigenous people are allowed to hunt other large mammals such as peccary and deer (which are the preferred prey of jaguar and puma). The tropical semi-deciduous forest in the Calakmul Biosphere Reserve is unusual in that areas close to the Mayan Ruins contain unusually high densities of large fruiting trees (the result of Ancient Mayan agro-forestry) in comparison to other areas. As there are no rivers or streams in the reserve, forest structure is also heavily affected by distance from the few permanent water sources in the reserve known as aguadas. The aim of the large mammal research project is to investigate the relationship between habitat characteristics and large mammal abundance and ranging, and to investigate the impact of hunting of preferred prey species on the abundance and distribution of felids. Mammal abundance data will be collected along a series of forest transects using distance sampling (based on visual sightings of more commonly encountered species such as primates) and patch occupancy sampling (based on tracks and signs of more elusive species such as tapir and jaguar). Additional data will be collected using camera traps enabling comparison of density estimates produced by the different types of surveys. The survey transects are distributed across a wide range of forest habitat types and each transect contains a number of 20m x 20m habitat survey plots. In each of these plots, tree species will be identified, and DBH and tree height will be measured. Large mammal data from each transect can then be related to mean habitat characteristics or the transect and comparisons between mammal abundance and habitat variables may be investigated.

Extended Project Summary

ME52 Abundance of immature green turtles in relation to seagrass biomass in Akumal Bay

There are seven species of sea turtle in the world, all of which are either threatened or endangered. Akumal (meaning “home of the turtles”) contains one of the few remaining healthy seagrass habitats in the Mexican Caribbean coastline and is home to a large resident population of green turtles, Chelonia mydas. Immature green turtles (roughly 5-20 years of age) feed exclusively on seagrasses before reaching sexual maturity and travelling out to sea. Due to an influx of sargassum macroalgae in the Yucatan Peninsula in 2015, many of the seagrass habitats in the region died, meaning that Akumal is one of only a small handful of suitable feeding grounds for immature turtles. Over 80 individuals have been recorded in the seagrasses of Akumal Bay, but several years of unregulated snorkel tours with these turtles resulted in a decline in the turtle population and considerable damage to the seagrasses. As Akumal Bay is now a marine protected area, the hope is that the turtle population will recover. Snorkel tours with turtles have been restricted to a set route around the bay and the use of snorkel fins is prohibited in order to allow seagrasses chance to recover. As the turtles preferentially graze in different areas each year, the distribution of seagrasses in the bay change over time and the location of the designated snorkel route needs to change in line with this to ensure the continued recovery of the ecosystem. Research into green turtle feeding preferences will involve snorkelling with the turtles throughout the day to record their foraging patterns. Seagrass quadrats surveys will be used to determine the availability of the various species of seagrasses, which can then be compared to turtle feeding preferences obtained from behavioural observations. Belt transects throughout the bay will be used to estimate population density of the turtles and photographs of turtles along transects will be used to identify individuals in order to monitor departure of turtles as they reach sexual maturity and new arrivals into the bay. Photographs will also be used to monitor the recovery of turtles suffering from tumours that resulted from the combination of water contamination and chronic stress from unregulated snorkel tours prior to the formation of the new protected area.

ME53 Effect of tourism on immature green turtle behaviour in Akumal Bay

Year-round you can find immature green turtles (Chelonia mydas) feeding on the seagrasses in Akumal Bay. These turtles have become a popular tourist attraction and there is concern that both the number of tourists and the behaviour of tourists is affecting the behaviour and welfare of the turtles. Multiple studies of “swim with wild dolphin” based tourism has indicated that when the number of tourists gets too high, or the tourists attempt to touch them, the dolphins issue evasive responses to attempt to escape from the tourist and, if the tourism continues to maintain high numbers, the dolphins simply move their home range to areas inaccessible by tour boats. As the availability of healthy seagrasses in the Mexican Caribbean coastline is limited, the turtles in Akumal Bay may not have the option of leaving the area to avoid large numbers of tourists so the snorkel with turtle tours need to be strictly regulated. As Akumal Bay has just been declared a protected area, data is urgently required to determine the carrying capacity of snorkel based tourism. Research into green turtle behaviour will involve snorkelling with the turtles throughout the day to record their activity budgets and rates of evasive responses to tourists using focal animal sampling with continuous recording. Each turtle can be recognized individually and at the start of each focal sample the turtle will be photographed from various angles for subsequent identification from the turtle photo ID database. The number of tourists within a 5m radius of each turtle and the behaviour of these tourists (whether they abide by the rules and maintain a safe distance from the turtles or attempt to interact with them) will be recorded throughout each focal sample to determine the effect of tourism on turtle behaviour.

Extended Project Summary

ME54 A comparison of pristine and degraded mangroves in Akumal and the impact of mangrove degradation on adjacent seagrasses and coral reefs

Mangrove forests are highly productive marine ecosystems that are essential for the health of adjacent ecosystems e.g. sea grass beds and coral reefs. Yet, as much as 1 – 2% of the global mangrove forests are lost per year. Mangroves draw down atmospheric CO2 sequester and trap fine sediments, facilitate vital biodiversity mechanisms (e.g. fish nurseries) and improve fishery productivity. Despite the obvious importance of mangroves, mangrove forests in the Yucatan Peninsula have been under considerable anthropogenic impact from harvesting, causing a reduction in important habitat and biodiversity, carbon sequestration, and the productivity of adjacent sea grass and coral reef ecosystems. If the ecosystem services that mangroves provide can be quantified, then there is scope to develop a mangrove equivalent of the REDD programme in which fishing communities could receive economic investment in exchange for continued protection of the mangroves. Projects could therefore focus on a comparison of the structure, function, and faunal diversity of pristine and degraded mangroves or an investigation of wood degradation processes across mangroves of differing quality. In addition, projects could investigate health and diversity of seagrasses and coral reefs in relation to the level of degradation of adjacent mangroves. Belt transects and permanent plots will be used to record tree composition, basal areas and tree densities. Biodiversity assessments will be conducted by investigation of the available mangrove substrata. Snorkel and dive based transect and quadrat surveys may be used to assess diversity and coverage of seagrasses, hard corals and algae.

ME57 The conservation of and improvement of Caribbean coral reefs: Reef restoration through plantation of Acropora cervicornis

Acropora is one of the most important Caribbean corals in terms of its contribution to reef growth and fishery habitat. Acroporid species are the Caribbean’s fastest growing reef-building corals. Since the 1970s, Caribbean acroporid populations have been decimated by disease outbreak. Their recovery has been impaired by the general poor health of Caribbean coastal ecosystems. In Akumal this decline is estimated at >90%, although it is unlikely that this truly represents the loss of coral due to the lack of reliable data. Coral restoration is increasingly considered to be a viable recovery plan. In Akumal preliminary research has been conducted to trial success rates of coral nurseries where Acropora cervicornis is grown, propagated and then transplanted onto the reef. The methods used are minimally invasive and require cheap materials. The trials have proved to be successful, with doubling of live tissue from dying rescued fragments within one year, combined with successful fusion and growth of transplanted colonies onto the reef. In order to measure the impact of coral restoration work, it is essential to develop baseline data from which to measure the successful colonies that have grown as a result of the restoration work. Using continuous belt transects on the reef, the mapping of acroporid colonies will be conducted to assess the distribution, abundance and surface area of the colonies. Coral frags will be out-planted at various distances from the mother colony to measure successful recruitment and growth at different sites from that of the mother colony. Reef fish assemblages, particularly juveniles, will be assessed on reefs with none or few acroporid colonies. Established acroporid frags will then be planted onto those reefs and re-assessed. These data will be compared to reefs with a high density of acroprids.

SA66 Assessing the ranging patterns and habitat use of African elephants in fenced reserves

Despite continental declines, elephant populations in South Africa are among the healthiest in the world. Many small, private game reserves promote high elephant densities as they are a huge draw for tourists. However, the reserves are almost always fenced, which restricts the natural movement of the elephants and can lead to the occurrence of negative human-elephant interactions. To mitigate conflict, it is important for the reserve management to understand these movements and the motivations behind them. Opwall and its partners are working in reserves across South Africa and Swaziland to assess the behavioural impacts of high local elephant densities. GPS location data on the elephants is collected daily and can be used to assess elephant ranging patterns in relation to other herds/individuals, human habitation, water sources or artificial barriers. Students will also collect detailed data on the elephants’ impact on the reserve through vegetation surveys. These surveys are carried out in all major habitat types found within the reserve and the data can be used to assess the elephants’ habitat usage and preference.

SA67 Assessing human-wildlife interactions in Dinokeng Game Reserve

Dinokeng Game Reserve is a 18,500 ha reserve that straddles the Gauteng and Limpopo provinces of South Africa. At just five years old, Dinokeng is one of the youngest provincial reserves in South Africa andrepresents a novel model for game reserve creation. Dinokeng was formed through the donation of land from multiple small and large landowners in the area, many of whom still live within the reserve in fenced homesteads. Along with these homesteads, there are several lodges within the reserve and a self-drive route that tourists can explore unaccompanied. This means that in certain areas of the reserve, human activity levels are high and interactions with wildlife common, leading to potential human-wildlife conflict. From roadkill to fence breakages, Opwall and its partners are currently monitoring these human-wildlife interactions to better understand the dynamics of the reserve. We also collect data on vegetation types, bird diversity and large mammal distributions, which can be combined with the data on human-wildlife interactions to identify patterns and associations between these factors. Detailed maps of the reserve are available that allow for distribution mapping and relation of interactions with physical boundaries such as loads and fences. The findings of this study will help inform reserve managers across southern Africa as reserves are increasingly surrounded by dense human populations.