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Marine ecology topics
IH270 The importance of different coral growth forms to overall reef biodiversity and potential consequences of large scale changes to reef architecture, Indonesia (Weeks 2 - 8; need to have completed IH007 and be dive trained if incorporating a diving element) Corals grow in a variety of forms ranging from smooth boulder-like colonies (termed “massive” growth form) through to highly complex heavily branched colonies. These different growth forms provide different levels of physical complexity (topographic diversity and spatial heterogeneity) and consequently support different levels of biodiversity. Recent research suggests that different growth forms, associated with different rates of growth, have different resilience levels to environmental change. This has led to many scientists suggesting that the physical structure of reefs of the future will be less complex, due to the loss of the architecturally-complex, but sensitive, branching species. One project could assess the relative importance of different coral growth forms in adding to the overall physical complexity of reef systems while also identifying the levels of biodiversity different growth forms support. Only through such primary research will it be possible to predict the future form and function of coral reef systems impacted by climate change. This research requires in-water activity and is suitable for those interested in diving or snorkelling-based research.
IH271 Fish and invertebrate assemblages on non-reefal coral communities in marginal environments, Indonesia (Weeks 2 - 8; need to have completed IH007) Coral communities that grow beyond the threshold of physico-chemical tolerance of reefal accretion (e.g. low aragonite saturation, high/low temperatures, high/low salinity, highly turbid environments or high light environments) are of high interest to the scientific community as these may inform us of the future of our coral reefs as increasingly reef environments become more marginal. These coral communities are not as diverse as those found on reefs with more optimal conditions, but they are important nonetheless, and have not been studied to the same extent as coral reefs. This research, involving detailed field surveys carried out by snorkelling through the mangrove, aims at increasing our understanding of the total community structure of coral but not reef habitats within these marginal systems. There are opportunities to compare such communities with reef environments through scuba diving.
IH272 Damselfish: Facilitators or Inhibitors in Indonesia (Weeks 2 - 8; need to have completed IH007 and be dive trained if incorporating a diving element) Damselfish range in their behaviour and feeding preferences and, through both aggressive and passive interactions, affect the fish species in proximity to their home range. This can have a positive effect as some damselfish species may act as facilitators for certain fish groups by enhancing food availability through their algal farming techniques or, conversely, negative effects could occur as some damselfish are highly aggressive and/or may actually reduce food available. Further understanding of these relationships will allow a more comprehensive understanding of fish community dynamics on the reef flat. One project could determine how different damselfish species affect the community structure of fish through a series of ecological surveys and behavioural studies.
IH273 Resource utilisation of reef fish across environmental gradients, Indonesia (Weeks 2 - 8; need to have completed IH007 and be dive trained if incorporating a diving element) As reef habitats become more degraded, resident fish species will have to constantly adapt to the changing environment. Arguably, it is the species that are most plastic in their behaviour that will fare best. One project could use behaviour-based studies to examine the degree of plasticity that exists between two important coral dependent butterflyfish species. This research could examine the feeding behavior (selectivity and feeding type) of two species of corallivore (Chaetodon baronessa & Chaetodon lunulatus) across reef sites of varying qualities through the use of scuba, snorkelling or a combination of both to determine the extent to which they are able to change the way they utilize resources. To contextualize variation in resource use patterns, behaviour studies will need to be supported by ecological surveys that examine variation in habitat quality and differences in the test species abundance.
IH274 Association between fish and host anemones, Indonesia (Weeks 2 - 8; need to have completed IH007 and be dive trained if incorporating a diving element) One of the more conspicuous groups of fish on tropical reefs is the anemone fish. Anemone fish are heavily collected for the aquarium trade and have a mutualistic relationship with their host anemones. However, preliminary investigations have shown that this relationship is much more plastic than first thought and may be dependent on the availability of different anemone species across different reef sites with more dominant anemone fish species being more selective than less aggressive species. Further investigations have also shown that some species co-inhabit single host anemones; but what dictates this dual association? Surprisingly little research has been carried out that adequately details the association between fish and anemones and, at present, it is not possible to identify the key ecological drivers of the partnership. One project could aim to fully characterize the association between hosts and fish using snorkelling, scuba or a combination of both.
IH275 The distribution and social structure of Anthias, Indonesia (Weeks 2 - 8; need to have completed IH007 and be dive trained) Anthias are a hugely abundant and diverse group of reef fish but surprisingly it is not known whether different species of Anthias occupy different niches or whether they co-exist with limited competition and no niche separation. Anthias live in harems with a dominant male, several lesser males and a large number of females and juveniles. Detailed behaviour-based investigations will provide important insights to the social structure of a model fish group. This research, which is primarily scuba-based, will examine the behavior of two abundant Anthia species (Psedanthias dispar and P. huchti), their fine scale distribution and within-harem interactions across reef sites of differing habitat quality.
IH276 The abundance, diversity and biomass of reef herbivores across environmental gradients, Indonesia (Weeks 2 - 8; need to have completed IH007 and be dive trained) The removal of algae from coral reefs is an extremely important functional role and influences successful coral recruitment and coral growth. Herbivores are therefore considered a key functional group whose characteristics (e.g. species and abundance) influence the structure and biodiversity of coral reefs. In reefs of the Caribbean, removal of grazing fish (Parrotfish) following the demise of grazing Diadema populations, has resulted in a phase shift from a once coral dominated system to an algal dominated system with major consequences for biodiversity. Within the Indo-Pacific region, there are many more grazing species and consequently a higher degree of functional redundancy. However, limited information exists on the relative importance of different herbivores. One project could identify the key grazers of coral reefs of the Wakatobi and, for the key species, determine their abundance and biomass in order to increase understanding of feeding behavior (e.g. rates) across sites of different habitat quality. Biomass can be very accurately estimated through the use of stereo videography. Stereo video cameras are used to take footage along reef transects, which can then be analysed back on land to determine fish density, community structure, size distributions and, through known relationships, biomass.
IH277 Morphological change and interactions between Gorgonians and Sponges, Indonesia (Weeks 2 - 8; need to have completed IH007 and be dive trained) What is the incidence level of sponges growing over and within gorgonians and what are the implications for gorgonian morphology? Gorgonian corals and sponges are associated with, and attract a variety of, symbionts and commensals and therefore can enhance coral reef biodiversity. However, little is known about such associations; for example, members of the gorgonian genus Bebryce are frequently overgrown by an unclassified encrusting sponge. It would appear that affected colonies have marked differences in morphology compared to those unaffected. One project could help increase understanding of the interaction between key gorgonian species and associated sponges through detailed scuba-based field investigations to determine the frequency of occurrence, environmental regulation of incidents, and implications of the association for growth morphology of the affected gorgonian.
Unfortunately the specialist academic advisor for this topic is now unable to join the expedition in 2012. Therefore this project is being withdrawn as we cannot guarantee the high level of academic support which we strive to provide.
IH278 Competition between hard coral species, Indonesia (Weeks 2 - 8; need to have completed IH007 and be dive trained) Reef-building corals are often the dominant component of reef systems providing both biological and physical complexity thereby greatly enhancing system biodiversity. Hard corals actively compete against each other for space, which is often the limiting factor on crowded reefs of the Indo-Pacific. However, relatively little is known about the methods and outcomes of competitive interactions between different coral species and whether environmental conditions (e.g. growth conditions) influence competitive outcomes and coral species dominance. This research aims at increasing the understanding of competitive interactions between reef building coral species, which can be broadly classified into passive (e.g. over growth) and active (e.g. digestion of neighbouring live tissue). One project could produce a typology of interactions and determine competitive outcomes of different coral species interactions across environmental gradients. This research will include extensive field based studies that would be most suitable for scuba divers but may also include simple laboratory experimentation.
IH279 The abundance and impact of coral bioeroding invertebrates across environmental gradients, Indonesia (Weeks 2 - 8; need to have completed IH007 and be dive trained) The growth of a coral reef is dependent on the balance between the process of accretion and erosion. In a healthy system, there is generally net growth as those organisms contributing to the physical structure of a reef (e.g. hard corals, coralline algae) are more dominant than abiotic physical erosive forces (e.g. wave energy), anthropogenic destruction (mining, blast finishing and anchor damage) and bioeroding. Many species bioerode corals, either during predation activities (e.g. Parrotfish) or during burrowing activities (e.g. several species of molluscs). One scuba-based project could assess levels of erosion by different molluscs species, levels of bioerosion caused by parrotfish and determine which coral species are most affected and whether the impact of bioerosion varies across environmental gradients.
IH280 Comparison between methods to assess coral reef habitat quality: physical and biological properties, Indonesia (Weeks 2 - 8; need to have completed IH007 and be dive trained) Coral reef habitats are one of the best studied marine ecosystems. However, methods of assessment, particularly of habitat quality, vary greatly between different organizations and researchers. Different techniques require different researcher experience and different levels of resources; however, variations in the techniques used make it very difficult to reliably compare results across different surveys. Also, little is known of the comparative accuracy and precision of the different techniques used. It may be possible, for example, to re-allocate efforts to ensure the best research strategy is used when undertaking surveys of reef systems. This research aims at comparing different techniques used to assess habitat quality. The numerous techniques include subjective research observations, large scale manta tows, line intercept techniques with variable intervals ranging from continuous techniques to very coarse 1 m intervals, use of coral quadrats underwater photography with specialized software (Coral Point Count technique) and benthic videography. It is likely that the accuracy of the different techniques used varies across reefs of different habitat quality (e.g. different levels of patchiness). This research will enable the best protocols for use within the Wakatobi to be determined, will identify sources of error and will enable better comparisons of data from this region with numerous others around the world.
IH281 Comparison between methods to assess coral reef fish community structure and the production of standardized protocols, Indonesia (Weeks 2 - 8; need to have completed IH007 and be dive trained) As for techniques used to assess habitat quality, methods used to assess the community structure and abundance of fish varies greatly. Techniques range from use of indicator species through to total counts across time and distance restricted belt transects. The different techniques require different levels of resources and expertise but which technique is best suited to be able to detect small rates of change in fish community structure? This research will compare the numerous different methods across reefs of different quality and fish community structure. Specifically, techniques to compare could include underwater visual census using different transect sizes and sampling effort, stereo-videography, and fisheries data. Effort versus accuracy plots will be produced and a set of protocols developed. The outcomes of this research will enable conservation managers to be most effective with their limited resources while ensuring the most accurate level of data is obtained for resources used. Importantly, the research will also identify the degree of error and enable us to identify levels of reliability, robustness and confidence limits. This research can be carried out by scuba or snorkelling and will include a number of field research techniques combined with onsite data analysis.
IH282 Coral reef patch dynamics in Indonesia (Weeks 2 - 8; need to have completed IH007 and be dive trained if incorporating a diving element) How stable are patch reef communities over time? What changes are occurring and over what time scales? What are the responses of fish communities to changes in benthic cover? Coral reefs are dynamic ecosystems and may actually exist in multiple stable states. Permanent transects have been used to successfully document changes in benthic cover, but assessing changes in mobile organisms are more difficult. However, smaller patch reefs or bommies provide a more ideal template to evaluate changes in mobile organisms, as they tend to house a greater number of resident species. One project using snorkel-based ecological surveys on a number of patch reefs of variable size, biological complexity and location within the reef flat-seagrass zone could help describe patch reef dynamics. Patch reefs could be repeatedly visited and variability in fish communities at different states of the tide and lunar cycle assessed.
HC283 Sea urchin population and ecology around the Cayos Cochinos, Honduras (Weeks 5 - 10; need to have completed HU007 or HC008) Sea urchins are a vital part of the ecology of Caribbean reefs where they act as one of the main herbivores of benthic algae and help prevent algal density increasing to levels where it can dominate and threaten the coral coverage of the reefs. However, in 1983, an unidentified disease decimated urchin numbers in the Caribbean, with up to 99% mortality in some areas. Urchins are long lived and slow growing so recovery is slow. To ensure the recovery of urchin populations, their distribution, population and position within the reef ecosystem need to be researched. Projects survey urchin populations on the reefs of the Cayos Cochinos and the data will be used as part of a long term dataset on urchin density. Data from previous years will be made available so temporal patterns in distribution can be assessed. Additional elements of urchin ecology can be studied, including their habitat preference, relationship to other herbivorous species on the reef and the amount of algal coverage in relation to urchin densities. This project is snorkelling based and does not require dive qualification.
HB284 Influences on reef fish populations on contrasting reef systems in Honduras (Utila: Weeks 2 – 5 and Cayos Cochinos: Weeks 6 - 10; need to have completed HU007 or HC008 and be dive trained) The reefs around the Cayos Cochinos and Utila offer a unique opportunity to study the variety of influences on fish community status. Reef fish populations are subjected to a huge variety of different pressures and variables, both natural and anthropogenic, that dictate their abundance and diversity and many of these variables are little understood. Specific influences that are particularly important in Honduras are those of fishing, coral/algal coverage on reefs and the role of mangrove systems as nursery grounds for juvenile reef fish species. Over fishing has become a significant issue in the area and of particular importance to the artisanal fisheries in the area. Development has led to pollution and disturbance, causing changes in the levels of coral and algal coverage while mangroves are being destroyed to allow coastal development. Fishing on the Cayos Cochinos is prohibited because of the MPA but is widespread around Utila. Utila has extensive mangrove systems whereas the Cayos Cochinos has none. Projects can be designed to study fish species, families or communities on the reefs around one or both of the sites. Conclusions from the projects may identify the importance of the MPA around the Cayos Cochinos or the mangrove nursery grounds on Utila, while links between reef status and fish populations can be addressed across the range of reefs surveyed. Results from all projects can be used to suggest suitable conservation measures around the sites. The data gathered from the stereo video system and the photoquadrats on the various reefs around Utila and Cayos Cochinos will be used for these studies and students developing research questions around this topic will have access to the full data sets from all the reefs.
MM285 Changes in reef fish and coral communities from 2009-2012 in Southern Mozambique (Weeks 3 - 10; need to have completed MM005 and be dive trained) This topic utilises the stereo video and quadrat photographic data gathered by the Operation Wallacea teams on reefs in southern Mozambique each year since 2009 and which will be repeated in 2012. Software is available in camp to identify each fish species recorded along the stereo video transects and to measure their fork length accurately. There is also software on site that can be used to accurately record the total area occupied by each coral community on the digital photos. The data set would consist of replicate transects surveyed at different depths on a series of reefs over 4 years and image analysis could be completed for total coral cover, hard and soft coral communities and reef fish communities and size groups to quantify changes that had occurred over the years. The data from this topic could also be analysed to assess the relative effectiveness of utilising different length transects, how coral cover, coral communities or fish communities and size groups change with depth. For those students at universities where completion of their dissertation/thesis outside of term time is not allowed, this topic provides an opportunity to gain experience in conducting fieldwork and a guaranteed data set for later analysis.
CP286 Changes in reef communities in the Punta Frances Marine Reserve, Cuba (Weeks 1 - 6; need to be dive trained or have completed a PADI Open Water dive training course in week 1) The Punta Frances APRM (Marine Protected Area, MPA) was established in 1996 to protect the reefs and reef-associated communities around the southwest part of the Isle of Youth. All marine life is protected within the MPA boundaries although some illegal fishing still occurs within the park. However, fishing pressure within the park is several orders of magnitude lower than outside the park. This protection is therefore highly likely to have an influence on the communities inhabiting the park. In 2011, a series of stereo video survey fish transects were completed within the MPA and in adjacent areas. In addition, coral intercept transect surveys were completed both within and adjacent to the MPA. These transect surveys will be completed again in 2012 and there is the potential to develop a great number of projects to investigate the effect of protection on several key species, including herbivorous species such as parrotfish or the sea urchin Diadema antillarum, economically-important fish such as groupers or snappers, or key benthic competitors such as fleshy algae.
One of the benefits of the establishment of Marine Protected Areas is the enhancement of fisheries adjacent to the reserve via fish movement from the reserve. This movement of larvae and individuals of economically important fish species to non-protected areas (spillover) has been shown to improve fish catches in areas near the reserve compared to more distant areas for many MPAs around the world. This potential spillover has not yet been quantified for the Punta Frances APRM. One dissertation project could use a combination of fish surveys, with the possibility of combining with mark-recapture studies, to try to quantify fish movement (e.g. groupers, snappers) from the MPA to adjacent non-protected areas.
CP287 Population dynamics of hard corals, Cuba (Weeks 1 - 6; need to be dive trained or have completed a PADI Open Water dive training course in week 1) Recruitment is a key process driving the population dynamics of hard corals. Several studies have reported recruitment failure at various locations around the Caribbean due to a number of reasons, including settlement inhibition by the presence of algae or increased post-settlement mortality due to eutrophication. Marine protected areas in the Caribbean have been shown to promote coral recruitment through trophic cascades: herbivore fish protection results in lower algae abundance, which in turn decreases mortality of coral settlers and promotes recruitment. Despite the importance of understanding the coral recruitment process, there is no coral recruitment information for the Punta Frances APRM. The aim of this project is to obtain baseline data for coral recruitment in the park and to investigate the effect of several physical and biological factors upon recruitment. One potential project could quantify coral juvenile abundance and diversity as a measure of recent recruitment events at different locations and depths in and out of the Punta Frances APRM to investigate the effects of protection upon recruitment.
In 2011, settlement panels were deployed at several locations inside and outside the Punta Frances Marine Reserve to investigate benthic invertebrate recruitment (e.g. corals, sponges, bryozoans, etc.). During 2012, these panels will be removed from the water, photographed for image analysis and surveyed under the microscope to identify and quantify the number of organisms that settled onto the panels. In addition to this, new panels will be placed in the water to continue the monitoring program in future years. One potential project could investigate the diversity and abundance of different invertebrate groups. Although this is mainly a laboratory based project, there is the potential to incorporate diving based surveys.
CP288 Sponge ecology, Cuba (Weeks 1 - 6; need to be dive trained or have completed a PADI Open Water dive training course in week 1) Sponges represent an important component of coral reef fauna with a number of important functional roles (such as bioerosion and filtering) whose abundance and biomass on Caribbean reefs can exceed that of corals and other benthic reef organisms. Because of their important functional roles and the fact that sponges have been shown to increase in abundance in response to declines in coral and fish populations, it is important to try and understand their natural patterns of temporal variation, as any changes in sponges may result in wider-scale ecosystem impacts. The primary aim of this project is to establish a sponge monitoring programme for reefs around Punta Frances, and test a range of methodologies to measure changes in sponge abundance and assemblage composition. One dissertation project could include the use of a morphological monitoring method that has been used successfully elsewhere in the world to monitor sponge assemblages. Also, the spatial distribution patterns of sponges are known to be influenced by a range of biological (e.g. competition and predation) and physical factors (e.g. sedimentation, water flow, salinity and light). The degree to which these different biological and physical factors influence sponge assemblage composition and abundance appears to vary between different geographic regions and also between localized reef systems. Another dissertation project could measure the spatial distribution of sponges on Cuban reefs to determine whether physical or biological factors are likely to be most important in explaining the patterns reported.
(Weeks 1 - 6; need to be dive trained or have completed a PADI Open Water dive training course in week 1) One of the most important functional roles of sponges on coral reefs is their ability to rework carbonate and act as bioeroders. Sponges have the potential to erode considerable amounts of carbonate from the reef, and bioeroding sponges have been reported to increase in abundance as coral declines. This project will focus on the relationship between coral abundance and bioeroding sponge abundance to determine the spatial relationships between these groups and estimate the amount of carbonate being broken down by sponges. This project could also estimate the total reef bicarbonate production to determine the proportion of carbonate production being eroded by sponges. It is important to understand this balance between accretion and erosion of carbonate because, for reefs to be maintained, there must be net carbonate production (or production must at least match erosion).
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