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The Common Myna Acridotheres tristis was originally introduced to the island of Atiu, Cook Islands, in 1915 to control the Coconut stick insect Graeffea crouanii but it has since become a pest itself. The Rimatara lorikeet Vini Kuhlii or ‘Kura’ was reintroduced, after disappearing from the Southern Cook Islands almost 200 years ago, to Atiu on 24th April 2007 from Rimatara, French Polynesia to create a reserve population due to there being only approximately 1000 birds left on Rimatara. Due to observations of mynas reportedly harassing and attacking adult and juvenile Kura at the nest, an eradication programme was introduced by Gerald McCormack, Director of the Cook Island Natural Heritage Trust (CINHT), in May 2009 to reduce the population size of myna birds to give the Kura a couple of peaceful nesting seasons to help establish a stable population on Atiu. A study by J. Mitchell of the University of Leeds in May/June 2009 estimated a starting count of approximately 6000 myna birds prior to the eradication programme. That survey was followed up in May 2010 using two strategies, the transect method and roost counts. Analysis of transect method counts, using the Distance software, estimate there are approximately 3128 mynas on Atiu. Roost counts were at variance with that figure and estimated only 1280 myna birds. The roost counts estimate of 1280 may be the most accurate because all mynas would be in the winter roosts for heat conservation from May to July alleviating the concern that females and young would be nesting away from the roosts during counts, whereas transect counts may involve recounting the same birds numerous times; a problem minimized by repeating transect counts twice daily and using different transects to cover as much of the expected habitat as possible. Only a limited survey of the population of Kura was possible during this visit to Atiu since almost all available time and logistics were focused on myna surveys. An estimate of the Kura population suggests there are approximately 100 birds, which suggests that since the 2007 introduction the Kura population is thriving on Atiu. However, comparisons with the exponential growth rate model of 184 birds suggest this difference could be due to myna bird harassment despite culling. A more comprehensive survey is recommended perhaps using similar strategies to determine whether the myna has any deleterious effect on the Kura. In July 2010 a new myna bounty was introduced and is proving successful as a further 383 myna birds were culled by the end of July. The Atiu Island Council may decide on complete eradication of the myna to give the Kura full advantage of living on Atiu in the absence of the competitive myna bird.

An invasive alien species are known to cause significant economic and environmental damage. Islands are much more vulnerable to the invasion of invasive alien species, and have higher rates of extinction. In the islands of the South Pacific, there are several species Polynesian land birds which are threatened with extinction due to invasive alien species and human interference. Without any intervention from humans, it is likely that these birds will suffer extinction in the next few decades. The island of Atiu in the Cook Islands (South Pacific) supports a range of avian fauna. In 2007 the Rimitara lorikeet (Vini kuhlii), also known locally as the ‘Kura’ was introduced to Atiu, to make a reserve population, as there were only approximatley 1000 left on the island of Rimitara, French Polynesia. There is concern for this species on Atiu due to the existence of the common myna (Acridotheres tristis). The myna is an aggressive invasive which is one of the world’s worst 100 invasive species. It was introduced to the Cook Islands by the government, with the intention to control the coconut-stick insect (Graeffea crouani), but is now a pest itself. A myna control programme on Atiu is being coordinated and controlled by Gerald McCormack (Cook Islands Natural Heritage Trust), working through George Mateariki, and using funding from various conservation organisations. Poisioning is being carried out by George in order to reduce myna numbers, and a bounty has been set on the birds or for every right foot so that the locals can help as much as possible. This investigation aimed to estimate the total population size on the island to use as a starting count to determine whether the programme is successful or not. Two methods were used which included roost counts to find an estimate of the population, and a transect method using a Distance programme to estimate the number of birds per hectare as well as the level of abundance in various habitat types. The two methods had overlapping results, giving a total estimated range of 3250 to 8460 birds on the island, although it is more likely to be at the higher end of this estimate at around 6000 to7000 birds. Further investigation will need to determine any change in the population size, any changes in habitat composition as well as the impact on the native species, especially the effect on the Kura and its population size.

This research focuses on the South Pacific region, an area of high global coral diversity. I examine reef health surrounding two islands in Fiji, Vatulele and Ovalau, and two Cook Islands, Aitutaki and Rarotonga. Each island has distinct differences based not only on reef type, environment, and ecology, but also upon social institutions. I will compare four islands with barrier and fringing reefs that have different levels of economic development, population pressure, land-use practices, and marine management practices. This research will assess coral health in areas that have not been previously surveyed.

Pacific islands are long-settled by mankind, dating back several hundreds to thousands of years ago since discovery by islanders traveling by boat. Amongst these islands are atoll islands, which are small coral islands that lie at a low elevation and are usually part of a ring-like coral reef formation. Past and present islanders collect water from rainwater catchments and groundwater wells, with rainwater used primarily for drinking water and groundwater used as a supplement for wash water. Unfortunately, this region can experience severe drought, over-wash events during strong tropical storms, and typhoons, all of which threaten the freshwater supply for these islands. Due to rising concerns over climate change, there is interest in studying the water security of these especially vulnerable land forms. This thesis evaluates the reliability of the water supplies on four atoll islands in Yap, Micronesia by modeling the reliability of the two main sources. To first analyze rainwater catchment performance, Ifalik Island is evaluated using data collected on the island in 2015 by a collaborative research field team and a water balance model. Second, the results are used to develop design curves as a tool for rainwater catchment design and improvement. The fresh groundwater source is also modeled for each of the four islands to test the effects of varying climate conditions on the shallow, freshwater lens. Rainwater catchment systems on Ifalik Island are evaluated for their performance using a mass balance model that quantifies water storage through time. Performance is quantified primarily by reliability, which is a term to represent the percentage of days a rainwater catchment supplies sufficient water to the users. Based on the data from the Ifalik field survey, ii the average household rainwater catchment system on Ifalik uses a 16.5 square meter guttered roof with a 2,000 liter storage tank and serves seven individuals at 12 liters per capita per day. As a result of a rainwater catchment system sensitivity analyses based on the average rainwater catchment conditions, the most important factors in performance are effective roof area size, water demand, and gutter-downspout efficiency. Further analyses using the mass balance model found that the performance of each individual catchment is sufficient to provide water to the community during conditions similar to the severe drought year of 1997-1998, as well as projected rainfall conditions for the next 30 years. Therefore, analyses suggest Ifalik Island has sufficient rainwater catchment performance to provide water for the community. However, to introduce a conservative measure for water security, it is recommended that the catchment area be extended to the full size of the roof area. This would thereby increase the storage supply for the community by 25 cubic meters on the day of lowest supply under the 1997-1998 severe drought conditions.