Citation:
Orem, W. H., Burnett, W. C., Landing, W. M., Lyons, W. B., & Showers, W. (1991). Jellyfish Lake, Palau: Early diagenesis of organic matter in sediments of an anoxic marine lake. Limnology and oceanography, 36(3), 526-543.
 
Purpose:
Jellyfish Lake on Eil Malk Island in the Western Pacific country of Palau is an isolated marine lake. Restricted circulation in the lake leads to formation of anoxic bottom water layer which helps preserve organic matter in sediments. The authors sought to measure the elementary contents and stable isotopes in sediments from Jellyfish Lake and studied the process of diagenesis.
 
Methods:
Wet sediment samples were collected from Jellyfish Lake for dissolved organic carbon analysis. Then the concentrations of elemental contents in organic matter obtained were measured. Carbonate shells of bivalves and gastropods from Jellyfish Lake sediments were collects for stable isotopes measurements.
 
Results:
The result of measurement shown that organic matter is abundant in sediments of Jellyfish Lake. Around 91% of organic matters in sediments are derived from vascular plant remains and 9% are from algal. Elementary content results and stable isotopic data of shells from the sediments suggest the differences between Jellyfish Lake and other marine lakes can caused by long-term geological changes, close climatic and ecological changes, vegetation around the lake.
 
Significance for Palau:
This research is relevant to conservation of jellyfish and other species in Palau because it studied the formation and composition of organic matters in Jellyfish Lake, a marine lake which sufficiently isolated. Permanently stratified marine lake like Jellyfish Lake is not usual. The stratification caused by restricted water circulation separate lake water into oxygenated top layer and highly sulfidic anoxic bottom layer. Special conditions of this lake affects speciation and migration of the golden jellyfish, Mastigias cf. papua etpisoni  and other species. Findings about the elementary content composition an organic matters in Jellyfish Lake helps maintain and protect the habitat for living species in Jellyfish Lake.

Citation:
Krushelnycky, P.D. & Gillespie, R.G. (2010) Sampling across space and time to validate natural experiments: an example with ant invasions in Hawaii. Biological invasions, 12, 643–655.
 
Purpose:
Studying the ecological impacts of invasive species on an ecosystem can be difficult because experimental approaches involving introduction or removal of an invasive species cannot be used. Instead, such studies are often done by comparing communities of invaded habitats to communities of similar, uninvaded habitats. Krushelnycky and Gillespie test a comparative method of sampling inside and outside of invasion boundaries as well as across time with invasive ant species in two sites on Hawaii Island.
 
Methods:
Invaded plots, uninvaded plots, and plots that were expected to become invaded were sampled at each site, examining arthopod species richness and the presence of indicator species associated with invaded and uninvaded conditions. The plots were sampled a second time two years later and community composition was compared between plots and between the two sampling events.
 
Results:
In one site, the community composition in plots before invasion was significantly different from that of invaded plots and not significantly different from uninvaded plots and became significantly different from uninvaded plots and not significantly different from invaded plots after invasion. In the other site, changes in community composition were found in plots before and after invasion. In both sites, several arthropod species that were found to be indicator species shifted in abundance before and after invasion. The results suggested that at least partial transition of community composition had occurred after two years in response to ant invasion.
 
Significance for Palau:
The two species of ants studied, Phelidole megacephala and Linepithema humile, are reported to be among the most dominant invasive ants in the world. Introduction of these or similar ant species may be a possible threat to Palauan biodiversity, based on their invasion of sites in Hawaii. The small size of some habitats in Palau and the exclusive range of many invertebrate species may further increase the impact of invading species on local communities. The sampling method used in this study may be useful for long term studies in Palau; the authors were able to use this method on another small tropical Pacific island. The study also suggested that more than two years would be needed for significant changes in response to invasion to be observed. Even if differences exist between the conditions described in the paper and Palau, conservation studies in Palau would likely involve similar procedures and comparisons of arthropod and invertebrate communities.

Citation:
Woesik, R., Houk, P., Isechal, A.L., Idechong, J.W., Victor, S., & Golbuu, Y. (2012) Climate-change refugia in the sheltered bays of Palau: analogs of future reefs. Ecology and evolution, 2, 2474–2484.
 
Purpose:
This study sets out to describe the effects of location on the degree of coral bleaching from thermal stress. They add the factor of taxonomy to determine which clades of coral are the most affected by this change. The scientists use this information to recommend where we should focus conservation efforts spatially in the face of climate change.
 
Methods:
Scientists used still pictures from video footage taken before and after a thermal stress event in 2010 to determine the degree of coral bleaching in Palauan reefs caused by the change in temperature. They recorded patterns in 35 genera of coral and three types of reef areas: bays, patch reefs, and outer reefs, and used a satellite to compare their respective geographical temperature.
 
Results:
Populations of the coral genus Pocillopora were the most affected by thermal stress, followed by Psammocora and Seriatopora. The warmest reefs experienced the least amount of temperature-derived damage. Therefore, the bay reefs were described as a possible refuge for coral during the event of thermal stress.
 
Significance for Palau:
Although the Palauan thermal stress event of 2010 serves as a microcosm of global climate change, the results apply directly to the health of Palauan coral reefs. This study tells us that the bay reefs of Palau should be the healthiest compared to any other type of Palauan reef. Therefore, Palauan bay reefs could be useful for the salvation of coral clades such as Pocillopora, which suffer greater consequences of thermal stress in out in patch and outer reefs. Additionally, it is possible that more diversity can be observed in these regions, which is helpful to understand for further research in Palau and even ecotourism.

Citation:
Green, Peter T., Dennis J. O’Dowd, Kirsti L. Abbott, Mick Jeffery, Kent Retallick, and Ralph Mac Nally. Invasional meltdown: Invader-invader mutualism facilitates a secondary invasion. Ecology, vol. 92, no. 9, 2011, pp. 1758-1768.

Purpose:
Green et al. discuss the increasing prevalence of species invasion in all ecosystems due to human invasion and note the unexplored idea that interactions between invasive species in the same environment could have notable consequences, such as impacting invasion success and propagule pressure. The focus is brought to the invader-invader mutualism between the yellow crazy ant and honeydew-secreting scale insects, two bioinvaders of Christmas Island that together create yellow crazy ant supercolonies. Their interactions facilitate a secondary invader, the giant African land snail, by suppressing the native red land crab. The authors observe the relationship between the mutualistic invaders and the giant African land snail over the course of 7 years to gain insight on the poorly-understood effects of interactions between invasive species.

Methods:
The authors used Bayesian hierarchical models to determine if the effect of the ant-scale insect invasion influences the spread of giant African land snails, which they tracked over the course of 7 years. Potential reversal effects of suppressing the ant-scale insect supercolonies were explored, as well as the effect of suppressing the red land crab on giant African land snail populations through site comparisons and experiments.

Results:
The probability of giant African land snails invading sites with abundant red land crabs is 14 times lower than that for sites with no crabs or supercolonies, and 253 times lower than that for sites with supercolonies and a suppressed crab population. Managing these supercolonies at certain sites reverses the probability of snail invasion and recovers the crab population for those sites. At sites with supercolonies, almost all snail mortality is due to starvation, and ants only feed on dead snails.

Significance for Palau:
Palau is an isolated archipelago with a plethora of unique endemic species inhabiting its many islands; as a similarly isolated land mass, Christmas Island has evolved into a unique environment, housing many endemic species of its own. This study demonstrates how just two small exotic organisms, introduced to the environment through human interference, can become a massive threat to biodiversity in a given area. Furthermore, it demonstrates the importance of studying the interactions between invaders, as well as the success of suppressing the invasive populations to recover native populations. As a republic with an economy heavily based on tourism, Palau continues to be subjected to more and more invasive species that disrupt the delicate native ecosystems. This study is especially relevant to conservation in such a place, as it lays some of the groundwork required for remediating the natural environments of isolated land masses such as Palau.

Citation:
Carr, S. A., & Davidar, P. (2015). Pollinator dependency, pollen limitation and pollinator visitation rates to six vegetable crops in southern India. Journal Of Pollination Ecology, 16 51-57.

Purpose:
The aim of the study is to observe and gather information on the levels of pollinator dependence, pollen limitation and identifying major pollinating insects that visit flowers and six vegetable crops in Southern India. The six different type of crops consist of brinjal, tomato, chili pepper, okra and bitter and snake gourds. Pollinators are crucial to the reproduction of plants and studying what affects the our produce/agriculture could further studies on that topic.

Methods:
The study was done in Tamil Nadu where six family farms were selected during December 2011 to June 2012, from November to December 2012, and from January to March 3013 which were main growing seasons for vegetables. In order to gather information of the plants, level of autogamy and pollinator dependancy Carr and Davidar used hand pollination experiments. Plants were randomly selected and stemens of the six plants would be collected in order to gather how much pollen there is. In order to collect pollinators they captured them after treatment of flowers using cotton mosquito mesh cloth bags. How much fruit each plants had was also looked at. There are two different treatments they did on the flowers: self, cross, and open pollination treatment. They observed the breeding system using the index of self-incompatibility; pollination dependacy was estimated by subtracting the percent fruit by autogamous pollination from percent fruit set bt open pollination and pollen limitation was found as the ratio of percent fruit set from hand cross pollination to open. Lastly pollinators were observed and categorized as well as doing a non parametric statistical analysis to test the differences between fruit set from the pollination treatments between crops, and visitation rates of different pollinator taxa.

Results:
The fruit set during the cross pollination treatment was lower than open which could damage floral parts during emasculation or poor quality pollen. Fruit set for the open pollination treatment was from 40-72% and didn’t differ in crop type. Pollinator dependacy average was 26+/- 21 where tomato was 0; it also ranged from 8-76% within crop variety except for tomato. There was no evidence of pollen limitation except for from brinjal at one site.The found that there five main pollinators: social bees, stingless bees, solitary bees, Lepidoptera (butterflies and moths), and wasps. Honeybees and butterflies visited all flowers but had the highest visitation rates for tomato, chili, and gourds. Solitary bees and butterflies to brinjal. Honeybees went to the okra.

Significance for Palau:
I will specifically be observing pollinators in Palau since it hasn’t been studied in depth there. I think this study can help me relate to what I would be looking for when I get the chance to do my own study. While reading the study it gives me a lot more depth and explain what certain things mean which can help me understand what I am looking at while observing the invertebrates that pollinate certain flowers in Palau. Even though this study was done looking at the agricultural background it would have the same effect as if I do it with any other flower.

Citation:
Fortunato, H. (2015) Mollusks: Tools in Environmental and Climate Research. American malacological bulletin, 33, 310-324.
 
Purpose:
The purpose of this paper is provide “an overview of the use of mollusks in environmental and impact studies,” ranging from paleo-environmental conditions to potential changes due to global warming. This paper looks at how the wide variety of mollusks provide insight into the environmental factors that influence ecosystem health and composition and why mollusks are key indicators of ecosystems around the world.
 
Methods:
This paper analyzes the use of mollusks as indicators for environmental conditions both in the past and for future changes in climate based on the composition of their shells. This meta-analysis bases its claims from a number of different studies regarding the use of magnesium calcite and aragonite compounds in mollusk shell composition as proxy data to evaluate paleo environmental conditions.
 
Results:
Due to the wide variety of mollusks habitats and the even wider variety of mollusk species globally, the various, yet specific chemical composition of their shells provides details in changes in environmental factors such as ocean warming, ocean acidification, and increased surface temperatures. The deposits of mollusk shells on the sea floor also gives indication of what past ocean conditions were like, acting as a proxy for ocean and climate data. Additionally, some species adapted better to changes in ocean temperature and pH, showing significant differences between the various species that show the versatility of the taxa for future studies as environmental indicators for climate change.
 
Significance to Palau:
As the paper examined, mollusks provide a way to gage ecosystem health and changes in climate and weather in the present and the past. Palau is home to hundreds of species of mollusks, both aquatic and terrestrial, that can provide insight into how each respective ecosystem will respond to climate change. Due to the rapid changes in climate in areas such as Palau, mollusk populations are more important than ever as a tool to study these effects. However, without considerable efforts made to conserve these populations, we are at risk of losing a vital part of the ecosystems of Palau and the regions around it. Conservation of mollusk populations in Palau will not only help an individual species, but all ecosystems on the islands as well as hundreds of other ecosystems worldwide through the knowledge studying mollusk populations can provide.

Citation:
Barry, J.P., Widdicombe, S., & Hall-Spencer, J.M. (2011) Effects of ocean acidification on marine biodiversity and ecosystem function. Ocean acidification, 192–209.

Purpose:
Barry, Widdicombe, and Hall-Spencer discussed the effects of ocean acidification on marine ecosystem functions and biodiversity, they focused far more on the large-scale issues and implications that controlled experiments cannot show in their limited scale. Large environmental changes can have broad effects on biodiversity, these effects can affect energy flow and other processes by the loss of keystone species who contribute to these processes. Other studies look at the survival of a single species and assumed that changes in the species effects the environment.

Methods:
The paper breaks up the topic into seven board categories and focus on how ocean acidification effects each.

Results:
Acidification of the ocean has effects that goes deeper than just a raise in ph of the water. It effects some of the earths most sensitive habitats. It also means that the servers that we rely on from the ocean will be affected negatively, from fishing to tourism. This problem is larger than most understand.

Significance for Palau:
As an island nation surrounded by the ocean and where fishing is a large part of the local’s life. During a lecture Dr. Rundell talked about how sea cucumbers are a large resource for the people of Palau. Along with the coral reefs many of the marine invertebrates are going to be directly affected by acidification. Any of the invertebrates who use calcium carbonate to make their skeletons it becomes harder for them to make their skeletons strong. This could lead to higher rates of predation and a reduction in prey populations.

Citation:
Golbuu, Y., Victor S., Wolanski, E., Richmond R.H. (2003) Trapping of fine sediment in a semi-enclosed bay, Palau, Micronesia. Estuarine, coastal and shelf science, 57, 941-949.

Purpose:
The purpose of this study was to collect data regarding the high sediment loading in Airai Bay that is smothering corals and creating a habitat shift from coral dominance to algae dominance. Airai Bay is semi-enclosed on the southeast coast of Palau, which is protected from tidal currents and the local winds are not strong enough to re-suspend the settled sediment. Environmental degradation like poor land use practices and destroying mangroves surrounding Airai Bay could be having a major impact of this coral reef system that is very ecologically and economically important.

Methods:
The researchers developed five stations that were used as testing sites in Airai Bay from the end of the Ngerikiil River to the mouth of the bay. They measured the vertical profile of the water column including salinity, temperature, and suspended sediment concentration at all the stations. At station one the mangrove swamp, they set up sediment traps on the river banks to determine how much sediment was being captured within the mangroves. Rainfall amounts were provided by the National Weather Service and during the time of the study two floods occurred.

Results:
At station 1 during river floods, the SSC (suspended sediment concentration) reading showed that the waters were very turbid as they exceeded the nephelometers saturation level. SSC was also higher at rising tide then during low runoff periods showing that sediment is being brought into the bay and settling in the mangroves. Following a river flood the river plume, freshwater exiting the estuary, could be traced though each stations readings. The readings at each station suggested that the sediment was being diluted, by lowering SSC and higher salinity levels. Based on the study’s results only about 2% of sediment is being exported out of the bay.

Significance for Palau:
Airai Bay is accumulating about 98% of the riverine sediment, which is an extremely high sediment loading. This is smothering corals and increasing turbidity which further stresses the system due to low light access and decreasing larval recruitment. These stressors are causing ecologically issues which is now effecting the local fisheries economy. In order for the ecosystem to restore itself the stressors would need to be lowered. The mangroves that are being cleared are exceptional at trapping sediment, lowering the sedimentation rate about 15-30% before the river plume continues throughout the bay. In order for the people of Palau to conserve this coral reef system, mangroves need to be stop being cleared and actually expanded. If the mangrove swamp had a higher land area, it would be able to trap more sediment. The next step in conservation efforts would be to educate and develop better land use practices. Perhaps during the nine-month period of heavy rainfall agricultural fields could be required to have a cover crop to prevent soil erosion. Lowering soil erosion without impacting the agricultural economy would be another important step to conservation and finding a balance between agriculture and fisheries.

Citation
Pusparini, Wulan, et al. “Rhinos in the Parks: An Island-Wide Survey of the Last Wild Population of the Sumatran Rhinoceros.” PLOS ONE, Public Library of Science, 16 Sept. 2015, journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0136643.
 
Purpose
The authors sought to asses the population size of the Sumatran rhinoceros, a critically endangered large mammal.  The population has dropped significantly in the last two hundred years since the species was first described by Fisher in 1814. The authors decided to conduct this survey in order to understand how best to conserve this rare species.
 
Methods
To get a solid idea of the rhinoceroses’ distribution and habitat the researchers searched for “signs” of the rhino’s presence, these “signs” includes rhino droppings, foot prints, and a few rare instances of actual sightings. After acquiring the data the researchers conducted statistical analyses of the populations by using PRESENCE var. 8.3 and R version 2.8.1 software.
 
Results
Despite this being the first systematic survey ever conducted on the species, the results were still inconclusive. This uncertainty in the data made the researchers conclude that immediate action must be taken to preserve the species in order to prevent a worst-case scenario.    
 
Relevance
This research is relevant to invertebrate conservation in Palau because it is an excellent example of population analysis of endemic species. Palau, being an archipelago, is home to countless endemic species, species that inhabit a small geographic range and are sometimes rare as a result. Palau is likely full of undescribed species, however just because they are undescribed does not mean they are safe from human impact. We can use this paper as a model to understand how we can more easily track rare and undescribed species in order to plan how we can save them.   

Citation:
Iwase, A., Sakai, K., Suzuki, A., & van Woesik, R. (2008) Phototropic adjustment of the foliaceous coral Echinopora lamellosa in Palau. Estuarine, coastal and shelf science, 77, 672–678. https://doi.org/10.1016/j.ecss.2007.10.022

Purpose:
Iwase et al. (2008) outline the concept of morphological adjustments by corals in response to wave action and light intensity. Many coral species have the ability to change their growth forms in response to light intensity while other coral species can only change their shape to a small extent. The coral species that express the latter for instance, may grow their branches toward the light or change the shape of their plates to maximize light intake. What previous studies didn’t focus on is the capacity of foliose corals (corals that can change shape to a small extent) in changing the shape of their plates to increase the number of tissue exposed to light.
 
Methods:
The researchers measure the angle of colonies of Echinopora lamellosa at various elevations of steep hills where light intensity is highest. They also produce a light model calculating both sun elevation and shade at any time and any location.
 
Results:
Foliose corals can change how much tissue on plates are exposed to light and E. lamellosa in particular can slightly change shape to look like it’s leaning with its plates taking on the shape of parabolic antennas. However, results show that sunlight intensity isn’t necessarily the only factor, suggesting that atmospheric diffusion or other factors may play an important role as well.
 
Significance for Palau:
Palau has a very rich diversity of coral communities because of its decent variety of reef habitats and lagoons. Reef flats around specific islands are quite notable for housing diverse coral communities even though the somewhat clear water limits visibility from the surface to between 10 and 12 meters. The diversity at these conditions shows the incredible adaptability of corals in limited sunlight. The paper by Iwase et al. may highlight the importance of morphological adjustments of corals in Palau and around the world when sea level increases with climate change and less sunlight reaches the corals underwater. Additionally, higher pollution levels in the air or from nutrient runoff may further diffuse sunlight intensity although corals may adapt very quickly and survive until conservation efforts are directed to coral reefs.