http://www.rssboard.org/rss-specification 720 https://escholarship.org/uc/bnhm_ucb_moorea_2009/rss Recent eScholarship items from Student Research Papers, Fall 2009 Wed, 29 Jul 2026 08:21:18 +0000 https://escholarship.org/uc/item/39w8v60q <p>Sponges constitute an important part of marine and aquatic ecosystems, however compared to other benthic groups little is known about sponges. Knowledge of sponge species and distribution is extremely limited on Mo’orea, French Polynesia. The purpose of this research was to describe the distribution of sponges using Rapid Habitat Assessment surveys at different locations around the island and to investigate distributional influences that cause zonation via a transplant experiment. Sponge species were given arbitrary species names and identified based on basic morphological characteristics. RHA’s were conducted at five sites around Mo’orea sampling the sub habitats present on the reef in terms of % cover of substrate types and ecological benthic attributes as well as taxon abundance for coral, fish and, sponges. To examine influences on distribution one sponge species was transplanted from the fringing to the barrier reef and caged against various factors then evaluated based... https://escholarship.org/uc/item/39w8v60q Thu, 14 Oct 2010 00:00:00 +0000 Desmet, Danielle N https://escholarship.org/uc/item/5t94w4gc <p>Color polymorphism has been implicated as an important component of cryptic coloration in organisms inhabiting complex environments. Recent studies have suggested that mantle color variation in Tridacnid clams may serve various functions, including as a mechanism to achieve background matching. The mantle color variation of Tridacna maxima was examined in a series of experiments, including a backgroundmatching photo survey, a predation experiment, and a zooxanthellae count. The results of the photo survey showed a significant correlation between T. maxima mantle and background color. T. maxima which did not match their background experienced a significantly greater rate of predation. Finally, the population of zooxanthellae was seen to increase for the same size of mantle area with age. These results suggest that balancing photosynthetic efficiency and anti‐predation needs can be addressed by mantle color variation throughout the lifetime of T. maxima.</p> https://escholarship.org/uc/item/5t94w4gc Mon, 8 Feb 2010 00:00:00 +0000 Ozog, Stosh Timothy https://escholarship.org/uc/item/58q9t3z0 <p>Jumping spiders (of the family Salticidae) are found around the globe including on the island of Mo’orea, French Polynesia. Unlike continents, an island system such as Mo’orea often magnifies the effects of an invasive species due to their increased frequency of unfilled ecological niches. In my distributional study most species I encountered were non-native, and in my behavioral study I investigated the potential for correlation between a species’ dominance in elevation-divided habitats and observed aggressive interspecies interactions. A total of 206 Salticidae were collected, 86 of which were utilized in my behavioral study. Of the eight jumping spider species encountered (six known, two unknown) I found there was no strong correlation between a species’ behavior towards other spiders and its distribution. Future studies could be directed concerning how spider behaviors besides interspecies aggression influence the dominance of that species in a given habitat.</p> https://escholarship.org/uc/item/58q9t3z0 Mon, 21 Dec 2009 00:00:00 +0000 Pena, Danielle L https://escholarship.org/uc/item/96k285wf <p>Sponges constitute an important part of marine and aquatic ecosystems, however compared to other benthic groups little is known about sponges. Knowledge of sponge species and distribution is extremely limited on Mo’orea, French Polynesia. The purpose of this research was to describe the distribution of sponges using Rapid Habitat Assessment surveys at different locations around the island and to investigate distributional influences that cause zonation via a transplant experiment. Sponge species were given arbitrary species names and identified based on basic morphological characteristics. RHA’s were conducted at fives sites around Mo’orea sampling the sub habitats present on the reef in terms of % cover of substrate types and ecological benthic attributes as well as taxon abundance for coral, fish and, sponges. To examine influences on distribution one sponge species was transplanted from the fringing to the barrier reef and caged against various factors then evaluated based... https://escholarship.org/uc/item/96k285wf Sun, 20 Dec 2009 00:00:00 +0000 Desmet, Danielle https://escholarship.org/uc/item/6q80v4hq <p>Land breeding sites are important conservation priorities for the preservation of seabirds that cannot breed over the ocean. An example of a seabird that must breed on land is the white-tailed tropicbird (Phaethon lepturus). This bird is frequently seen on the island of Mo’orea in French Polynesia, but little is known about whether this species spends time there for the purpose of breeding. I hypothesized that these birds are breeding on Mo’orea and therefore conducted a study that included (1) observations of group interactions; (2) time budget construction; and (3) number surveys. My group interaction observations revealed courtship behavior previously described by the literature but I observed no definite evidence of cliff‐face nesting. The time budget results showed that the tropicbirds spend a significant portion of their time flying over the land by themselves (73%), and at low elevation near vegetation (61%). The number survey revealed that the birds preferred to be... https://escholarship.org/uc/item/6q80v4hq Sun, 20 Dec 2009 00:00:00 +0000 Maguire, Annie https://escholarship.org/uc/item/6cw9k97b <p>Geomorphological changes occur on a range of spatial and temporal scales. In the past, they have been primarily driven by abiotic factors like storm events and wave action. More recently, human impacts have begun to affect geomorphological processes. It is critical to understand where and how humans impact such processes in order to minimize environmental impact of activities like boating and adding infrastructure. I studied human impacts on the formation and continuous alteration of Motu Tiahura, Mo'orea, French Polynesia. By studying velocities, sediment distribution, beach profiles and wave heights in areas with and without human activity, it was found that humans are in fact having a geomorphological impact on Motu Tiahura.</p> https://escholarship.org/uc/item/6cw9k97b Sun, 20 Dec 2009 00:00:00 +0000 Hassen, Julia A https://escholarship.org/uc/item/5nq4z2s0 <p>Secondary compounds, often found in medicinal plants, are believed to have evolved as chemical defenses for many species. These bioactive chemicals have been shown to protect the plant from their numerous insect predators and pathogens through a wide variety of mechanisms. The purpose of this study is to examine the effect these secondary compounds have on the amount of predation towards medicinal species. Looking at the amount of leaf herbivory and an antifungal bioassay of six species of Leguminosae, the main objective of the study was to find a correlation between predation and medicinal properties. Herbivore feeding preference appeared averse to medicinal leaves, although no relationship between leaf damage and yeast inhibition was found. A feeding experiment conducted using common herbivores inadvertently demonstrated the antifungal properties of the medicinal species, and gave further indication of an herbivore aversion to leaves with bioactive secondary compounds.</p> https://escholarship.org/uc/item/5nq4z2s0 Sun, 20 Dec 2009 00:00:00 +0000 Chan, Elliot https://escholarship.org/uc/item/47k0q1v2 <p>Studies on island biogeography in the Pacific have shown a biodiversity gradient that decreases from west to east, a pattern followed by numerous land and marine organisms. Based on this gradient, it has been hypothesized that Scleractinian coral biodiversity should follow the same gradient and be considerably lower in Mo‟orea, French Polynesia, than in the Great Barrier Reef (GBR). Rapid ecological assessments on six barrier reef sites surrounding Mo‟orea, as well as transects following the line intercept method at one site, provided data on Scleractinian coral species richness and composition. A phylogenetic study of character evolution was also performed to examine the evolutionary history of four characters related to coral reproduction and dispersal. Results revealed site-to-site heterogeneity between the six Mo‟orea sites and a mean site species richness of 30 species. Alpha diversity of the Mo‟orea barrier reefs and the GBR were not found to be statistically different,... https://escholarship.org/uc/item/47k0q1v2 Sun, 20 Dec 2009 00:00:00 +0000 Title, Alexandra C https://escholarship.org/uc/item/3nf0d8tr <p>The gastropod communities around motu Tiahura are currently under various stresses, both natural and anthropogenic. Distribution studies can help understand how these pressures are affecting gastropod communities. The shallow waters around motu Tiahura were partitioned into six distinct habitats. Transects were examined in each habitat to observe gastropod abundance and diversity. Results show that the waters off the conglomerate platform are the most diverse, while the lagoon is least diverse. Three of the habitats were relatively similar in gastropod community, while the other three were distinct. Night transects revealed that burrowing gastropods form a distinct nocturnal community. Differences between gastropod communities may arise from biotic interactions and unique physical factors in each habitat.</p> https://escholarship.org/uc/item/3nf0d8tr Sun, 20 Dec 2009 00:00:00 +0000 Wilson, Ryan W https://escholarship.org/uc/item/9hs4c5cx <p>Abstract. Zooplankton is an essential component of every coral reef system, not only because it is the base of many marine food chains, but also because it is an important stage in many marine animals’ life cycles. While by definition plankton is free floating, zooplankton ha been known to move in predictable patterns. This includes a daily diel vertical migration towards the surface at night and back to the depths during the day and fluctuations in abundance over the lunar cycle, usually peaking around the full moon. This study aimed to look at the amount of control plankters have in choosing their horizontal position over the reef by looking at substrate preferences of demersal zooplankton in the fringing reef. It was found that zooplankton emerge in the largest numbers from branching coral followed by coral rubble and sand and in significantly lower numbers from smooth coral. This suggests that demersal zooplankton is able to select the substrate on which it seeks... https://escholarship.org/uc/item/9hs4c5cx Sat, 19 Dec 2009 00:00:00 +0000 kobervig, carolyn p https://escholarship.org/uc/item/7tg1m3wr <p>This study aims to determine and compare survivorship of two populations of Sophora tomentosa (Fabaceae) on Mo'orea, French Polynesia. The two populations studied were on separate reef islets, or motu. One population, on the motu Tiahura, appeared healthy while the population, on the motu Fareone, appeared distressed. The life cycle of S. tomentosa was broken into four life-stages: developing seed, mature seed, immature and mature plant. The three parts of this study are designed to determine the percent survival between each of these four life-stages and address some of the potential factors effecting survivorship at each transition. To assess survival of developing seeds and the impact of insect granivores, seedpods were collected from each population and the seeds were inspected for evidence of insect damage. The rate of granivory was shown to be significantly higher than expected in the Fareone population, while it was shown to be significantly lower than expected in the... https://escholarship.org/uc/item/7tg1m3wr Sat, 19 Dec 2009 00:00:00 +0000 Ahlgren, Christopher L https://escholarship.org/uc/item/5xs7j02h <p>Color polymorphism has been implicated as an important component of cryptic coloration in organisms inhabiting complex environments. Recent studies have suggested that mantle color variation in Tridacnid clams may serve various functions, including as a mechanism to achieve background matching. The mantle color variation of Tridacna maxima was examined in a series of experiments, including a background-matching photo survey, a predation experiment, and a zooxanthellae count. The results of the photo survey showed a significant correlation between T. maxima mantle and background color. T. maxima which did not match their background experienced a significantly greater rate of predation. Finally, the population of zooxanthellae was seen to increase for the same size of mantle area with age. These results suggest that balancing photosynthetic efficiency and anti-predation needs can be addressed by mantle color variation throughout the lifetime of T. maxima.</p> https://escholarship.org/uc/item/5xs7j02h Sat, 19 Dec 2009 00:00:00 +0000 Ozog, Stosh Timothy https://escholarship.org/uc/item/5qf941wv <p>Mo’orea, French Polynesia of the Society Islands archipelago is a highly isolated volcanic Pacific Island. It is vulnerable to invasion by introduced species due to this isolation in conjunction with its small size and disharmonic native biota. Falcataria moluccana is one such invader; since its introduction in the 1960s to reforest burned and eroded ridges it has established monodominant stands throughout the island. I studied the effects of this species on vegetation ecology, specifically native and non-native understory diversity, tree community dynamics, and species spread potential. Contrary to expectations, I found that native understory was able to persist despite ecosystem modifications caused by F. moluccana. However, the majority of native species present were post-disturbance taxa. Tree community analysis revealed that F. moluccana trees are able to grow to large sizes where other trees cannot, which suggests either niche differentiation or resource monopolization.... https://escholarship.org/uc/item/5qf941wv Sat, 19 Dec 2009 00:00:00 +0000 Minnich, Amanda https://escholarship.org/uc/item/56h1b2h5 <p>Early Polynesians created monumental structures called marae, using coral as a major element in the construction of the ahu. This study will analyze the relative frequency of coral genera found in the ahu of three different royal coastal marae sites on Mo‘orea and evaluate its correspondence to the composition of adjacent coral communities. Volumetric measurements of the ahu and its constituent coral genera composition were calculated. Transects were performed in both the fringing and barrier reefs surrounding the marae sites in order to record size and frequency of the coral genera present there. Some marae site survey results revealed a strong correlation between the usage of coral as a major element of construction in marae, and modern coral genera distribution and abundance in the surrounding fringing reef. The barrier reef environment suffered minimal impact resulting from marae construction. When all coral genera were combined, there was a significant difference in coral... https://escholarship.org/uc/item/56h1b2h5 Sat, 19 Dec 2009 00:00:00 +0000 Pickard, Alexandria E https://escholarship.org/uc/item/2k21b65b <p>Sessile invertebrates are important for their contributions to community assemblages in terms of their competitive and trophic interactions. Colonial invertebrates make excellent model organisms for the study of ecological processes. Bryozoans, modular colonial filter feeders, are important competitors in a range of habitats and represent a potentially significant source of diversity. Little work has been done to catalog the Bryozoa of Mo’orea, French Polynesia. By examining coral rubble, artificial substrates and Turbinaria spp. algal fronds, I quantified the distribution of bryozoans in a shallow lagoon and simultaneously recorded their competitive interactions. I also quantified patterns of bryozoan richness and abundance with respect to depth and location. Finally, I conducted an experiment to determine the degree to which predation effects an abundant genus, Rhynchozoon spp. I found more bryozoans further from the barrier reef and in deeper water. There were vastly more... https://escholarship.org/uc/item/2k21b65b Sat, 19 Dec 2009 00:00:00 +0000 Dibble, Connor D https://escholarship.org/uc/item/73t4j6xs <p>The factors contributing to biodiversity of terrestrial gastropods on Mo’orea, French Polynesia are investigated. Gastropods are sampled from four native forests of predominately Hibiscus tiliaceus, and four nonnative forests of predominately Falcataria moluccana within two elevational ranges. It is determined that the type of forest has an effect on the species composition of that habitat. Additionally, it is determined that elevation is a determinant in relative species composition. An additional variable possibly contributing to species distribution is the predatory detection of the introduced flatworm, Platydemus manokwari, by two predominant species of this study. This is primarily a study on the current biodiversity of a vastly neglected group of molluscs on island of Mo’orea.</p> https://escholarship.org/uc/item/73t4j6xs Fri, 18 Dec 2009 00:00:00 +0000 Lovenburg, Vanessa https://escholarship.org/uc/item/2jz4s7z8 <p>Uca crassipes (Adams and White 1848) is one of two species of fiddler crabs found on Mo’orea, French Polynesia. Much like other animal populations, U. crassipes is subject to density dependent processes, such as competition, which increase with density. To better understand the relationship between competition and density, this study first looked at habitat differences between 8 distinct populations of U. crasspies on Mo’orea. It then explored differences in aggressive interactions between crabs at one high-density and one low-density site. In the field, both male and female fiddler crabs were found to fight more in the high-density population. Subsequent investigation of the effect of density on aggression in laboratory settings did not yield significant results. Though laboratory results were not significant, trends in data showed more fighting under high-density conditions. Further investigation is necessary to fully understand the effects of density dependent processes... https://escholarship.org/uc/item/2jz4s7z8 Fri, 18 Dec 2009 00:00:00 +0000 Mansfield, Christine https://escholarship.org/uc/item/1cc0f0mn <p>Islands of the south pacific are fragile ecosystems, home to native land and sea birds that evolved in the absence of predators. On Mo’orea, French Polynesia the first humans arrived around 600 AD bringing with them invasive vertebrate predators. This study examines one of these predators on Mo’orea by observing swamp harrier (Circus approximans) habitat preference and behavior to determine if it has changed in comparison to its source population. Also it will examine their role in seabird predation on Mo’orea through a series of animal waste sample collections at high elevations. Since swamp harrier introduction in 1885 their habitat preference has not much changed from their Australian source population. The majority of its time and foraging is spent over low vegetation, though some expansion into other habitats has occurred since there are no other raptors on the island with which to compete. Feral cats (Felis catus) are also prevalent on the island and along with the swamp... https://escholarship.org/uc/item/1cc0f0mn Fri, 18 Dec 2009 00:00:00 +0000 Wilcox, Rebecca C https://escholarship.org/uc/item/5ds2z0rn <p>Abstract. A large cause of degradation of coral reefs is increased sedimentation and eutrophication caused by human modification of freshwater input into the marine environment. Effective tools must be used to monitor the effects of freshwater input before long-term damage is done to the fringing reef zone. One powerful tool is the use of bioindicators. This study attempts to identify possible bioindicators in coral rubble-inhabiting crustacean micro communities. Coral rubble was collected from 5 stream sites with paired controls and crustaceans were counted from each site. This study found that there were significant differences between stream and control sites in percent algal cover of rubble as well as 3 crustacean species (Thalamita admete, Alpheus parvirostris, Psuamis cavipes). Cuapetes sp. density also showed a significant negative correlation with pH levels. A colonization experiment was performed with no significant difference between stream and control sites.</p> https://escholarship.org/uc/item/5ds2z0rn Thu, 17 Dec 2009 00:00:00 +0000 Fletcher, Nicholas K https://escholarship.org/uc/item/1ft6r4hf <p>Parasites are ecologically significant organisms and must be understood to properly appreciate nearly any community. Parasitism is one of the most common (if not the most common) lifestyles, and parasites can influence species throughout a community. One group of parasites, the Eulimidae, is a large family of marine gastropods. Unfortunately, eulimids have not been thoroughly studied and host use behaviors have not been well characterized at the specific, or even generic levels. Therefore, this study seeks to describe host preference, host detection and tracking, and dependence on host access for two eulimid species, both sharing the macrohabitat environment. A series of experiments and a field survey showed that Peasistilifer nitidula was host specific, actively located hosts by chemical cues, reattached to hosts quickly, and required frequent access to the host for survival. Conversely, Melanella acicula had a preferred host but parasitized others as well, did not actively... https://escholarship.org/uc/item/1ft6r4hf Thu, 17 Dec 2009 00:00:00 +0000 Will, Ian https://escholarship.org/uc/item/58c023v0 <p>Classical biological control aims to actively manage threats that cause immense losses in biological diversity. The introduction of a biological control agent Colletotrichum gloeosporioides f. sp. miconiae (Cgm) in April 2000 to Tahiti, French Polynesia was intended to control the massive spread of an invasive weed Miconia calvescens. However, while Cgm has subsequently spread to Mo’orea, its impact on reducing M. calvescens remains uncertain. The main objectives of this study are: (1) to quantify the amount of the fungal pathogen infecting the M. calvescens plants at three elevation ranges on Mo’orea, (2) to understand the impact of moisture on the proliferation of disease development, and (3) to test the influence of endophytic fungal communities on the competitive ability of Cgm. Results from quantifying leaf damage showed that at higher elevations, Cgm disease development is more rampant. In laboratory experiments, varying moisture did not significantly affect the health... https://escholarship.org/uc/item/58c023v0 Wed, 16 Dec 2009 00:00:00 +0000 Chen, Irene Y https://escholarship.org/uc/item/3f59q25s <p>The island of Mo’orea in French Polynesia functions as a model system to study the biological and ecological concept of niche differentiation, whereby two or more species are forced into different habitats so as to avoid competition with each other. In the waters surrounding this island, two species of sea urchin within the genus Echinometra live in distinctly different habitats. Previous studies document Echinometra sp. A located exclusively on the fringing reef and Echinometra mathaei located exclusively on the barrier reef. This study investigated three short-term factors (available space, nutrient supply, and predation) that might be influencing this spatial distribution. None of these factors appear to be causing the separation of E. sp. A and E. mathaei. In fact, they all support the distributional findings of this study that showed non-mutually exclusive distribution data on the two reef types.</p> https://escholarship.org/uc/item/3f59q25s Wed, 16 Dec 2009 00:00:00 +0000 Zizka, Maria D https://escholarship.org/uc/item/14b9h07p <p>Abstract. Humans have continually interacted with and transformed their surroundings. Cordyline fruticosa Chevalier 1919, was among the many plants Polynesians brought with them as they voyaged from western Polynesia to eastern Polynesia. Polynesian culture is historically associated with C. fruticosa, which was centered around the ancient marae, or temples. The distribution of the large, sterile, green leaf variety was studied at marae and contemporary areas such as homes and businesses on Mo’orea, French Polynesia. I expected to find the sacred green variety around marae and the ornamental red varieties in contemporary locations. No C. fruticosa plants were found around marae sites. Contrary to predictions, the green variety of C. fruticosa was more prevalent at the contemporary sites than the red varieties. Local Tahitians were consulted on current attitudes towards and uses of C. fruticosa. These elders indicated that the sacred green variety continues to be utilized... https://escholarship.org/uc/item/14b9h07p Wed, 16 Dec 2009 00:00:00 +0000 borland, trisha m