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Open Access Publications from the University of California

UCB Moorea Class: Biology and Geomorphology of Tropical Islands is an intensive field course (13 units), taught every Fall semester by UC Berkeley. A highly selective group of 20-22 undergraduate students spend a month on campus in Berkeley for lectures and labs five days a week, then go to the Richard Gump Biological Station on the island of Moorea in French Polynesia for nine weeks to carry out an intensive research project and to do some general educational field trips and labs, supervised by a number of professors and graduate student instructors. They learn all the stages of scientific research from conception of a project to giving talks and and writing. These papers are the result of their research.

Cover page of Distribution, Ecology, and Systematics of the Filmy Ferns (Hymenophyllaceae) of Moorea, French Polynesia

Distribution, Ecology, and Systematics of the Filmy Ferns (Hymenophyllaceae) of Moorea, French Polynesia

(2006)

Ferns present an interesting case in island biogeography because of their unusually high dispersal ability. A general survey of the filmy ferns (Hymenophyllaceae) of Moorea, French Polynesia was undertaken by observing distribution in the field, conducting tests of desiccation tolerance, and inferring a phylogeny based on morphological characters. A total of 12 filmy fern species (including three species previously unreported in the literature for Moorea) were found to occur in moist, wellcovered habitats throughout the island, with distinct sets of high elevation and low elevation species. Five species were included in an experiment to determine relative degree of desiccation tolerance; results indicate that terrestrial species have lower desiccation tolerance than epiphytic or epipetric species. In order to place the Moorea filmy ferns in the larger archipelago context, eight additional Society Island species were included in the phylogeny for a total of 20 taxa based on 21 morphological characters; interspecies relationships reflect the taxonomy of Hymenophyllaceae sensu lato. Filmy fern species are widely dispersed throughout the Society Islands, and there is no indication of an adaptive radiation on Moorea.

Cover page of Does the River Continuum Concept Work in Small Island Streams? Functional Feeding Group Variation Along a Longitudinal Gradient

Does the River Continuum Concept Work in Small Island Streams? Functional Feeding Group Variation Along a Longitudinal Gradient

(2006)

The River Continuum Concept (RCC) predicts that as the form of particulate organic matter available in streams and rivers varies longitudinally, so will the functional feeding groups (FFGs) of benthic macroinvertebrates. The RCC was developed based on data from continental streams; therefore, its applicability to the unique ecology of island streams is virtually untested. The purpose of this study was to discover if the RCC works in the small streams of Moorea, French Polynesia. Three sites along an elevational gradient were sampled for benthic macroinvertebrates in five streams of similar catchment size. Each sample was sorted and all taxa were assigned to a FFG. Species richness and FFG variation along a longitudinal gradient were compared to RCC predictions. Patterns in the longitudinal variation of crustacean/mollusc species richness and shredder, grazer, and predator percent composition were found to match RCC predictions. However, total species richness, insect species richness, and the percent composition of collecting organisms did not. Therefore, an alternative theoretical framework is needed to accurately describe FFG variation in tropical streams.

Cover page of Resource Partitioning By Wintering Shorebirds : A Behavioral Comparison of Two Species in a Tropical Estuary

Resource Partitioning By Wintering Shorebirds : A Behavioral Comparison of Two Species in a Tropical Estuary

(2006)

Shorebirds often feed in multispecies groups that display interesting niche dynamics. On Moorea, French Polynesia, the Wandering Tattler (Tringa incana) and Pacific Golden Plover (Pluvialis fulva) are the dominant shorebird species during the northern winter. These species’ feeding behavior was observed at the Temae estuary on the northeast side of the island. Relative abundance of the two species was determined using transect counts at the estuary and an adjacent beach. T. incana displayed more striking and sprinting behavior, while P. fulva displayed more picking and walking behavior. T. incana also consumed more crabs than P. fulva. The two species existed in relatively equal abundance in the estuary; T. incana was more common on the beach. Though these data suggest some differences in feeding niche, a great deal of overlap was observed. The degree of niche partitioning appears to be greater in this study than in similar studies conducted on these species’ breeding grounds.

Cover page of Ancient Lawns in a Modern Day World: Distribution and Characterization of Marine Microbial Mats at Temae Beach, Moorea, French Polynesia

Ancient Lawns in a Modern Day World: Distribution and Characterization of Marine Microbial Mats at Temae Beach, Moorea, French Polynesia

(2006)

The study of microorganisms and filamentous blue-green algae holds great ecological and geological importance; such microbial communities to be on of the first forms of life as well as the initial source of atmospheric oxygen. In Moorea, an island in the South Pacific, the microbial communities found on the intertidal mudflats have been widely studied and characterized. However, little is known about the marine mats that are consistently covered with seawater. This study surveyed the algal communities present in the shallow lagoon formed at Temae Beach, a public sand beach located on the northeast tip of Moorea. Seven morphologically different mats were observed and their distributions determined and mapped throughout two regions: the littoral (intertidal and sub-tidal) and back reef. The majority of mats were found within the sub-tidal while none were seen within the intertidal and very few observed within the back reef region. A common trend observed within this distribution found specific morphological types consistently located within the same general areas. Additional observations of fish herbivory as well as shear stress and current flow over these mats were also briefly investigation. Overall, while this study provides a brief characterization of what is found in the lagoon, further studies of these marine mats are needed to strengthen these initial findings and, in particular, to investigate specific factors attributing to why the mats disperse as they do.

Cover page of Habitat and Bleaching in the Foraminiferan Peneroplis Pertusus

Habitat and Bleaching in the Foraminiferan Peneroplis Pertusus

(2006)

The effects of human activities on the earth’s environment have gained increasing attention in recent years. With coral reefs declining worldwide, efficient tools for assessing reef health are more important than ever. The species of larger foraminifera known as Peneroplis pertusus share key characteristics with reef building corals. By examining the populations’ natural distribution along with the abiotic factors affecting bleaching, a better understanding of reef systems as a whole is achieved. In this study, P. pertusus was collected from ten different sites on a fringing reef in Moorea, French Polynesia. Collected from coral rubble at one, two, and three meters depths, they were analyzed for abundance, size, and extent of bleaching. Light experiments were used in the laboratory to determine response to increased solar radiation. One-way statistical analysis, along with the Wilcoxon test found no strong correlation between depth and percent bleaching. A difference between individual size and percent bleaching was found and a natural population dynamics are presumed to occur n Moorea. Light experiments found increased bleaching in P. pertusus showing increased solar radiation to be a factor in bleaching.

Cover page of Mutiny on the Bounty or Bountiful Mutants? Diversity and Composition of Wood-Decaying Macrofungi on Hibiscus Tiliaceus Wood in French Polynesia

Mutiny on the Bounty or Bountiful Mutants? Diversity and Composition of Wood-Decaying Macrofungi on Hibiscus Tiliaceus Wood in French Polynesia

(2006)

Wood-decaying macrofungi are an important component of forest ecosystems because they are the major decomposers of dead woody debris and are crucial for nutrient cycling. This is especially true in the tropics where biomass is high. However, most studies to date have focused on temperate forests in the northern hemisphere. Little is known about wood-inhabiting fungi in French Polynesia. In fact, no identification materials exist. The following study seeks to fill this gap in knowledge. First, a general survey was done of the wood-fungi occurring in the mountains of Moorea. Next, in a pilot study, all Hibiscus tiliaceus dead wood (>1cm) was measured and surveyed for fungi using 10, 25-meter line transects. The aim of this phase was to determine if wood with fungi has different characteristics than wood without. Fungi were found on 61% of wood surveyed, but larger logs, and wood of intermediate decay were more likely to have at least one species. An additional 20 transects focused only on wood with fungi. A total of 114 species were found on 644 pieces of Hibiscus tiliaceus wood. However, 36.8% species were found only once and most wood had only 1 or 2 species. There were a few very abundant species, and the others were rare. When common species were examined individually, it was evident that many had preferences for certain wood sizes and decomposition. Species richness was found to positively correlate with average diameter, and wood of intermediate decay was also found to have greater species richness. In general, the results of this study were found to support much of the research conducted in temperate forests. Although the details differ, the underlying trends of diversity and succession are surprisingly similar.

Cover page of Is the Tamanu Losing Turf? DIstribution and Propogation of the Economically Important Calophyllum Inophyllum of Moorea

Is the Tamanu Losing Turf? DIstribution and Propogation of the Economically Important Calophyllum Inophyllum of Moorea

(2006)

French Polynesia’s indigenous tamanu Tree (Calophyllum inophyllum) is an important natural resource harvested for lumber, resin, and oil. Being a marine-seed dispersed species it self-propagates and can be found growing along the coastline of Moorea. Development and harvest patterns on Moorea may be slowing the natural reproductive rate of the species. Fifty years ago it was recommended as a species to include in management programs as it had been noted to be in decline due to its slow growth and high use rates. Interviews with elders, carvers and healers indicated that the range has indeed diminished. A total island survey was performed and the resulting map of C. Inophyllum’s distribution indicates that the range is healthy- but it will continue to compete with human development for the diminishing resource of coastal terrain.

Cover page of Morphological and Chemical Differences Among Populations of Hibiscus Tiliaceus Along an Elevational Gradient in Moorea, French Polynesia

Morphological and Chemical Differences Among Populations of Hibiscus Tiliaceus Along an Elevational Gradient in Moorea, French Polynesia

(2006)

Environmental variables change over elevational gradients and can isolate plant populations. Three varieties of Hibiscus tiliaceus L. exist on an elevational gradient in Moorea, French Polynesia. These variety’s morphological and chemical characteristics are associated with the differences between their environments. Leaf and flower morphological data were collected and analyzed and found significant differences in petal width and length, anther count, burgundy center color, and leaf width and length between the varieties, particularly between the coastal and mountain types. The increased rainfall and lower temperatures of the high mountains lowered net primary production for the mountain variety as compared to the coastal and mid-mountain varieties. The mid-mountain variety was found to have greater competition for light than the other varieties. These can be linked to the significant size differences in leaves and inflorescence. Chemical differences were analyzed using anti-microbial and anti-cancer bioscreens. Significant differences were found in the anti-microbial bioscreen between the mid-mountain variety, which showed little activity, and both the coastal and mountain varieties. The anti-cancer screen showed increased activity from the coastal and mountain leaves. Chemical differences are influenced by increased insolation and chemical protection from microbes in wet conditions. Anthropological uses of the varieties are linked to the greater size of the coastal type. The plant populations studied are associated with the differences in their environments.

Cover page of Ontogeny of Defense : Does Life History Affect Predator Response Behavior in the Pygmy Octopus, Octopus Bocki?

Ontogeny of Defense : Does Life History Affect Predator Response Behavior in the Pygmy Octopus, Octopus Bocki?

(2006)

Organisms experience physiological and ecological changes during ontogenesis, and studies have shown that such changes have an impact on behavior over the life cycle. However, little is known about how octopus behavior changes during ontogeny. The pygmy octopus, Octopus bocki (Adam 1941), expresses differences in chromatophore development and mantle length between developmental stages. These changes may be important in predator defense, therefore I hypothesized that predator response behavior also changes over the life cycle. Timed interactions between an octopus and a fish predator were used to compare the behaviors and color displays exhibited by three different size categories of O. bocki; juvenile, sub-adult, and adult. Color display diversity was analyzed using the Shannon-Weiner diversity index. The analysis revealed a negative correlation between color display diversity and size during predator interactions, supporting the hypothesis that behavior changes over the life cycle. Counter-intuitively color display diversity decreases while chromatophore development increases. To broaden the context in which behavior was examined, interactions between adult O. bocki were used to investigate how adults use color displays. The number of color/texture combinations was graphed to compare displays expressed during predator interactions with those expressed during intraspecific interactions. A Wilcoxon test revealed that adult O. bocki used significantly more color and texture displays during intraspecific interactions than during predator interactions. I concluded that adult octopuses use color displays for communication rather than predator defense and that these displays change during ontogenesis.

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Cover page of Predator Defense Mechanisms in Shallow Water Sea Cucumbers (Holothuroidea)

Predator Defense Mechanisms in Shallow Water Sea Cucumbers (Holothuroidea)

(2006)

The various predator defense mechanisms possessed by shallow water sea cucumbers were surveyed in twelve different species and morphs. While many defense mechanisms such as the presence of Cuverian tubules, toxic secretions, and unpalatability have been identified in holothurians, I hypothesized that the possession of these traits as well as the degree to which they are utilized varies from species to species. The observed defense mechanisms were compared against a previously-derived phylogeny of the sea cucumbers of Moorea. Furthermore, I hypothesized that while the presence of such structures is most likely a result of the species’ placement on a phylogenetic tree, the degree to which they utilize such structures and their physical behavior are influenced by their individual ecologies. The presence of a red liquid secretion was restricted to individuals of the genus Holothuria (Linnaeus 1767) however not all members of the genus exhibited this trait. With the exception of H. leucospilota, which possessed both Cuverian tubules and a red secretion, Cuverian tubules were observed in members of the genus Bohadschia (Ostergren 1896). In accordance with the hypothesis, both the phylogenetics and individual ecology appear to influence predator defense mechanisms. However, even closely related species of similar ecology may differ considerably.