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TCBES Research Symposium Abstracts

11th Annual TCBES Research Symposium

Thursday, April 11th, 2019

Keynote Speaker
Paula Ayotte, National Oceanic and Atmospheric Administration (NOAA)

1st Session: 5 and 15 min talks

Watershed Management: Investigating Microalgal Nitrogen Isotopes in Kīholo Bay

Maya Goodoni, UH Hilo TCBES Graduate Student

In Hawaiʻi, and globally, groundwater transports ecological subsidies from terrestrial to marine ecosystems; which can act as a primary food source for marine organism. The coral reef system within Kīholo Bay (on Hawaiʻi Island) was found to have the most resilience to bleaching in West Hawaiʻi. Prosopis pallida (kiawe trees) are a nitrogen-fixing species that grow widely across the Kīholo Watershed and have deep taproots that allow them to access groundwater, which is a trait of all species within the Prosopis genus. Consequently, kiawe trees may decrease the amount of total groundwater availability and increase nitrate (N) concentrations within the groundwater that flow into Kīholo Bay via submarine groundwater discharge (SGD), and then onto the coral reef. The relationship between the kiawe N inputs and the coral reef systems on Hawaiʻi Island is unknown. The proposed research will determine if the macroalgal N isotope concentrations on coral reefs associate with kiawe trees. Studying the N isotopes within macroalgae is essential because they are often used as N bioindicators. Macroalgal tissues rapidly assimilate N inputs and can be used to find a point-source of the N. Furthermore, the proposed research will help scientists better understand the relationship between terrestrial and marine ecosystems within the Kīholo Watershed, which will help organizations and resource managers conserve watersheds in Hawaiʻi.

Hawaiʻi Hawksbill Sea Turtle Recovery Project

Kelsey Meagher, UH Hilo TCBES Graduate Student

As an intern at the Hawai’i Hawksbill Sea Turtle Recovery Project, my professional wondering will be invested on, (1) how Hawai’i hawksbill sea turtles thrive with minimal reproduction and population sizes, and (2) how important protecting Endangered Species is to members of the public. The purpose of my internship, as indicated by the Hawai’i Island Hawksbill Turtle Recovery Project handbook, is: (1) identify hawksbill nesting activity and collect baseline data, manage and protect nesting habitat, (2) protect nests and ensure hatchlings safely reach the ocean, control non-native predators and vegetation, and (3) promote public stewardship on marine ecosystems through educational outreach.

Puʻuwaʻawaʻa Forest Reserve, an amazing place to do research

Elliott Parsons, UH Hilo Faculty/Natural Resource Manager

Puʻuwaʻawaʻa Forest Reserve, located on the northern slope of Hualālai on Hawaiʻi Island, is a place of incredible biological diversity and a great place to do graduate research. Part of the Hawaiʻi Experimental Tropical Forest system since 2007, Puʻuwaʻawaʻa contains a diversity of forest structure with at least 36 unique combinations of substrate age and precipitation, miles of underground lava tubes with endemic cave-adapted invertebrates, and the highest density of rare dry forest plant species on the leeward side of the island. The area also has multiple restoration and reforestation projects where ungulates are excluded and native plants have been planted across the reserve since 2010. The types of both pure and applied graduate research questions that can be asked and studied are numerous, and in this talk I'll present some of the most interesting biological diversity, advantages of studying at Puʻuwaʻawaʻa, and some of the most interesting recent research findings as well as unanswered questions that could be pursued by UH Hilo students.

Behavioral landscape of ʻŌmaʻo (Myadestes obscurus) vocalizations in a naturally fragmented habitat

Erin Netoskie, UH Hilo TCBES Graduate Student

Habitat use has long been studied by ecologists to understand how organisms utilize their environment, but they often do not evaluate the diversity of behaviors that coincide with resource selection. We combined movement and vocalization data to create a behavioral landscape model that identifies where different types of vocalizations (i.e. song, call, whisper song) most frequently occur across the landscape, while linking these locations with their underlying habitat features. Using automated telemetry towers, we collected precise location data from radio-transmittered ʻŌmaʻo (Myadestes obscurus), a species of thrush endemic to Hawaiʻi Island, to establish core zones and movements across the landscape. In addition, we recorded individual bird vocalizations using a new transmitter technology, which broadcasts all sound emitted from an individual through a miniature microphone. We found calls were more strongly associated with shrub habitat in the matrix while whisper songs were associated more often with the forested kīpuka. These results indicate that behaviors such as calling while foraging in the matrix or the use of whisper songs for courtship may occur within different habitat types. Furthermore, as distance from a bird’s core zone increases, total time spent vocalizing decreased. Determining the effects of habitat type, composition, and distance from the core zone may clarify context specific uses of sound across the landscape. Moreover, this study provides a comprehensive methodology to document the relationship between habitat use and vocalizations, which can be applied to many taxa across different ecological landscapes.

Two recently reported deadly-poisonous fungi from the Hilo and Puna Districts of Hawaiʻi Island

Jeff Stallman, UH Hilo TCBES Graduate Student

A project documenting fungal species in the genus Lepiota (Agaricaceae) from Hawaiʻi Island from September 2016 - January 2019 reports Lepiota cf. elaiophylla occurring in woodchip, landscaped garden, and coastal Casuarina equisetifolia habitats. An additional Lepiota species is reported from the Puna District under C. equisetifolia. Morphological, molecular, and chemical testing evidence suggests both species contain potentially deadly-poisonous amatoxins. An overview of these two species is presented with information on other fungi in the genus Lepiota and relatives.

Identifying sewage pollution hotspots in Pohnpei, Federated States of Micronesia (FSM)

Bryan Tonga, UH Hilo TCBES Graduate Student

Sewage pollution is prevalent in coastal waters worldwide. It contains pathogens, nutrients, and toxic elements that are harmful to coral reefs and human health. Most sewage treatment plants in developing countries are poorly operated, or non-existent, resulting in discharge of untreated sewage into coastal waters. In Pohnpei, Federated States of Micronesia (FSM), and elsewhere in the world, coastal development leads to an increase in the amount of sewage entering into nearshore waters. In addition, climate change impacts such as sea level rise may amplify the risk of sewage leakage into coastal water. Currently, there is a lack of water quality data on coastal waters especially with regards to sewage pollution in Pohnpei. The proposed research will assess water quality, measuring sewage indicators, including: fecal indicator bacteria (FIB), nutrients, and stable nitrogen isotopes in macroalgae tissue and nitrate dissolved in water. Data from this project will be used to identify sewage pollution hotspots for management actions and establish a baseline data set for future comparisons to evaluate potential changes. Multiple methods of detecting sewage pollution in this proposed research will allow Pohnpei and other island nations in the Pacific to apply to their management strategies on sewage pollution with higher resolutions. Pohnpei, the largest and most developed island in FSM, therefore, assessing coastal water quality will contribute baseline information for conservation, resource management, human health safety, monitoring, and improved sanitation efforts.


2nd Session: 15 min talks

Examining the Effect of Helicopter Noise on Bird Assemblages in Hawaiʻi’s Protected Natural Areas

Karen Gallardo, UH Hilo TCBES Graduate Student

Anthropogenic noise has been shown to have adverse effects on birds, including decreased breeding success, increased flushing behavior, and changes in vocalization patterns. The avifauna in Hawaiʻi is among the most threatened in the world, and helicopter noise in Hawai’i’s forests could be another stressor native birds face in addition to disease, habitat loss, and non-native species. The number of helicopter overflights in Hawai’i Volcanoes National Park (HAVO) is one of the highest in the National Park system, but the effect of helicopter noise on native birds within the park has not been assessed. Our primary objective was to determine if helicopter noise affects the acoustic behavior of native bird assemblages within protected natural areas. We placed automated acoustic recorders in three forested areas that are subjected to helicopter traffic from air tours, two in HAVO and one in the Upper Waiakea Forest Reserve on the Island of Hawai’i. We addressed the following questions: 1) Does helicopter noise affect biophony? 2) Is there a threshold at which helicopter noise affects vocalizing behavior of birds? And 3) does response to helicopter noise vary among bird species? We found that Japanese White-eye and Hawai’i ‘Amakihi increase their vocalization time in response to helicopter noise. Our results may serve as the foundation of an air tour management plan that considers potential effects of air tours on native forest birds.

Investigating the relationship between the feeding territory area of Ornate Butterflyfish and live coral coverage

Mia Lamirand, UH Hilo Undergraduate Student

Reef fish abundance is associated with the presence of live coral. Fishes whose diet is made primarily of coral polyps, also known as corallivores, are one of the fishes that have shown to have a strong relationship between fish abundance and live coral cover. In response to loss of coral, corallivore populations have declined and feeding territories have been documented to expand in areas with lower coral cover. To date, no study has examined the relationship between the feeding territory area of Chaetodon ornatissimus, a corallivore with a broad diet, and live coral coverage. This study investigated the relationship between percent live coral cover and the feeding territory of C. ornatissimus at three locations on Hawai'i Island that varied in live coral coverage after the 2014-2015 coral bleaching event. Data collection of feeding territory size and live coral coverage were conducted via SCUBA at Puakō, Honokohau Harbor, and Richardson Ocean Park between October 2018 and February 2019. This research illustrates the importance of coral as a food resource for corallivores in areas that experienced varying degrees of coral loss and helps provide a mechanistic understanding of the processes operating at an individual level between live coral cover that drive population-level responses to changes in coral cover.

Spatial distribution and sources of land-based nutrients at two coastal developments in South Kohala

Jazmine Panelo, UH Hilo TCBES Graduate Student

Hawai‘i’s coral reefs are declining due to anthropogenic impacts and multiple stressors. Land-based sources of pollution, including transport of elevated concentrations of nutrients via groundwater is a stressor that is ha¬rmful to reefs in Hawai‘i. Nutrient pollution has been linked to higher susceptibility to and lower recovery from coral reef bleaching. Previous research found that coral reefs are in decline in South Kohala. Hence, more research is needed to identify and assess impacts of nutrient sources. Pau'oa and Kūki'o Bays located within South Kohala are adjacent to coastal developments. This study aimed to identify sources and spatial distribution of nutrient concentrations within waters fronting coastal developments in South Kohala. Water samples were collected twice at each development from high elevation wells, anchialine ponds, shoreline, surface and benthic waters, and analyzed for salinity, temperature, NO2-/NO3-, d15N and d18O in NO3- , and d15N in algal tissue. Groundwater discharge was present at both bays and transported nutrients because of higher nutrient concentrations with lower salinities. Nutrient concentrations decreased from high elevation wells to offshore stations. Mixing plots for NO3- + NO2- and PO43- at Pau'oa Bay revealed landscaping may be contributing nutrients to groundwater. Information generated from this project can be used by resource managers to develop management strategies to reduce nutrient pollution that may be impairing coral reefs and recreational waters. With reduced nutrient loads, these reefs will be more resistant to other stressors in a changing climate.

The Hawaiian Blue Octocoral, Sarcothelia edmondsoni, as a pollution indicator species

Ashley Pugh, UH Hilo TCBES Graduate Student

Nearshore coral reef ecosystems in Hawaiʻi are subject to altered water quality due to ground water influx and river discharge that carry pollutants from urban development and agriculture runoff. Shifts in coral reef benthic community species composition have been observed as a reflection of changes in water quality, such as conditions of elevated nutrients. Species that display a predictable biological response to environmental conditions, bioindicators, are desirable and often cost-effective tools for assessing water quality and environmental change. The endemic Hawaiian species of Blue Octocoral, Sarcothelia edmondsoni, has been suggested as a potential bioindicator of land-based pollution because this species is notably abundant near heavily developed coastlines of Hawaiʻi Island (Walsh et al. 2013). Through a laboratory experiment, the growth of S. edmondsoni was assessed under three (3) treatment levels of nitrate concentration. Octocoral growth was observed through two metrics; polyp growth and tissue expansion. The results suggest that S. edmondsoni does not exhibit greater growth in conditions of increased biologically available nitrogen. This growth response is novel information that characterizes this endemic Hawaiian octocoral species. The research at hand provides significant indication of the influence of nitrate on the species growth, and provides a platform from which to further address the potential of S. edmondsoni as a bioindicator of land based nutrient pollution in nearshore marine ecosystems.

Hehihehi management for microbially mediated sediment removal in fishponds

Michaela Setzer, UH Hilo Undergraduate Student

This study has investigated a traditional method of fishpond restoration, meant to specifically deal with the problem of sedimentation as a result of plant debris. Hehihehi, or the stomping and mixing of the mud, is a historical management strategy once used to control and prevent the accumulation of sediment within a fishpond. It was hypothesized that the stomping mechanism of hehihehi forced oxygen into the sediment from the overlying water column, subsequently increasing the rate at which the microbes present were able to decompose the organic matter. In order to test the effectiveness of this method, two batch experiments were established in which the water quality parameters varied and hehihehi was simulated. Each experiment was composed of two aquariums, in which open jars of sediment and artificial seawater were placed. For experiment one, the first aquarium was kept oxic and the process of hehihehi was simulated, while the second aquarium was kept anoxic and did not undergo hehihehi. For experiment two, both aquariums underwent the process of hehihehi but had varying temperatures and salinities. Additionally, two field plots were established at the Kīholo fishpond owned by The Nature Conservancy on the South Kohala side of Hawaiʻi Island, in which hehihehi was simulated monthly. The results of this study have allowed for a cost-benefit analysis regarding the process of hehihehi, and the more modern solution to sedimentation, dredging.


3rd Session: 15 min talks

Sewage Pollution Monitoring on a South Kohala Reef

Devon Aguiar, UH Hilo TCBES Graduate Student

Coral reefs are one of the most biodiverse ecosystems on Earth, providing numerous goods and services. In Hawai‘i, they are an important cultural, subsistence, and economic resource. Puakō, a popular tourist destination in West Hawai‘i, was considered to have some of the richest coral reefs in the State of Hawaiʻi. However, over the course of 28 years, coral cover has decreased by 78-95%, while coral disease has become prevalent. Pollution from nearby sewage disposal systems may be contributing to degraded reef conditions. Measuring salinity, stable nitrate isotopes, and nutrient concentrations, we found evidence of sewage pollution on Puakō’s reefs. Associations between coral health, sewage pollution, and water motion were also examined. This multi-indicator approach will allow for a better understanding of sewage impacts to coral reefs, and can be used to guide community decision making.

Characterizing Habitat Complexity and Fish Assemblage Structure at French Frigate Shoals Using 3-Dimensional Reconstruction Techniques

Brianna Craig, UH Hilo Undergraduate Student

This study examines the pristine reefs of French Frigate Shoals in the Northwestern Hawaiian Islands for relationships between structural habitat complexity and reef fish assemblages. During the 2017 RAMP expedition, fish census surveys were conducted, and photographs of benthos were taken at 31 survey locations, randomly stratified by reef zone and depth. Utilizing Structure-from-Motion photogrammetry techniques, photographs from each site were combined using Agisoft Photoscan to produce a 3-dimensional (3D) reconstruction and Digital Elevation Model (DEM). The 3D model was flattened to a 2D orthophotomosaic, and then analyzed together with the DEM using ArcMap. Arbitrary survey plots were digitized onto orthophotomosaics and processed for 15 different complexity parameters using the Benthic Terrain Modeler tool. Orthophotomosaics were analyzed using CoralNet, an online annotation tool for classifying benthic coverage by genus and morphology. Fish diversity was found to positively correlate to reef slope, 3D surface area complexity, percent coral coverage, and coral genus diversity. Further analyses are being conducted in order to determine potential relationships between fish assemblage trophic structure and complexity parameters. Characterizing the links between habitat complexity and ecological processes on pristine coral reef systems can help to guide conservation and management efforts to effectively improve the resiliency of reefs and associated reef fish assemblages.

Using citizen science to evaluate the influence of the marine ornamental fishery on Hawaiian reef fish occurrence and abundance

Tim Grabowski, UH Hilo Faculty/Agency Researcher

The impact of the marine ornamental fishery on the populations of targeted reef fishes is a contentious issue in Hawaiʻi, in large part because the data necessary to assess impact do not exist on sufficient spatial or temporal scales. My objective was to use volunteer citizen diver fish survey data to evaluate trends in the occurrence and abundance of the most commonly collected reef fish species in areas open to collecting to those in areas where the collection of marine ornamentals is prohibited. Fish surveys were collected by volunteer citizen divers using the Reef Environmental Education Foundation roving diver survey methodology. Fishes were identified to species and assigned a relative abundance score. The most common species of reef fishes exported from Hawaii were identified using customs declarations provided by U.S. Fish and Wildlife Service. For most of the top species, there was no evidence that being targeted in the marine ornamental fishery influenced their occurrence or reported abundance in volunteer citizen diver surveys. However, two species, Achilles Surgeonfish, Acanthurus achilles, and Hawaiian Cleaner Wrasse, Labroides phthirophagus, did show declines in both occurrence and reported abundance during the study period. The majority of species that are most frequently targeted in the marine ornamental fishery seem to have stable or increasing populations based on volunteer citizen diver survey data, suggesting that these populations are not being overexploited on Hawaiian reefs. However, species that are also targeted in subsistence and recreational fisheries, such as Achilles Surgeonfish, or that might exhibit naturally low population densities, such as Hawaiian Cleaner Wrasse, may warrant special management considerations.

The global ecological signature of extinction risk in terrestrial vertebrates

Maya Munstermann, UH Hilo TCBES Graduate Student

Current extinction rates in terrestrial vertebrates globally exceed background intervals in the fossil record and may rival rates of extinction during the “Big Five” mass extinctions. To better understand what types of species are most at risk in the current global biodiversity crisis, we assigned 16,046 species of terrestrial vertebrates to an ecological mode of life, which is defined by the combination of a species’ habitat association, method of locomotion, and feeding mode, and tested for an association with International Union for Conservation of Nature (IUCN) Red List conservation status. We used logistic regression to analyze the association of extinction risk with ecological mode variables for all Vertebrata and for Mammalia, Reptilia, Amphibia, and Aves separately. Results show vertebrates that are arboreal or semi-fossorial, move by brachiating or jumping, are a predator, forager, browser, or grazer are at significantly elevated risk. Individually, the four vertebrate classes display some differences in which ecological modes are associated with elevated risk. Additionally, species that are endangered or critically endangered face a significantly higher number of main extinction drivers than species listed as vulnerable or near threatened, with agriculture and hunting being the most prevalent drivers. With approximately 1/3 of all terrestrial vertebrate species threatened with extinction, swift action is necessary to avoid catastrophic loss of ecological functions.

Moving toward data-driven ecological restoration of vegetation in the Hawaiian Islands

Jonathan Price, UH Hilo Faculty

Numerous ecological restoration efforts seek to expand native dominated vegetation and provide habitat for endangered species in Hawai’i. However many of these efforts are limited by incomplete information about baseline conditions. Here, we assess appropriate population densities of dominant and rare plant species in a spatial context. First, an extensive collection of vegetation plot data from over 1400 locations across all of the main islands provides a quantitative basis for assessing canopy cover across climatic environments. Second, a comprehensive set of habitat suitability models provides a spatial context for evaluating potential habitat. For a baseline set of 176 woody species with sufficient data, we assessed vegetation plots falling within each species' habitat envelope to determine its canopy cover under high quality habitat conditions. For these baseline species, we used ecological traits (dispersal mode, pollination mode, breeding system) and phylogenetic traits (whether it belongs to a monotypic, small or large colonist lineage) to build a multivariate model, which estimates the potential local abundance as measured by canopy cover. Species exhibiting wind pollination or a dioecious breeding system, or belonging to monotypic or small colonist lineages exhibited greater cover than species without those traits. This model was then used to estimate potential local canopy cover for the remaining species with insufficient data from vegetation plots. Combined with using habitat envelopes (among other criteria) to identify suitable reintroduction sites, these estimated densities represent a data-driven technique for rebuilding populations that have fallen due to severe anthropogenic alteration.

Coastal Staphylococcus aureus concentrations in relation to tidal fluctuations in Hilo, Hawaiʻi

Maria Steadmon, UH Hilo Undergraduate Student

Staphylococcus aureus is a bacterium commonly found on the skin or in the nose of about 33% of the population. This bacteria can result in skin infections, but can also lead to infections in the bloodstream, joints, bones, and the heart if it enters the body. Individuals with higher amounts of seawater contact are four times more likely to be infected by S. aureus. In order to help reduce the chance of infection, this study focuses on determining if tidal height impacts the concentration of S. aureus. Five popular beach locations, Richardsons Ocean Park, Onekahakaha, Reed’s Bay, Bayfront, and Honoli’i, in Hilo, Hawai’i, will be analyzed for S. aureus concentrations. Triplicate seawater samples will be collected during high and low tides. Water quality parameters such as temperature, salinity, dissolved oxygen and turbidity will be measured. Seawater samples are analyzed for S. aureus and concentrations are compared to tidal height. Therefore, this study aims to find an association between tidal height and S. aureus concentrations to increase awareness and to provide information for people to make informed decisions about recreational water use.


Friday, April 12th, 2019

Keynote Speaker
Dr. John Burns, UH Hilo Marine Science Department

4th Session: 5 and 15 min talks

2019 Puʻu Mali Palila Reintroduction

Alex Bischer, UH Hilo TCBES Graduate Student

Palila (Loxioides balleui) are the last remaining finch-billed honeycreeper found in the main Hawaiian Islands. Over the past 20 years population numbers have declined by over 75% and have been isolated to montane areas on the southwestern slopes of Mauna Kea. Primary threats to the species include degradation of the dry māmane (Sophora chrysophylla) and māmane-naio (Myoporum sandwichensis) forest by feral ungulates, introduced predators (primarily cats), introduced pathogens and insects to māmane and naio, habitat-altering weeds, and fire. The establishment of a second self-sustaining population would be instrumental for the future survival of the species. A total of 30 captive-reared individuals are planned to be released into the Pu‘u Mali Restoration Area in 2019. Post-release monitoring of survival, movements and reproduction of the birds will provide valuable information for future releases and translocations.

Is Biological Nitrogen Fixation Strategy Tied to Invasive Success for Non-Native Woody Legumes in Hawaiʻi?

Angalee Kirby, UH Hilo TCBES Graduate Student

Hawai‘i has been subject to biological invasion since the first settlers on the island chain. Invasive plant species have been shown to disrupt nutrient cycling and outcompete native flora. Many invasive trees have a nitrogen-fixing symbiosis, allowing them to contribute excess nitrogen to Hawaiian ecosystems that have evolved to survive in nitrogen limited conditions, facilitating further invasion by exotic plants that can utilize the nitrogen surplus. The spectrum of biological nitrogen fixation strategies includes over-regulation, obligate, facultative, and under-regulation. The present study investigates whether nitrogen fixation strategy is tied to the invasiveness of ten non-native woody legumes (Fabaceae) found in Hawai‘i, using the Hawai‘i/Pacific Weed Risk Assessment system to categorize trees as either high risk or low risk for invasion. In a greenhouse experiment trees are being treated with three levels of isotopically labelled nitrogen fertilizer, whose signature is distinct from atmospheric nitrogen, in order to calculate the percent of nitrogen derived from fixation. These data and relative growth rate data will explain which strategy each species uses in order to evaluate relationships between strategies and risk assessments. Results of this study will give insight into which plants should be monitored more carefully on the islands and which should have limited or restricted introduction to the islands, as well as contribute to the limited but growing knowledge of nitrogen fixation regulation in several species that have not yet been documented.

The application of sUAS and LiDAR in new and emerging erosion mitigation strategies

Kimo Melcher, UH Hilo TCBES Graduate Student

Erosion is a global issue whose impacts can been seen locally through the loss of arable topsoil which is then deposited on our coastal reef systems. Using the latest remote sensing technologies and computer software, this project aims to use small unmanned aerial systems and Light Detection and Ranging to create hydrology and habitat suitability models to ascertain areas where erosion measures and out-planting will have the most positive impact. Our two project sites are located in the 1) Kailapa watershed in collaboration with Department of Hawaiian Home Lands and the Kohala Watershed Partnership and in the 2) Keawe Nui watershed in collaboration with the Kamehameha Schools and the East Maui Watershed Partnership. This process will involve the community at every level, and the final elevation, hydrology, and habitat suitability models as well as detailed maps will be provided to the community whom is ready and prepared to take action.

Can compost from a nitrogen-fixing tree, Falcataria moluccana, replace synthetic fertilizer and store carbon in agricultural systems?

Joanna Norton, UH Hilo TCBES Graduate Student

The challenges of food production, invasive species control, and climate change intersect with each other, and while solutions in one field have generally exacerbated problems in the others, some new approaches seek to create co-benefits. Climate-smart agriculture is a suite of management practices that can create co-benefits for the climate by lessening emissions from ag and storing carbon in croplands. One climate-smart practice is application of compost, which can supply key nutrients and add organic matter to the soil while decreasing the need for synthetic fertilizers. Abundant biomass for producing this compost is present in the nitrogen-fixing albizia tree (Falcataria moluccana), which is highly invasive across the Hawaiian Islands; a use for chipped albizia could facilitate its control. This research applied albizia compost to croplands and compared those results to treatment controls of no inputs and synthetic fertilizer only, and a combination of compost and fertilizer. The test crops used were cassava and corn, and the resulting plant yields and plant and soil nutrients (C, N, P and more) were analyzed. We found that corn had higher yields using synthetic fertilizer, and cassava yields remained the same across all treatments. Results from nutrient tests and an analysis of carbon storage/loss will be reported at the upcoming conference.

Comparison of fish assemblages and habitat use of native and introduced estuarine species in a fishpond complex in Hilo, Hawaiʻi

Ricky Tabandera, UH Hilo TCBES Graduate Student

Traditional Hawaiian fishponds (loko iʻa) are enclosed structures strategically placed to retain inputs from surface water flow and submarine ground water resulting in an increase of productivity. In terms of their hydrology and geomorphology, Hawaiian fishponds are essentially artificial estuaries, but their ecology remains largely unexamined. The abundance and species composition of the fishes inhabiting a complex of Hawaiian estuary ecotypes consisting of an inactive fishpond, two fishponds actively under production, and the adjacent natural estuary were examined using shore-based cast net sampling. Four fish species commonly associated with fishponds and natural estuaries: Striped Mullet, Kanda, Reticulated Flagtail, and Hawaiian Flagtail were assessed for their survival, movement, and habitat use using Passive integrated transponders (PIT tags) and robust mark recapture design. Community composition differences were primarily driven by differences in salinity. Locations with salinity less than 5 ppt containing lower overall richness and higher proportion of invasive species. Conversely intermediate salinity ~15 ppt locations contained higher overall species richness. These results suggest that target species may be unable to utilize some locations due low salinity stress. Connectivity between a fishpond and the bay was observed and potentially indicates that these sites share a population as fish of ~150mm size class were able to transit the pond’s structures.


5th Session: 5 and 15 min talks

Spatial Differences of Invasive and Native Plant Species on UH-Hilo Campus

John T. Flint, Thatmini Kularatna, Emma Sinclair, Kimo Melcher, UH Hilo TCBES Graduate Students

This study surveyed plants on the University of Hawaiʻi at Hilo campus. We recorded the species, its apparent age, and GPS coordinates. We used Optimized Hotspot analyses and Nearest Neighbor Analysis, and Two-Sample T-tests to compare the density and spread of nine different tree species. The species were classified into groups native or invasive species, and invasive plants with either bird- or wind-dispersed seeds. When we compared the number of adults and saplings for the species we found a significant positive relationship between them. We also found the average density of invasive species was higher than native species. However, the native species showed a higher average spread (Nearest Neighbor Ratio) value, but this was likely due to the planting of native plants on different part of the school’s grounds. When we compared the same values for the invasive plants with wind and bird dispersed seeds, we found there was not a significant difference in the average values of average density or average spread (Nearest Neighbor Ratio). The purpose of this study was to attempt to build support for a movement to get the school’s administration to implement invasive species removal efforts and help direct these efforts towards key species.

Identification of individual Achilles Tang Acanthurus achilles using digital photography and machine learning algorithms

Bobbie Suaerz, UH Hilo TCBES Graduate Student

The ability to reliably discern an individual during intermittent observations is an essential tool to understand the movements and behavior of individuals as well as estimating abundance and population parameters. Marking individuals with external tags, injections of elastomers, or surgical implantation of electronic radio tags is a common tool used to achieve individual identification, but these approaches require the capture and handling of the study animals which can be difficult, time-consuming, and impact the health and behavior of the animals. This is particularly the case for relatively small-bodied fishes inhabiting a structurally complex environment that is sensitive to disturbance, such as a coral reef. Therefore, our objective is to assess the reliability using machine learning to identify individuals of a reef fish, Achilles Tang Acanthurus achilles, based on individual variations in body shape and markings as part of a “mark”-resight population estimation. We conducted multiple video and photography transects over a six-month time period. A subset of collected photos were analyzed using image analysis program image where area of fish and caudal spot were calculated. Area of the caudal spot and total length exhibited a strong correlation, but a weak relationship between the total length when compared to the spot area divided by the total area of the fish. Collected videos were analyzed using a photo recognition algorithm and convolutional neural network, this application of machine learning is currently under investigation and shows promise of accuracy ≥ 95%.

Leaf fungal endophyte diversity varies among Metrosideros (Myrtaceae) taxa on Oʻahu

Gary Sur, UH Hilo TCBES Graduate Student

Tree fungal endophyte (FEs) communities are not only influenced by abiotic environmental conditions, but also display varying degrees of affinity to their host plants. The tree genus Metrosideros (Myrtaceae) is a useful evolutionary model, comprising many morphologically unique taxa that occupy different habitats throughout the Hawaiian archipelago. This study used Metrosideros on Oʻahu to assess the relative importance of environment versus host taxon on FE composition and diversity. From each of four elevation gradients, leaves were collected from four Metrosideros taxa (two high-elevation and two low-elevation taxa; 11 trees/taxon/gradient, n=176 trees). DNA was extracted from surface-sterilized leaf samples. Fungal DNA was amplified using barcoded internal transcribed spacer (ITS) forward and reverse primers, and the barcoded amplicons underwent metagenomic IonTorrent sequencing. The sequences were filtered in RStudio, and bioinformatically processed with the vegan, and dada2 packages. The remaining samples (n=113 trees) yielded 1,637 operational taxonomic units (OTUs) with dissimilar FE diversity among individual trees, sample taxa, and collection sites. Permutation tests, diversity indices, and Akaike information criterion (AIC) models implicate Metrosideros taxa, and geographic distance among collection sites as significantly affecting FE diversity. However, ordination plots showed much overlap among sites, indicating all sites shared similar FE communities. The frequency of host-specific FEs may be significantly greater in high-elevation taxa.

Seed Dispersal & Germination by Native vs. Exotic Avian Frugivores of Hawaiʻi

Koa Matsuoka, UH Hilo TCBES Graduate Student

On islands worldwide, mass avian extinctions related to anthropogenic activity have allowed smaller avian generalist to fill ecological niches left open by larger native specialist. Consequently, ensuring the survival of Hawaiʻi Island’s remaining native frugivores, the ʻōmaʻo (Myadestes obscurus) and ʻalalā (Corvus hawaiiensis), is integral in preserving seed dispersal function and native plant recruitment in upland forests. In lieu of relying completely on exotic birds as proxies for native seed dispersers, conservationist have begun re-introducing native frugivores into historic ranges to refill the empty niches previously left open by their localized extinction. In light of this, I compared how exotic and native birds influence the recruitment of Hawaiian fruiting plants. To identify native plant species dispersed by avian frugivores, I used seed rain traps and collected fecal samples from native ʻōmaʻo and ʻalalā and exotic Japanese white-eye (Zosterops japonicus). Seed rain traps were used to identify fruiting plants dispersed in the landscape while fecal samples were used to distinguish the diversity of plant species dispersed by each avian species. Additionally, these seeds were placed in growth media to compare gut-passage effects on seed germination for each avian species. The preliminary results show that in native dominated forests both native and exotic frugivores benefit the seed dispersal of native plants. However, a higher diversity of native seeds were dispersed by native frugivores. These results substantiate the use of ‘ōmaʻo and ʻalalā reintroductions as a strategy to increase their ranges while simultaneouly promoting the regeneration of native Hawaiian fruiting plants.

Microplastic accumulation patterns of a newly formed beach

Nicolas Vanderzyl, UH Hilo Undergraduate Student

Microplastics (< 5 mm) are a pervasive contaminant in the marine environment, with global concentrations anticipated to increase as marine debris is abundant and continuously fragmenting. Microplastics concentrations are greater in the sediment than the water column, suggesting a sink. Recent volcanic activity has provided the opportunity to examine the sediment of a newly formed beach. It is the researcher’s goal to investigate the presence and spatial distribution of microplastics at Isaac Hale State Park (Pohoiki) on the Island of Hawaiʻi. Samples were collected at the berm crest and high tide line, microplastics were extracted via density flotation and, visually sorted by shape via dissecting scope. Fragments and fibers were discovered in equal proportions with no difference in spatial distribution. This study further supports universality of microplastics in the marine environment.


6th Session: 15 min talks

Mapping Biological Soil Crusts in the Kawaihae Watershed

Eszter Collier, UH Hilo TCBES Graduate Student

Arid and semi-arid landscapes compose nearly half of the Earth’s terrestrial surface, and many are vulnerable to erosion. Due to the high temperatures and limited water availability of these environments, it is important to explore any naturally-occurring soil stabilizing agents that can withstand harsh conditions. Biological soil crusts are communities of photosynthetic microorganisms that are known to increase soil stability in dryland ecosystems. They may be especially important for areas such as the Kawaihae watershed on leeward Hawaiʻi Island, which has been identified as experiencing high erosion rates. The need to investigate erosion-mitigation factors is particularly acute for this watershed because it drains into Pelekane bay, which is home to coral reef habitat that is important for many native marine species. This project mapped biocrusts in the Kawaihae watershed using imagery collected by small unmanned aerial systems (sUAS) ,which resulted in biocrust spatial distribution data at much higher resolutions than previously available. In addition to developing a mapping technique for biocrusts, we also explored the relationship between soil stability and biocrust development within this landscape and applied our mapping methodology to investigate research topics that are relevant to conservation efforts: the effects of grazing ungulates on biocrust abundance and the impacts of biocrusts on sediment transport. Our project provides insight into the potential erosion-controlling capabilities of biocrusts and provides highly-detailed spatial data that can be used by researchers and land managers working in the Kawaihae watershed as well as other semi-arid landscapes in Hawaiʻi.

Effect of sex ratios on captive social behavior and mating systems of Potter’s Angelfish, Centropyge potteri

Jon Gabriel Ehrenberg, UH Hilo Undergraduate Student

Centropyge potteri is an endemic Hawaiian dwarf angelfish found in throughout the Main and Northwestern Hawaiian Islands. This genus of angelfish is well known and coveted in the aquarium trade for its vibrant colors and small size. Research on this species has been conducted in the wild or through semi/natural caged studies; however, little is known about the social or reproductive behavior of C. potterii in captivity. As a target species for the aquarium industry in Hawaiʻi, knowledge of captive behavior and mating systems could be important for the captive culture of this species. The purpose of this study was to observe the effects of two sex ratios on the number and strength of interactions and number of spawning events among captive individuals and groups. Video of the two groups was recorded for a total of 62 days during the peak spawning months of December and January. Videos were analyzed to determine; which individuals were interacting with one another, what the strength of those interactions were, and how many spawning events occurred per female. Sex ratios were as follows; one male to one female and one male to three females. It was expected that the group with more females would have a greater number of interactions compared to the pair. It was hypothesized that the mean number of spawning events would be less in the pair compared to the group with more females. These results could aid future captive breeding programs for C. potteri.

The urbanization of the Hawaiian stilt: Meet the new neighbors

Marty Kawasaki, UH Hilo TCBES Graduate Student

The Hawaiian stilt, or Aeʻo, is an endangered waterbird endemic to the Hawaiian Islands. Loss of wetland habitats due to anthropogenic development is a leading cause for decline, as well as the introduction of non-native predators and invasive wetland plants. While other Hawaiian waterbirds are largely restricted to wetlands, Hawaiian stilts appear to be adapting to the urban environment, using heavily modified upland habitats. In our study, we fitted four Hawaiian stilts with GPS satellite tags to document their use of developed areas, undeveloped fields, sports fields and wetland habitats over a 6 month period. We found a high use of non-wetland habitat, with significant differences in habitat occupancy among the individual stilts and across different times of day. Wetlands were the dominant habitat occupied from morning to early afternoon, but non-wetland habitats were occupied in higher frequency in the evening and early morning hours. The use of habitats outside wetlands implies management strategies may need to be updated to encompass these additional habitats.

Developing an underdominance gene drive system in the southern house mosquito

Jared Nishimoto, UH Hilo TCBES Graduate Student

Since its initial introduction to Hawai‛i, avian malaria has decimated native Hawaiian forest bird populations. The main vector for avian malaria, the southern house mosquito (Culex quinquefasciatus), continues to threaten native birds and will become a larger threat with global warming expanding the range in which both the vector and disease can develop. We are developing an underdominance-based gene drive system in the southern house mosquito to potentially transform and control wild mosquito populations with the goal of mitigating the decline of native Hawaiian birds. An underdominance gene drive has safety measures in that the transformed population is geographically stable and the transgene can be removed from the population if desired. Such a system has already been established in Drosophila melanogaster and was shown to remain stable for over 200 generations. In the current study, we perform the first steps to adapt this underdominance gene drive system for use in mosquitoes for the first time, by integrating a synthetic genetic construct containing a “self-docking site” in a lab colony of southern house mosquitoes. As a component of our overall gene drive system, this self-docking site is intended to allow subsequent constructs (e.g., disease refractory genes) to be site-specifically integrated in the mosquito genome. We are now working on assessing a new phenotypic marker for the synthetic construct to increase screening efficiency. Possible future integration and expression of the underdominance gene drive in the southern house mosquito would open possibilities to control wild mosquito populations, whether for animal or human diseases.

Applying object recognition technology to identify plastic marine debris objects during beach surveys

Leah Sherwood, UH Hilo TCBES Graduate Student

Current marine debris surveys rely on the collective efforts of scientists and volunteers who go on-site to conduct visual surveys and hand-count and photograph plastic objects. Our research seeks to demonstrate that modern object recognition technology can be harnessed to improve current plastic marine debris survey methods and to make plastic marine debris quantification and prediction more effective. We have adopted the technology platform Darknet, an open source framework for convolutional neural networks written in C and CUDA. Within Darknet, we adopt the state-of-the-art image detection algorithm YOLO (You Only Look Once), which is able to quickly predict objects and their bounding boxes in input images by applying a single neural network in a single pass. A smaller version of YOLO (Tiny YOLO) has also been developed for mobile machine learning and IoT devices. Our goal is to create a smartphone application that allows researchers and citizen scientists to update existing databases of plastic marine debris (such as the MDMAP database used by NOAA’s Marine Debris Program) in a way that is faster, cheaper, more consistent, and more accurate. By applying new technical capabilities to existing survey methods and protocols, we hope to improve the accuracy of estimates of the amount and type of on-shore marine debris. Our test site is the beach at Kamilo Southpoint on the Island of Hawaiʻi, which is known for its large and rapid accumulation of plastic marine debris.


7th Session: 15 min talks

Variability in the Repertoires and Singing Behavior of Male and Female ‘I‘iwi (Drepanis coccinea)

Angela Beck, UH Hilo TCBES Graduate Student

Song is a defining characteristic of the songbird clade, and there is great diversity in song structure, function, and learning plasticity across this animal group. Until recently, very little research has been done on the vocal behavior of Hawaiian forest birds. The ‘i‘iwi (Drepanis coccinea), is a tropical, non-migratory, monomorphic songbird. The behavior and vocalizations of 7 male and 6 female ‘i‘iwi from Hakalau Forest NWR were recorded and analyzed to determine whether aspects of vocal behavior were grouped according to sex. ‘I‘iwi vocal behavior in both sexes can be defined primarily by high individual variability.

Soil Sources of Staphylococcus aureus and Fecal Indicator Bacteria in the Hilo Bay Watershed

Tyler Gerken, UH Hilo Undergraduate Student

Staphylococcus aureus and Methicillin-resistant S. aureus (MRSA) are opportunistic and pathogenic bacteria that are found increasingly prevalent in the environment. Consequently, community-associated outbreaks of MRSA (CA-MRSA) have been increasing globally. In the United States, Hawaiʻi has the highest rates of CA-MRSA infections – almost twice the national average. These infections are thought to be associated with recreational water use. Studies in Hawaiʻi have shown that S. aureus and MRSA concentrations increase in streams and estuaries following storms suggesting they have watershed sources. These sources have not yet been identified. Enterococcus spp., a fecal indicator bacteria (FIB), is found in tropical soils; it is likely that S. aureus and MRSA are present too. Subsurface soil samples were collected, three times each, in triplicate, on 24 days between June 2017 and November 2018 at urban, agriculture, and native forest land-use types. S. aureus, MRSA, and FIB (Enterococcus spp., Clostridium perfringens) were prevalent among all land-use types. However, their concentrations significantly differed among them up to three orders of magnitudes. Bacteria concentrations were highest in urban soils and lowest in native forest soils. These results suggest that tropical soils are a watershed reservoir for these bacteria, and may be contributing to their high levels in streams and estuaries during storms. Determining watershed reservoirs of human pathogens will allow natural resource and health managers to take appropriate management actions to reduce pathogen loads to coastal waters and transmission to recreational water users.

Fine-scale population genetic diversity of an invasive species in Hawaiʻi

Jonathan Koch, UH Hilo Post-doc

In the context of evolutionary theory, invasion biology provides a fantastic enigma: how does a species with limited standing genetic variation survive and adapt to a novel environment? In this study, we demonstrate the roles of phenotype plasticity, colonization history, and genetic diversity in driving the success of an invasive species. We generated wing phenotype and genome-wide single nucleotide polymorphism (SNP) data from invasive populations of Drosophila suzukii in the Hawaiian archipelago. Wing phenotype analysis revealed that altitude is a significant predictor of wing size, with high altitude populations possessing larger wings than low altitude populations. While we discovered low genetic diversity and differentiation in all populations, three unique genetic clusters were detected with a model-free, multivariate statistical approach. With two complementary analyses to detect selection across the genome, we discovered 39 candidate loci for adaptive evolution, three of which were highly supported in both analyses. By placing SNPs in a chromosomal context, we found that a significant proportion of the differentiated candidate loci were present on the X chromosome. Our results support the faster-X hypothesis, which predicts that beneficial mutations will quickly accrue in the X chromosome relative to autosomes. Despite a genetic bottleneck, adventive D. suzukii populations are beginning to differentiate across the Hawaiian archipelago, and adaptive evolution is disproportionately occurring on the X chromosome. By studying selection across the genome of an invasive species we provide insight into the early stages of speciation.

Machine annotation of Puaiohi calls in environmental acoustic recordings

Madori Rumpungworn, UH Hilo Undergraduate Student

Falling hardware costs has made large-scale passive acoustic monitoring of wildlife increasingly affordable in recent years. Wildlife conservationists and scientists have a variety of potential uses for bioacoustic data, but usually require accurate annotations as a first processing step. Manual methods for producing annotations of these recordings (using Raven, for example) are time consuming, tedious, and prone to human error. Using machine learning techniques to assist in this task has the potential to greatly reduce the costs associated with producing these annotations. In this study, we employ a deep neural network to produce an automated annotation pipeline targeting the Puaiohi (M. palmeri). Puaiohi are a critically endangered songbird endemic to the Alakai plateau on the island of Kaua’i with an estimated population of only 500 remaining in the wild. They are threatened by multiple factors, such as climate change, habitat loss, and mosquitos carrying avian malaria. The call of the Puaiohi is particularly amenable to automatic detection, due to its simplicity and regularity. Using a human-annotated dataset consisting of approximately 30 hours of forest environmental recordings, we trained a deep convolutional network to annotate environmental recordings. The automatically generated annotations feature accuracy and recall which are similar to a first-pass manual annotation. Using retail commodity hardware, the network can be trained in approximately 15 minutes and can annotate a new 15-minute sample in under a minute. This demonstrates the utility of machine learning approaches for targeted annotation of environmental recordings.


Poster Session & Pau Hana Reception

  1. Isolation and Characterization of Endorhizzal Bacteria in Root Nodules of Leguminous Plants at Leeward Community College, O‘ahu Hawai‘i Brennan Palani Buccat, Leeward Community College

  2. Optimization of the use of Procambarus clarkii in Aquaponics Briana Banua, Leeward Community College

  3. Synthesis, Computational Analysis, and Antimicrobial Evaluation of Electron-donating and Electron-withdrawing Substituents on Chalcone Derivatives Diana Le, Leeward Community College

  4. An update on the survey of antibacterial efficacy of native Hawaiian plant extracts: Focus on ‘Ohia lehua and gram-positive bacteria E. Escobar, K. Agnoias, and S.T. Nakanishi, UH Hilo

  5. Cecal Microbiome Profile of Hawaiian Feral Chickens and Pastured Commercial Chickens Kayla Caliboso, Leeward Community College

  6. Effects of mycorrhizae inoculants on Theobroma cacao and its potential use in agroforestry Kiana Rich, Leeward Community College and Daniela Dutra Elliott, LCC Faculty

  7. A software tool for producing annotations of prolonged audio recordings using machine learning and deep neural networks Lindsey Howells, UH Hilo Undergraduate Student

  8. Assessment of the Impact of Artificial Reefs on Shoreline Erosion through Physical Modeling Maverick Kaopio, UH Hilo Undergraduate Student

  9. Identification of fungal contaminants using DNA barcoding Michele Pangelinan, Leeward Community College and Ashley Yuen, UH Mānoa

  10. Modification of body regeneration using Hawaiian plant extracts in planaria M.R. Morrissey, M.L. Webber, and S.T.Nakanishi, UH Hilo

  11. On the ecological restoration of Kahoʻolawe S. Brandenstein and S.T. Nakanishi, UH Hilo

  12. Expression of Gonadotropin-Releasing Hormone Receptor(GnRHR) in the Oviduct of Laying Hens Valeria Alicea-Colon, Leeward Community College

View archived abstracts from previous years.