Developing tools to support resiliency in marine communities
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“The signal is the truth. The noise is what distracts us from the truth.” |
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My research uses quantitative methods to provide solutions for marine conservation problems. My particular interests include population resilience and species recovery, evaluation of population dynamics that result from individual-based ecology, and integration of tools and methods to understand species ecology, distributions, and response to management strategies. I prefer to focus on conservation success stories and find ways to apply them to find solutions for communities and species still at risk. I am motivated more by interesting conservation problems, rather than taxa or community type. My Ph.D. research specifically focused on models to improve how green sea turtles, an US ESA threatened species, are monitored to increase the accuracy of population assessments. My future research foci include extending my Monitoring Strategy Evaluation tool (MoSE) to include spatial dynamics, and to apply the modeling framework to other species, particularly those with limited detection or difficulty in effective monitoring. Overall, I plan to evaluate spatio-temporal variability in life history traits of recovering marine species, and to continue developing tools for prospective evaluation of marine spatial planning.
Projects
Quantitative Tools for Monitoring Strategy Evaluation and Assessment of Sea Turtle Populations
Green sea turtles, Chelonia mydas, have endangered and threatened populations globally, but several populations show signs of population recovery. Nesting female green turtles in Hawaii have increased since 1973, but wide fluctuations in nesting females make recovery diagnosis difficult. Using sea turtle nesting beach surveys as a population index for assessment is problematic, yet often pragmatic because this is the only population index that is easily accessible. An advantageous modelling approach would be one that estimates inter-annual variability in life history traits, accounts for uncertainty from individual-level variability, and allows for population dynamics to emerge from individual behaviors. To this end, I analyzed a long-term data set of marked green sea turtles to determine the degree of temporal variability in key life history traits. From this analysis, I built the Green Sea Turtle Agent-Based Model (GSTABM) to form the basis of a new assessment tool – Monitoring Strategy Evaluation (MoSE). Altogether, my research suggests certain life history traits of green sea turtles have important temporal variation that should be accounted for in population models and may be useful indicators of population-level change. Importantly, basing population assessments from nesting beach data alone is likely to result in incorrect or biased estimates of status indicators. The quantitative tools I developed can be applied to other sea turtle populations and will improve monitoring, and result in better estimates of current population trends that enhance conservation planning for all species of sea turtles.
Future work will include extending the GSTABM to include a spatial dimension, and to ascertaining which demographic indicators are the most valuable for population assessment accuracy. I will also expand the MoSE tool to be easily adaptable to other marine species, particularly those species where monitoring is limited or problematic. Ultimately, this will result in a freely available software program with a guided user interface (i.e. requires no coding knowledge) to biologists to enter ecological and management parameters to determine optimal monitoring strategies specific to the population.
Future work will include extending the GSTABM to include a spatial dimension, and to ascertaining which demographic indicators are the most valuable for population assessment accuracy. I will also expand the MoSE tool to be easily adaptable to other marine species, particularly those species where monitoring is limited or problematic. Ultimately, this will result in a freely available software program with a guided user interface (i.e. requires no coding knowledge) to biologists to enter ecological and management parameters to determine optimal monitoring strategies specific to the population.
The current and potential contribution of manmade reef habitats to fisheries
resources and protected species recovery in southern California
For my postdoctoral research, I am working with the Vantuna Research Group to (1) evaluate the current state of reefs in the Southern California Bight (SCB), including natural and manmade reefs, (2) Identify characteristics of high quality reef habitat, and (3) Identify high quality locations for manmade reefing projects to enhance and host fisheries important and protected species. Stay tuned for more information as this project proceeds! I'm in collaboration with Drs. Dan Pondella, Jeremy Claisse, and Amanda Zellmer of the Vantuna Research Group.
Spatiotemporal Patterns of Benthic Biodiversity in the California Current
During my PhD, I was also the Graduate Student Lead on an analysis project as part of the multi-institutional NSF-funded Dimensions of BioDiversity Graduate Seminar (DBDGS; http://grantome.com/grant/NSF/DEB-1050680). This research was a collaborative effort among 14 graduate students and one faculty advisor, across three colleges at Oregon State University. We used data from the US West Coast Groundfish Bottom Trawl Survey (WCGBTS) and worked with NOAA Northwest Fisheries Science Center (NWFSC) biologists responsible for conducting those surveys.
Using a variety of spatial analysis tools and multi-variate statistics, we characterized the spatiotemporal patterns of benthic biodiversity along the US West Coast and created an approach to test if biodiversity hotspots are consistent over time. First, we found that benthic biodiversity did not strictly adhere to the latitudinal gradient, and patterns of diversity depended on taxa (fish vs. invertebrates), latitude, depth, substrate, and year. Next, we adapted an existing tool to objectively identify biodiversity hotspots and assess the consistency of hotspots over time (rather than the more common approach of combining surveys across all years). We created a novel approach to deal with decision points for hotspot definition and new methodological steps to prepare our dataset for the analysis. Unexpectedly, we found no areas containing consistently high biodiversity through the entire study period based on the mean thresholds, and no grid cell was designated as a hotspot for greater than 50% of the time. Our finding of low temporal consistency in benthic fish biodiversity hotspots was upheld, regardless of biodiversity metric used, whether thresholds were calculated per year or across all years, or the spatial extent for which we calculated thresholds and identified hotspots. Given that ecological communities are responding to a changing climate and other environmental perturbations, our work highlights the need for scientists and conservation managers to consider both spatial and temporal dynamics when designating biodiversity hotspots.
This research has many future directions I would like to pursue. Application of the biodiversity hotspots consistency tool to other large marine ecosystems and taxa may show a similar lack of temporal consistency, or reveal consistency in diversity patterns that can identify critical areas for conservation. We used data from soft bottom communities in the Eastern Pacific (WCGBTS) that can be highly variable, and perhaps, rocky substrate communities or coral reef communities have more stability in spatial patterns of biodiversity. Using additional data from other large marine ecosystems, and including additional biodiversity indices (i.e. functional or phylogenetic diversity) may be helpful in elucidating placement and even timing (e.g. closures to protect temporary mating aggregations or recruitment booms) of marine protected areas. The hotspot consistency evaluation tool has the potential to greatly impact how marine spatial planning proceeds.
Using a variety of spatial analysis tools and multi-variate statistics, we characterized the spatiotemporal patterns of benthic biodiversity along the US West Coast and created an approach to test if biodiversity hotspots are consistent over time. First, we found that benthic biodiversity did not strictly adhere to the latitudinal gradient, and patterns of diversity depended on taxa (fish vs. invertebrates), latitude, depth, substrate, and year. Next, we adapted an existing tool to objectively identify biodiversity hotspots and assess the consistency of hotspots over time (rather than the more common approach of combining surveys across all years). We created a novel approach to deal with decision points for hotspot definition and new methodological steps to prepare our dataset for the analysis. Unexpectedly, we found no areas containing consistently high biodiversity through the entire study period based on the mean thresholds, and no grid cell was designated as a hotspot for greater than 50% of the time. Our finding of low temporal consistency in benthic fish biodiversity hotspots was upheld, regardless of biodiversity metric used, whether thresholds were calculated per year or across all years, or the spatial extent for which we calculated thresholds and identified hotspots. Given that ecological communities are responding to a changing climate and other environmental perturbations, our work highlights the need for scientists and conservation managers to consider both spatial and temporal dynamics when designating biodiversity hotspots.
This research has many future directions I would like to pursue. Application of the biodiversity hotspots consistency tool to other large marine ecosystems and taxa may show a similar lack of temporal consistency, or reveal consistency in diversity patterns that can identify critical areas for conservation. We used data from soft bottom communities in the Eastern Pacific (WCGBTS) that can be highly variable, and perhaps, rocky substrate communities or coral reef communities have more stability in spatial patterns of biodiversity. Using additional data from other large marine ecosystems, and including additional biodiversity indices (i.e. functional or phylogenetic diversity) may be helpful in elucidating placement and even timing (e.g. closures to protect temporary mating aggregations or recruitment booms) of marine protected areas. The hotspot consistency evaluation tool has the potential to greatly impact how marine spatial planning proceeds.
Taking Stock of Oregon’s nearshore fisheries: development of simple assessment tools for better
Management
During my Ph.D., I also participated in a working group to conduct population assessments on data-poor nearshore species in Oregon. This work was supported by an Oregon Sea Grant, and consisted of five graduate students, and two undergraduate students, and one faculty advisor. Scientifically sound and transparent evaluation of the status of Oregon’s nearshore fisheries resources is essential for effective management. Recent advances in assessment techniques for data-poor species could allow the harvest caps set by the Oregon Department of Fish and Wildlife (ODFW) to reflect a true local assessment process by working with the available data, and therefore within limited budget constraints. To this end, we performed gap and productivity-susceptibility analyses, and data-poor assessments using data specific to Oregon on several nearshore species. We were able to rank nearshore species on the amount of data available to conduct regional assessments and performed complete population assessments on Black Rockfish, a data moderate species, and partial assessments on several other data-poor species. In addition, we conducted a Stock Assessment 101 workshop geared at making stock assessment process and data poor methods more comprehensible and transparent to stakeholders, such as local fishers. ODFW biologists and managers benefited from this analysis by having a better understanding of the data available for nearshore species, and how stock assessments for data-poor nearshore species can be applied at a smaller geographic scale. In the future, I would like to pursue developing and applying data-poor assessment methods for fisheries in Florida and the Caribbean, where data tends to be extremely limited, to support sustainable harvest.