Words are monuments: Patterns in US national park place names perpetuate settler colonial mythologies including white supremacy

1. Ecologists, outdoor professionals and the public work and play in lands with complex histories. Part of decolonizing our professional and recreational practices is to expose settler colonial biases and recognize the histories of colonized lands and the peoples who have stewarded these lands for millennia prior to colonization. 2. To provide a quantitative example of settler colonial biases in a familiar context, we examined the origins of over 2,200 place names in 16 national parks in the United States (US; 26% of the parks). Through iterative thematic analysis of place name origins and meanings, we constructed a decision tree for classifying place names according to emergent categories, which enabled the quantification and spatial analysis of place name meanings. 3. All national parks examined have place names that tacitly endorse racist or, more specifically, anti-Indigenous ideologies, thus perpetuating settler colonialism and white supremacy at the system scale for future generations. 4. Looking east to west across the US, the proportion of place names per national park that appropriated Indigenous names increased in parallel with the westward expansion and evolution of US settler colonialism. 5. This examination of place names, name origins and their consequences is an opportunity to make everyday complicity in systemic oppression more visible and to more actively advance decolonizing practices for land and language

Patterns and Variation in Benthic Biodiversity in a Large Marine Ecosystem

While there is a persistent inverse relationship between latitude and species diversity across many taxa and ecosystems, deviations from this norm offer an opportunity to understand the conditions that contribute to large-scale diversity patterns. Marine systems, in particular, provide such an opportunity, as marine diversity does not always follow a strict latitudinal gradient, perhaps because several hypothesized drivers of the latitudinal diversity gradient are uncorrelated in marine systems. We used a large scale public monitoring dataset collected over an eight year period to examine benthic marine faunal biodiversity patterns for the continental shelf (55–183 m depth) and slope habitats (184–1280 m depth) off the US West Coast (47°20′N—32°40′N). We specifically asked whether marine biodiversity followed a strict latitudinal gradient, and if these latitudinal patterns varied across depth, in different benthic substrates, and over ecological time scales. Further, we subdivided our study area into three smaller regions to test whether coast-wide patterns of biodiversity held at regional scales, where local oceanographic processes tend to influence community structure and function. Overall, we found complex patterns of biodiversity on both the coast-wide and regional scales that differed by taxonomic group. Importantly, marine biodiversity was not always highest at low latitudes. We found that latitude, depth, substrate, and year were all important descriptors of fish and invertebrate diversity. Invertebrate richness and taxonomic diversity were highest at high latitudes and in deeper waters. Fish richness also increased with latitude, but exhibited a hump-shaped relationship with depth, increasing with depth up to the continental shelf break, ~200 m depth, and then decreasing in deeper waters. We found relationships between fish taxonomic and functional diversity and latitude, depth, substrate, and time at the regional scale, but not at the coast-wide scale, suggesting that coast-wide patterns can obscure important correlates at smaller scales. Our study provides insight into complex diversity patterns of the deep water soft substrate benthic ecosystems off the US West Coast

Evaluating Temporal Consistency in Marine Biodiversity Hotspots

With the ongoing crisis of biodiversity loss and limited resources for conservation, the concept of biodiversity hotspots has been useful in determining conservation priority areas. However, there has been limited research into how temporal variability in biodiversity may influence conservation area prioritization. To address this information gap, we present an approach to evaluate the temporal consistency of biodiversity hotspots in large marine ecosystems. Using a large scale, public monitoring dataset collected over an eight year period off the US Pacific Coast, we developed a methodological approach for avoiding biases associated with hotspot delineation. We aggregated benthic fish species data from research trawls and calculated mean hotspot thresholds for fish species richness and Shannon’s diversity indices over the eight year dataset. We used a spatial frequency distribution method to assign hotspot designations to the grid cells annually. 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-series. To test if our approach was sensitive to sampling effort and the geographic extent of the survey, we followed a similar routine for the northern region of the survey area. Our finding of low consistency in benthic fish biodiversity hotspots over time 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. Our results suggest that static measures of benthic fish biodiversity off the US West Coast are insufficient for identification of hotspots and that long-term data are required to appropriately identify patterns of high temporal variability in biodiversity for these highly mobile taxa. 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

Effects of Predator Introductions on Population and Community Dynamics

There is increasing awareness that human activities are altering the ways that natural systems operate and that local shifts in species composition and abundance can lead to abrupt and irreversible global change. Therefore, understanding the processes that buffer biological communities from critical shifts and how our actions affect natural stabilizing feedbacks are important goals of ecology. One human activity with far reaching consequences for global ecosystems is the introduction of exotic species outside of their native ranges. Introduced predators, whose effects may be exacerbated by lack of shared evolutionary history with native prey, can have particularly strong effects on recipient communities. As trophic interactions play a central role in both population regulation and community persistence, it is essential to determine the extent to which introduction of novel predators can alter the function of stabilizing mechanisms. The goals of this dissertation were to use a combination of manipulative field experiments and theoretical modeling to explore how introduced predators influence invaded communities through their effects on the processes that naturally maintain bounded prey population dynamics and promote community coexistence. Density-dependent predation can regulate prey populations by providing a negative feedback in response to changes in population size. In my first experiment (Chapter 2), I investigated the effects of invasive Indo-Pacific red lionfish (Pterois volitans) on density-dependent mortality patterns previously documented to regulate a common native Atlantic prey species, the fairy basslet (Gramma loreto) on coral reefs in the Bahamas. By repeating a pre-invasion density-manipulation experiment, now in the context of predation by both native piscivores and lionfish, I demonstrated that per capita loss of fairy basslet remained density-dependent in the presence of lionfish, but the overall magnitude of loss was substantially greater compared to pre-invasion rates. Per capita loss was higher in 13 out of 16 basslet populations with an average increase of over 60% in the presence of the invader. The before-and-after design provided no evidence for a change in the intensity of density dependence between experiments, indicating the addition of destabilizing density-independent mortality caused by lionfish. In my second experiment (Chapter 3), I employed a split-plot, cross-factored experimental design, manipulating both fairy basslet density and lionfish presence absence such that differences in per capita loss rates were attributable only to predation by the invader. Over four weeks, mortality of fairy basslet was far greater on lionfish reefs compared to reefs with only native predators, displaying 2.4 times higher net loss on recruitment-enhanced fairy basslet populations and a five-fold increase in net loss at unmanipulated prey populations. Per capita loss was density-dependent in both predator treatments, but high mortality rates at low prey density on lionfish reefs resulted in extirpation of 15% of unmanipulated fairy basslet populations. In contrast, no prey populations were extirpated on reefs with only native predators. In addition to field experiments, this dissertation includes a theoretical model (Chapter 4) that explored the effects of predator novelty on the coexistence of an intraguild predation web with adaptive antipredator defense in the shared prey. Adaptive prey responses can promote multi-predator coexistence by creating a stabilizing tradeoff in the allocation of predator-specific defense effort. Yet to date, all such theory has assumed that prey have accurate perception of predation risk and appropriate antipredator responses, assumptions that may not be justified when considering a novel predator. The model showed that the parameter region of IGP coexistence is dramatically reduced by an exotic predator but that effects of novelty on community persistence are complex and context-dependent. Specifically, the model predicts that predator novelty can weaken the effect of adaptive defense, causing exclusion of native predators that would persist in the absence of novelty. Coexistence is predicted to be more sensitive to the effects of suboptimal defense compared to naïveté and differentially leads to exclusion of native predators in highly productive environments and when defense costs are low. Moderate novelty of the omnivore can increase resource density via a trophic cascade, while consumer novelty can either lead to omnivore exclusion or facilitate three-species coexistence by providing a subsidy to the otherwise excluded native omnivore. The results suggest that models of adaptive defense are sensitive to assumptions regarding predator-prey eco-evolutionary experience and that predator novelty has significant implications for food web dynamics. Overall, the research described in this dissertation illuminates the mechanisms by which introduced predators can disrupt the boundedness and persistence of otherwise stable systems and provides insight into how predator novelty can alter biological communities via novel trophic and non-trophic interactions. As natural systems across the globe face multiple stressors that can alter their functioning, it is increasingly vital to understand the stabilizing mechanisms that buffer these systems from change, and how species introductions may modify the capacity for communities to respond to natural and human-caused disturbance

Ocean recoveries for tomorrow's Earth: Hitting a moving target.

Growing scientific awareness, strong regulations, and effective management have begun to fulfill the promise of recovery in the ocean. However, many efforts toward ocean recovery remain unsuccessful, in part because marine ecosystems and the human societies that depend upon them are constantly changing. Furthermore, recovery efforts are embedded in marine social-ecological systems where large-scale dynamics can inhibit recovery. We argue that the ways forward are to (i) rethink an inclusive definition of recovery that embraces a diversity of stakeholder perspectives about acceptable recovery goals and ecosystem outcomes; (ii) encourage research that enables anticipation of feasible recovery states and identifies pathways toward resilient ecosystems; and (iii) adopt policies that are sufficiently nimble to keep pace with rapid change and governance that works seamlessly from local to regional scales. Application of these principles can facilitate successful recoveries in a world where environmental conditions and social imperatives are constantly shifting

Record of lionfish sighted near Eleuthera, Bahamas during reef surveys in 2012 (Lionfish Invasion project)

Dataset: lionfish sightings EleutheraThis dataset includes dates, locations, and estimated length of lionfish (Pterois volitans) that were sighted near Eleuthera, Bahamas during the summer of 2012. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/3969NSF Division of Ocean Sciences (NSF OCE) OCE-085116

Record of lionfish collected near Eleuthera, Bahamas during reef surveys in 2012 (Lionfish Invasion project)

Dataset: lionfish collections EleutheraThis dataset includes dates, locations, and biological information (e.g. length) of lionfish (Pterois volitans) that were handled (collected) near Eleuthera, Bahamas during the summer of 2012. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/3968NSF Division of Ocean Sciences (NSF OCE) OCE-085116

Is the Lionfish Invasion Waning? Evidence from The Bahamas

Indo-Pacific lionfishes (Pterois volitans/miles) have undergone rapid population growth and reached extremely high densities in parts of the invaded Atlantic. However, their long-term population trends in areas without active management programs are unknown. Since 2005, we have monitored lionfish abundance in the Exuma Cays of the central Bahamas on 64 reefs ranging in size from 1 to 4000 m2. Lionfish densities increased from the first sighting in 2005 through 2009, leveled off between 2010 and 2011, and then began to decrease. By 2015, densities had noticeably declined on most of these reefs, despite a lack of culling or fishing efforts in this part of The Bahamas. There was no consistent change in lionfish size structure through time. We discuss possible causes of the decline, including reductions in larval supply or survival, hurricanes, interactions with native species, and intraspecific interactions. Further studies are required to determine whether the declines will persist. In the meantime, we recommend that managers continue efforts to control invasive lionfish abundances locally