<p> This study provides the first assessment of demographic and habitat information for pinto abalone (<i>Haliotis kamtschatkana</i>) in San Diego, California, two decades after the closure of all abalone fisheries in southern California. SCUBA surveys conducted from June 2014 to December 2016 indicate that current low densities (0-0.03 individuals/m²) were far below critical thresholds identified for other abalone species (0.15-0.30 abalone/m²) for successful spawning and recruitment. A broad range of sizes were represented (13-146 mm), however, only 95 individuals were found. Some sites showed significant aggregation of adult (> 50 mm) pinto abalone, 30% of adults had a nearest-neighbor within a critical spawning distance of 2 m, and 65% had a neighbor within 5 m, indicating that at least a small proportion of individuals may be capable of reproducing successfully. Pinto abalone showed a significant preference for boulder habitat at a lower relief (&lt; 10 cm) relative to available habitat&ndash; a preference that may influence aggregation around habitat features and enhance reproduction. The frequency, timing, and broad spatial distribution of these surveys was not sufficient to measure patterns in recruitment or changes in abundance, particularly over a strong El Ni&ntilde;o event that occurred during the study period. There is a critical need for consistent long-term monitoring in southern California to better understand demographic and environmental processes affecting recovery and persistence of populations, particularly at the southern edge of the broad range of pinto abalone.</p><p>

<p> Reliable estimates of species abundance, distribution, and population trajectories are critical in conservation and management. However, for many tropical species that information is missing. We conducted Sharp-shinned Hawk (SSHA) searches during the breeding seasons of 2013, 2014, and 2016 in eight montane forest reserves and their adjacent private lands of Puerto Rico. Further, we developed a maximum entropy model (MaxEnt) of the SSHA&rsquo;s potential distribution using the following environmental variables: aspect, canopy closure, elevation, rainfall, slope, and terrain roughness. Elevation accounted for 89.8% of model fit, predicting the greatest probability of occurrence (> 60%) at elevations above 900 m. The model estimated 0.6%Puerto Rico (56.1 km²) has the greatest probability of occurrence. We developed a periodic population matrix model to describe the influence of early life stages on population growth of the Red-tailed Hawk (RTHA) in eastern Puerto Rico. Our results suggest that the RTHA population has an average annual population increase of 5%, with rates differing between highlands (&lambda;_h = 1.05) and 27% lowlands (&lambda;_l = 1.27). Adult survival was the most important population growth parameter, with more effect in highlands (elasticity = 0.86) than in lowlands (elasticity = 0.53). Sensitivity of &lambda; to changes in nestling survival was greater than for other life-stages (sensitivity lowlands = 0.46, sensitivity highlands = 0.48). I developed an open population N-mixture model to estimate abundance, availability, and detection probability of RTHA in the Luquillo Mountains and western Cordillera Central. The abundance estimates were 0.05 RTHA/ha, with an availability of (&phis;) = ~1 RTHA/per survey point and a detection probability (r) = ~0.25. In Luquillo Mountains, abundance was positively influenced by slope and elevation. In the western Cordillera Central, abundance of RTHA was constant across elevation, slope, and canopy closure. Detection probability decreased with increasing slope and wind conditions and showed a gradual small negative decrease with slope with reduced winds conditions. My findings are a contribution to our knowledge of how population traits and ecological constraints imposed by insular environments are influencing distribution, abundance, and population dynamics of raptors to propose management or conservation schemes.</p><p>

abstract: Small-scale fisheries are globally ubiquitous, employing more than 99% of the world’s fishers and providing over half of the world’s seafood. However, small-scale fisheries face many management challenges including declining catches, inadequate resources and infrastructure, and overcapacity. Baja California Sur, Mexico (BCS) is a region with diverse small-scale fisheries; these fisheries are intense, poorly regulated, and overlap with foraging hot spots of endangered sea turtles. In partnership with researchers, fishers, managers, and practitioners from Mexico and the United States, I documented bycatch rates of loggerhead turtles at BCS that represent the highest known megafauna bycatch rates worldwide. Concurrently, I conducted a literature review that determined gear modifications were generally more successful than other commonly used fisheries management strategies for mitigating bycatch of vulnerable megafauna including seabirds, marine mammals, and sea turtles. I then applied these results by partnering with researchers, local fishers, and Mexico’s federal fisheries science agency to develop and test two gear modifications (i.e. buoyless and illuminated nets) in operating net fisheries at BCS as potential solutions to reduce bycatch of endangered sea turtles, improve fisheries sustainability, and maintain fisher livelihoods. I found that buoyless nets significantly reduced mean turtle bycatch rates by 68% while maintaining target catch rates and composition. By contrast, illuminated nets did not significantly reduce turtle bycatch rates across day-night periods, although they reduced mean turtle bycatch rates by 50% at night. Illuminated nets, however, significantly reduced mean rates of total bycatch biomass by 34% across day-night periods while maintaining target fish catch and market value. I conclude with a policy analysis of the unilateral identification of Mexico by the U.S. State Department under section 610 of the Magnusson-Stevens Fishery Conservation and Management Act for failure to manage bycatch of loggerhead turtles at BCS. Taken together, the gear modifications developed and tested here represent promising bycatch mitigation solutions with strong potential for commercial adoption, but fleet-wide conversion to more selective and turtle-friendly gear (e.g. hook and line and/or traps) at BCS, coupled with coordinated international conservation action, is ultimately needed to eliminate sea turtle bycatch and further improve fisheries sustainability. / Dissertation/Thesis / Doctoral Dissertation Biology 2015

<p> Mammalian carnivores are a vital component of many ecosystems and can be particularly sensitive to human disturbance, even within protected areas (PAs). Our objective was to understand how human disturbance affects carnivore communities in southern Arizona, U.S.A., by studying habitat occupancy based on data collected using non-invasive methods in three PAs with different levels of human disturbance. We examined the impacts of human disturbance variables and disturbance level on carnivore occupancy, co-occurrence, temporal activity, and habitat associations. Carnivore occupancy varied based on human disturbance variables (i.e., roads, trails, etc.). Edges of PAs appeared to negatively impact occupancy of nearly all carnivore species. We also found that the presence of roads and trails, and not necessarily how much they are used, had a significant negative impact on the occupancy of most carnivore species. Furthermore, the overall level of disturbance within a PA influenced how sensitive carnivores were to human disturbance variables. Carnivores were more sensitive in PAs with higher levels of disturbance and were relatively unaffected by disturbance variables in a PA with low base levels of disturbance. In areas with low levels of disturbance, we found that many carnivore species have lower than expected levels of co-occurrence, which suggests spatial partitioning. As disturbance within an area increased, spatial partitioning became less prominent, and carnivores exhibited higher levels of temporal partitioning within these areas. We found that habitat associations varied among carnivore species, and associations were often different across different scales. We also found evidence of different habitat preferences in protected areas with higher levels of disturbance (e.g., avoidance of water sources). Information on the impacts of human disturbance is important when developing conservation plans, which is especially true for protected areas, given their important role in carnivore conservation, particularly as they are experiencing ever increasing rates of visitation.</p><p>

South Africa is one of the driest countries in the world and rivers and dams are the main source of water. The continuous pollution of the rivers and streams as well as the growing demand for water has led to stringent environmental regulations to limit the consumption of water as well as to set the acceptable contamination levels of water before it is discharged to the main water cycle. Various techniques have been used to address the issue of the usage and contamination of water in industry. In recent years, Pinch Analysis has been extended to cooling water systems design following its success in heat exchanger networks (HENs) and mass exchanger networks (MENs). The most significant work on cooling water network design was developed by Kim and Smith (2001) where a graphical methodology for designing cooling water systems was developed. Research on cooling water networks was necessitated by the need to optimize the amount of cooling water used in process industries. It is always important to conserve water as well as reduce the amount of contaminated water that is discharged to the main sources of water. In this study, the consumption of water and effluent reduction opportunities in a nitric acid production plant at African Explosives Limited (AEL), Modderfontein, South Africa, was investigated. This investigation led to the development of a cooling water network design technique for systems with multiple cooling water sources. The results from this analysis have shown that there is potential to reduce the blowdown by 47%. Moreover, the cooling water used in the cooling water network could be reduced by 23% and freshwater makeup by 10%. / Dissertation (MEng (Chemical Engineering))--University of Pretoria, 2007. / Chemical Engineering / MEng / unrestricted

<p>Billions of dollars have been invested in land protection as a strategy to conserve biodiversity based on the assumption that protected areas buffer species from processes that drive extinction. Increasingly, protected area expansion and connectivity are being incorporated into climate change adaptation strategies to facilitate anticipated shifts in species ranges in response to predicted changes in temperature and precipitation. However, the effectiveness of protected areas at maintaining biodiversity, either by reducing the risk of extinction or facilitating colonization into new areas, has not been well established. In addition, the growing reliance on multiple-use protected areas that allow resource extraction, such as timber harvest and mineral mining, has raised questions about whether multiple-use protected areas are equally beneficial for long-term biodiversity conservation as more strictly protected areas that limit active resource management. In order to address these questions using repeated Breeding Bird Atlas data, I first had to confront the limitations of existing approaches to account for imperfect detection by developing a novel modelling approach to addresses the gap between requirements of other multi-season occupancy models (i.e. repeated sampling) and existing datasets. I then applied that single-visit dynamic occupancy modelling approach to Atlas data in New York and Pennsylvania for 97 species to quantify drivers of colonization and extinction while accounting for imperfect detection in landscapes that varied by type and amount of land cover and area under protection. In general, protected areas increased colonization and lowered extinction probabilities to an increasing degree as both forest cover and neighborhood protection decreased, with particular benefits for forest breeding birds. Both strict and multiple-use protected areas increased colonization and reduced extinction more for mature forest species than early forest species, with the greatest benefits accruing when forest cover was relatively low. These results provided the most comprehensive evidence to date that protected areas can facilitate species persistence by both reducing the risk of extinction and providing attractive colonization sites as species? ranges shift and that biodiversity conservation can be compatible with renewable resource extraction.

Understanding the processes and mechanisms governing animal movement is a fundamental goal in ecology. Processes driving movement can occur across multiple spatiotemporal scales and have important consequences for the structure and dynamics of populations, communities and ecosystems. The study of movement provides insights into the ecological resources and habitats necessary for persistence of species and communities. It also provides a theoretical and applied basis from which to formulate informed conservation plans. Waterbirds in semiarid southern Africa are an ideal study group for understanding interactions between movement and environmental factors because they exhibit a wide range of movement strategies and are located within a landscape in which resources are characterised by high levels of spatiotemporal variability. Emphasis has been placed on understanding movement phenomena from individually-tracked animals, but cases which consider this approach in conjunction with traditional community ecology perspectives are rare. In this thesis I explored questions of movement in both individuals and communities, and argue that an integrated multi-scale approach is necessary to advance our broader understanding of movement in waterbirds. In the first part of the study I addressed an individual-level movement perspective. I used fine-scale telemetry data from 35 individually tracked Egyptian Geese Alopochenaegyptiaca and Red-billed Teal Anas erythrorhyncha with novel analytical techniques to explore questions of trade-offs in habitat selection, functional responses and whether movement responses to landscape resources are reactive or prescient. My findings suggested that, at the home-range scale, both forage optimisation and predation risk were limiting factors of movement and habitat selection of Egyptian Geese. I also showed for the first time that waterbirds exhibit functional responses in relation to changes in the availability of habitat types. I subsequently showed that the proximate drivers of waterfowl movement are the dynamics of rainfall and primary productivity. Egyptian Geese and Red-billed Teal were able to perceive and respond to temporal shifts in resource conditions prior to habitat patch occupation. This in turn suggested that their movements in semi-arid landscapes are underpinned by an intimate knowledge of the local environment and that waterfowl exhibit a complex behavioural movement strategy. In the second part of the study I used waterbird count data collected from wetlands in KwaZulu-Natal, South Africa, to address the community-level movement perspective.

Montane forests provide habitat for unique assemblages of flora and fauna that contribute significantly to a region's biodiversity. Previous work indicates that montane forest ecosystems are exceedingly vulnerable to a host of anthropogenic stressors including climate change, atmospheric deposition, and recreation, to name a few. Montane forests and other high elevation ecosystems are considered to be among the first and most severely impacted by climate change. It is therefore, imperative to evaluate anthropogenic impacts on montane ecosystems and maintain reliable monitoring methods that are capable of tracking potential shifts in the distribution of species dependent on these systems. I surveyed birds at various distances from hiking trails in the White Mountain National Forest from 2006–2009 to determine whether existing monitoring programs, all of which are based on trail-centered surveys, are accurately reflecting bird abundance, abundance stability and recruitment. Contrary to previous studies, I found that recreational trails generally did not alter estimates of abundance, recruitment, abundance stability, and detection probability for five species of birds considered to be indicators of montane forest ecosystem integrity in northeastern North America. Therefore, trail-based monitoring programs for montane birds appear to accurately reflect dynamics of bird communities undisturbed by hiking trails. These conclusions were supported by my finding that the daily nest survival of a montane spruce-fir indicator species, blackpoll warbler (Steophaga striata), did not vary as a function of distance from trail. I then used data from the White Mountain National Forest's montane bird monitoring program from 1994 through 2009 to assess potential shifts in the elevational distribution of montane birds in conjunction with documented habitat shifts in the region. My results provide evidence that low elevation forest birds have expanded their upper elevational boundary while high elevation birds have expanded their lower elevation boundary. These results highlight the complicated relationship between habitat, climate, and other anthropogenic stressors such as atmospheric deposition and that even in the face of climate change other stressors may be playing a significant role in shifts of species distributions. Understanding how climate affects the reproductive ecology of montane organisms is an important step toward unraveling the potential mechanisms by which climate change will alter the distribution of these species. I used blackpoll warbler breeding data from the Green Mountains, VT from 1994 to 2003 to determine if temporal variation in climate influenced blackpoll nesting initiation and found that years with warm Mays and typical precipitation lead to earlier nest initiation. I also examined the effect of spatial variation in climate on blackpoll reproductive ecology and demography. I found a gradient in habitat quality associated with the spatial variation in climate along an elevation gradient. Blackpolls were less abundant, younger, had lower pairing success, lower daily nest survival, higher nest predator occupancy, and lower fecundity at lower elevations. The climatic conditions at these lower elevations represent the climatic conditions predicted to encompass increasingly larger portions of montane areas. Collectively, these findings contribute to filling in a dearth of knowledge regarding management and an understanding of how species dependent on montane ecosystems are responding to climate change.

The eastern spadefoot (Scaphiopus holbrookii) is an ephemeral wetland breeding amphibian that ranges from southern Florida north and westward to southeastern Missouri and northward along the Atlantic coastal plain to Massachusetts. This species is listed as either "threatened" or "endangered" in the four states (Connecticut, Massachusetts, New York, and Rhode Island) in the northeastern United States where it is known to exist. Population declines and extirpations throughout the region over the past century have been documented and are largely believed to be the result of habitat loss and/or alteration. Very limited empirical results exist on many life history attributes of S. holbrookii anywhere in its range, including movement patterns, upland habitat selection, and breeding habitat preferences. These are critical information gaps that must be filled in order to effectively conserve and manage for this rare species in the northeastern U.S. While S. holbrookii is extremely rare throughout most of the Northeast, it is locally common in specific areas of Cape Cod National Seashore, most notably in an extensive sand-dune ecosystem known as the Province Lands located at the northern terminus of the Cape Cod peninsula. During 2005 and 2006, we conducted larval trapping surveys at 102 wetlands in the Province Lands primarily to: 1) identify breeding wetlands and 2) to assess breeding habitat use and preferences of S. holbrookii with respect to a suite of selected abiotic and biotic covariates. We captured S. holbrookii larvae at 140/652 (~21.5%) trap locations and 41/102 (~40.2%) wetlands sampled. Model results identified a number of additional habitat covariates that exhibited a statistically significant relationship with larval S. holbrookii abundance including: the percent cover of 1) cranberry (positive relationship), and 2) woody shrub (positive relationship) at a 4m radius from the trap location; 3) percent woody shrub cover at the wetland-scale (negative relationship); 4) percent canopy cover at the wetland-scale (positive relationship); 5) wetland pH (positive relationship); 6) distance to the closest paved road (positive relationship); and the kernel density cover of 7) deciduous shrubland edge (positive relationship), 8) deciduous shrubland (negative relationship), 9) pine (positive relationship), and 10) open dune (positive relationship) in the uplands surrounding the study wetlands. During 2006 and 2008 we radio-tracked adult S. holbrookii in the Province Lands using surgically implanted radio-transmitters to: 1) describe movement patterns and estimate home range sizes, and 2) assess upland habitat preferences of S. holbrookii. We tracked 19/20 individuals (11 males and 8 females) and 12/20 individuals (7 males and 5 females) for at least the first 30 and 100 days post-surgery, respectively, during 2006. During 2008 we successfully tracked 15/25 individuals (10 males and 5 females) and 5/25 individuals (3 males and 2 females) for at least the first 30 and 100 days post-surgery, respectively. In addition to results obtained on a suite of movement attributes we identified a number of upland habitat preferences for S. holbrookii. Use locations were: 1) closer to the nearest deciduous shrub edge, 2) had a greater percent cover of ground-running pitch pine branches at a 1 m scale, 3) had a greater percent cover of deciduous shrubs at a 1 m scale, and 4) had a greater percent cover of reindeer lichen at a 5 m scale. Results from this research provide much needed empirical results on these critical life history attributes related to the movement and breeding ecology of S. holbrookii. These results will aid biologists and Park management staff at Cape Cod National Seashore in more effectively employing conservation and management strategies aimed at enhancing the long-term persistence probability of this regionally rare species in the Province Lands.

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