Energetic Consequences for a Northern, Range-Edge Lizard Population

Lizards at the northern, cool edge of their geographic range in the northern hemisphere should encounter environmental conditions that differ from those living near the core of their range. To better understand how modest climate differences affect lizard energetics, we compared daily feeding and metabolism rates of individual Sceloporus occidentalis in two populations during mid-summer. Chuckanut Beach (CB) was a cool, maritime climate in northern Washington State, and Sondino Ranch (SR) was a warmer, drier climate in southern, inland Washington. We found no difference between populations in daily energy expenditure (DEE), as calculated from doubly labeled water estimates. The CB population, however, had significantly higher prey availability and rate of daily energy intake (DEI) as estimated from fecal pellet masses. Consequently, CB lizards had higher size-adjusted body masses than lizards from SR. Within CB, during midsummer, DEE was similar to DEI. Within the SR population, DEE trended higher than DEI during midsummer, but was not significantly different. We found no population differences in lizard activity, active body temperature, or preferred body temperature. Hence, we infer the longer activity season for the SR population may compensate for the low food availability and high daily energy cost of midsummer. Moreover, for the CB population, we infer that cooler temperatures and higher food availability allow the lizards to compensate for the shorter activity. We also suggest the CB population may benefit from the predicted warmer temperatures associated with climate change given the similar activity-period body temperatures and DEE between these lizard populations assuming food availability is sufficient

Climate, Physiology, and Distributions: The Role of Thermal Physiology in Biological Invasions

Climate is a primary factor influencing species range dynamics, particularly for ectotherms whose body temperature is closely tied to the surrounding conditions. While range shifts of ectotherms are attributed to climate warming, the mechanism driving these shifts are not well understood. Studies in macrophysiology demonstrate that the interaction of climate with thermal physiology plays a key role in determining large-scale spatial and temporal patterns for many temperature-sensitive physiological traits. This work has revealed a clear relationship between thermal tolerance breadth and range size. However, more recent analyses of this relationship demonstrate that thermal tolerance breadth only provides a partial explanation for patterns in range size. Resting metabolism is a trait closely tied to energy balance, a key determinant of species distribution and abundance. At the whole-organism level, resting metabolism represents the energetic cost to fuel the maintenance of biological processes. Variation in this trait is related to climate and has a significant impact on how energy is allocated towards growth and reproduction. The aim of this dissertation was to understand the impact of climate on thermal physiology and species range dynamics using the Spongy moth (Lymantria dispar dispar) as a model system. The chapters of this dissertation addressed three primary questions: (Chapter 1) Do metabolic rate-temperature relationships (MR-T) vary across the invasive Spongy moth range and is that variation related to climate? (Chapter 2) How does MR-T vary with ontogeny? (Chapter 3) How does thermal performance at the cellular level compare to whole-organism performance? In the first chapter, we found that MR-T of third instar Spongy moth larvae showed significant variation among wild populations and this variation followed a latitudinal cline that was significantly related to climate variation. In the second chapter, larval MR-T showed significant variation across the first five instars of the larval stage. However, we found that the third instar was the most temperature-sensitive and showed the largest increase in metabolic rate after accounting for differences in body size among instars. In the third chapter, we found that whole-organism performance of metabolic rate and growth were mismatched at temperatures beyond the thermal optimum for growth and development of Spongy moth larvae. As temperature increased, metabolic rate continued to increase while growth rapidly declined. However, mitochondrial performance matched growth performance at these supraoptimal temperatures. Furthermore, this response of MR-T, growth, and mitochondrial performance was consistent across five Spongy moth populations. These results produced three primary conclusions. First, the latitudinal variation in whole-organism MR-T among Spongy moth populations was consistent with a pattern of thermal adaptation to divergent climates and suggests that Spongy moth populations have evolved in response to climate as they have spread and expanded their invasive range. Second, the thermal physiology of Spongy moth show significant variation during ontogeny. However, while MR-T does change with instar, our findings suggest it would not alter the conclusions of chapter 1 which is based on the third instar. Finally, the mismatch of MR-T with growth and mitochondrial performance follows the predictions made by the mitochondrial efficiency hypothesis which posits that changes in mitochondrial coupling efficiency is a key mechanism for reducing ectotherm performance. These provide strong evidence for a temperature-dependent link between mitochondria and whole-organism performance. The implications of these findings for the Spongy moth invasion, species range dynamics, and ectotherm performance are discussed further in each chapter

Offensive line coaches\u27 training manual

The purpose of this training manual is to provide the high school and college coach with a complete guide of the necessary fundamentals of offensive line play. [This is an excerpt from the abstract. For the complete abstract, please see the document.

Seasonal variability in ichthyoplankton abundance and assemblage composition in the northern Gulf of Mexico off Alabama

Multiyear ichthyoplankton surveys used to monitor larval fish seasonality, abundance, and assemblage structure can provide early indicators of regional ecosystem changes. Numerous ichthyoplankton surveys have been conducted in the northern Gulf of Mexico, but few have had high levels of temporal resolution and sample replication. In this study, ichthyoplankton samples were collected monthly (October 2004–October 2006) at a single station off the coast of Alabama as part of a long-term biological survey. Four seasonal periods were identified from observed and historic water temperatures, including a relatively long (June–October) “summer” period (water temperature >26°C). Fish egg abundance, total larval abundance, and larval taxonomic diversity were significantly related to water temperature (but not salinity), with peaks in the spring, spring–summer, and summer periods, respectively. Larvae collected during the survey represented 58 different families, of which engraulids, sciaenids, carangids, and clupeids were the most prominent. The most abundant taxa collected were unidentified engraulids (50%), sand seatrout (Cynoscion arenarius, 7.5%), Atlantic bumper (Chloroscombrus chrysurus, 5.4%), Atlantic croaker (Micropogonias undulatus, 4.4%), Gulf menhaden (Brevoortia patronus, 3.8%), and unidentified gobiids (3.6%). Larval concentrations for dominant taxa were highly variable between years, but the timing of seasonal occurrence for these taxa was relatively consistent. Documented increases in sea surface temperature on the Alabama shelf may have various implications for larval fish dynamics, as indicated by the presence of tropical larval forms (e.g., fistularids, labrids, scarids, and acanthurids) in our ichthyoplankton collections and in recent juvenile surveys of Alabama and northern Gulf of Mexico seagrass habitats

Compression and Relaxation of Fishing Effort in Response to Changes in Length of Fishing Season for Red Snapper (Lutjanus campechanus) in the Northern Gulf of Mexico

A standard method used by fisheries managers to decrease catch and effort is to shorten the length of a fishery; however, data on recreational angler response to this simple approach are surprisingly lacking. We assessed the effect of variable season length on daily fishing effort, measured by using numbers of boat launches per day, anglers per boat, and anglers per day from video observations, in the recreational sector of the federal fishery for red snapper (Lutjanus campechanus) in coastal Alabama. From 2012 through 2017, season length fluctuated from 3 to 40 d. Daily effort, measured by using mean number of boat launches per day (coefficient of multiple determination [R2]=0.58) and mean number of anglers per day (R2=0.67), increased linearly with season shortening, indicating effort compression. In 2017, 2 seasons were allowed: an early season (3 d) and an unanticipated late season (39 d). Daily effort decreased during the late season, indicating that effort can also be relaxed if anglers anticipate longer seasons. Model fit for mean number of anglers per day improved with the addition of a daily wind factor (R2=0.94). The results of this study indicate that responses of anglers to changing fishing seasons are dynamic

Estimates of Red Drum Mortality via Acoustic Telemetry

Subadult (age \u3c 3) Red Drum Sciaenops ocellatus support a valuable recreational fishery, and mortality estimates for young Red Drum are needed for proper management. To obtain these estimates, age-1 and age-2 Red Drum were implanted with acoustic transmitters and external Floy tags in two coastal Alabama rivers (Fowl and Dog rivers). Fates of tagged fish were inferred from stationary receiver detections and active relocations over 1 year. These fates were used in a Bayesian multistate model to estimate instantaneous monthly and annual mortality and emigration rates for each river and overall from both rivers. Instantaneous monthly fishing mortality (F) ranged from 0.001 to 0.112 (annual F = 0.414) in Dog River, from 0.001 to 0.126 in Fowl River (annual F = 0.309), and was 0.001–0.054 (annual F = 0.337) overall. Instantaneous monthly natural mortality (M) ranged from 0.001 to 0.002 (annual M= 0.069) in Dog River, from 0.001 to 0.036 (annual M= 0.178) in Fowl River, and from 0.001 to 0.017 (annual M= 0.090) overall. The overall annual estimate of instantaneous total mortality (Z) was 0.435. The median escapement percentage was estimated at 36.3% (95% posterior credible interval = 19.5–56.0%) using M and Z from the overall model. Unfortunately, the error on this estimate was large and inconclusive as to whether the 30% escapement goal for juvenile Red Drum to the adult population from Dog and Fowl rivers is being met. Monthly residency estimates were typically greater than 0.90, and overall annual residency was estimated at 0.716. Fishing mortality estimates from the current study are higher than recent catch curve estimates that did not include young Red Drum. These results demonstrate that young Red Drum need to be accounted for when generating mortality estimates and provide needed data for the Red Drum recreational fishery

Red Drum and Spotted Seatrout Live-Release Tournament Mortality and Dispersal

Although catch-and-release fishing tournaments undoubtedly reduce mortality of target species, postrelease mortality and fish stockpiling at release sites remain common concerns related to these tournaments. The impacts of liverelease tournaments on freshwater species have been widely studied. However, research on estuarine sport fishes is lacking even though catch-and-release tournaments targeting these species are prevalent and popular recreational fisheries exist. Therefore, we estimated the post-weigh-in mortality and dispersal of Red Drum Sciaenops ocellatus and Spotted Seatrout Cynoscion nebulosus released from the 2016–2018 Alabama Deep Sea Fishing Rodeo live-weigh-in categories using acoustic telemetry. To concurrently estimate overall post-weigh-in mortality and dispersal, we used a Bayesian multistate model. Overall Red Drum post-weigh-in mortality (median = 6.12%; posterior credible interval [CrI] = 5.67–9.24%) was lower than overall Spotted Seatrout mortality (median = 30.63%; CrI = 26.74–40.00%). These estimates were within reported catch-and-release mortality ranges; however, they were higher than recent estimates for Spotted Seatrout. Within 1 week postrelease, Spotted Seatrout dispersal estimates (median = 87.03%; CrI = 72.96–95.72%) were higher than Red Drum (median = 55.62%; CrI = 42.75–68.10%) or Micropterus spp. in coastal and inland ecosystems. Long-term stockpiling at the release site was also not present; at the end of our 8-week observation period, median dispersal estimates were 94.41% (CrI = 87.15–98.19%) and 98.54% (CrI = 93.68–99.82%) for Red Drum and Spotted Seatrout, respectively. Red Drum fisheries may benefit most from live-release tournaments given that maximum mortality was \u3c10%, but Spotted Seatrout fisheries may also benefit, especially if considerations are made to further reduce tournament mortality. Although we do not know the ratio of tournament mortality to recreational harvest for these species, live-release tournaments may be able to relieve some harvest pressure on heavily exploited inshore marine fisheries and research validating their usefulness should continue

Age composition and distribution of red drum (Sciaenops ocellatus) in offshore waters of the north central Gulf of Mexico: an evaluation of a stock under a federal harvest moratorium

Because of a lack of fishery-dependent data, assessment of the recovery of fish stocks that undergo the most aggressive form of management, namely harvest moratoriums, remains a challenge. Large schools of red drum (Sciaenops ocellatus) were common along the northern Gulf of Mexico until the late 1980s when increased fishing effort quickly depleted the stock. After 24 years of harvest moratorium on red drum in federal waters, the stock is in need of reassessment; however, fisherydependent data are not available in federal waters and fishery-independent data are limited. We document the distribution, age composition, growth, and condition of red drum in coastal waters of the north central Gulf of Mexico, using data collected from a nearshore, randomized, bottom longline survey. Age composition of the fishery-independent catch indicates low mortality of fish age 6 and above and confirms the effectiveness of the federal fishing moratorium. Bottom longline surveys may be a cost-effective method for developing fishery-independent indices for red drum provided additional effort can be added to nearshore waters (<20 m depth). As with most stocks under harvest bans, effective monitoring of the recovery of red drum will require the development of fishery-independent indices. With limited economic incentive to evaluate non-exploited stocks, the most cost-effective approach to developing such monitoring is expansion of existing fishery independent surveys. We examine this possibility for red drum in the Gulf of Mexico and recommend the bottom longline survey conducted by the National Marine Fisheries Service expand effort in nearshore areas to allow for the development of long-term abundance indices for red drum

How does spatial variation in climate cause spatiotemporal patterns in lizard energetics?

Sceloporus occidentalis occurs in two locales near the northern end of its geographic range that contrast markedly in climate. Both locales are in Washington state; one is cool, moist coastal temperate forest and the other is warm, dry pine-oak woodland in the state\u27s interior. The focus of this thesis was to investigate differences in lizard production and population structure between these locales by correlating daily and seasonal patterns of temperature, precipitation, and cloud cover with the measured and estimated patterns of lizard activity, energy expenditure, feeding rates and food availability. Based on air temperature records, the estimated activity season length for Sceloporus occidentalis was greater at the inland locale, at 207 days than at the coastal locale, at 191 days. Within the activity season there were more 138 warm, sunny days available for S. occidentalis activity at the inland locale, but only there were only 79 of these days available at the coastal locale. Daily activity on these sunny days was estimated to be about 9.5 hours at both locales. The combination of equal foraging time available at both locales on warm sunny days during mid-summer and higher arthropod abundances at the coastal locale in mid-summer were correlated with higher rates of daily fecal production by the coastal lizards (0.0252 g • g-1 • d-1) than by the inland lizards (0.0221 g • g-1 • d-1). Hence, calculated food intake rates of coastal lizards (0.0360 kJ • g-1 • d-1) were greater than food intake rates of inland lizards (0.0165 kJ • g-1 • d-1). Water influx rates, as measured by the doubly-labeled water technique corroborated the fecal production analysis. Moreover, the daily field metabolism of lizards at the two locales were similar during mid-summer, corroborating the similar activity period estimates based on weather data. Despite lower rates of lizard production during mid-summer for inland S. occidentalis, the greater number of days available for activity during the activity season for the inland lizards, and the larger body sizes reached by one-year old lizards inland provides correlative evidence from which to infer that inland lizards may become reproductive at an earlier age. Relative to the coastal S. occidentalis, the inland lizards (1) hatch 2 -- 3 weeks earlier, (2) have a longer activity season into the fall, (3) followed by an earlier beginning to the activity season in the spring, and (4) presumably have adequate food availability for growth when active. Both locales are in the northern portion of the geographic range of Sceloporus occidentalis. The expectations are that climate change will result in longer activity seasons for lizards at both locales, and that heat of summer may be severe for the inland population, perhaps necessitating migration of the inland population further upslope and further west toward cooler and more mesic conditions. But if one considers the many possible anthropogenic effects on the landscape as well as the potentially rapid rate of climate change, it is unclear whether there will be available habitat to be occupied upslope and further west, thus possibly imperiling inland populations of Sceloporus occidentalis

Participatory Conservation of Coastal Habitats: The Importance of Understanding Homeowner Decision Making to Mitigate Cascading Shoreline Degradation

Along densely populated coasts, the armoring of shorelines is a prevalent cause of natural habitat loss and degradation. This article explores the values and decision making of waterfront homeowners and identifies two interlinked and potentially reversible drivers of coastal degradation. We discovered that: (1) misperceptions regarding the environmental impacts and cost-effectiveness of different shoreline conditions was common and may promote armoring; and (2) many homeowners reported only altering their shorelines in response to damage caused by armoring on neighboring properties. Collectively, these findings suggest that a single homeowner’s decision may trigger cascading degradation along a shoreline, which highlights the necessity of protecting existing large stretches of natural shoreline. However, our study also found that most homeowners were concerned with environmental impacts and preferred the aesthetics of natural landscapes, both of which could indicate nascent support and pathways for conservation initiatives along residential shorelines