Genetic variation among sea turtle life stages and species suggests connectivity among ocean basins.

Regional genetic differentiation of mitochondrial lineages occurs in migratory species with natal philopatry such as sea turtles. However, early juvenile dispersal represents a key opportunity for gene flow and colonization of new regions through founder events, making it an important yet under-studied life stage. To assess connectivity among sea turtle life stages and ocean basins, we sequenced mitochondrial DNA (mtDNA) fragments from 35 juveniles sampled in the Gulf of Mexico from the rarely observed dispersal stage across three species: green turtles (Chelonia mydas; n = 30), hawksbills (Eretmochelys imbricata; n = 3), and loggerheads (Caretta caretta; n = 2). We estimated green turtle rookery contributions using a many-to-many Bayesian mixed stock analysis that incorporated dispersal probabilities based on rookery size and transport via ocean currents. We assembled a gene tree including 709 distinct mtDNA control region haplotypes from the literature for all seven extant sea turtle species to assess gaps in life-stage data across ocean basins, as well as contextualize the lineages we sampled from dispersing juveniles. Our results indicate a high likelihood that green turtles sampled in the Gulf of Mexico originated from rookeries along the coast of Mexico, with smaller contributions from Costa Rica and Suriname. The gene tree analysis yielded species-level relationships consistent with those presented previously, while intra-species relationships between lineages and ocean basins differed, particularly within loggerhead and green turtle clades. Our results highlight the lack of genetic data from juvenile sea turtles, especially the early dispersal stage, and the potential for these data to answer broader questions of connectivity and diversification across species and lineages.

Evaluation of a Home-Based Behavioral Treatment Model for Children With Tube Dependency.

OBJECTIVE: To evaluate a home-based behavioral treatment model for children with tube dependency. METHODS: Nine children (aged 4-14 years) dependent on nasogastric and gastrostomy tubes were consecutively admitted into a home-based behavioral treatment program. A psychologist specializing in applied behavior analysis led the assessment and treatment phases with the support of caregivers and a multidisciplinary team. Caregivers participated in a caregiver training program and continued the intervention once the service was discontinued. We conducted follow-up visits up to 12 months after treatment. The program was evaluated with a multiple-baseline across participants design. We computed on-treatment and intention-to-treat effects according to the Hedges-Pustejovsky-Shadish model. We monitored behavioral (food acceptance and swallowing) and nutritional outcomes (body weight, oral intake, and tube intake), treatment acceptability and satisfaction, caregiver stress, and estimated treatment cost savings. RESULTS: Food acceptance, swallowing, oral intake, and tube intake demonstrated large treatment gains relative to pretreatment levels (effect size range of the intention-to-treat analysis = 0.74-2.1). All participants maintained or increased their body weight. Follow-up effect sizes indicated further improvements. By the final follow-up assessment, six out of the nine children had ceased tube feeding, and one had tube feeds reduced. Caregivers and health professionals provided strong ratings of treatment satisfaction. The cost-savings analysis suggested that a home-based treatment may be a cost-effective alternative to prolonged tube feeding as well as to other treatment approaches. CONCLUSIONS: This study provides evidence supporting home-based multicomponent behavioral interventions in the treatment of pediatric feeding disorders. CLINICAL TRIAL IDENTIFIER: ACTRN12614001127695, https://goo.gl/XSQ4ZH.

Biomarkers reveal sea turtles remained in oiled areas following the Deepwater Horizon oil spill.

Assessments of large-scale disasters, such as the Deepwater Horizon oil spill, are problematic because while measurements of post-disturbance conditions are common, measurements of pre-disturbance baselines are only rarely available. Without adequate observations of pre-disaster organismal and environmental conditions, it is impossible to assess the impact of such catastrophes on animal populations and ecological communities. Here, we use long-term biological tissue records to provide pre-disaster data for a vulnerable marine organism. Keratin samples from the carapace of loggerhead sea turtles record the foraging history for up to 18 years, allowing us to evaluate the effect of the oil spill on sea turtle foraging patterns. Samples were collected from 76 satellite-tracked adult loggerheads in 2011 and 2012, approximately one to two years after the spill. Of the 10 individuals that foraged in areas exposed to surface oil, none demonstrated significant changes in foraging patterns post spill. The observed long-term fidelity to foraging sites indicates that loggerheads in the northern Gulf of Mexico likely remained in established foraging sites, regardless of the introduction of oil and chemical dispersants. More research is needed to address potential long-term health consequences to turtles in this region. Mobile marine organisms present challenges for researchers to monitor effects of environmental disasters, both spatially and temporally. We demonstrate that biological tissues can reveal long-term histories of animal behavior and provide critical pre-disaster baselines following an anthropogenic disturbance or natural disaster.

Determining origin in a migratory marine vertebrate: a novel method to integrate stable isotopes and satellite tracking.

Stable isotope analysis is a useful tool to track animal movements in both terrestrial and marine environments. These intrinsic markers are assimilated through the diet and may exhibit spatial gradients as a result of biogeochemical processes at the base of the food web. In the marine environment, maps to predict the spatial distribution of stable isotopes are limited, and thus determining geographic origin has been reliant upon integrating satellite telemetry and stable isotope data. Migratory sea turtles regularly move between foraging and reproductive areas. Whereas most nesting populations can be easily accessed and regularly monitored, little is known about the demographic trends in foraging populations. The purpose of the present study was to examine migration patterns of loggerhead nesting aggregations in the Gulf of Mexico (GoM), where sea turtles have been historically understudied. Two methods of geographic assignment using stable isotope values in known-origin samples from satellite telemetry were compared: (1) a nominal approach through discriminant analysis and (2) a novel continuous-surface approach using bivariate carbon and nitrogen isoscapes (isotopic landscapes) developed for this study. Tissue samples for stable isotope analysis were obtained from 60 satellite-tracked individuals at five nesting beaches within the GoM. Both methodological approaches for assignment resulted in high accuracy of foraging area determination, though each has advantages and disadvantages. The nominal approach is more appropriate when defined boundaries are necessary, but up to 42% of the individuals could not be considered in this approach. All individuals can be included in the continuous-surface approach, and individual results can be aggregated to identify geographic hotspots of foraging area use, though the accuracy rate was lower than nominal assignment. The methodological validation provides a foundation for future sea turtle studies in the region to inexpensively determine geographic origin for large numbers of untracked individuals. Regular monitoring of sea turtle nesting aggregations with stable isotope sampling can be used to fill critical data gaps regarding habitat use and migration patterns. Probabilistic assignment to origin with isoscapes has not been previously used in the marine environment, but the methods presented here could also be applied to other migratory marine species.

Teaching individuals with profound multiple disabilities to access preferred stimuli with multiple microswitches.

We replicated and extended previous research on microswitch facilitated choice making by individuals with profound multiple disabilities. Following an assessment of stimulus preferences, we taught 6 adults with profound multiple disabilities to emit 2 different responses to activate highly preferred stimuli. All participants learnt to activate both microswitches. Five participants showed a higher overall level of responding when both switches activating preferred stimuli were available concurrently. After completion of microswitch training, a choice assessment was conducted in which participants had access to 2 microswitches concurrently, with 1 connected to the most highly preferred stimulus and the other to a least preferred stimulus. Choice making behavior was shown in 3 participants and provided support for the preference assessment results. The results of the 3 remaining participants showed that both the most highly preferred and the least preferred stimuli may serve as reinforcers for microswitch activation responses.

Identifying potential prey of the pelagic larvae of the spiny lobster Jasus edwardsii using signature lipids.

Signature lipid analyses were used to identify the natural prey of the pelagic phyllosoma larvae of the spiny lobster Jasus edwardsii. Lipid class, fatty acid and sterol composition were determined for associated potential prey items and for phyllosomes captured between 50 and 90 km offshore from the northeastern coast of New Zealand. Phospholipid was the dominant lipid class in all potential prey items and the transparent phyllosomes. The levels of other lipid classes varied between potential prey items, with the next most abundant classes being triacylglycerols, free fatty acids and sterols. A limited number of the potential prey items also contained wax ester. Major fatty acids in all potential prey items were generally 22:6omega3 (docosahexaenoic acid), 16:0, 18:1omega9c, and 20:5omega3 (eicosapentaenoic acid). Multivariate analyses of fatty acid and sterol content of the samples grouped the phyllosoma samples together regardless of their developmental stage or their collection location. However, the phyllosomes were not associated with any of the general groupings of pelagic ascidians, amphipods, chaetognaths, pteropods, euphausiids, fish, copepods or particulate matter that were formed by the statistical analyses. Although the sterol profiles of the potential prey items showed considerable variation, the phyllosomes contained predominantly cholesterol, suggesting that other dietary sterols are converted to cholesterol or metabolised by the phyllosomes. Therefore, the use of sterols for tracing the prey of J. edwardsii phyllosoma appears to be limited. Our results suggest that phyllosomes are opportunistic predators that feed on a variety of prey and are preferentially retaining specific diet-derived fatty acids.

Ice core evidence for Antarctic sea ice decline since the 1950s.

The instrumental record of Antarctic sea ice in recent decades does not reveal a clear signature of warming despite observational evidence from coastal Antarctica. Here we report a significant correlation (P < 0.002) between methanesulphonic acid (MSA) concentrations from a Law Dome ice core and 22 years of satellite-derived sea ice extent (SIE) for the 80 degrees E to 140 degrees E sector. Applying this instrumental calibration to longer term MSA data (1841 to 1995 A.D.) suggests that there has been a 20% decline in SIE since about 1950. The decline is not uniform, showing large cyclical variations, with periods of about 11 years, that confuse trend detection over the relatively short satellite era.

You are what you eat: describing the foraging ecology of southern elephant seals (Mirounga leonina) using blubber fatty acids.

Understanding the trophodynamics of marine ecosystems requires data on the temporal and spatial variation in predator diet but, particularly for wide-ranging species, these data are often unavailable. The southern elephant seal (Mirounga leonina) consumes large quantities of fish and squid prey in the Southern Ocean relative to other marine mammals; however, how diet varies relative to seasonal and spatial foraging behaviour is unknown. We used fatty acid (FA) signature analysis of 63 blubber cores from adult female M. leonina over three seasons (winter 1999, summer 2000 and winter 2001) to determine diet structure. We detected significant differences between seasons and between the main foraging regions (Antarctic continental shelf versus pelagic). We used the FA profiles from 53 fish, squid and krill species to construct a discriminant function that would classify each seal, from its blubber sample as having a fish- or squid-FA profile. We determined that a higher proportion of M. leonina had fish-dominated diets during the winter and when foraging around the Antarctic continental shelf, and the majority had more squid-dominated diets during the summer when foraging pelagically. Thus, we were able to measure the coarse-scale diet structure of a major marine predator using FA profiles, and estimate its associated seasonal and temporal variation.