Statistics for Spatial Data.

The influence of diet on the distribution of nitrogen isotopes in animals was investigated by analyzing animals grown in the laboratory on diets of constant nitrogen isotopic composition. 
The isotopic composition of the nitrogen in an animal reflects the nitrogen isotopic composition of its diet. The δ^(15)N values of the whole bodies of animals are usually more positive than those of their diets. Different individuals of a species raised on the same diet can have significantly different δ^(15)N values. The variability of the relationship between the δ^(15)N values of animals and their diets is greater for different species raised on the same diet than for the same species raised on different diets. Different tissues of mice are also enriched in ^(15)N relative to the diet, with the difference between the δ^(15)N values of a tissue and the diet depending on both the kind of tissue and the diet involved. The δ^(15)N values of collagen and chitin, biochemical components that are often preserved in fossil animal remains, are also related to the δ^(15)N value of the diet. 
The dependence of the δ^(15)N values of whole animals and their tissues and biochemical components on the δ^(15)N value of diet indicates that the isotopic composition of animal nitrogen can be used to obtain information about an animal's diet if its potential food sources had different δ^(15)N values. The nitrogen isotopic method of dietary analysis probably can be used to estimate the relative use of legumes vs non-legumes or of aquatic vs terrestrial organisms as food sources for extant and fossil animals. However, the method probably will not be applicable in those modern ecosystems in which the use of chemical fertilizers has influenced the distribution of nitrogen isotopes in food sources. 
The isotopic method of dietary analysis was used to reconstruct changes in the diet of the human population that occupied the Tehuacan Valley of Mexico over a 7000 yr span. Variations in the δ^(15)C and δ^(15)N values of bone collagen suggest that C_4 and/or CAM plants (presumably mostly corn) and legumes (presumably mostly beans) were introduced into the diet much earlier than suggested by conventional archaeological analysis.

Influence of Diet On the Distribtion of Nitrogen Isotopes in Animals

In this book, Andrew Harvey sets out to provide a unified and comprehensive theory of structural time series models. Unlike the traditional ARIMA models, structural time series models consist explicitly of unobserved components, such as trends and seasonals, which have a direct interpretation. As a result the model selection methodology associated with structural models is much closer to econometric methodology. The link with econometrics is made even closer by the natural way in which the models can be extended to include explanatory variables and to cope with multivariate time series. From the technical point of view, state space models and the Kalman filter play a key role in the statistical treatment of structural time series models. The book includes a detailed treatment of the Kalman filter. This technique was originally developed in control engineering, but is becoming increasingly important in fields such as economics and operations research. This book is concerned primarily with modelling economic and social time series, and with addressing the special problems which the treatment of such series poses. The properties of the models and the methodological techniques used to select them are illustrated with various applications. These range from the modellling of trends and cycles in US macroeconomic time series to to an evaluation of the effects of seat belt legislation in the UK.

Forecasting, Structural Time Series Models and the Kalman Filter

The purpose of this paper is to provide a comprehensive presentation and interpretation of the Ensemble Kalman Filter (EnKF) and its numerical implementation. The EnKF has a large user group, and numerous publications have discussed applications and theoretical aspects of it. This paper reviews the important results from these studies and also presents new ideas and alternative interpretations which further explain the success of the EnKF. In addition to providing the theoretical framework needed for using the EnKF, there is also a focus on the algorithmic formulation and optimal numerical implementation. A program listing is given for some of the key subroutines. The paper also touches upon specific issues such as the use of nonlinear measurements, in situ profiles of temperature and salinity, and data which are available with high frequency in time. An ensemble based optimal interpolation (EnOI) scheme is presented as a cost-effective approach which may serve as an alternative to the EnKF in some applications. A fairly extensive discussion is devoted to the use of time correlated model errors and the estimation of model bias.

The Ensemble Kalman Filter: Theoretical formulation and practical implementation

The Pacific Decadal Oscillation (PDO) has been described by some as a long-lived El Nino-like pattern of Pacific climate variability, and by others as a blend of two sometimes independent modes having distinct spatial and temporal characteristics of North Pacific sea surface temperature (SST) variability. A growing body of evidence highlights a strong tendency for PDO impacts in the Southern Hemisphere, with important surface climate anomalies over the mid-latitude South Pacific Ocean, Australia and South America. Several independent studies find evidence for just two full PDO cycles in the past century: “cool” PDO regimes prevailed from 1890–1924 and again from 1947–1976, while “warm” PDO regimes dominated from 1925–1946 and from 1977 through (at least) the mid-1990's. Interdecadal changes in Pacific climate have widespread impacts on natural systems, including water resources in the Americas and many marine fisheries in the North Pacific. Tree-ring and Pacific coral based climate reconstructions suggest that PDO variations—at a range of varying time scales—can be traced back to at least 1600, although there are important differences between different proxy reconstructions. While 20th Century PDO fluctuations were most energetic in two general periodicities—one from 15-to-25 years, and the other from 50-to-70 years—the mechanisms causing PDO variability remain unclear. To date, there is little in the way of observational evidence to support a mid-latitude coupled air-sea interaction for PDO, though there are several well-understood mechanisms that promote multi-year persistence in North Pacific upper ocean temperature anomalies.

https://link.springer.com/content/pdf/10.1023%2FA%3A1015820616384.pdf

The Pacific Decadal Oscillation

Filtering and interpreting location errors in satellite telemetry of marine animals

We investigate the application of quantitative techniques for distinguishing adaptive search behaviour in Atlantic bluefin tuna (Thunnus thynnus). The analysis demonstrates the application of a novel spectral analysis technique for resolving and measuring periodicity in animal behaviour patterns. Two different search strategies are identified that include regulation of turning (klinokinesis) and speed (orthokinesis). Our results provide evidence that bluefin tuna attempt to optimize their searching efficiency through adjustments in the duration and timing of switching between these two searching strategies. Repetitive, diurnal deep dives were also found to coincide with switching of search behaviour. Additional tracking experiments with larger sample sizes are needed to better identify how individuals switch between the two search strategies and how such decisions may collectively improve the searching and foraging efficiency of their schools (synchrokinesis, social taxis) in response to changes in the size or composition of prey aggregations.

Analysis of foraging movements of Atlantic bluefin tuna (Thunnus thynnus) : individuals switch between two modes of search behaviour

Summary The optimal management of the commercially important, but mostly over-exploited, pelagic tunas, albacore (Thunnus alalunga Bonn., 1788) and Atlantic bluefin tuna (BFT; Thunnus thynnus L., 1758), requires a better understanding of population structure than has been provided by previous molecular methods. Despite numerous studies of both species, their population structures remain controversial. This study reports the development of single nucleotide polymorphisms (SNPs) in albacore and BFT and the application of these SNPs to survey genetic variability across the geographic ranges of these tunas. A total of 616 SNPs werediscoveredin35albacoretunabycomparingsequencesof54nuclearDNAfragments.A panel of 53 SNPs yielded FST values ranging from 0.0 to 0.050 between samples after genotyping 460 albacore collected throughout the distribution of this species. No significant heterogeneity was detected within oceans, but between-ocean comparisons (Atlantic, Pacific and Indian oceans along with Mediterranean Sea) were significant. Additionally, a 17-SNP panel was developed in Atlantic BFT by cross-species amplification in 107 fish. This limited number of SNPs discriminated between samples from the two major spawning areas of Atlantic BFT (FST = 0.116). The SNP markers developed in this study can be used to genotype large numbers of fish without the need for standardizing alleles among laboratories.

Single nucleotide polymorphism discovery in albacore and Atlantic bluefin tuna provides insights into worldwide population structure.

,SUMMARY Although there have been several studies of the migratory movements of Atlantic bluefin tuna (Thunnus thynnus, L.) between the Western and Eastern Atlantic, the two-stock hypothesis remains untested and exchange rates are still unidentified. TUNASAT, an EU-funded research programme involving Italy, Spain, Greece and the UK, which was carried out during the threeyear period 1998-2000 in the Mediterranean Sea and the Strait of Gibraltar, and a subsequent tagging program funded by the Italian Ministry of Agriculture and Forestry Policies, which was carried out during 2003 in the Eastern Mediterranean, aimed to better understand this problem. Both bluefin tuna tagging programs were executed using pop-up satellite tags. Results from both tagging programs indicated that adults < 100 kg remain in Mediterranean after spawning and feed in areas of high primary productivity, as indicated by SeaWiFS satellite data for chlorophyll-a concentration. After spawning large bluefin 150-230 kg migrate into the eastern North Atlantic, either south towards the Cape Verde Islands or north to Iceland and the Norwegian Sea. Some large bluefin move to and fro between the Alboran Sea and Atlantic, feeding on both sides of the Strait of Gibraltar. No evidence of transatlantic movement was observed.

/pdf/movements-of-bluefin-tuna-thunnus-thynnus-l-tagged-in-the-4h0iqwdnr2.pdf

Movements of bluefin tuna (thunnus thynnus l.) tagged in the mediterranean sea with pop-up satellite tags

We have investigated aerobic metabolism and blood O₂ transport properties of the leatherback sea turtle (Dermochelys coriacea). During nesting, at a body temperature of 29° C, resting ventilation (9.2 ± 1. 7 mL min⁻¹ kg⁻¹) and O₂ consumption (0. 25 ± 0.04 mL min⁻¹ kg⁻¹; three turtles) were slightly below values given for other sea turtles. Tidal volume was considerably smaller than in other turtles (4.0 ± 1.06 mL kg⁻¹) suggesting that Dermochelys has small lungs. Blood (measured in four turtles) had an extremely high Hb concentration (15. 6 ± 1.8 g dL⁻¹), hematocrit (39% ± 1.2%), and carried 21 ± 2.5 mL · dL⁻¹ blood, which exceeds the blood O₂ carrying capacity of other sea turtles and was similar to that of most mammals. Pectoral muscle myoglobin content, indicative of tissue O₂ stores, was 4.9 g dL⁻¹, twice that of other sea turtles. The $P_{50}$, however, was similar to that of the loggerhead sea turtle: 31 and 40 mmHg for blood equilibrated with 2.2% (pH 7. 84) and 5% (pH 7.52) CO₂, respectively. We s...

Molly Lutcavage

Papers

Filtering and interpreting location errors in satellite telemetry of marine animals

Analysis of foraging movements of Atlantic bluefin tuna (Thunnus thynnus) : individuals switch between two modes of search behaviour

Single nucleotide polymorphism discovery in albacore and Atlantic bluefin tuna provides insights into worldwide population structure.

Movements of bluefin tuna (thunnus thynnus l.) tagged in the mediterranean sea with pop-up satellite tags

Oxygen Transport in the Leatherback Sea Turtle Dermochelys coriacea