Relevant bibliographies by topics / Arctic fox – Age determination

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  1. Journal articles
  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers

Academic literature on the topic 'Arctic fox – Age determination'

Author: Grafiati
Published: 4 June 2021
Last updated: 8 February 2022

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Journal articles on the topic "Arctic fox – Age determination"

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Mellows, Andrew, Ross Barnett, Love Dalén, Edson Sandoval-Castellanos, Anna Linderholm, Thomas H. McGovern, Mike J. Church, and Greger Larson. "The impact of past climate change on genetic variation and population connectivity in the Icelandic arctic fox." Proceedings of the Royal Society B: Biological Sciences 279, no. 1747 (September 12, 2012): 4568–73. http://dx.doi.org/10.1098/rspb.2012.1796.

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Previous studies have suggested that the presence of sea ice is an important factor in facilitating migration and determining the degree of genetic isolation among contemporary arctic fox populations. Because the extent of sea ice is dependent upon global temperatures, periods of significant cooling would have had a major impact on fox population connectivity and genetic variation. We tested this hypothesis by extracting and sequencing mitochondrial control region sequences from 17 arctic foxes excavated from two late-ninth-century to twelfth-century AD archaeological sites in northeast Iceland, both of which predate the Little Ice Age (approx. sixteenth to nineteenth century). Despite the fact that five haplotypes have been observed in modern Icelandic foxes, a single haplotype was shared among all of the ancient individuals. Results from simulations within an approximate Bayesian computation framework suggest that the rapid increase in Icelandic arctic fox haplotype diversity can only be explained by sea-ice-mediated fox immigration facilitated by the Little Ice Age.
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Wang, Xiaoming, Zhijie Jack Tseng, Qiang Li, Gary T. Takeuchi, and Guangpu Xie. "From ‘third pole’ to north pole: a Himalayan origin for the arctic fox." Proceedings of the Royal Society B: Biological Sciences 281, no. 1787 (July 22, 2014): 20140893. http://dx.doi.org/10.1098/rspb.2014.0893.

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The ‘third pole’ of the world is a fitting metaphor for the Himalayan–Tibetan Plateau, in allusion to its vast frozen terrain, rivalling the Arctic and Antarctic, at high altitude but low latitude. Living Tibetan and arctic mammals share adaptations to freezing temperatures such as long and thick winter fur in arctic muskox and Tibetan yak, and for carnivorans, a more predatory niche. Here, we report, to our knowledge, the first evolutionary link between an Early Pliocene (3.60–5.08 Myr ago) fox, Vulpes qiuzhudingi new species, from the Himalaya (Zanda Basin) and Kunlun Mountain (Kunlun Pass Basin) and the modern arctic fox Vulpes lagopus in the polar region. A highly hypercarnivorous dentition of the new fox bears a striking resemblance to that of V. lagopus and substantially predates the previous oldest records of the arctic fox by 3–4 Myr. The low latitude, high-altitude Tibetan Plateau is separated from the nearest modern arctic fox geographical range by at least 2000 km. The apparent connection between an ancestral high-elevation species and its modern polar descendant is consistent with our ‘Out-of-Tibet’ hypothesis postulating that high-altitude Tibet was a training ground for cold-environment adaptations well before the start of the Ice Age.
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DIVLJAN, ANJA, KERRYN PARRY-JONES, and GLENDA M. WARDLE. "Age Determination in the Grey-Headed Flying Fox." Journal of Wildlife Management 70, no. 2 (April 2006): 607–11. http://dx.doi.org/10.2193/0022-541x(2006)70[607:aditgf]2.0.co;2.

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Stasiak, K., B. Janicki, and J. Glogowski. "Determination of sperm acrosin activity in the arctic fox (Alopex lagopus L.) – using method developed for human spermatozoa." Polish Journal of Veterinary Sciences 15, no. 4 (December 1, 2012): 799–800. http://dx.doi.org/10.2478/v10181-012-0121-4.

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Abstract The aim of the study was to adapt a method to determine acrosin activity of human spermatozoa to arctic fox (Alopex lagopus L.) spermatozoa. We modified this method by reducing sperm count per sample from 1÷10 × 106 to 25÷200 × 103, incubation time from 180 minutes to 60 minutes, and Triton X-100 concentration in the reaction mixture from 0.01% to 0.005% per 100 cm3. It has also confirmed that arctic fox seminal plasma is rich in proteinases and their inhibitors. To completely abolish the inhibitory effect of seminal plasma on acrosin activity it is recommended to wash the spermatozoa four times. Benzamidine served an inhibitor of acrosin activity.
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Careau, V., J. F. Giroux, G. Gauthier, and D. Berteaux. "Surviving on cached foods — the energetics of egg-caching by arctic foxes." Canadian Journal of Zoology 86, no. 10 (October 2008): 1217–23. http://dx.doi.org/10.1139/z08-102.

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Food-caching by arctic foxes ( Vulpes lagopus (L., 1758)) is a behavioural adaptation thought to increase winter survival, especially in bird colonies where a large number of eggs can be cached during a short nesting season. In this paper, we measured the energy content of greater snow goose ( Chen caerulescens atlantica Kennard, 1927) eggs and evaluated their perishability when cached in tundra soil for a whole summer. We estimated that eggs lost only ~8% of their dry mass over 60 days of storage in the ground. We used published estimates on digestibility of nutrients by arctic foxes to estimate that fresh and stored goose eggs contained 816 and 730 kJ of metabolizable energy, respectively, a difference of 11%. Using information on arctic fox energetics, we evaluated that 145 stored eggs were required to sustain the growth of one pup from the age of 1 to 3 months (nutritional independence). Moreover, 23 stored eggs were energetically equivalent to the average fat deposit of an arctic fox during winter. Finally, we calculated that an adult arctic fox would need to recover 160–220 stored eggs to survive 6 months in resting conditions during cold winter temperatures. This value increased to 480 when considering activity cost. Based on egg acquisition and caching rates observed in many goose colonies, we conclude that cached eggs represent an important source of energy relative to the needs of an arctic fox during winter, and have thus a high fitness value.
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Wierzbicki, H. "Breeding value evaluation in Polish fur animals: Estimates of direct heritability and portion of litter variation of fur coat and reproduction traits." Czech Journal of Animal Science 49, No. 11 (December 13, 2011): 474–82. http://dx.doi.org/10.17221/4334-cjas.

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The study presents estimates of heritability for fur coat and reproduction traits in arctic and silver foxes kept on Polish farms. The estimates of variance components were calculated using the DFREML and single-trait animal models. Due to a discrete character of fur coat traits, they were analysed twice: (1) without normalisation of their scores distribution, (2) after the normal probability scale transformation of their scores. Linear models included random additive genetic and common litter environment effects, and fixed effects of farm × year × birth season in the silver fox or year × birth season in the arctic fox as well as the fixed effect of female age when the reproduction traits were analysed. Moreover, the estimation of variance components for fur coat traits was done by a linear model with (Model 2) or without (Model 1) inbreeding coefficients included as linear covariable. In the arctic fox accounting for inbreeding and the data transformation did not markedly influence the estimates of heritability and the portion of litter variation calculated for the fur coat traits. An inbreeding effect was negligible (except for body size – BS) likely due to the low inbred level of the arctic fox population. In the silver fox the comparison of estimates derived using 2 different linear models and 2 data sets revealed more differences than it was found in the arctic fox. Accounting for inbreeding usually led to lower estimates of heritability, mainly when heritabilities were derived from the normal probability scale-transformed data. Most of the estimates of heritability of reproduction traits were found within the range reported by other authors. However, somewhat higher heritabilities were found for litter size at birth – LSB (0.205) and litter size at weaning – LSW (0.250).    
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Zhdanova, O. L., and Е. Ya Frisman. "EFFECT OF AGE STRUCTURE AND MATERNAL SELECTION IN POLYMORPHISM MAINTENANCE ON LONG-LIVED SPECIES UNDER A CYCLICALLY CHANGING ENVIRONMENT." Regional problems 24, no. 2-3 (2021): 188–91. http://dx.doi.org/10.31433/2618-9593-2021-24-2-3-188-191.

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Maternal selection and overlapping generations can facilitate stable coexistence of alleles under temporally fluctuating environment. The work studies a complex effect of both factors under asymmetric cyclic selection, which simulates environment fluctuation by analogy of food resources cycles with rare peaks and prolonged decline of prey abundance. Our modeling intends to describe a situation demonstrated by the community of “arctic foxes – mouse-like rodents” and explain maintaining polymorphism on litter size in arctic fox.
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Storck, Peter L., and Arthur E. Spiess. "The Significance of New Faunal Identifications Attributed to an Early Paleoindian (Gainey Complex) Occupation at the Udora Site, Ontario, Canada." American Antiquity 59, no. 1 (January 1994): 121–42. http://dx.doi.org/10.2307/3085506.

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Analysis of calcined bone from the Udora site in south-central Ontario, Canada, indicates that the subsistence of Early Paleoindian (Gainey complex) peoples in the lower Great Lakes region included a mix of both large and small mammals: caribou, hare, and arctic fox. The presence of arctic fox and other paleoecological data indicate that the Paleoindian occupation at Udora occurred in a spruce parkland environment between 10,000 and 10,500 years ago, the minimum age of that habitat, or earlier. Evidence that Paleoindian peoples in northeastern North America also hunted caribou suggests that the concept of a “northern” adaptive zone in the greater Northeast (including the Great Lakes region) has some validity; however, the presence of both parkland and forested environments in this zone and presumed caribou behavioral responses to those environments indicate that Paleoindian adaptations to caribou may have been quite variable.
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Stasiak, K., and B. Janicki. "Effect of age and breeding season on sperm acrosin activity in the arctic fox (Alopex lagopus L.)." Polish Journal of Veterinary Sciences 17, no. 1 (March 1, 2014): 177–79. http://dx.doi.org/10.2478/pjvs-2014-0025.

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Abstract The objective of this study was to determine the effect of age and reproductive season on selected properties of semen from the arctic fox, Alopex lagopus L. The experiment used 40 ejaculates collected manually from 6 animals (3 foxes aged one year and 3 foxes older than three years). Statistically less semen (0.39 cm3) was collected from the young compared to the older animals, and the ejaculates obtained were characterized by higher concentration of spermatozoa (195.04 x 106/cm3). In turn, sperm acrosomal extracts from the older animals contained statistically more acrosin (6,4 mU/106 spermatozoa). In the sperm acrosomal extracts prepared during the first semen sampling, the mean acrosin activity did not exceed 2.3 mU/million spermatozoa. At subsequent semen sampling dates, the activity of the analysed enzyme increased to reach 7.72mU/million spermatozoa. In the extracts obtained from the semen collected at the end of the breeding season of arctic foxes, the acrosin activity again reached a value obtained at the beginning of the season.
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Stasiak, Karolina, Stanisław Kondracki, and Maria Iwanina. "Relationship of arctic fox (Alopex lagopus L.) sperm morphology with age of males, sperm concentration, ejaculate volume and acrosin activity." Annals of Animal Science 18, no. 3 (July 1, 2018): 741–52. http://dx.doi.org/10.2478/aoas-2018-0023.

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Abstract The aim of the study was to determine the relationship of sperm morphology with age of males, ejaculate concentration and volume, as well as with acrosin activity determined in sperm acrosome extracts. The study used manually collected ejaculates from 9 male arctic foxes, including 6 young males aged one year and 3 older males (between 3 and 5 years of age). All of the 39 ejaculates used in the study were classified as normal based on motility exceeding 70%. The ejaculates collected from the foxes were evaluated for volume, sperm concentration and frequency of morphological changes including primary and secondary defects. The spermiograms of the male arctic foxes were classified according to a six-grade subjective scale. In addition, acrosin activity was determined in the sperm acrosome extracts. The data were analysed using the criteria of male age, sperm concentration, ejaculate volume, and acrosin activity. The morphology of arctic fox spermatozoa was dependent on the age of the male. A greater number of morphologically altered spermatozoa tended to occur in the ejaculates of young foxes, which were in their first breeding season. In addition, statistical analysis revealed positive relationships between the frequency of morphological changes in sperm and their ejaculate concentration. In contrast, there were no significant correlations between the percentages of morphologically changed spermatozoa and the ejaculate volume and the content of acrosin, which is an indicator of acrosomal integrity. Semen quality is dependent on the number of sperm in ejaculate with morphological defects which prevent oocyte fertilization. Therefore, morphological assessment of semen, which covers both the number and type of morphological changes, is highly useful when selecting appropriate males for reproduction.
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Dissertations / Theses on the topic "Arctic fox – Age determination"

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Walter, Scott Edward. "Aspects of Canada goose nesting ecology in northern Manitoba age, visibility, and Arctic fox predation /." 1996. http://catalog.hathitrust.org/api/volumes/oclc/36286070.html.

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Friesen, Olwyn C. "Ecology of parasites in northern canids: impacts of age, sex, behavior, life history, and diet." 2013. http://hdl.handle.net/1993/18337.

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Host behavior, age, sex, diet, and condition, as well as variation in parasite specificity, drive variation in parasite infection, and ultimately determine the host parasite community. The objectives of this thesis were to 1) examine intraspecific variation in arctic fox parasites, 2) determine relationships between diet and parasites in sympatric arctic and red fox, and 3) compare wolf parasites and diet. Male arctic fox had more cestodes than females and juveniles had more nematodes than adults, likely due to diet and exposure. Red fox carried fewer parasites than arctic fox, likely due to diet, evolved resistance behaviors and higher immune investment, but diet affected cestode abundance in both species. Wolves that ate more white-tailed deer had more cestodes, suggesting increasing deer populations could enhance parasite transmission to moose. However, body condition was unaffected by parasites, suggesting northern canids may have not reached a threshold of infection.
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Books on the topic "Arctic fox – Age determination"

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Merritt, Margaret F. Evaluations of various structures for use in age determination of arctic grayling. Anchorage, Alaska: Alaska Dept. of Fish and Game, Division of Sport Fish, 1991.

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United States. National Marine Fisheries Service., ed. Preparation of acetate peels of valves from the Ocean Quahog, Arctica islandica, for age determinations. Seattle, Wash: U.S. Dept. of Commerce, National Oceanic and Atmospheric Administration, National Marine Fisheries Service, 1987.

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3

Hall, Michael N. Parameters associated with cyclic populations of arctic fox (Alopex lagpopus) near Eskimo Point, Northwest Territories: Morphometry, age, condition, seasonal and multiannual influences. [s.l: s.n.], 1989.

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Book chapters on the topic "Arctic fox – Age determination"

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Hamill, Chad S. "The Earth Is (Still) Our Mother." In Transforming Ethnomusicology Volume II, 115–25. Oxford University Press, 2021. http://dx.doi.org/10.1093/oso/9780197517550.003.0007.

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As many large-scale protests by Indigenous people have articulated, lands inhabited by Indigenous communities (such as desert margins, small islands, lakes and rivers, high-altitude zones, and the circumpolar Arctic) are particularly vulnerable to the dramatic shifts in climate currently underway. The delicate ecosystems upon which Indigenous communities rely are in flux, and the accelerating rate of climate change—outpacing the direst scientific projections—amounts to a crisis that is every bit as threatening as the legacy of European colonialism. Fortunately, for millennia Indigenous communities have cultivated an intimate awareness of their ecology and have remained, throughout the era of world-wide industrial devastation, adept at adapting to environmental change. This awareness and adaptive power has been discussed within the framework of Traditional Ecological Knowledge (TEK). Using traditional stories and songs in Indigenous communities as a touchstone, this chapter will explore three interrelated aspects of TEK: (1) its role in assisting Indigenous communities in adapting to the effects of climate change; (2) its potential to inform and influence Western-generated climate science; and (3) its promise as a unifying thread tying Indigenous communities together, strengthening global self-determination.
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Conference papers on the topic "Arctic fox – Age determination"

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Sun, Haihong, Xiaozhi Wang, Bret C. Montaruli, and Anil Thayamballi. "Renewal Scantling Evaluation for FPSO Conversions Considering Pitting Corrosion Effects." In ASME 2010 29th International Conference on Ocean, Offshore and Arctic Engineering. ASMEDC, 2010. http://dx.doi.org/10.1115/omae2010-20798.

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When considering an existing tanker for conversion to an FPSO with an expected service life of 15 or more years, a comprehensive reassessment of the hull structure should be conducted and appropriate corrosion margins for the hull girder and local scantlings should be established. Among all structural deteriorations incurred by trading tankers with an age of 10 years or more, corrosion wastage represents the most dominant one. There are two types of corrosion found to occur most frequently in aging tankers, namely general corrosion and pitting corrosion. In the case of general corrosion, the yielding and buckling strength of plating and structural members can be readily determined by deducting the corrosion wastage from the as-built scantling values. However, the determination of the strength reduction due to pitting corrosion is more difficult and complex, and the use of nominal loss of material may be insufficient. This paper discusses the findings from the authors’ investigations of a number of different pitting corrosion distributions, and proposes recommendations for considering pitting corrosion effects during the establishment of renewal scantlings at the time of conversion.
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Keprate, Arvind, R. M. Chandima Ratnayake, and Shankar Sankararaman. "Comparing Different Metamodelling Approaches to Predict Stress Intensity Factor of a Semi-Elliptic Crack." In ASME 2017 36th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/omae2017-62333.

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This paper examines the applicability of the different meta-models (MMs) to predict the Stress Intensity Factor (SIF) of a semi-elliptic crack propagating in topside piping, as an inexpensive alternative to the Finite Element Methods (FEM). Five different MMs, namely, multi-linear regression (MLR), second order polynomial regression (PR-2) (with interaction), Gaussian process regression (GPR), neural networks (NN) and support vector regression (SVR) have been tested. Seventy data points (SIF values obtained by FEM) are used to train the aforementioned MMs, while thirty data points are used as the testing points. In order to compare the accuracy of the MMs, four metrics, namely, Root Mean Square Error (RMSE), Average Absolute Error (AAE), Maximum Absolute Error (AAE), and Coefficient of Determination (R2) are used. Although PR-2 emerged as the best fit, GPR was selected as the best MM for SIF determination due to its capability of calculating the uncertainty related to the prediction values. The aforementioned uncertainty representation is quite valuable, as it is used to adaptively train the GPR model, which further improves its prediction accuracy.
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Stadie-Frohbös, Gundula, and Jörg Lampe. "Risk Based Inspection for Aged Offshore Pipelines." In ASME 2013 32nd International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/omae2013-11119.

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Today risk based inspection (RBI) has become very popular as it allows the inspection budget to be used more efficiently compared to conventional inspection procedures. The key parts of a risk based inspection programme for aged pipelines is the determination of all relevant risk driving effects for each specific pipeline, the definition of acceptance criteria and the assessment of the residual lifetime for the pipeline. These tasks require a high level of co-operation with the pipeline operator and the RBI-experts. This paper describes some of the major aspects of the methodology developed to estimate the risk to offshore pipelines. Based on the assessment of the risk an optimised inspection strategy can be developed. The complete RBI-process typically starts by gathering all relevant data used in design phase (including construction phase) and operation phase. In most cases a variety of risk assessment methods will be used, depending on the quality of existing pipeline data. When insufficient data is available a simple qualitative assessment with an index procedure can be used. With more detailed data available the method becomes a semi-quantitative approach. This paper presents the results of a general risk assessment of 22 aged offshore pipelines. Although only basic data has been available this was sufficient to work out reliable results within a semi-quantitative approach. Depending on varying wall thickness, diameter, etc. a pipeline was divided into several different segments. The assessment reveals different governing threats and failure modes for pipelines and risers, like ageing, free span or corrosion. In a final step the results of the risk assessment are used for the optimisation of the inspection intervals within the proposed risk based inspection framework.
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Keprate, Arvind, R. M. Chandima Ratnayake, and Shankar Sankararaman. "Validation of Adaptive Gaussian Process Regression Model Used for SIF Prediction." In ASME 2018 37th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/omae2018-78608.

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The main aim of this paper is to perform the validation of the adaptive Gaussian process regression model (AGPRM) developed by the authors for the Stress Intensity Factor (SIF) prediction of a crack propagating in topside piping. For validation purposes, the values of SIF obtained from experiments available in the literature are used. Sixty-six data points (consisting of L, a, c and SIF values obtained by experiments) are used to train the AGPRM, while four independent data sets are used for validation purposes. The experimental validation of the AGPRM also consists of the comparison of the prediction accuracy of AGPRM and Finite Element Method (FEM) relative to the experimentally derived SIF values. Four metrics, namely, Root Mean Square Error (RMSE), Average Absolute Error (AAE), Maximum Absolute Error (MAE), and Coefficient of Determination (R2), are used to compare the accuracy. A case study illustrating the development and experimental validation of the AGPRM is presented. Results indicate that the prediction accuracy of the AGPRM is comparable with and even higher than that of the FEM, provided the training points of the AGPRM are aptly chosen.
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Challa, Ravi, Solomon Yim, V. G. Idichandy, and C. P. Vendhan. "Finite-Element and Smoothed Particle Hydrodynamics Modeling of Rigid-Object Water-Entry Impact Dynamics and Validation With Experimental Results." In ASME 2010 29th International Conference on Ocean, Offshore and Arctic Engineering. ASMEDC, 2010. http://dx.doi.org/10.1115/omae2010-20659.

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A numerical study on the dynamic response of a generic rigid water-landing object (WLO) during water impact is presented in this paper. The effect of this impact is often prominent in the design phase of the re-entry project, to determine the maximum force it is subjected to, for material strength determination to ensure structural and equipment integrity, human safety and comfort. The predictive capability of the explicit finite-element arbitrary Lagrangian-Eulerian (ALE) and smoothed particle hydrodynamics (SPH) methods of a state-of-the-art nonlinear dynamic finite-element code for simulation of coupled dynamic fluid structure interaction (FSI) responses of the splashdown event of a WLO were evaluated. The numerical predictions are first validated with experimental data for the maximum impact accelerations and then used to supplement experimental drop tests to establish trends over a wide range of conditions including variations in vertical velocity, entry angle and object weight. The results show that the fully coupled FSI models can capture the water-impact response accurately for all range of drop tests considered and the impact accelerations are practically linearly with the increase in the height of the drop. The reliability of the maximum impact accelerations was calibrated with approximate classical von Karman and Wagner closed-form solutions.
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Bhardwaj, Sachin, R. M. Chandima Ratnayake, Arvind Keprate, and Xavier Ficquet. "Machine Learning Approach for Estimating Residual Stresses in Girth Welds of Topside Piping." In ASME 2020 39th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/omae2020-18703.

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Abstract Residual stresses are internal self-equilibrating stresses that remain in the component even after the removal of external load. The aforementioned stress when superimposed by the operating stresses on the offshore piping, enhance the chances of fracture failure of the components. Thus, it is vital to accurately estimate the residual stresses in topside piping while performing their fitness for service (FFS) evaluation. In the present work, residual stress profiles of girth welded topside sections of P91 pipes piping are estimate using a machine learning approach. The training and testing data for machine learning is acquired from experimental measurements database by Veqter, UK. Twelve different machine learning algorithms, namely, multi-linear regression (MLR), Random Forest (RF), Gaussian process regression (GPR), support vector regression (SVR), Gradient boosting (GB) etc. have been trained and tested. In order to compare the accuracy of the algorithms, four metrics, namely, Root Mean Square Error (RMSE), Estimated Variance Score (EVS), Maximum Absolute Error (AAE), and Coefficient of Determination (R^2) are used. Gradient boosting algorithm gives the best prediction of the residual stress, which is then used to estimate the residual stress for the simulated input parameter space. In the future work authors shall utilize the residual stress predictions from Gradient boosting algorithm to train the Bayesian Network, which can then be used for estimating less conservative through-thickness residual stresses distribution over a wide range of pipe geometries (radius to thickness ratio) and welding parameters (based on heat input). Furthermore, besides topside piping, the proposed approach finds its potential applications in structural integrity assessment of offshore structures, and pressure equipment’s girth welds.
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Bos, Mark, Olger Koop, and Ernst Bolt. "Safety Level of a Probabilistic Admittance Policy." In ASME 2011 30th International Conference on Ocean, Offshore and Arctic Engineering. ASMEDC, 2011. http://dx.doi.org/10.1115/omae2011-49357.

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The main factor restricting admission of deep-draught ships to ports is the risk of bottom contact. In the approach channels to Rotterdam and IJmuiden such ships are subject to tidal windows because of the limited depths in the approach channels. Some decades ago probabilistic methods were introduced for the allocation of tidal windows for the Euro-Maas channel to Rotterdam and later also for the IJ channel to IJmuiden. These methods are being further developed. The increased accuracy of computational methods and of forecasted wave conditions and water levels may lead to an increased accessibility of the port. Recent developments have resulted in the new tidal window advice program Protide (PRObabilistic TIdal window DEtermination). The objective of the work presented in this paper is the verification and validation of Protide for the Euro-Maas channel to Rotterdam and for the IJ channel to IJmuiden. The probability of bottom contact during channel transit is simulated for time series of ten years of measured wave data and water levels. The fleet of ships is represented by a limited number of ships and for each ship all possible tidal windows for the ten year period are determined with Protide. A database is developed with motion response characteristics for each of the representative ships. For all possible arrival times in the ten-year period, indicated as safe by Protide, a channel transit is simulated. The probability of bottom contact during the simulated transit is computed from the motion response characteristics of the ship and with the measured wave spectra and the measured water level. Two safety criteria are applied. Firstly the probability of bottom contact during a single channel transit should not be excessive. Secondly the total probability of bottom contact during a long period of application of the admittance policy should be limited. To determine the probability that a certain ship is in a certain section of the channel some elements from queuing theory are applied. The probability that the ship is present in each channel section combined with the probability of bottom contact results in the probability of bottom contact for the ship in the channel. This leads to a long term probability of bottom contact for the channel. This paper presents the analysis method and selected simulation results for Euro-Maas channel in detail.
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