Dietary triggers of gut inflammation following exclusive enteral nutrition in children with Crohn's disease: a pilot study.

BACKGROUND: The anti-inflammatory effect of exclusive enteral nutrition on the gut of children with Crohn's disease is rapidly lost after food reintroduction. This study assessed disease dietary triggers following successful treatment with exclusive enteral nutrition. METHODS: Nutrient intake, dietary patterns and dietary biomarkers in faeces (gluten immunogenic peptides, undigestible starch, short chain fatty acids) were assessed in 14 children with Crohn's disease during early food reintroduction, following exclusive enteral nutrition. Groups above (Group A) and below (Group B) the median levels of faecal calprotectin after food reintroduction were assigned for comparative analysis. RESULTS: Intakes of fibre, gluten-containing cereals and red and processed meat were significantly higher in Group A than Group B; (median [Q1, Q3], g/day; Fibre: 12.1 [11.2, 19.9] vs. 9.9 [7.6, 12.1], p = 0.03; Red and processed meat: 151 [66.7, 190] vs. 63.3 [21.7, 67], p = 0.02; gluten-containing cereals: 289 [207, 402] vs. 203 [61, 232], p = 0.035). A diet consisting of cereals and meat products was predictive (92% accuracy) of higher faecal calprotectin levels after food reintroduction. In faeces, butyrate levels, expressed as absolute concentration and relative abundance, were higher in Group A than Group B by 28.4 µmol/g (p = 0.015) and 6.4% (p = 0.008), respectively. Levels of gluten immunogenic peptide and starch in faeces did not differ between the two groups. CONCLUSIONS: This pilot study identified potential dietary triggers of gut inflammation in children with Crohn's disease after food reintroduction following treatment with exclusive enteral nutrition. TRIAL REGISTRATION: Clinical trials.gov registration number: NCT02341248; Clinical trials.gov URL: https://clinicaltrials.gov/ct2/show/NCT02341248 (retrospectively registered).

Epstein-Barr Virus Status and Subsequent Thiopurine Exposure Within a Paediatric Inflammatory Bowel Disease Population.

ABSTRACT: The use of thiopurine therapy in Epstein-Barr virus (EBV)-naïve inflammatory bowel disease (IBD) patients remains controversial due to a risk of EBV-associated complications. We evaluated EBV status and outcomes within our paediatric IBD population over an 8-year period; finding that 217 of 409 (53%) screened patients were seropositive for EBV at IBD diagnosis; that thiopurines were used in 189 of 217 (87%) seropositive and 159 of 192 (83%) seronegative patients (P = 0.22); and that 7 of 192 (4%) previously seronegative patients subsequently tested positive for EBV with 6 of 7 (86%) patients having concurrently recorded thiopurine use. All six patients continued thiopurine with/without a period of cessation; no EBV-associated lymphoproliferative disorders/serious complications were recorded within our cohort. A significant proportion of our patients would not receive thiopurine therapy should their use be avoided in EBV-negative patients (47%) or seronegative males (30%). The small but significant risks of thiopurine treatment must be balanced against the potential benefits of successful IBD management; further research into this is required.

Variants in STXBP3 are Associated with Very Early Onset Inflammatory Bowel Disease, Bilateral Sensorineural Hearing Loss and Immune Dysregulation.

BACKGROUND AND AIMS: Very early onset inflammatory bowel disease [VEOIBD] is characterized by intestinal inflammation affecting infants and children less than 6 years of age. To date, over 60 monogenic aetiologies of VEOIBD have been identified, many characterized by highly penetrant recessive or dominant variants in underlying immune and/or epithelial pathways. We sought to identify the genetic cause of VEOIBD in a subset of patients with a unique clinical presentation. METHODS: Whole exome sequencing was performed on five families with ten patients who presented with a similar constellation of symptoms including medically refractory infantile-onset IBD, bilateral sensorineural hearing loss and, in the majority, recurrent infections. Genetic aetiologies of VEOIBD were assessed and Sanger sequencing was performed to confirm novel genetic findings. Western analysis on peripheral blood mononuclear cells and functional studies with epithelial cell lines were employed. RESULTS: In each of the ten patients, we identified damaging heterozygous or biallelic variants in the Syntaxin-Binding Protein 3 gene [STXBP3], a protein known to regulate intracellular vesicular trafficking in the syntaxin-binding protein family of molecules, but not associated to date with either VEOIBD or sensorineural hearing loss. These mutations interfere with either intron splicing or protein stability and lead to reduced STXBP3 protein expression. Knock-down of STXBP3 in CaCo2 cells resulted in defects in cell polarity. CONCLUSION: Overall, we describe a novel genetic syndrome and identify a critical role for STXBP3 in VEOIBD, sensorineural hearing loss and immune dysregulation.

Prevalence of home parenteral nutrition in children.

BACKGROUND: Use of HPN in paediatrics in the UK has increased rapidly over the last 20 years but the prevalence of HPN has been challenging to define. Clinicians in the UK have noted an evolving complexity of cases and perceive improved outcomes and increased acceptability of long-term PN. These factors combined have the potential to increase the burden on existing paediatric gastroenterology services in the UK. METHODS: A national database was interrogated to define the prevalence of HPN in children in the UK and to explore outcomes for patients receiving HPN. RESULTS: Since 2015, 525 children were notified to the database; of these patients, mortality was <5% and intestinal transplant occurred in 1%. In 2019, 389 children received HPN in the UK; this is nearly double the number last reported in 2012 and is a prevalence of 30 per million children. Short bowel syndrome is the largest category of these patients. However, a poorly defined group including those with multisystem disease has increased 10 fold since 2012 and is now the second largest category. CONCLUSIONS: Long term HPN in childhood is safe and associated with good survival and low risk of the need for intestinal transplantation.

Ferric Carboxymaltose Across All Ages in Paediatric Gastroenterology Shows Efficacy Without Increased Safety Concerns.

OBJECTIVES: The aim of the study was to assess the efficacy, safety and side-effect profile of ferric carboxymaltose (FCM) for correcting IDA in children and adolescents in paediatric gastroenterology, hepatology, and nutrition. METHOD: This was a retrospective study of all gastroenterology patients <18 years who had FCM (October 2015 to October 2017). Haematological and biochemical parameters were recorded pre-infusion, at 4 weeks, 3 months, 6 months, and 1 year post-infusion. Recognised side-effects were documented. RESULTS: Sixty-six children received FCM during this period. Data was analysed on 61 children, 5 excluded because of inadequate data. The median age at administration was 14 years (IQR 7). Thirty-two (52%) were boys. Twenty-six (42%) were <14 years old. Seven (11.5%) were <5 years old. Seventeen (28%) were switched from oral iron supplements to FCM. The median dose of FCM delivered was 19 mg/kg. The median haemoglobin increased from 108 to 126 g/L at 1 month post-infusion (P value <0.00001). The mean cell volume also improved from 80 to 84 fL at 1 month post-infusion (P value = 0.0007). Forty-eight (94%) children corrected their anaemia after receiving FCM. Two patients (3%) reported side-effects with skin bruising and staining. CONCLUSIONS: FCM appears to be effective in correcting IDA in children across a wide range of gastroenterology indications and all ages. It is effective and generally well tolerated including in very young patients. Potential side-effects can be avoided by careful monitoring during infusions.

A Decade of Varicella Screening Within a Paediatric Inflammatory Bowel Disease Population.

INTRODUCTION: Increased risk of opportunistic infection-e.g., varicella zoster infection-secondary to therapies is a cause of morbidity in inflammatory bowel disease [IBD] patients. The UK vaccination schedule does not include varicella immunisation. We aimed to evaluate the varicella screening and immunisation programme in a paediatric IBD population. METHODS: Data regarding IBD diagnosis, varicella status, and consequent immunisations/treatment interventions were collected retrospectively from the records of patients diagnosed with IBD over a 10-year period [2009-2018]. RESULTS: In all, 520 IBD patients were diagnosed; 505/520 [97%] had varicella testing; 46/505 [9%] were naïve. Of 501 patients, 391[78%] were tested before or within 7 days of diagnosis; this increased in the second 5-year period compared with the first (229/268 [85%] versus 162/233 [70%]; p <0.00001). Median diagnosis age of naïve patients was lower [8.3 years versus 12.8 years; p <0.00001]. Where vaccination was feasible, 21/31 [68%] had two and 7/31 [23%] one immunisation. Prednisolone induction led to lower rates of vaccination (5/13 [39%] versus 23/33 [70%] for other induction therapies; p =0.02). Of 28 vaccinated patients, 5 [18%] had suspected breakthrough varicella; and 6/18 [33%] unimmunised patients required post-exposure prophylaxis or treatment for varicella. Immunisation was associated with a decrease in patients requiring post-exposure prophylaxis (0/28 [0%] versus 5/18 [28%]; p =0.0006) and varicella-related hospital admission (1/28 [4%] versus 4/18 [22%]; p =0.01). CONCLUSIONS: High rates of varicella screening and immunisation within a PIBD population are possible, resulting in a reduction in hospital admissions for varicella treatment. Varicella immunisation may be of increasing importance within the PIBD population with the emergence of novel therapeutic strategies.

Prehabilitation: The Impact of Preoperative Exclusive Enteral Nutrition on Paediatric Patients With Crohn Disease.

Exclusive enteral nutrition (EEN) is effective in inducing remission in paediatric Crohn Disease (CD) and has been shown to reduce inflammation and improve outcomes in adult CD patients when used before resectional surgery. This retrospective study demonstrates that preoperative EEN is achievable in paediatric CD patients undergoing right hemicolectomy and is associated with positive peri-operative outcomes. Seventeen patients (8 who received preoperative EEN and 9 who did not) were included in the study. Six of 8 (75.0%) managed EEN orally; 1 via nasogastric tube and another via a previously sited gastrostomy. Use of preoperative EEN was associated with a decreased rate of moderate/severe disease on resection pathology (5/8 [62.5%] vs 9/9 [100%]; P = 0.04). Larger studies are required to determine the wider potential benefits of preoperative EEN on postoperative outcomes within paediatric practice.

Using a Steroid-sparing Tool in Paediatric Inflammatory Bowel Disease to Evaluate Steroid Use and Dependency.

OBJECTIVES: The aim of the study was to evaluate the use of steroids within the paediatric inflammatory bowel disease (PIBD) population at a tertiary paediatric centre over a year; to identify cases of steroid dependency; and assess factors associated with steroid excess. METHODS: The prevalent PIBD population (May 1, 2017-April 30, 2018) were reviewed. Data were collected retrospectively from patient records and entered into an online steroid assessment tool (modified for paediatrics). RESULTS: A total of 229 patients (181 Crohn disease, 31 ulcerative colitis [UC], and 17 inflammatory bowel disease-unclassified) were included. Of the 229 patients 38 (16.6%) received oral steroids; 12 of 38 (31.6%) receiving >3-month course. Eleven of 38 (28.9%) received >1 steroid course (maximum 2). Of the 229 patients 37 (16.2%) had exclusive enteral nutrition, with 26 of 37 (11.4% total cohort) avoiding steroid use during the study period.Quiescent disease activity had a negative correlation with steroid use (11/127 [8.7%] vs 27/102 [26.5%] P < 0.01), and steroid dependency (3/127 [2.4%] vs 12/102 [11.8%] P < 0.01). Patients with UC were more likely to be steroid dependent (5/31 [16.1%] UC vs 10/198 [5.1%]; P = 0.02); as were network-managed patients (8/11 [72.7%] vs 7/27 [25.9%]; P = 0.01). Fourteen of 15 (93.3%) of steroid-dependent patients had active steroid sparing strategies in place (eg, commencement, switching, or optimization of therapies). CONCLUSIONS: We have described rates of steroid use and dependency within our PIBD population. Exclusive enteral nutrition served as a steroid sparing tool in 11.4% of the total cohort. Replication of this study in other paediatric centres would allow comparative analysis.

The reduction of faecal calprotectin during exclusive enteral nutrition is lost rapidly after food re-introduction.

BACKGROUND: Faecal calprotectin decreases during exclusive enteral nutrition in children with active Crohn's disease. It is unknown how faecal calprotectin changes during food re-introduction and the influence of maintenance enteral nutrition. AIMS: To study changes to faecal calprotectin during exclusive enteral nutrition and at food reintroduction, and explore associations with maintenance enteral nutrition. METHODS: Children with Crohn's disease were followed during exclusive enteral nutrition and during food-reintroduction. Faecal calprotectin was measured before, at 33 and 54 days of exclusive enteral nutrition, and at 17, 52 and 72 days after food-reintroduction. Maintenance enteral nutrition use was recorded with estimated weight food diaries. Data are presented with medians and Q1:Q3. RESULTS: Sixty-six patients started exclusive enteral nutrition and 41 (62%) achieved clinical remission (weighted paediatric Crohn's disease activity index <12.5). Baseline faecal calprotectin (mg/kg) decreased after 4 and 8 weeks of exclusive enteral nutrition (Start: 1433 [Q1: 946, Q3: 1820] vs 33 days: 844 [314, 1438] vs 54 days: 453 [165, 1100]; P < .001). Within 17 days of food reintroduction, faecal calprotectin increased to 953 [Q1: 519, Q3: 1611] and by 52 days to 1094 [660, 1625] (both P < .02). Fifteen of 41 (37%) children in remission used maintenance enteral nutrition (333 kcal or 18% of energy intake). At 17 days of food reintroduction, faecal calprotectin was lower in maintenance enteral nutrition users than non-users (651 [Q1: 271, Q3: 1781] vs 1238 [749, 2102], P = .049) and correlated inversely with maintenance enteral nutrition volume (rho: -0.573, P = .041), kcals (rho: -0.584, P = .036) and % energy intake (rho: -0.649, P = .016). Maintenance enteral nutrition use was not associated with longer periods of remission (P = .7). Faecal calprotectin at the end of exclusive enteral nutrition did not predict length of remission. CONCLUSIONS: The effect of exclusive enteral nutrition on faecal calprotectin is diminished early during food reintroduction. Maintenance enteral nutrition at ~18% of energy intake is associated with a lower faecal calprotectin at the early phase of food reintroduction but is ineffective in maintaining longer term remission.

Database of multi-parametric geophysical data from the TOMO-DEC experiment on Deception Island, Antarctica.

Deception Island volcano (Antarctica) is one of the most closely monitored and studied volcanoes on the region. In January 2005, a multi-parametric international experiment was conducted that encompassed both Deception Island and its surrounding waters. We performed this experiment from aboard the Spanish oceanographic vessel 'Hespérides', and from five land-based locations on Deception Island (the Spanish scientific Antarctic base 'Gabriel de Castilla' and four temporary camps). This experiment allowed us to record active seismic signals using a large network of seismic stations that were deployed both on land and on the seafloor. In addition, other geophysical data were acquired, including bathymetric high precision multi-beam data, and gravimetric and magnetic profiles. To date, the seismic and bathymetric data have been analysed but the magnetic and gravimetric data have not. We provide P-wave arrival-time picks and seismic tomography results in velocity and attenuation. In this manuscript, we describe the main characteristics of the experiment, the instruments, the data, and the repositories from which data and information can be obtained.

Extensive Modulation of the Fecal Metagenome in Children With Crohn's Disease During Exclusive Enteral Nutrition.

OBJECTIVES: Exploring associations between the gut microbiota and colonic inflammation and assessing sequential changes during exclusive enteral nutrition (EEN) may offer clues into the microbial origins of Crohn's disease (CD). METHODS: Fecal samples (n=117) were collected from 23 CD and 21 healthy children. From CD children fecal samples were collected before, during EEN, and when patients returned to their habitual diets. Microbiota composition and functional capacity were characterized using sequencing of the 16S rRNA gene and shotgun metagenomics. RESULTS: Microbial diversity was lower in CD than controls before EEN (P=0.006); differences were observed in 36 genera, 141 operational taxonomic units (OTUs), and 44 oligotypes. During EEN, the microbial diversity of CD children further decreased, and the community structure became even more dissimilar than that of controls. Every 10 days on EEN, 0.6 genus diversity equivalents were lost; 34 genera decreased and one increased during EEN. Fecal calprotectin correlated with 35 OTUs, 14 of which accounted for 78% of its variation. OTUs that correlated positively or negatively with calprotectin decreased during EEN. The microbiota of CD patients had a broader functional capacity than healthy controls, but diversity decreased with EEN. Genes involved in membrane transport, sulfur reduction, and nutrient biosynthesis differed between patients and controls. The abundance of genes involved in biotin (P=0.005) and thiamine biosynthesis decreased (P=0.017), whereas those involved in spermidine/putrescine biosynthesis (P=0.031), or the shikimate pathway (P=0.058), increased during EEN. CONCLUSIONS: Disease improvement following treatment with EEN is associated with extensive modulation of the gut microbiome.

The continued rise of paediatric home parenteral nutrition use: Implications for service and the improvement of longitudinal data collection.

BACKGROUND & AIMS: Robust data from the United Kingdom (UK) regarding the current epidemiology of patients with types II and III intestinal failure (IF; ≥28 day parenteral nutrition; home parenteral nutrition) are limited. We aimed to analyse trends in type II and III IF in children in the UK using historical and novel data. METHODS: A point survey of the 32 nutrition support teams that register patients with the British Intestinal Failure Survey was carried out in November 2012. Basic demographics for patients on home parenteral nutrition and receiving parenteral nutrition for ≥28 days were collected. Data were anonymised, collated by the registry coordinator and compared to previous surveys by the British Paediatric Surveillance Unit in 1993 and data from 2010. RESULTS: All 32 participating centres responded giving complete UK ascertainment. There were 195 type III patients, representing a four-fold increase since 1993. The proportion of patients with short bowel syndrome had almost doubled from 1993 (27% vs. 50% p = 0.001). The ratio of type II to type III IF patients varied considerably between centres. CONCLUSION: These data suggest that type III IF point prevalence has risen in the short term, coincident with individual centres' reporting improved survival in IF. Refinement in the methodology for prospective data collection is needed to gather more accurate incidence, period prevalence and outcome data for UK type II and type III IF.

A retrospective study showing maintenance treatment options for paediatric CD in the first year following diagnosis after induction of remission with EEN: supplemental enteral nutrition is better than nothing!

BACKGROUND: A limited body of research suggests that ongoing maintenance enteral nutrition (MEN) can be beneficial in maintaining disease remission in Crohn's Disease (CD). We aimed to assess how achievable MEN is and whether it helps to prolong remission. METHODS: Patients newly diagnosed with CD in 2010 and 2011 who commenced exclusive enteral nutrition (EEN) for 8 weeks were followed up for a year post diagnosis. All patients who took EEN were encouraged to continue MEN post EEN. Data on azathioprine use was also collected. Categorical variables were compared using chi-square/Fischer's exact test. Medians were expressed along with complete data ranges. RESULTS: 59 patients (34 male, median age 11.07 years, range 2.5-16.33 years) were identified. 11/59 (18%) had a poor response to EEN and were switched to steroids. 48/59 patients completed 8 weeks EEN and achieved clinical remission/response. 46/48 patients received Modulen IBD®, 29/48 (60%) consumed EEN orally and 19/48 (40%) via NGT. 15/48 (31%) patients were able to continue MEN post EEN completion. MEN was consumed for a mean of 10.8 months (range 4-14 months). 14/15 patients drank MEN and 1/15 had MEN via NGT. Remission rates at 1 year in patients continuing MEN were 60% (9/15) compared to 15% (2/13) in patients taking no treatment (p = 0.001) and 65% (13/20) in patients taking azathioprine (p = 0.14). CONCLUSION: A sub group of patients can continue MEN as a maintenance treatment and this seems a useful strategy, especially in those who are not commencing azathioprine.

The epidemiology of anemia in pediatric inflammatory bowel disease: prevalence and associated factors at diagnosis and follow-up and the impact of exclusive enteral nutrition.

BACKGROUND: Anemia is poorly studied in pediatric inflammatory bowel disease. This study explored the epidemiology and associated factors of anemia at diagnosis, after 1 year, and during treatment with exclusive enteral nutrition (EEN). METHODS: Three cohorts were included: (1) a representative population of newly diagnosed inflammatory bowel disease children (n = 184); (2) patients currently receiving care with data available at diagnosis (n = 179) and after 1 year (n = 139); and (3) 84 children treated with EEN. RESULTS: At diagnosis, 72% were anemic. Abnormal inflammatory markers were more common in Crohn's disease with severe anemia (severe versus no anemia [%]: raised C-reactive protein; 89% versus 48%; suboptimal albumin; 97% versus 29%; P < 0.002). Anemic children with Crohn's disease had shorter diagnosis delay and lower BMI than nonanemic patients (severe versus mild versus no anemia, median [interquartile range]; diagnosis delay [months]: 3 [3.9] versus 6 [10] versus 8 [18], P < 0.001; BMI z score [SD]: -1.4 [1.4] versus -1.3 [1.5] versus -0.2 [1.4], P = 0.003). Extensive colitis was associated with severe anemia in ulcerative colitis. The proportion of severely anemic patients decreased from 34% to 9% and mild anemia doubled at 1 year. After EEN, severe anemia decreased (32% to 9%; P < 0.001) and the hemoglobin concentration increased by 0.75 g/dL. This was observed only after 8 weeks of treatment. Disease improvement and low hemoglobin at EEN initiation but not weight gain were associated with hemoglobin improvement. CONCLUSIONS: Anemia is high at diagnosis and follow-up and should receive more attention from the clinical team; however, the focus should remain suppression of inflammatory process in active disease.

Scottish outcomes for extra hepatic biliary atresia post-rationalisation of services.

AIMS: To evaluate the outcome of Scottish children with extra hepatic biliary atresia (EHBA) since rationalisation of Kasai services to three English centres in 2002 (The 'Group A' centres). METHODS: All Scottish children with EHBA diagnosed between 2002 and 2009 were identified via the Scottish Society of Paediatric Gastroenterology, Hepatology and Nutrition (SSPGHAN) clinicians. A case-note review was conducted with demographics, presentation and outcome data recorded. These data were compared with historical Scottish data and data published previously by the supraregional liver units. RESULTS: 25 patients were identified, of whom 22 were referred for Kasai in the group A centres, and of whom 19 had a Kasai. 2 year transplant-free survival (TFS) was significantly lower in the SSPGHAN 2002-2009 group than the group A centres in (1) (6/18 (33%) vs 36/57 (63%), p=0.023). CONCLUSIONS: These postrationalisation data are disappointing. The emphasis for care will now focus on improved communication between, primary care, general paediatricians and surgical centres through regional and national managed clinical networks, aiming to improve future outcomes for Scottish children with BA.

Use of stable isotopes to measure the metabolic activity of the human intestinal microbiota.

The human intestinal microbiota is a complex biological system comprising a vast repertoire of microbes with considerable metabolic activity relevant to both bacterial growth and host health. Greater strides have been made in the analysis of microbial diversity than in the measurement of functional activity, particularly in vivo. Stable isotope probing offers a new approach by coupling measurements of metabolic activity with microbial identification. Using a low-enrichment labeling strategy in vitro, this study has identified metabolically active bacterial groups via magnetic-bead capture methodology and stable isotope ratio analysis. Using five probes (EUB338, Bac303, Bif164, EREC482, and Clep866), changes in the activities of key intestinal microbial groups were successfully measured by exploiting tracers of de novo RNA synthesis. Perturbation of the nutrient source with oligofructose generated changes in the activity of bifidobacteria as expected, but also in the Bacteroides-Prevotella group, the Eubacterium rectale-Clostridium coccoides group, and the Clostridium leptum subgroup. Changes in activity were also observed in response to the medium type. This study suggests that changes in the functional activity of the gut microbiota can be assessed using tracers of de novo nucleic acid synthesis combined with measurement of low isotopic enrichment in 16S rRNA. Such tracers potentially limit substrate bias because they are universally available to bacteria. This low-enrichment labeling approach does not depend on the commercial availability of specific labeled substrates and can be easily translated to in vivo probing experiments of the functional activity of the microbiota in the human gut.

Genetic differentiation of Alaska Chinook salmon: the missing link for migratory studies.

Most information about Chinook salmon genetic diversity and life history originates from studies from the West Coast USA, western Canada and southeast Alaska; less is known about Chinook salmon from western and southcentral Alaska drainages. Populations in this large area are genetically distinct from populations to the south and represent an evolutionary legacy of unique genetic, phenotypic and life history diversity. More genetic information is necessary to advance mixed stock analysis applications for studies involving these populations. We assembled a comprehensive, open-access baseline of 45 single nucleotide polymorphisms (SNPs) from 172 populations ranging from Russia to California. We compare SNP data from representative populations throughout the range with particular emphasis on western and southcentral Alaska. We grouped populations into major lineages based upon genetic and geographic characteristics, evaluated the resolution for identifying the composition of admixtures and performed mixed stock analysis on Chinook salmon caught incidentally in the walleye pollock fishery in the Bering Sea. SNP data reveal complex genetic structure within Alaska and can be used in applications to address not only regional issues, but also migration pathways, bycatch studies on the high seas, and potential changes in the range of the species in response to climate change.