Seasonal flexibility in energy stores of Hudson Bay beluga whales: Insights from blubber lipid analysis

During the primary feeding season, marine mammals often accumulate fat reserves, primarily in the form of blubber. Despite the ecological significance of feeding, uncertainty remains surrounding the timing of energy store accumulation in Hudson Bay beluga whales (Delphinapterus leucas (Pallas, 1776)). Blubber samples were collected from whales hunted by Inuit along the whale’s migration route, from 2015 to 2021 (excl. 2018). Sampling occurred in spring and fall, assumed to represent feeding in winter and summer, respectively. We analyzed blubber for lipid content and adipocyte size, two related indices of lipid dynamics, across three blubber sections (outer, middle, and inner). We found interannual variability in the season with the highest fat content, with some years showing higher lipid content in spring than fall. While adipocyte size did not differ seasonally, minima were observed in 2017 and 2019. Fat stores differed across blubber sections, with the highest lipid content and..., The dataset includes data on 53 Hudson Bay beluga whales harvested near Sanikiluaq, Nunaut. Primary analysis was on lipid content and adipocyte size, used to evaluate the primary feeding season of these whales. Subsamples of blubber were collected from the outer, middle, and inner sections of the blubber. The data includes when the whale was harvested (year, month, season), genetically determined sex, and lipid content measured during fatty acid analysis. Histological analysis was conducted to obtain adipocyte size (average area). Age of the individuals was determined using teeth. Note: The blubber was seldom present down to the muscle. Blubber length represents the length of the blubber available and not necessarily the blubber depth of the whale. 
Teeth were aged by Matson's Laboratory. 
Sex was determined genetically at the Freshwater Institute (Fisheries and Oceans Canada) with DNA extracted from skin tissue (Qiagen DNeasy Kit) and analyzed following PCR procedures describ..., , # Data from: Seasonal flexibility in energy stores of Hudson Bay beluga whales: Insights from blubber lipid analysis

Dataset DOI: [10.5061/dryad.ht76hdrqk](10.5061/dryad.ht76hdrqk)

## Description of the data and file structure

Blubber samples were collected and provided by Inuit from Sanikiluaq, Nunavut, during beluga whale subsistence harvests 2015-2021.

### Files and variables

#### File: Belanger_etal_2025_SupplementalFile_Data.csv

##### Variables

* BelugaID: Beluga whale individual
* Blubber Length (cm): Measured in centimeters (cm) perpendicular to the skin, to the end of the longest part of the blubber. This represents the end of the blubber sample available, and not necessarily the full blubber depth, as muscle was seldom present.
* Blubber Section: All cut in ~ 1cm3
* Outer - 1 cm subsample starting from the skin, along the depth of the blubber
* Middle - 1 cm subsample, 0.5 cm on each side of the midpoint of the blubber length (e.g., 5cm blubber depth, middle sample i...,

在主要摄食季，海洋哺乳动物通常会以鲸脂（blubber）的形式积累脂肪储备。尽管摄食行为具有重要的生态意义，但学界对哈德逊湾白鲸（Delphinapterus leucas (Pallas, 1776)）的能量储备积累时间仍存在诸多不确定性。2015年至2021年（2018年除外），研究团队从因纽特人在白鲸迁徙路线上捕猎的个体身上采集了鲸脂样本。采样分别于春季和秋季进行，默认分别对应冬季和夏季的摄食活动。我们针对鲸脂的三个层级（外层、中层和内层），分析了脂质含量与脂肪细胞大小这两项与脂质动态相关的指标。研究发现，脂质含量最高的季节存在年际差异，部分年份春季的脂质含量高于秋季。尽管脂肪细胞大小未表现出显著季节差异，但在2017年和2019年观测到了最小值。不同鲸脂层级的脂肪储备存在差异，脂质含量最高的层级为……。本数据集涵盖了在努纳武特地区萨尼卢阿克（Sanikiluaq）附近捕获的53头哈德逊湾白鲸的相关数据。核心分析围绕脂质含量与脂肪细胞大小展开，用于评估该种群的主要摄食季节。鲸脂子样本取自鲸脂的外层、中层与内层。数据集包含白鲸的捕获时间（年份、月份、季节）、遗传鉴定的性别，以及脂肪酸分析中测得的脂质含量。通过组织学分析获取脂肪细胞大小（平均面积）。研究通过牙齿鉴定个体年龄。注：鲸脂极少延伸至肌肉层。鲸脂长度指可获取的鲸脂样本长度，而非白鲸实际的鲸脂厚度。牙齿年龄鉴定由Matson实验室完成。性别鉴定由加拿大渔业与海洋部淡水研究所通过遗传方法完成：从皮肤组织中提取DNA（使用Qiagen DNeasy试剂盒），并按照所述PCR程序进行分析……。

# 数据来源：《哈德逊湾白鲸能量储备的季节灵活性：基于鲸脂脂质分析的洞察》
数据集DOI：[10.5061/dryad.ht76hdrqk](10.5061/dryad.ht76hdrqk)

## 数据与文件结构说明
2015年至2021年期间，萨尼卢阿克的因纽特人在白鲸生存性捕猎过程中采集并提供了鲸脂样本。

### 文件与变量
#### 文件：Belanger_etal_2025_SupplementalFile_Data.csv
##### 变量
* BelugaID：白鲸个体编号
* Blubber Length (cm)：垂直于皮肤方向测量的鲸脂长度（厘米，cm），至鲸脂最长端。该指标代表可获取的鲸脂样本长度，而非白鲸实际的鲸脂厚度，因鲸脂极少延伸至肌肉层。
* Blubber Section：均切割为约1cm³的样本
* 外层：从皮肤沿鲸脂深度方向起始的1cm子样本
* 中层：以鲸脂长度中点为中心，两侧各0.5cm的1cm子样本（例如，鲸脂厚度为5cm时，中层样本……）