Data from: Geographic variation in diet, prey resources and exposure to parasites and saxitoxin in Steller sea lions in the Gulf of Alaska

Using 12S rRNA and mitochondrial cytochrome c oxidase subunit I (COI) gene
metabarcoding, we examined diet composition, prey resources, and saxitoxin
(STX) and parasite exposure in Steller sea lions (SSL) in the Gulf of
Alaska in July and October 2022–2023 using 251 scat samples and 45
seawater samples. SSL scat and water were sampled from a broad geographic
area in the the Gulf of Alaska, from Southeast Alaska through Kodiak
Island. The COI gene region was amplified with the Leray-XT primers and
the 12S gene region was amplified with the MiFish-U primers. Data
available here include: 1. SSL diet and parasite and saxitoxin exposure
information from scat samples, including metadata (for each scat sample:
collection location and date, host sex determined via molecular methods,
saxitoxin level), unfiltered results of taxonomic groups detected in each
scat sample for each gene region, and filtered results of prey species
detected which were used in our published study in Frontiers in Marine
Science. And 2. Taxonomic diversity of the nearshore waters of the Gulf
Alaska for initial examination of geographic variation in the nearshore
prey field for SSL in July (informed by the 12S gene region metabarcoding)
for comparison to prey composition determined from SSL scat. 
Information about other taxonomic groups of interest in water samples
included geographic variation in saxitoxin-producing Alexandrium spp.,
possible from COI gene metabarcoding which sampled well lower trophic
levels.  Also included are 3. Information concerning reference
databases used for bioinformatics for both gene regions and 4. raw
sequence data for scat and water samples for each gene region (fastq
files).

本研究采用12S核糖体RNA（12S rRNA）与线粒体细胞色素c氧化酶亚基I（COI）基因宏条形码技术，于2022-2023年7月及10月，在阿拉斯加湾覆盖阿拉斯加东南部至科迪亚克岛的广阔地理范围内，采集251份斯特勒海狮（Steller sea lion, SSL）粪便样本与45份海水样本，用以分析该海域斯特勒海狮的饮食组成、猎物资源，以及其面临的麻痹性贝毒（saxitoxin, STX）与寄生虫暴露风险。
本研究使用Leray-XT引物扩增COI基因区域，使用MiFish-U引物扩增12S基因区域。本次公开的数据集包含以下内容：
1. 来自粪便样本的斯特勒海狮饮食、寄生虫与麻痹性贝毒暴露信息，附带元数据（每份粪便样本的采集位置与日期、通过分子方法鉴定的宿主性别、麻痹性贝毒水平）、两个基因区域在每份粪便样本中检测到的未过滤分类群结果，以及本研究发表于《Frontiers in Marine Science》的论文中所使用的过滤后猎物物种检测结果；
2. 阿拉斯加湾近岸海域的分类多样性数据，用于初步分析2022年7月斯特勒海狮近岸猎物群落的地理变异（基于12S基因区域宏条形码技术），以对比从海狮粪便中得到的猎物组成；该部分还涵盖水样中其他关注类群的信息，例如通过可高效检测低营养级生物的COI基因宏条形码技术检出的产麻痹性贝毒亚历山大藻属（Alexandrium spp.）的地理变异情况；
3. 针对两个基因区域进行生物信息学分析所用的参考数据库信息；
4. 两个基因区域对应的粪便与水样样本的原始序列数据（fastq格式文件）。