Table of Contents

• Coverage
• Dataset Description
  • Methods & Sampling
  • Data Processing Description
• Data Files
• Related Publications
• Parameters
• Instruments
• Project Information
• Funding

This dataset is referred to as "Dataset S2" in the supplementary material of Chen et al. The data were used in Figure 3.

Lancetfish Sample Collection:

Whole lancetfish (n = 69) were collected by fisheries observers of the National Oceanic and Atmospheric Administration (NOAA) Pacific Islands Region and West Coast Region Observer Programs from 2018 to 2023 between 20 – 40° N and 115 – 160° W in the central and eastern North Pacific Ocean. Observers sampled lancetfish from the Hawaii-based shallow- and deep-set pelagic longline fisheries. Lancetfish were frozen whole at sea and capture location was recorded. In the lab, specimens were defrosted, measured to the nearest mm (FL), and weighed whole to the nearest 0.1 g. 

Dorsal muscle tissue from each lancetfish was sampled posterior to the operculum at the base of the dorsal fin insertion and anterior to the vent. Only white muscle tissue was sampled, and skin, bones, and cartilage were removed from white muscle tissues before analysis. Following dissection, all tissues were gently rinsed with Milli-Q to avoid contamination between samples, placed in pre-weighed Whirl-Paks, and weighed before and after drying to measure moisture content. Tissues were frozen at -80˚C before being freeze-dried and homogenized within the Whirl-Pak or using an electronic mill (IKA Tube Mill 100 Control). Milling vessels and tools were cleaned with 95% ethanol between samples. 

Tuna THg Data:

We used published size and THg data from muscle tissues of bigeye tuna (Thunnus obesus) and yellowfin tuna (Thunnus albacares) collected in the central North Pacific ​(Brooks, 2004; Choy et al., 2009; Kaneko and Ralston, 2007; Kraepiel et al., 2003; Rivers et al., 1972; Thieleke, 1973​; as compiled in ​Drevnick and Brooks, 2017)​, along with data from ​Choy (2013)​. Life history, metabolism, and diet information for bigeye and yellowfin tuna are available in the literature and were used to explain changes in THg burden with size.

Analytical Methods:

Total mercury (THg) concentrations were determined using a Nippon Instruments MA-3000 Direct Mercury Analyzer (DMA), which uses direct thermal decomposition, gold amalgamation, and cold vapor atomic absorption spectroscopy. For quality assurance and quality control, certified reference materials National Research Council Canada (NRCC) DORM-4 (fish protein) and NRCC TORT-3 (lobster hepatopancreas) were analyzed at the beginning and end of each analysis day. Around 20 mg of dried, homogenized tissues were weighed out for THg analysis, and replicate samples and DORM-4 were analyzed every seven samples. A blank boat was combusted after samples expected to have high THg concentrations to reduce any potential THg carryover to subsequent samples. The average variation of replicate measurements was 4.1%, and analyses of DORM-4 (average measured THg = 417 ± 26 ng Hg/g dry weight, n = 161) and TORT-3 (296 ± 15 ng Hg/g dry weight, n = 40) were within 1.2% and 1.5% of mean certified values, respectively. Only data collected between standard reference materials that were within the range of certified values were included in analyses.

All data processing was performed in R Statistical Software (version 4.3.2; ​R Core Team, 2023).

The Scripps Center for Oceans and Human Health (SCOHH) is a five-year effort to advance the science and community engagement surrounding seafood pollutants, on a rapidly changing planet. The project brings together a multidisciplinary team of biomedical and oceanographic researchers with expertise in fish ecology, microbiology, marine chemistry, climate modeling, technology development, bioaccumulation, genomics, toxicology, and public health. The Center’s scientific goals and focus are guided by the needs of society, established through bidirectional community engagement, and led by a proven community engagement team. The proposed research program of SCOHH spans four main areas:

1. Climate change impacts on the human intake of seafood micronutrients and contaminants.
2. The marine microbiome as a source for the synthesis, transformation, and distribution of seafood contaminants.
3. Mechanisms of bioaccumulation and developmental toxicity of seafood pollutants.
4. Bidirectional public engagement and literacy surrounding seafood risks and benefits.

The outcomes of the SCOHH will inform policies, consumption guidelines, and individual decisions to lower risk and enhance greater benefits associated with seafood consumption. Internally, SCOHH will take deliberate measures to enhance equity, diversity, and inclusion in all aspects of its functioning, from the investigator team and graduate student/postdoctoral trainees to engagement with community partners. The Center is jointly supported by NSF’s Division of Ocean Sciences and by the National Institute for Environmental Health Sciences (NIEHS).

The central scientific theme of SCOHH is to advance knowledge of marine contaminants and seafood security. Natural and anthropogenic contaminants such as mercury, DDT, and PCBs drive seafood consumption advisories. Yet understanding of their sources, microbial transformations, toxicity, and potential for climate driven change remain incomplete. The SCOHH team will study and track the distribution of essential micronutrients and harmful contaminants in marine food webs to the three billion people who consume seafood globally, the roles that the marine microbiome play in their production and transport, and the developmental toxicity of seafood pollutants and their interactions with transporters that determine uptake and bioaccumulation.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.