Differential scanning calorimetry (DSC): An important tool for polymer identification and characterization of plastic marine debris.

Differential scanning calorimetry (DSC), a routine thermoanalytical method in material science, is gaining utility in plastic pollution research to improve polymer identification. We optimized a DSC method, experimentally testing pan types, temperature ramps, number of melts, and minimum sample masses. Using the optimized method, we created an in-house thermogram library from 201 polymer reference standards.

Microplastics absent from reef fish in the Marshall Islands: Multistage screening methods reduced false positives.

Island communities, like the Republic of the Marshall Islands (RMI), depend on marine resources for food and economics, so plastic ingestion by those resources is a concern. The gastrointestinal tracts of nine species of reef fish across five trophic groups (97 fish) were examined for plastics >1 mm. Over 2100 putative plastic particles from 72 fish were identified under light microscopy.

Large floating abandoned, lost or discarded fishing gear (ALDFG) is frequent marine pollution in the Hawaiian Islands and Palmyra Atoll.

Abandoned, lost, or discarded fishing gear (ALDFG) is a major source of marine debris with significant ecological and economic consequences. We documented the frequency, types, sizes, and impacts of ALDFG recovered from Hawai'i and Palmyra Atoll in the Central North Pacific Ocean (CNPO) from 2009 to 2021. A total of 253 events weighing 15 metric tons were recovered, including 120 drifting fish aggregating device (dFAD) components, 61 conglomerates, fewer distinct nets, lines, buoys, and unique gear.

Polymer identification of floating derelict fishing gear from O'ahu, Hawai'i.

Discarded fishing gear (DFG) comprises most of the plastic in the North Pacific Ocean and causes environmental and economic losses. Building evidence on the material construction of fishing gear types is critical to develop solutions to reduce DFG amounts and impacts. We forensically assessed the construction and chemical composition of eight different gear types removed as DFG around O'ahu, Hawai'i.

Using Plasma Vitellogenin in Loggerhead Sea Turtles to Assess Reproductive Maturation and Estrogen-Like Contaminant Exposure.

Vitellogenin (VTG), an egg yolk precursor, is abnormally produced by male and juvenile oviparous species after exposure to estrogens. Plasma VTG in loggerhead sea turtles (Caretta caretta) helped us understand their reproductive maturation and investigate it as a biomarker of contaminant exposure. The presence of VTG was screened in plasma from 404 loggerheads from the northwestern Atlantic Ocean using a freshwater turtle antibody in western blots.