Assessing microplastics contamination in unviable loggerhead sea turtle eggs.

Sea turtles, in comparison with marine mammals, sea birds, and fishes, are the most affected by microplastics in terms of number of individuals impacted and concentration within each organism. The ubiquitous nature and persistence of microplastics in the environment further compromises sea turtles as many species are currently vulnerable, endangered, or critically endangered. The objective of this study was to quantify microplastic contamination in unviable loggerhead sea turtle eggs (Caretta caretta). Eggs were collected from seven locations along the northwest coast of Florida. A total of 70 nests and 350 eggs were examined. Microplastics (n = 510) were found in undeveloped loggerhead sea turtle eggs across all seven sites, suggesting that maternal transference and/or exchange between the internal and external environment were possible. The frequency found was 7.29 ± 1.83 microplastic pieces per nest and 1.46 ± 0.01 per egg. Microplastics were categorized based on color, shape, size, and type of polymer. The predominant color of microplastics were blue/green (n = 236), shape was fibers (n = 369), and length was 10-300 µm (n = 191). Identified fragments, films, beads and one foam (n = 187) had the most common area of 1-10 µm2 (n = 45). Micro-Fourier Transform Infrared (µ-FTIR) spectroscopy analysis demonstrated that polyethylene (11 %) and polystyrene (7 %) were the main polymer types. For the first time microplastics were found in unviable, undeveloped loggerhead sea turtle eggs collected in northwest Florida. This work provides insight into the distribution patterns of microplastic pollutants in loggerhead sea turtle eggs and may extend to other species worldwide.

Microplastics in sandy environments in the Florida Keys and the panhandle of Florida, and the ingestion by sea cucumbers (Echinodermata: Holothuroidea) and sand dollars (Echinodermata: Echinoidea).

Microplastic pollution is an increasing problem in the marine environment. This study had three objectives: 1) determine if seagrass beds and adjacent sand flats in the Florida Keys differed in microplastics concentration, 2) determine if sea cucumbers from the Florida Keys and sand dollars from the panhandle of Florida contain microplastics, and 3) conduct a laboratory experiment on the sand dollar Mellita tenuis to determine if it will ingest plastic microbeads contained in sediment. Both seagrass beds and sand flats in the Florida Keys contained microplastics. Sediment near Pensacola Beach and in St. Joseph Bay contained microplastics. Sea cucumbers from the Florida Keys and sand dollars from the panhandle of Florida contained microplastics in their gut contents. In the laboratory, M. tenuis ingested microbeads in slightly lower proportions compared to surrounding sediment. Both sea cucumbers and sand dollars may make useful animals for monitoring sandy environments for microplastics pollution.

Color development time of the Lowry protein assay.

Color development of the Lowry protein assay was tracked over time for bovine serum albumin (BSA) concentrations ranging from 40 to 600 microg/ml. The time interval between 2 and 4h produced the most stable readings. This time frame also improved linearity of the standard curve.