Plasma lead, silicon and titanium concentrations are considerably higher in green sea turtle from the suburban coast than in those from the rural coast in Okinawa, Japan

Abstract

The purpose of this study was to compare the concentration of trace elements in the plasma of sea turtles that inhabited the suburban (Okinawa Main Island, n=8) and the rural coast (Yaeyama Island, n=57) in Okinawa, Japan. Particle induced X-ray emission allowed detection of 20 trace and major elements. The wild sea turtles in the suburban coast in Okinawa were found to have high concentrations of Pb, Si and Ti in the plasma when compared to the rural area but there were no significant changes in the Al, As and Hg concentrations. These results may help to suggest the status of some elements in a marine environment. Further, monitoring the plasma trace and major element status in sea turtles can be used as a bio-monitoring approach by which specific types of elements found here could indicate effects that are related to human activities.

Study of trace elements in stranded green turtles (<i>Chelonia mydas</i>), hawksbill turtles (<i>Eretmochelys imbricata</i>), and olive ridley turtles (<i>Lepidochelys olivacea)</i> in Gulf of Thailand and Andaman Sea

“…Green turtles may acquire Pb by grazing eel grass which has been proved to absorb Pb in sediment [ 9 ]. The serum concentration of Pb of G GT (0.844 ± 0.678 µg/mL) was lower than that of green turtles from the studies conducted at the high populated suburban area, the Coast of Yomitan Son, Okinawa Main Island, Japan (0.959 ± 0.579 µg/mL [ 55 ] and 1.032 ± 0.585 µg/mL [ 50 ]). In contrast, the serum concentration of Pb of G AS was 0.411 ± 0 µg/mL which was higher than that of green turtles from a study conducted at the low populated rural coast of Yaeyama Island, Okinawa, Japan (0.197 ± 0.141 µg/mL) [ 55 ].…”

“…The serum concentration of Pb of G GT (0.844 ± 0.678 µg/mL) was lower than that of green turtles from the studies conducted at the high populated suburban area, the Coast of Yomitan Son, Okinawa Main Island, Japan (0.959 ± 0.579 µg/mL [ 55 ] and 1.032 ± 0.585 µg/mL [ 50 ]). In contrast, the serum concentration of Pb of G AS was 0.411 ± 0 µg/mL which was higher than that of green turtles from a study conducted at the low populated rural coast of Yaeyama Island, Okinawa, Japan (0.197 ± 0.141 µg/mL) [ 55 ]. The results of this study was in agreement with the previous study that green turtles living at the coast near the higher industrial activity and higher populated area had higher Pb concentration than green turtles living at the coast near the less industrial activity and less populated area [ 55 ].…”

“…In contrast, the serum concentration of Pb of G AS was 0.411 ± 0 µg/mL which was higher than that of green turtles from a study conducted at the low populated rural coast of Yaeyama Island, Okinawa, Japan (0.197 ± 0.141 µg/mL) [ 55 ]. The results of this study was in agreement with the previous study that green turtles living at the coast near the higher industrial activity and higher populated area had higher Pb concentration than green turtles living at the coast near the less industrial activity and less populated area [ 55 ].…”

“…The higher serum concentration of Cu in H and O was higher, but not significantly so, than in green turtles from either marine coast may be due to hemocyanin, as an important component in the blood of crustaceans [ 1 ] which are a main source of food for these sea turtles. The serum concentration of Cu in G GT (0.349 ± 0.092 µg/mL) was higher than that of green turtles from the suburban area in Japan (0.283 ± 0.143 µg/mL [ 55 ]; 0.276 ± 0.135 µg/mL [ 50 ]). The serum concentration of Cu of G AS (0.390 ± 0.307 µg/mL) was lower than that of green turtles from the rural area in Japan (0.433 ± 0.291 µg/mL [ 55 ]).…”

“…The serum concentration of Cu in G GT (0.349 ± 0.092 µg/mL) was higher than that of green turtles from the suburban area in Japan (0.283 ± 0.143 µg/mL [ 55 ]; 0.276 ± 0.135 µg/mL [ 50 ]). The serum concentration of Cu of G AS (0.390 ± 0.307 µg/mL) was lower than that of green turtles from the rural area in Japan (0.433 ± 0.291 µg/mL [ 55 ]). The higher Fe concentration in the serum from green turtles than for H (carnivorous turtles) and O (omnivorous turtles) may be due to chlorophyll, which is an important component of chloroplasts in eel grass.…”