A non-invasive method of microplastics pollution quantification in green sea turtle Chelonia mydas of the Mexican Caribbean.

Due to the amply exposure of marine turtles to marine plastic pollution, this is a reason that the green sea turtle Chelonia mydas makes a good candidate species as a bioindicator for plastic pollution. Turtle feces were collected at Isla Blanca on the northeast Caribbean coast of the Yucatan Peninsula, Mexico. Microplastic extraction was done following Hidalgo-Ruz et al. (2012) and Masura et al. (2015) methods. After organic matter degradation of the feces samples, microplastics were identified and quantified by stereomicroscope. Their morphostructure was analyzed by scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy, while their composition was determined by Fourier transform infrared spectroscopy and Raman spectroscopy. Microplastics (MP) abundance ranged from 10 ± 2 MP·g-1 to 89 ± 3 MP·g-1. Kruskal Wallis test (KW = 70.31, p < 0.001) showed a significant difference between 22 green turtles analyzed. Most of the microplastics were fiber type. Blue, purple, and transparent fibers were the most abundant. The identified microplastics were nylon (polyamide), PVC, polypropylene, polyester, and viscose (cellulose). The non-invasive method used here allowed the detection of microplastic pollution and is promising for long-term microplastic pollution monitoring.

[Turbinella angulata and Busyconperversum (Mesogasteropoda: Turbinellidae and Melongenidae) population and reproductive dynamics in the Campeche Bank, Mexico]. / Dinámica poblacional y reproductiva de Turbinella angulata y Busycon perversum (Mesogasteropoda: Turbinellidae y Melongenidae) en el Banco de Campeche, México.

Turbinella angulata and Busycon perversum are two marine gastropods that support the 90% of conch fisheries in the Gulf of Mexico, nevertheless there is no information available to support a management strategy for both species. The aim of this work was to obtain preliminary fishery information to promote management actions for both species in the Campeche Bank. The population of conchs was sampled in 12 transects (150x1.5m) by SCUBA diving from April 2008 to March 2010. All conchs were collected and siphonal length (SL) was measured. These samples were complemented with data from the commercial catches, analyzing a total of 2 832 individuals of T angulata. Siphonal length varied between 63 and 282mm. Sex ratio was of 0.98:1 female:male. The von Bertalanffy growth equation parameters were: L infinity =346mm; K=0.30 and t(0)=-0.24. Spawning extended from January to May with a long resting stage from June to September for over 80% of the adult population. The first gonadic maturity (L50) was at 210mm (SL) for females and 200mm for males. For B. perversum a total of 1655 individuals were analyzed. Siphonal length varied between 78 and 291mm with significant differences between male and female (p<0.05). Sex ratio was of 1:0.25 female:male. The growth parameters obtained were: Linifinity=360mm; K=0.35 and t(0)=-0.19. The spawning period was from August to December with resting stage from January to April. The L50 was 215mm (LS) for females and 190mm for males. Both species presented one recruitment pulse. These results will be useful to design management schemes based on population dynamics and reproductive attributes.