Bioaccumulation and biomagnification of arsenic in the muscle and liver of the speckled guitarfish Pseudobatos glaucostigmus in Santa Rosalía, Gulf of California, Mexico.

Arsenic (As) concentrations were measured in the muscle and liver of the speckled guitarfish Pseudobatos glaucostigmus and its main prey Penaeus californiensis, in Santa Rosalia, western Gulf of California, to determine bioaccumulation and biomagnification. Higher mean wet weight (w.w.

Heavy metal concentrations in the Pacific sharpnose shark Rhizoprionodon longurio from the Santa Rosalia mining zone, Baja California Sur, Mexico.

Rhizoprionodon longurio is an important commercial species captured in an area with heavy metal presence due to the mining waste from Santa Rosalia, Gulf of California, and levels of heavy metals in its muscle remain unknown. This study aimed to investigate whether contamination levels are below the limits allowed for human consumption and to prevent health damage. Concentrations of essential (Cu, Fe, Mn, and Zn) and non-essential (Ag, Cd, and Pb) trace elements were determined in fifty-seven muscle samples of R.

Nitrogen isotopic characterisation of macroalgae blooms from different sites within a subtropical bay in the Gulf of California.

In La Paz Bay conspicuous macroalgal blooms of Ulva spp. are recurrent in the waterfront of the city; studies relate its growth to seasonality and nutrient enrichment but their relative influence is not known. We use the δN to discern amongst nitrogen sources at three sites with different substratum and anthropogenic activities.

Macroalgae blooms and delta 15N in subtropical coastal lagoons from the Southeastern Gulf of California: discrimination among agricultural, shrimp farm and sewage effluents.

Macroalgae blooms of Gracilaria vermiculophylla, Hypnea spinella and Spyridia filamentosa have been found in coastal lagoons in the SE Gulf of California. Agriculture, livestock, shrimp and poultry farms and sewage contribute anthropogenic nitrogen to the systems. The delta(15)N of these sources, water column and macroalgae were studied in order to identify the N supply for macroalgae blooms.