Heavy metals dynamics in seaweeds and seagrasses in Bahía Magdalena, B.C.S., México

Abstract

The process of metal bioaccumulation in marine food chains is poorly understood because very little data is available on metal concentration at different trophic levels and their temporal or spatial variation. Because of that, we were interested to (1) determine the concentration range of heavy metals in seaweed and seagrasses species in Magdalena Bay; (2) describe the spatial and temporal variation of heavy metal concentrations in the seaweeds and seagrasses. Seasonal collections were done at Estero Banderitas in November 2004, February, and April 2005 wherein we divided the estuary into three major areas (upper, middle, and lower), and within each area, two sites were selected. Our results showed that iron, copper, and magnesium were the most significant metals found in seagrasses, red, and green algae. We found significant more variation in temporal heavy metal concentrations in relation to the maximum abundance in the samples and spatial variation in relation to the studied taxa suggesting that hervibores have a differential intake of the metals. Also, our results suggest that heavy metals might be incorporated regularly in the diet of many herbivorous animals with severe consequences to their health. Management strategies for these species should consider monitoring the levels of metals.

Outstanding appearance of Ruppia maritima along Baja California Sur, México and its influence in trophic networks

“…There is an outstanding expansion of Ruppia maritima's distribution in northwest México compared to its historical known distribution, based on our current sampling efforts and the periodic measurements performed for over 20 years (since 1986) as part of the research conducted by the Programa de Botánica Marina in several wetlands of northwest México (Riosmena-Rodríguez and Sánchez-Lizaso 1996;Sánchez-Lizaso and Riosmena-Rodríguez 1997;Meling-López and Ibarra-Obando 1999;Santamaría-Gallegos et al 2001Riosmena-Rodríguez et al 2010;Rodríguez-Salinas et al 2010). In 4 of the 10 sampled sites for this work (Bahía Magdalena, Bahía Balandra, Laguna San Ignacio, Bahía Concepción), it seems that the appearance or greater abundance of R. maritima begun around 2007.…”

“…Wigeongrass is distributed along the Pacific and Atlantic coasts of México (Dawson 1962;Felger et al 1980;Flores-Verdugo et al 1988;Reyes and Merino 1991). At the Gulf of California and the west coast of the Baja California peninsula, R. maritima has been documented as a component of the seagrass community in some wetlands (MelingLópez and Ibarra-Obando 1999;Santamaría-Gallegos et al 2001Riosmena-Rodríguez et al 2010). However, information regarding R. maritima is not complete as records referring its presence do not give any information on its geographic location within these wetlands or its abundance.…”

Metal mobility and bioaccumulation differences at lower trophic levels in marine ecosystems dominated bySargassumspecies

“…However, Zn and Fe levels in C. simulans and S. sinicola tend to be higher than concentrations in species of the same genus from undisturbed sites with influence of upwelling, for example in S. sinicola (Zn: 9.3 mg g 21 and Fe: 186 mg g 21 ) (Huerta-Díaz et al, 2007) and C. cuneatum (Zn: 7.3 mg g 21 and Fe: 284 mg g 21 ) (Riosmena-Rodríguez et al, 2010).…”

An examination of coastal conservation by remote sensing in Baja California Sur, México

“…Their ecosystems perform key ecological functions (nutrient cycling, critical habitats, offspring dispersal, recruitment, nursery and breeding sites) and provide important ecosystem services (fisheries biomass, climate stability, leisure, tourism, food production) (Álvarez-Romero et al 2013;Carmona and Danemann 1997;Costanza et al 1997;de Groot et al 2002;Enríquez-Andrade et al 2005;Kremen 2005;Liu et al 2010). Specifically, the predominance of Ruppia maritima associated with coastal water bodies on the Gulf coast and of Zostera marina associated with coastal water bodies on the Pacific coast (Ramírez-García and Lot 1994;Riosmena-Rodríguez et al 2009;Ward et al 2004) are worth highlighting as a biological expression of the differences between the Gulf and the Pacific areas. The importance of the ecological functions and ecosystem services of seagrasses (Orth et al 2006) Fig.…”