Ecological monitoring of intertidal phytobenthic communities of the Basque Coast (N. Spain) following the Prestige oil spill

Abstract

Following the Prestige oil spill, six-monthly samplings (spring and autumn) of intertidal macroalgal assemblages were carried out from 2004 to 2006 in twelve locations along the Basque coast. Macroalgal species appeared to be little modified, but species richness, diversity, and algal cover were significantly lower in the first year of the study, so it cannot be ruled out that the arrival of oil on the Basque coast might have had a damaging effect on intertidal communities. On the other hand, no significant differences were detected between locations slightly and moderately affected by oil in any of the structural parameters considered. By contrast, significant differences were detected between locations within each oiling level that indicate that other natural environmental factors play a greater role in the differences between locations than the oiling level. Likewise, significant differences were detected between areas within each location which were not consistent with time, indicating that communities are highly heterogeneous in species richness, diversity and algal cover at the scale of tens of meters. The dominant Corallina elongata and most of the accompanying species did not show significant year-on-year differences in terms of cover. Also, there were no differences between the two oiling levels. Analyses revealed a high spatial variability at the scale of kilometers (locations) and tens of meters (areas) for most of the taxa. The results obtained provide detailed quantitative data on intertidal phytobenthic assemblages of the Basque coast at different spatial and temporal scales that were hitherto unavailable for the region.

Environmental DNA (eDNA) metabarcoding reveals strong discrimination among diverse marine habitats connected by water movement

“…Samples were taken immediately following high tide on 22 October 2016 within a 3-hr window to ensure the detection of intertidal species assemblages. This community was targeted for their high levels of impact by human activities (Suchanek, 1994) and their frequent inclusion in monitoring programs due to ease of sampling (Díez, Secilla, Santolaria, & Gorostiaga, 2008;Moyses, Junqueira, & Lavrado, & Silva, 2007). Immediate post-high-tide sampling also ensured a unidirectional water flow out of Otago Harbor (Old & Vennell, 2001).…”

The chronic effects of oil pollution on marine phytoplankton in a subtropical bay, China

“…The median effective concentrations (EC 50 ) of certain kinds of microalgae exposed to oil were measured (Liu et al 2006;Bopp and Lettieri 2007;Meng et al 2007;Paixão et al 2007; and different toxicities of oil components and oil products were compared (Gordon and Prouse 1973;Pulich et al 1974;Liu et al 2006;. Field researchers investigated the change of phytoplankton after oil spillage in certain sea areas (Linden et al 1979;Salas et al 2006;Varela et al 2006;Díez et al 2009). Some researchers focused on the gene (Bopp and Lettieri 2007) or protein (Wolfe et al 1999) levels of certain types of microalgae exposed to oil contamination.…”

Variation in rocky shore assemblages and abundances of key taxa along gradients of stormwater input

“…Taxon richness was lowest between 0 and 20 m from a stormwater outfall and highest after 20 m, with effects generally negated after 60 m. The lowest percentage cover of both perennial and ephemeral algae was recorded at 10 m for all shores. Although some studies (Diez et al 2009) have reported lower algal cover close to the source of pollution, many studies have reported the proliferation of ephemeral algae in areas associated with pollution (Soltan et al 2001;Barille-Boyer et al 2004). An increase in ephemerals has been linked to direct enrichment by nutrients (Borowitkza, 1972) or a decrease in the number of grazers.…”