Coastal pollution from the industrial park Quintero bay of central Chile: Effects on abundance, morphology, and development of the kelp Lessonia spicata (Phaeophyceae).

The industrial park of Quintero Bay (QB) in the central coast of Chile was established in the 1960s, presents high levels of pollution due to the industrial activity, and it is known as one of the five Chilean "sacrifice zones". Lessonia spicata is the most important habitat-forming kelp species in the intertidal along the central and south shores of Chile, and currently there are no morphometric and population studies of L. spicata (or other seaweed species) nor studies about the effects of pollution on its development in QB and neighbouring sites. In this context, the aims of this study were (i) to register the abundance and morphological features of L. spicata populations from Ventanas, Horcón and Cachagua (sites with different pollution histories and located only up to 40 km from the QB); ii) to determine the heavy metals (HMs) concentration in seawater and marine sediments; and (iii) to evaluate in vitro the effects of exposure to seawater from the three sampling sites on spore release and early developmental stages, up to the juvenile sporophyte. Results showed that the chronically exposed Ventanas kelp population had the smallest adult individuals in comparison with the other sites. Ventanas and Horcón registered high HMs concentration in the seawater and marine sediments exceeding the international permissible limits (e.g in seawater Cu 20-859 µg L-1; sediments Cu > 50,000 µg kg-1). Unexpectedly in Cachagua, a site often considered unpolluted, high concentrations of Cu and As were also registered in the seawater (859 and 1,484 µg L-1, respectively) and of As in marine sediments (20,895 µg kg-1). Exposure of gametophytes to the seawater from Ventanas resulted in a developmental delay compared to the other treatments; however, low sporophyte production was determined in all treatments. Our results indicate that QB, more notably Ventanas, induce highly negative effects on individual development, and consequently on seaweed populations, which suggest a long-term negative impact on the community structure of these marine zones. Furthermore, the high concentrations of HMs reported here at Cachagua suggest a recent expansion of pollution along the central coast of Chile, evidencing effects on the marine ecosystem health even on sites far from the pollution source.

Effects of seven antifouling compounds on photosynthesis and inorganic carbon use in sugar kelp Saccharina latissima (Linnaeus).

Macroalgae depend on carbon-concentrating mechanisms (CCMs) to maintain a high photosynthetic activity under conditions of low carbon dioxide (CO(2)) availability. Because such conditions are prevalent in marine environments, CCMs are important for upholding the macroalgal primary productivity in coastal zones. This study evaluated the effects of seven antifouling compounds-chlorothalonil, DCOIT, dichlofluanid, diuron, irgarol, tolylfluanid, and zinc pyrithione (ZnTP)-on the photosynthesis and CCM of sugar kelp (Saccharina latissima (L.)). Concentration-response curves of these toxicants were established using inhibition of carbon incorporation, whereas their effects over time and their inhibition of the CCM were studied using inhibition of O(2) evolution. We demonstrate that exposure to all compounds except ZnTP (< 1000 nM) resulted in toxicity to photosynthesis of S. latissima. However, carbon incorporation and O(2) evolution differed in their ability to detect toxicity from some of the compounds. Diuron, irgarol, DCOIT, tolylfluanid, and, to some extent, dichlofluanid inhibited carbon incorporation. Chlorothalonil did not inhibit carbon incorporation but clearly inhibited oxygen (O(2)) evolution. Photosynthesis showed only little recovery during the 2-h postexposure period. Inhibition of photosynthesis even increased after the end of exposure to chlorothalonil and tolylfluanid. Through changes in pH of the medium, toxic effects on the CCM could be studied isolated from photosynthesis effects. The CCM of S. latissima was inhibited by chlorothalonil, DCOIT, dichlofluanid, and tolylfluanid. Such inhibition of the CCM, or the absence thereof, deepens the understanding the mechanism of action of the studied compounds.

The use of kelp sieve tube sap metal composition to characterize urban runoff in southern California coastal waters.

This study introduces an innovative method for biomonitoring using giant kelp (Macrocystis pyrifera) sieve tube sap (STS) metal concentrations as an indication of pollution influence. STS was sampled from fronds collected from 10 southern California locations, including two reference sites on Santa Catalina Island. Using ICP-MS methodology, STS concentrations of 17 different metals were measured (n=495). Several metals associated with pollution showed the highest STS concentrations and most seasonal variation from populations inside the Port of Los Angeles/Long Beach. Lowest concentrations were measured at less-urbanized areas: Santa Catalina Island and Malibu. Some metals showed a spatial gradient in STS metal concentration with increasing distance from point sources (i.e. Los Angeles River). Cluster analyses indicate that polluted seawater may affect kelp uptake of metals essential for cellular function. Results show that this method can be useful in describing bioavailable metal pollution with implications for accumulation within an important ecosystem.

Effects of copper on early developmental stages of Lessonia nigrescens Bory (Phaeophyceae).

Copper effects on the early developmental gametophytic and sporophytic stages of the kelp Lessonia nigrescens were tested in gradients of increasing concentrations of ASV-labile copper. The results demonstrated a high sensitivity to copper of all life-history stages of the alga, where even the lowest tested concentration affected spore release as well as their subsequent settlement. More significant, concentrations higher than 7.87 microg L(-1) totally interrupted the development of the spores after they settle. This effect led to a failure in the formation of male and female gametophytes and, as a consequence, to a complete disruption of the normal life cycle of the kelp. Thus, we suggest that the absence of L. nigrescens from copper-enriched environments results from the high sensitivity of its early life cycle stages, which limits growth and maturation of the gametophytic microscopic phase and, as a consequence, prevents development of the macroscopic sporophytic phase.