Negative Consequences on the Growth, Morphometry, and Community Structure of the Kelp <i>Macrocystis pyrifera</i> (Phaeophyceae, Ochrophyta) by a Short Pollution Pulse of Heavy Metals and PAHs

• Main Authors: Roddy Jara-Yáñez, Andrés Meynard, Gladys Acosta, Nicolás Latorre-Padilla, Carolina Oyarzo-Miranda, Francisco Castañeda, Florentina Piña, Jorge Rivas, Cristian Bulboa, Loretto Contreras-Porcia
• Format: Article
• Language: English
• Published: MDPI AG 2021-08-01
• Series: Toxics
• Subjects: community structure; ecosystem health; growth; heavy metals; <i>Macrocystis pyrifera</i>; marine contamination
• Online Access: https://www.mdpi.com/2305-6304/9/8/190

The study of pollution effects in the marine environment has become important in recent decades, and the exposure to simultaneous pollutants has become especially relevant. Indeed, the study of key organisms, such as ecosystem engineers, can show a broader view of the effects of pollutants. In this context, we evaluate in situ the effects of a short (7-day) pollution pulse of combined solutions of heavy metals and polycyclic aromatic hydrocarbons (PAHs) (Cu + PAHs, Cd + PAHs, Cu + Cd, and Cu + Cd + PAHs) on the development and morphological features of <i>Macrocystis pyrifera</i> sporophytes over a period of 90 days. Additionally, we determined the effects on the community structure associated with this kelp. This study evidenced a smaller number of blades and a decreased size of blades and holdfasts, as well as the death of individuals exposed to a secondary mix of metals (Cu + Cd) and a tertiary mix of pollutants (Cu + Cd + PAHs). Regarding the effects on the accompanying fauna, low richness and diversity were registered. <i>M. pyrifera</i> grazers, according to the mixture of pollutants, were either absent or diminished. These results show that the pulse of contamination in the early stages of <i>M. pyrifera</i> negatively affects its development and morphometry, as well as its role as an ecosystem engineer, due to a negative alteration in the species composition.