Going deeper into phosphorus adsorbents for lake restoration: Combined effects of magnetic particles, intraspecific competition and habitat heterogeneity pressure on Daphnia magna

Autor: Ana del Arco, Inmaculada de Vicente, Gema Parra
Rok vydání: 2018
Předmět:
0106 biological sciences
congenital
hereditary
and neonatal diseases and abnormalities
Health
Toxicology and Mutagenesis
media_common.quotation_subject
Daphnia magna
Population
Context (language use)
010501 environmental sciences
01 natural sciences
Population density
Intraspecific competition
Competition (biology)
Lethal Dose 50
Magnetics
Animal science
Abundance (ecology)
Animals
Particle Size
skin and connective tissue diseases
education
Ecosystem
Environmental Restoration and Remediation
0105 earth and related environmental sciences
media_common
education.field_of_study
biology
Chemistry
Ecology
010604 marine biology & hydrobiology
Public Health
Environmental and Occupational Health
nutritional and metabolic diseases
Phosphorus
General Medicine
biology.organism_classification
Pollution
Spatial heterogeneity
Lakes
Daphnia
Water Pollutants
Chemical
Zdroj: Ecotoxicology and Environmental Safety. 148:513-519
ISSN: 0147-6513
DOI: 10.1016/j.ecoenv.2017.11.001
Popis: Aquatic population responses to chemical exposure may be exacerbated by intraspecific competition pressures, being also shaped by habitat heterogeneity. Magnetic particles (MPs) have been recently proposed as promising phosphorus (P) adsorbents for lake restoration. This study focuses on assessing the effects of MPs on the abundance of the crustacean Daphnia magna under different levels of both intraspecific competition pressure and habitat heterogeneity. The experimental design consisted of two experiments (in homogeneous and heterogeneous habitats) done in glass jars with four concentrations of MPs: controls of 0 g MPs L−1, and treatments of 1, 1.5 and 2 g MPs L−1. In addition, competition treatments were established by using different population densities, and hence, no competition (C), low (L) and high (H) competition pressures were simulated. The experiments lasted for 7 days, with a 4-day pre-exposure period, in which competition was all allowed to take place, and a 3-day post-exposure period. Twenty-four hours after adding MPs, the MPs were removed by applying a magnetic separation technique. The results showed that competition pressures occurred and significantly reduced population abundances during the pre-exposure period. During the post-exposure period, the combined effects of competition and MPs were detected in both homogeneous (Ho-) and heterogeneous (He-) habitat experiments, showing a significantly drastic reduction in abundances. In fact, the lethal concentration for 50% of the population (LC50 -24 h) was 0 and 0.16 g MPs L−1 in the Ho- and He-experiments respectively, indicating that the addition and especially the removal of MPs cause extreme mortality. These results indicated that even though competition plays a role in shaping populations, its influence was down-weighted by the stronger pressures of MPs. In addition, as no significant differences between homogeneous and heterogeneous habitats were found, we may state that the refuge offered was not protective enough to avoid the effects of MPs. In conclusion, the removal of the MPs causes drastic effects on D. magna abundances despite the concentration of MPs, competition or habitat structure. Finally, considering the validated high efficiency of MPs for P removal, and in the context of a future whole-lake application, it is essential to restrict the use of MPs to the moments when D. magna is absent in the study site. Further research on the effects of MP removal on other organisms is required before implementing the addition of MPs as a restoration tool.
Databáze: OpenAIRE
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