| 1. |
- Ger, Kemal Ali, et al.
(författare)
-
The interaction between cyanobacteria and zooplankton in a more eutrophic world
- 2016
-
Ingår i: Harmful Algae. - : Elsevier BV. - 1568-9883. ; 54, s. 128-144
-
Forskningsöversikt (refereegranskat)abstract
- As blooms of cyanobacteria expand and intensify in freshwater systems globally, there is increasing interest in their ecological effects. In addition to being public health hazards, cyanobacteria have long been considered a poor quality food for key zooplankton grazers that link phytoplankton to higher trophic levels. While past laboratory studies have found negative effects of nutritional constraints and defensive traits (i.e., toxicity and colonial or filamentous morphology) on the fitness of large generalist grazers (i.e., Daphnia), cyanobacterial blooms often co-exist with high biomass of small-bodied zooplankton in nature. Indeed, recent studies highlight the remarkable diversity and flexibility in zooplankton responses to cyanobacterial prey. Reviewed here are results from a wide range of laboratory and field experiments examining the interaction of cyanobacteria and a diverse zooplankton taxa including cladocerans, copepods, and heterotrophic protists from temperate to tropical freshwater systems. This synthesis shows that longer exposure to cyanobacteria can shift zooplankton communities toward better-adapted species, select for more tolerant genotypes within a species, and induce traits within the lifetime of individual zooplankton. In turn, the function of bloom-dominated plankton ecosystems, the coupling between primary producers and grazers, the stability of blooms, and the potential to use top down biomanipulation for controlling cyanobacteria depend largely on the species, abundance, and traits of interacting cyanobacteria and zooplankton. Understanding the drivers and consequences of zooplankton traits, such as physiological detoxification and selective vs. generalist grazing behavior, are therefore of major importance for future studies. Ultimately, co-evolutionary dynamics between cyanobacteria and their grazers may emerge as a critical regulator of blooms.
|
|
| 2. |
- Sarnelle, Orlando, et al.
(författare)
-
Effects of cyanobacteria on fitness components of the herbivore Daphnia
- 2010
-
Ingår i: Journal of Plankton Research. - : Oxford University Press (OUP). - 0142-7873 .- 1464-3774. ; 32:4, s. 471-477
-
Tidskriftsartikel (refereegranskat)abstract
- Cyanobacteria are known to negatively affect their herbivores either by being of low nutritional value, by clogging the feeding apparatus or by producing toxins, and specifically, the role of toxins has been debated. Hence, in order to assess to what extent cyanobacterial toxins affect a major herbivore (Daphnia magna) that has had previous experience of cyanobacterial toxins, we conducted a life-table study using two otherwise-similar strains of Microcystis aeruginosa, one producing and one not producing the toxin microcystin. In contrast to previous studies, we found that Daphnia population growth was positive (r > 0.1 day(-1)) on a diet containing toxic Microcystis. However, we also found that the presence of the toxin negatively affected early survival and population growth of a microcystin-tolerant D. magna clone. Although there was no effect of toxin presence on per-capita fecundity of surviving adults, Daphnia produced smaller neonates when fed toxin-containing M. aeruginosa than when fed the non-toxic mutant. Hence, although Daphnia survival, population growth and neonate size were negatively affected by microcystin presence, Daphnia populations that have prior experience with toxic cyanobacteria may show positive population growth even at high concentrations of cyanobacterial toxins. This conclusion may have considerable implications for interactions between toxic cyanobacteria and herbivores in natural systems.
|
|
| 3. |
- Soranno, Patricia A., et al.
(författare)
-
LAGOS-NE : A multi-scaled geospatial and temporal database of lake ecological context and water quality for thousands of U.S. lakes
- 2017
-
Ingår i: GigaScience. - : Oxford University Press (OUP). - 2047-217X. ; 6:12, s. 1-22
-
Tidskriftsartikel (refereegranskat)abstract
- Understanding the factors that affect water quality and the ecological services provided by freshwater ecosystems is an urgent global environmental issue. Predicting how water quality will respond to global changes not only requires water quality data, but also information about the ecological context of individual water bodies across broad spatial extents. Because lake water quality is usually sampled in limited geographic regions, often for limited time periods, assessing the environmental controls of water quality requires compilation of many data sets across broad regions and across time into an integrated database. LAGOS-NE accomplishes this goal for lakes in the northeastern-most 17 US states. LAGOS-NE contains data for 51101 lakes and reservoirs larger than 4 ha in 17 lake-rich US states. The database includes 3 datamodules for: lake location and physical characteristics for all lakes; ecological context (i.e., the land use, geologic, climatic, and hydrologic setting of lakes) for all lakes; and in situmeasurements of lake water quality for a subset of the lakes fromthe past 3 decades for approximately 2600–12 000 lakes depending on the variable. The database contains approximately 150000 measures of total phosphorus, 200 000 measures of chlorophyll, and 900 000 measures of Secchi depth. The water quality data were compiled from87 lake water quality data sets fromfederal, state, tribal, and non-profit agencies, university researchers, and citizen scientists. This database is one of the largest andmost comprehensive databases of its type because it includes both in situmeasurements and ecological context data. Because ecological context can be used to study a variety of other questions about lakes, streams, and wetlands, this database can also be used as the foundation for other studies of freshwaters at broad spatial and ecological scales
|
|
