Plankton crustaceans in bays with different trophic status in Llanquihue lake (41° S Chile) (original) (raw)
Related papers
Evidence of the Anthropic Impact on a Crustacean Zooplankton Community in Two North Patagonian Lakes
Sustainability
Lately, agriculture, livestock, forestry, and aquaculture activities have been greatly developed in Chilean North Patagonia, negatively impacting the balance of the environmental conditions in lakes and affecting the development and survival of several native species. The aim of this study was to assess the anthropic impact on a zooplankton community in two North Patagonian lakes. We collected samples from four sites belonging to Lake Icalma and Lake Llanquihue, including four replicates per site. Water samples were analyzed for physicochemical characteristics and zooplankton communities. We focused on the presence of Daphnia pulex, a species of zooplanktonic crustacean that performs a key role in capturing energy from primary producers to deliver it to final consumers such as fish. We found that Llanquihue showed higher total phosphorus, nitrogen, copper, iron, manganese, total dissolved solids (TDS), and conductivity (EC) than Icalma. Furthermore, ecological variables were greatly...
Annales de Limnologie - International Journal of Limnology, 2004
Zooplankton biomass was investigated monthly from September 1997 to August 1998 in a shallow eutrophic lake (San Miguel del Monte, Argentina). Duplicate samples of zooplankton were obtained from three stations with different limnological characteristics. The density of zooplankton community was dominated by rotifers and small cladocerans related to the trophic status of this shallow lake. The zooplankton biomass showed similar values to other eutrophic shallow lakes. The annual biomass distribution was bimodal (winter and summer peaks). The contribution of crustaceans, mainly copepods, determined the total biomass. The total zooplankton biomass was significantly correlated with chlorophyll «a» in the sampling station located at the deep part of this shallow lake. There were factors and processes promoting changes in the zooplankton biomass, such as food availability, grazing ability, fish predation, eutrophication process with alternation of turbid and clear water periods, and also the addition of organisms from the Salado River during floods.
Canadian Journal of Fisheries and Aquatic Sciences, 2005
The influence of trophic status on the crustacean zooplankton community was investigated in lakes and reservoirs in temperate and subtropical-tropical regions. We tested if there is a consistent relationship between crustacean species richness, assemblages, and abundance and trophic indices such as total phosphorus and chlorophyll a. We also examined if these patterns differ between regions. Cumulative species richness and assemblages varied among regions. The greatest number of crustacean species was found in the temperate oligotrophic region with the largest number of lakes sampled. However, cumulative species richness was similar in temperate and subtropical-tropical regions when comparing subsets with a similar number of lakes and reservoirs. The relationships between species richness and latitude or trophic status were difficult to assess owing to imbalance among regions in number of lakes and reservoirs sampled and to biogeography and fish predation potential influences. Trophic status was associated with changes in abundance of all major crustacean zooplankton groups. Eutrophic ecosystems supported greater crustacean abundances at all latitudes. However, cladocerans and cyclopoids were more abundant in eutrophic lakes and reservoirs, whereas calanoids were more abundant in temperate oligotrophic lakes. Total phosphorus was found to be a better predictor of the biomass of major crustacean groups than chlorophyll a in all regions.
Dynamics of the planktonic food web in Colgada Lake (Lagunas de Ruidera Natural Park)
Limnetica
In Colgada Lake, one of the 15 lakes belonging to Lagunas de Ruidera Natural Park, the components of the lineal food chain (phytoplankton and metazooplankton) and the microbial loop phytoplankton, metazooplankton, ciliates, autotrophic picoplankton, and bacterioplankton) were studied from June 2003 to December 2004 with a monthly sampling frequency. This lake has monomictic and mesotrophic characteristics and a mean depth of 8 m. Sixty-two species of the phytoplankton community, 27 species of metazooplankton community, and 12 species of ciliates were identified. Phytoplankton and metazooplankton integrated biomass followed seasonal patterns with higher values in summer, up to 10 5 mg WW/m 2 and 2 × 10 4 mg WW/m 2 , respectively. Autotrophic picoplankton did not exceed 500 mg WW/m 2 . Microbial loop components did not show seasonality, and its biomass concentration fluctuated between 500-2500 mg WW/m 2 for ciliates and 100-2000 mg WW/m 2 for bacterioplankton. Centric Bacillariophyceae, Cryptophyceae, and Dinophyceae represented most of the phytoplanktonic biomass throughout the studied period, although an increase of cyanobacteria was also observed. Cladocerans and calanoid copepods dominated during summer stratification, rotifers and cyclopoid copepods were present during the winter mixing period. The microbial loop biomass in relation to total planktonic biomass was higher in winter and spring 2004. Interannual changes in the presence of planktonic groups were observed in the different periods of the year: i) the algal composition included larger and non-edible species (Cyanobacteria, Dinophyceae), ii) a reduction in the clearance function by cladocerans was produced, which were substituted by a cyclopoid predator that iii) can feed on rotifers and ciliates, favouring in this way bacterioplankton and autotrophic pico-nanoplankton. This interannual variation could be related to the ongoing eutrophication process in the Lake. All of this may change the way the lake looks: if spring primary production is not strongly controlled by herbivory, this could threaten the annual recruitment of submerged macrophytes that significantly contribute to improve the water quality of the lake.
Brazilian Journal of Biology, 2021
The zooplankton communities often exhibit daily vertical migrations to avoid natural ultraviolet radiation and/or fish predation. However there is no information on this topic in Chilean North Patagonian lakes up to date. Therefore, this study deals with a first characterization of plankton crustacean daily vertical migration in two temperate, oligotrophic lakes (Villarrica and Panguipulli lakes, 39°S) in Southern Chile. Zooplankton were collected at different depths intervals (0-10m, 10-20 m, 20-30m, 30-40m) at early morning, middle day, evening and night in the studied site. The results revealed that zooplankton species (Daphnia pulex, Ceriodaphnia dubia, Neobosmina chilensis, Mesocyclops araucanus, and Tropocyclops prasinus) are abundant in surface zones at night, early morning and evening, whereas at middle day the zooplankton abundances are high at deep zones. The results agree with observations for Argentinean and North American lakes where these daily migration patterns in cr...
Journal of King Saud University - Science, 2020
The Chilean Patagonian lakes are characterized by their marked oligotrophic or oligomesotrophic status and low zooplankton species abundances, many of these lakes with oligomesotrophic status is associated to human intervention due towns in their shores. The aim of the present study was determine the relations between spectral properties (LANDSAT/OLI), chlorophyll and plankton abundances in two north Patagonian lakes, Villarica, that has two towns in its shore, and Caburgua, that has native forest in its shores as basis of environmental pollution monitoring tools. The results revealed that Villarica lake has high reflectances in near infrared, red and green bands, high chlorophyll (a, b and c) concentrations, and high bacterial and plankton abundances, whereas Caburgua lakes has low reflectance in the same bands, and low chlorophyll concentrations, low bacterial and plankton abundances, with exception to high mixotrophic ciliates. The obtained results agree with limnological observations about both lakes, and the comparison with spectral properties agree with similar observations for glacial north Patagonian lakes about spectral properties and zooplankton community.
Crustaceana, 2017
The Chilean north Patagonian inland waters are characterized by their low mineral concentrations. In their original status, many of these ecosystems have native vegetation in their surrounding drainage basins, but in the last decades the native vegetation was replaced by agricultural, urban, and industrial zones, with as a result of these human alterations that those aquatic communities changed. The aim of the present study was to make a literature review about the ecological role of crustaceans in Chilean north Patagonian lakes and rivers. The literature mentioned the presence of amphipods (Hyalella), crayfishes (Samastacus spinifrons), and freshwater crabs (genusAegla), and many of these species hold a conservation risk due to the consequences of habitat damage and/or their high endemism. These crustaceans are important for the degradation of particulate organic matter originating from the surrounding vegetation, and are prey for native and introduced salmonid fishes. Similar patt...
Revista chilena de historia natural, 2003
Lake Riñihue is the last in a chain of glacially derived oligotrophic lakes in southern Chile and was the subject of limnological research by Dr. Hugo Campos and co-workers at the Universidad Austral de Chile, Valdivia, Chile, since the 1970's. Prof. Campos died in the field in 1998, and this paper now presents a review of these data with comments on methodology relevant to trophic parameters of this lake. Data are presented on inorganic nutrients, chlorophyll a, phytoplankton biomass, primary production and Secchi depth obtained over a period of 21 years between 1978 and 1997 in order to evaluate potential changes in these parameters over time. Non-parametric Wilcoxon rank sum tests were applied to determine temporal trends and revealed: (1) total phosphorus showed a significant increase (TP: 2.7 mg P L-1 to 6.5 mg P L-1), (2) Secchi depth, soluble reactive phosphorus and primary production did not change significantly, (3) chlorophyll a changed significantly among different years, but did not reveal a clear temporal trend, (4) nitrate showed an upward trend and increased concentrations during the early 1990 period, although this data remain in doubt due to methodological anomalies, and (5) the phytoplankton biomass showed significantly higher values during the 1980 period. The significant increase in total phosphorus may reflect increasing usage of grassland within the catchment area. A number of anomalies discovered in historical data sets related to methodology are analysed and discussed within the context of the study.