scholarly journals Cladoceran Zooplankton Abundance under Clear and Snow-Covered Ice

2003 ◽  
Vol 18 (1) ◽  
pp. 169-170 ◽  
Author(s):  
Timothy J. DeBates ◽  
Steven R. Chipps ◽  
Matthew C. Ward ◽  
Kent B. Werlin ◽  
Paul B. Lorenzen
2011 ◽  
Vol 4 (2) ◽  
pp. 163-169 ◽  
Author(s):  
Ritwik Dasgupta

The facts that small hatchlings emerged from small eggs laid under high predation levels prevailing at the lower altitudes of distribution of this species in Darjeeling while larger hatchlings emerged from larger eggs laid under lower levels of predation at higher altitudes, show that predation is not selected for large egg and initial hatchling size in this salamandrid species. Metamorphic size was small under high predation rates because this species relied on crypsis for evading predators. Egg and hatchling size are related inversely to levels of primary productivity and zooplankton abundance in lentic habitats. Hatchling sizes are related positively to egg size and size frequency distribution of zooplankton. Small egg and small hatchling size have been selected for at the lower altitudes of distribution of this salamandrid in Darjeeling because predation rates increased in step with improvement in trophic conditions at the lower altitudes.


2017 ◽  
Vol 4 (1) ◽  
pp. 151
Author(s):  
Hasanuddin Parulian Sihombing ◽  
I Gede Hendrawan ◽  
Yulianto Suteja

Lemuru fish is one of fishery commodity that has high economical value and one of fish that most catched by fisherman in Bali Strait. Lemuru fish had been caught in Bali Strait was fluctuating every month and every years. This condition was related with food source of Lemuru fish such as phytoplankton and zooplankton. So this research was conducted to explained the relationship phytoplankton and zooplankton abundance with Lemuru fish catched  in Bali strait. This study focus in Bali strait during March until May 2017. Determination of sampling point used area sampling method while water sampling occured in surface water with pouring method. Total of phytoplankton and zooplankton abundance in Bali strait in March until May had formed the sinusoidal model with their abundance ranged 301 ind/L – 604 ind/L and 7 ind/L – 12 ind/L. Plankton abundance in Bali strait in March until May (transisonal season 1) was categorized low abundance if compared with plankton abundance in another season. The low value of phytoplankton abundance caused by non upwelling phenomenon and grazing process and the low abundance of zooplankton caused by low rate of zooplankton and predation by Lemuru fish. Phytoplankton and zooplankton abundance had  strong relationship with Lemuru fish catched with correlation coefficient value 0.76 and 0.69. This condition caused by phytoplankton and zooplankton are source of Lemuru fish food.


1991 ◽  
Vol 38 (6) ◽  
pp. 677-691 ◽  
Author(s):  
Karen J. Heywood ◽  
S. Scrope-Howe ◽  
E.D. Barton

2011 ◽  
Vol 83 (2) ◽  
pp. 575-588 ◽  
Author(s):  
Charrid Resgalla Jr

This paper presents information from different sampling surveys carried out along the Santa Catarina coast in order to outline the biogeographical characteristics of the zooplankton in this region and identify species or groups of species with potential use as bioindicators. Based on a checklist of species of the zooplankton community in the state, it was observed that, in the warmer months of the year, the fauna is similar to that of the states of Paraná and São Paulo (e.g. Creseis virgula f. virgula, Penilia avirostris; Acartia lilljeborgi and Oithona oswaldocruzi), while in the colder months there are coastal representatives of the fauna of Rio Grande do Sul (e.g. Acartia tonsa). However, the zooplankton consists predominantly of warm water species for most of the year, which is typical of Tropical Shelf Waters. Various species of zooplankton can be used as hydrological indicators, enabling a distinction to be made between coastal waters which are influenced by continental inputs (e.g. Paracalanus quasimodo and Parvocalanus crassirostris), common in the north of the state, and processes of upwelling (e.g. Podon intermedius) and the influence of the Subtropical Shelf Front (e.g. Pleopis polyphemoides), coming from the south. The different environments investigated present a zooplankton abundance that depends on the influence of continental inputs and the possibility of their retaining and contribution for the coastal enrichment, which varies seasonally


2001 ◽  
Vol 58 (2) ◽  
pp. 421-436 ◽  
Author(s):  
E E Prepas ◽  
B Pinel-Alloul ◽  
D Planas ◽  
G Méthot ◽  
S Paquet ◽  
...  

Eleven headwater lakes in Alberta's Boreal Plain were monitored for nutrients and plankton 2 years before and 2 years after variable watershed harvesting (harvesting mean 15%, range 0-35%). After harvesting, variations in annual precipitation resulted in lake water residence times that differed by an order of magnitude from one year to the next. During the first posttreatment year, total phosphorus concentrations increased (overall 40%) in most lakes; however, response was most consistent in lakes that were shallow and the water column mixed or weakly thermally stratified. Chlorophyll a, cyanobacteria (Aphanizomenon-Anabaena), and cyanotoxins (microcystin-LR) increased after harvesting, primarily in shallow lakes. Zooplankton abundance and biomass decreased after harvesting, particularly in stratified lakes where edible phytoplankton biomass declined. In the weakly or nonstratified lakes, declines in zooplankton biomass were associated with higher cyanobacterial biomass and cyanotoxins. Posttreatment change in total phosphorus concentration was strongly related to weather (greatest response in a wet year) and relative drainage basin size (drainage basin area to lake volume, r2 = 0,78, P << 0,01). There was no evidence that buffer strip width (20, 100, and 200 m) influenced lake response. These results suggest that activities within the entire watershed should be the focus of catchment-lake interactions.


2017 ◽  
Vol 65 (3) ◽  
pp. 495-508
Author(s):  
William Bauer ◽  
Paulo Cesar Abreu ◽  
Luis Henrique Poersch

Abstract Water quality, chlorophyll a, phytoplankton, proto and mezo-zooplankton abundance were spatiotemporally evaluated in an estuary receiving effluents from a Pacific white shrimp Litopenaeus vannamei farm in Patos Lagoon estuary, Southern Brazil. Samples were taken before (BD) and; 1 day (1 PD) 5 days (5 PD), 10 days (10 PD), 20 days (20 PD) and 30 days (30 PD) after the effluents discharge. Some water quality parameters were affected by the effluents discharge; however, these changes were restricted to a distance of 20 m from the effluent discharge channel for a period of 5 days. The microbial community was dominated by chlorophyceae, followed by diatoms, cyanobacteria and ciliates. There was an increase in the abundance of different groups on the 1 PD sampling compared to BD. The zooplankton abundance was low in practically all sites, except for 30 PD sampling. The meso-zooplanktonic organisms were represented by copepods, mostly Acartia tonsa. Despite some effects on water quality and phytoplankton and protozooplankton abundance until 5 PD sampling, these alterations dissipated in a short period of time. We conclude that the environment quickly assimilated the effluents discharge, and the water quality parameters remained within the limits stipulated by standard guidelines.


Sign in / Sign up

Export Citation Format

Share Document