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Nano- and picoplankton growth and production in the Bay of Villefranche sur Mer (N.W. Mediterranean)
R. W. Sheldon F. Rassoulzadegan F. Azam T. Berman D. S. Bezanson M. Bianchi D. Bonin Å Hagström M. Laval-Peuto J. Neveux P. Raimbault A. Rivier B. Sherr E. Sherr F. Van Wambeke J. Wikner A. M. Wood C. M. Yentsch 《Hydrobiologia》1992,241(2):91-106
Plankton production in the Bay of Villefranche was relatively constant during March and April 1986 but the particle size at which the production occurred was more variable. At the beginning of the study, production was dominated by the larger (ca. 6 m) flagellates but towards the end it was more or less equally divided between the nano- and picoplankton. There were considerable differences in the estimates of population growth rates, depending on the methods used, but on average the population doubling times were close to 12 hours for autotrophs and 24 hours for heterotrophs. As autotrophs do not grow during the night, each population was therefore doubling once per day. It seemed that each of the nanoor picoplankton populations could adversely affect the growth of the others. This could be either by simple predation or by some form of inhibition. Although nutrient levels in the bay were uniformly low, the addition of nutrients did not always stimulate algal growth. The plankton populations seemed to be both in a state of equilibrium and intense ecological competition. 相似文献
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Lourdes Vásquez-Yeomans Enrique Carrillo-Barrios-Gómez Eloy Sosa-Cordero 《Environmental Biology of Fishes》1990,29(3):193-200
Synopsis The nanoflagellateTetraselmis suecica was tested both as the sole food source and as a diet complement toArtemia nauplii for grunion,Leuresthes tenuis, larvae. A total of 4800 grunion larvae, obtained through artificial insemination and incubation, were cultivated under laboratory conditions. Growth and survival rates were registered for 14 days in two experimental series. In the first series the nanoflagellateT. suecica was offered as the sole food source at five different concentrations. Survival and growth increased in agreement with the increase inT. suecica concentration. In the second series,Artemia nauplii were offered at six concentration levels. This series was divided into two groups: the nanoflagellateT. suecica was added to one group at a concentration of 5000 cells ml–1; the other group was maintained without nanoflagellates. In this series, survival and growth were directly related to nauplii concentration, but significant effects of the nanoflagellates were evident only in relation to the survival; the greatest difference (58% without nanoflagellates vs. 69% with nanoflagellates) was observed at anArtemia concentration of 1000 nauplii 1–1. The mechanism responsible for increased survival ofL. tenuis larvae in presence of phytoplankton is unclear. 相似文献
3.
The distribution of picoplankton and nanoplankton in Kongsfjorden,Svalbard during late summer 2006 总被引:2,自引:0,他引:2
Abundance and biomass of pico- (<2 μm) and nanoplankton (2–20 μm) were investigated in relation to hydrography in Kongsfjorden,
Svalbard (79°N, 12°E) during late summer 2006. Autotrophic and heterotrophic picoplankton abundance ranged from 0.1 × 106 to 35.2 × 106 cells L−1 and from 0.4 × 106 to 20.3 × 106 cells L−1, respectively. The highest number of bacteria in the entire water column was recorded at station 2 at 10 m (22.3 × 108 cells L−1); the lowest concentration was observed at station 1 (6.0 × 108 cells L−1). The abundance of autotrophic and heterotrophic nanoplankton varied from 0.4 × 105 cells L−1 to 46 × 105 cells L−1 and from 0.3 × 106 to 9.1 × 106 cells L−1, respectively. Our results demonstrated that heterotrophic nanoflagellates and bacteria in Kongsfjorden microbial community
were relatively important. The structure of plankton communities integrated with environmental variables could act as indicators
of the variability of the inflow of Atlantic Water into Kongsfjorden. 相似文献
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Standing stocks of ciliate plankton and its prey candidates, both picoplankton and nanoplankton, were investigated in spring
in the East China Sea. The former was 1.36 × 105–1.54 × 108 μm3 l−1 in biovolume, and the latter was 5.33 × 106–1.11 × 108 μm3 l−1. The biovolume ratio of ciliate plankton to prey candidates ranged from 1.31 × 10−2 to 2.00 × 100; it was larger in abundant prey conditions and smaller in sparse preys. Making some plausible assumptions about physiological
activity on both organisms, every ratio meet the quantitative restriction that prey production should be equal to or larger
than ciliate consumption. However, prey candidates would be so sparsely distributed that ciliate plankton could not capture
sufficient prey organisms in its random filter-feeding manner. Even though planktonic ciliates must have some extraordinary
mechanisms to capture preys efficiently, this quantitative imbalance might be one of the reasons for decreasing ciliate/prey
ratio in sparse prey conditions.
Handling editor: K. Martens 相似文献
5.
Cláudia Fileto Marlene S. Arcifa Aloysio S. Ferrão-Filho Lúcia Helena S. Silva 《Aquatic Ecology》2005,38(4):503-514
The influence of two seston fractions, < 20 µm (nanoplankton) and 20 µm (microplankton), on growth and reproduction of cladoceran species with different sizes, from Lake Monte Alegre, was evaluated through individual growth and life table experiments. Size, shape and other features of the algae in the fractions were described. The procedure of filtering lake water through a 20 µm net for seston fractionation caused mutual contamination. The smallest cladoceran species, Ceriodaphnia cornuta Sars and Moina micrura Kurz, produced larger clutch sizes and exhibited higher intrinsic rates of population growth (r) in the nanoplankton, despite contamination of their food by inedible algae. The largest species, Simocephalus mixtus Sars, produced larger clutch sizes in the microplankton. There were no differences in juvenile biomass growth between treatments for M. micrura and Daphnia gessneri Herbst, but lower value of the exponential growth rate (g) in the microplankton was significant for M. micrura. Fecundity (eggs/total female) of M. micrura was significantly lower in the microplankton, while D. gessneri did not reproduce in this fraction, at the end of growth experiments. Spines, colonies, cenobium, filaments, hard cell wall, and gelatinous sheaths, represented constraints to cladoceran reproductive performance, besides algae size. Microplankton contamination by nanoplanktonic algae, in the experiments, probably minimized the negative effect of inedible algae. Nanoplankton was more suitable for the smallest species and microplankton for the largest one. 相似文献
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Prymnesium parvum invasion success into coastal bays of the Gulf of Mexico: Galveston Bay case study
《Harmful algae》2015
The toxic haptophyte Prymnesium parvum regularly forms fish-killing blooms in inland brackish water bodies in the south-central USA. Along the Texas coast smaller blooms have occurred in isolated areas. There appears to be an increasing risk that harmful P. parvum blooms will propagate into open coastal waters with implementation of future water plans. These plans will include increased interbasin water transfers from the Brazos River, regularly impacted by P. parvum blooms, to the San Jacinto-Brazos Coastal Basin, which ultimately flows into Galveston Bay (GB). Persisting source populations of P. parvum in inland waters elevates this risk. Thus, there is a need for an increased understanding of how P. parvum might perform in coastal waters, such as those found in GB. Here, two in-field experiments were conducted to investigate the influence of various plankton size-fractions of GB water on inoculated P. parvum during fall and winter, periods when blooms are typically initiating and developing inland. Stationary- and log-growth phase P. parvum were used to represent high and low toxicity initial conditions. Results revealed that P. parvum could grow in GB waters and cause acute mortality to silverside minnows (Menidia beryllina). Depending on season and growth phase, however, P. parvum growth and toxicity varied in different size fractions. During the fall, P. parvum inoculated from stationary-, but not log-growth phase culture, was negatively affected by bacteria-sized particles. During the winter, bacteria and nanoplankton together had a negative effect on P. parvum inoculated from stationary- and, to a lesser degree, log-growth phase cultures. Intermediate- and large-sized grazers when combined with bacteria and nanoplankton had complex relationships with inoculated P. parvum, sometimes stimulating and sometimes suppressing population growth. Toxicity to fish occurred in almost all plankton size fractions. The inclusion of progressively larger sized plankton fractions resulted in trends of decreased toxicity in treatments inoculated with stationary-, but not log-growth phase P. parvum in the fall. In the winter, however, inclusion of larger sized plankton fractions resulted in trends of increased toxicity to fish in treatments inoculated with both stationary- and log-growth phase P. parvum. This study indicates that understanding P. parvum population dynamics in open waters of estuaries and bays will be challenging, as there appears to be complex relationships with naturally occurring components of the plankton. The observations that P. parvum is able to grow to high population density and produce fish-killing levels of toxins underscores the need for advanced risk assessment studies, especially in light of water use plans that will result in P. parvum invasions of greater size. 相似文献
7.
From field and laboratory experiments it has been observed that low concentrations (ppb) of mineral hydrocarbons can cause an increase in photosynthesis among the nanoplankton. In field experiments, the increase in photosynthetic activity among the nanoplankton led to a bloom of µ-flagellates predominated by a member of the Haptophyceae,Chrysochromulina kappa. 相似文献
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