Life stage sensitivity of the marine musselMytilus edulisto ammonia

2016 ◽  
Vol 36 (1) ◽  
pp. 89-95 ◽  
Author(s):  
Alan J. Kennedy ◽  
James H. Lindsay ◽  
James M. Biedenbach ◽  
Ashley R. Harmon
Keyword(s):  
Life Stage ◽  
Life Stage Sensitivity

Effects of pH, Aluminum, and Calcium on Survival and Growth of Eggs and Fry of Brook Trout (Salvelinus fontinalis)

1990 ◽  
Vol 47 (8) ◽  
pp. 1580-1592 ◽  
Author(s):  
C G. Ingersoll ◽  
D. R. Mount ◽  
D. D. Gulley ◽  
T. W. La Point ◽  
H. L. Bergman
Keyword(s):  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Aluminum Toxicity ◽  
Life Stage ◽  
Recovery Period ◽  
Yolk Sac ◽  
Aluminum Concentration ◽  
Effects Of Ph ◽  
Life Stage Sensitivity ◽  
Acid Toxicity

Freshly fertilized eggs, eyed eggs, yolk-sac fry, and swim-up fry of brook trout (Salvelinus fontinalis) were exposed to a matrix of 84 combinations of pH (4.0–6.5), aluminum (0–1000 μg/L), and calcium (0.5–8.0 mg/L) in 21–91-d experiments. The response to pH, aluminum, and calcium exposure was dependent on life stage. Sensitivity to acid toxicity generally decreased with age (freshly fertilized eggs>eyed eggs>yolk-sac fry = swim-up fry). Survival or hatching of freshly fertilized and eyed eggs decreased at pH 5.2 and below, whereas survival of yolk-sac and swim-up fry was reduced at pH 4.4–4.0. Sensitivity to aluminum toxicity generally increased with age (freshly fertilized eggs = eyed eggs<yolk-sac fry<swim-up fry). At low pH, survival of freshly fertilized and eyed eggs increased with exposure to increasing aluminum concentrations, in contrast, elevated aluminum [Formula: see text] was often toxic to fry. Increasing calcium was beneficial to all life stages, although the magnitude of this benefit depended on life stage and on the specific pH and aluminum concentration. Survival after previous exposure to toxic combinations of pH, aluminum, and calcium generally improved during a post-exposure recovery period at pH 6.5. However, increased mortality in many exposure combinations did not begin until this recovery period.

Compatibility of Insecticides with Natural Enemies to Control Pests of Greenhouses and Conservatories

2006 ◽  
Vol 41 (3) ◽  
pp. 189-197 ◽  
Author(s):  
Raymond A. Cloyd
Keyword(s):  
Natural Enemies ◽  
Natural Enemy ◽  
Life Stage ◽  
Host Acceptance ◽  
Insect Growth Regulators ◽  
Plant Feeding ◽  
Sensitivity Rate ◽  
Bacteria And Fungi ◽  
Life Stage Sensitivity ◽  
Microbial Agents

Natural enemies used as biological control agents may not always provide adequate control of plant-feeding insects in greenhouses and conservatories. Research continues to assess the utilization of natural enemies in conjunction with biorational insecticides including insect growth regulators, insecticidal soaps, horticultural oils, feeding inhibitors, and microbial agents (entomogenous bacteria and fungi, and related microorganisms); and the potential compatibility of both strategies when implemented together. A variety of factors influence the ability of using natural enemies with insecticides. These include whether the natural enemy is a parasitoid or predator, the species of the natural enemy, life stage sensitivity, rate and timing of insecticide application, and mode of action of the insecticide. Insecticides may impact natural enemies by affecting longevity (survival), host acceptance, sex ratio, reproduction (fecundity), foraging behavior, emergence, and development. Despite the emphasis on evaluating the compatibility of natural enemies with insecticides, it is important to assess if this is a viable and acceptable pest management strategy in greenhouses and conservatories.

Habitat fragmentation causes collapse of kelp recruitment

2020 ◽  
Vol 648 ◽  
pp. 111-123
Author(s):  
C Layton ◽  
MJ Cameron ◽  
M Tatsumi ◽  
V Shelamoff ◽  
JT Wright ◽  
...  
Keyword(s):  
Habitat Fragmentation ◽  
Patch Size ◽  
Life Stage ◽  
Extended Period ◽  
Anthropogenic Disturbances ◽  
Anthropogenic Sources ◽  
Kelp Forests ◽  
Natural Disturbances ◽  
Short Term ◽  
Turf Algae

Kelp forests in many regions are experiencing disturbance from anthropogenic sources such as ocean warming, pollution, and overgrazing. Unlike natural disturbances such as storms, anthropogenic disturbances often manifest as press perturbations that cause persistent alterations to the environment. One consequence is that some kelp forests are becoming increasingly sparse and fragmented. We manipulated patch size of the kelp Ecklonia radiata over 24 mo to simulate persistent habitat fragmentation and assessed how this influenced the demography of macro- and microscopic juvenile kelp within the patches. At the beginning of the experiment, patch formation resulted in short-term increases in E. radiata recruitment in patches <1 m2. However, recruitment collapsed in those same patches over the extended period, with no recruits observed after 15 mo. Experimental transplants of microscopic and macroscopic juvenile sporophytes into the patches failed to identify the life stage impacted by the reductions in patch size, indicating that the effects may be subtle and require extended periods to manifest, and/or that another life stage is responsible. Abiotic measurements within the patches indicated that kelp were less able to engineer the sub-canopy environment in smaller patches. In particular, reduced shading of the sub-canopy in smaller patches was associated with proliferation of sediments and turf algae, which potentially contributed to the collapse of recruitment. We demonstrate the consequences of short- and longer-term degradation of E. radiata habitats and conclude that habitat fragmentation can lead to severe disruptions to kelp demography.

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