scholarly journals Effect of UVB and temperature on the invasive algae Undaria pinnatifida

2021 ◽  
Author(s):  
◽  
Fernanda Piraud Monsalve
Keyword(s):  
Environmental Factors ◽  
Early Life ◽  
Environmental Changes ◽  
Interactive Effect ◽  
The Other ◽  
Life Stages ◽  
Early Life Stages ◽  
Wide Range ◽  
Effect Of Light

<p>The introduction of non-indigenous species and environmental changes are both important threats to marine ecosystems. Environmental changes occur simultaneously and might impact marine organisms synergically or antagonistly. The success of invasive species has been attributed in part to their greater capacity to acclimate to changing conditions. However, the effect of environmental factors on marine invasive species has been little studied. This thesis studied the tolerance of different life stages of the invasive brown seaweed Undaria pinnatifida to UVB and temperature. Also, the possible interactive effect of an increase of temperature and UVB on U. pinnatifida was evaluated.  The tolerance of motile zoospores U. pinnatifida to increasing UVB irradiances was studied in laboratory experiments, and a strong negative effect of UVB on motile zoospores of U. pinnatifida was observed. However, zoospores can recover from UVB stress and the degree of recovery depended on UVB irradiances and exposure time. Their ability to recover could increase the opportunity of zoospores to survive and succeed in the invasion process and shows that U. pinnatifida can survive after UVB stress when environmental conditions improve.  The effect of light treatments combined with temperature was also investigated in early life stages of U. pinnatifida. Both treatments affected early life stages independently. Early life stages were particularly sensitive to UVB; more so than the other light treatments and temperature. The tolerance of early life stages to a wide range of light and temperature conditions might allow this species to maintain viable populations where they already exist, but also might permit it to invade other areas if predicted environmental changes occur in the future.  The effect of consecutive exposures to PAR and UV treatments at different temperatures on sporophytes of U. pinnatifida and the possible photoprotective role of phlorotannins were investigated. There was an interactive effect of light treatments, temperature during the exposure of sporophytes. Sporophytes were highly sensitive to UVB but not to the other light treatments nor to an increase of water temperature. There was no evidence of induction of phlorotannins by UVB and the other light treatments in U. pinnatifida. The sensitivity of sporophytes of U. pinnatifida to UVB and the lack of photoprotective role of phlorotannins suggests this species might have other strategies for success in the intertidal and might direct its energy mainly to growth and reproduction rather than to photoprotection and repair.  The response of the photosynthetic capacity and phlorotannins content to seasonal variations of light and UVB of U. pinnatifida was investigated. A clear seasonal trend in the photosynthetic capacity was observed in sporophytes that were correlated to PAR and UVB irradiances measured in the field. Phlorotannins were variable throughout the sampling period where soluble phlorotannins had seasonal and interannual variation, while there was no clear seasonal variation in cell wall phlorotannins concentration. No correlation between both phlorotannins and PAR and UVB was detected. The response of the photosynthetic apparatus to variations of light illustrates the capacity of this species to acclimate to ambient light conditions. Variation of phlorotannins throughout the year could be attributed to a combination of factors such as grazer and wound healing rather than only to the light conditions.  This research contributed to a better understanding of the tolerance of U. pinnatifida to environmental factors. This study showed that the tolerance and response to environmental factors is life stage specific. The major factor affecting U. pinnatifida negatively was UVB, while temperature had little impact on this species. The capacity of U. pinnatifida to inhabit a wide range of light and temperature conditions permits this species to succeed in coastal ecosystems, and these characteristics could permit this species to succeed under future climate change scenarios.</p>

scholarly journals Effect of UVB and temperature on the invasive algae Undaria pinnatifida

2021 ◽  
Author(s):  
◽  
Fernanda Piraud Monsalve
Keyword(s):  
Environmental Factors ◽  
Early Life ◽  
Environmental Changes ◽  
Interactive Effect ◽  
The Other ◽  
Life Stages ◽  
Early Life Stages ◽  
Wide Range ◽  
Effect Of Light

<p>The introduction of non-indigenous species and environmental changes are both important threats to marine ecosystems. Environmental changes occur simultaneously and might impact marine organisms synergically or antagonistly. The success of invasive species has been attributed in part to their greater capacity to acclimate to changing conditions. However, the effect of environmental factors on marine invasive species has been little studied. This thesis studied the tolerance of different life stages of the invasive brown seaweed Undaria pinnatifida to UVB and temperature. Also, the possible interactive effect of an increase of temperature and UVB on U. pinnatifida was evaluated.  The tolerance of motile zoospores U. pinnatifida to increasing UVB irradiances was studied in laboratory experiments, and a strong negative effect of UVB on motile zoospores of U. pinnatifida was observed. However, zoospores can recover from UVB stress and the degree of recovery depended on UVB irradiances and exposure time. Their ability to recover could increase the opportunity of zoospores to survive and succeed in the invasion process and shows that U. pinnatifida can survive after UVB stress when environmental conditions improve.  The effect of light treatments combined with temperature was also investigated in early life stages of U. pinnatifida. Both treatments affected early life stages independently. Early life stages were particularly sensitive to UVB; more so than the other light treatments and temperature. The tolerance of early life stages to a wide range of light and temperature conditions might allow this species to maintain viable populations where they already exist, but also might permit it to invade other areas if predicted environmental changes occur in the future.  The effect of consecutive exposures to PAR and UV treatments at different temperatures on sporophytes of U. pinnatifida and the possible photoprotective role of phlorotannins were investigated. There was an interactive effect of light treatments, temperature during the exposure of sporophytes. Sporophytes were highly sensitive to UVB but not to the other light treatments nor to an increase of water temperature. There was no evidence of induction of phlorotannins by UVB and the other light treatments in U. pinnatifida. The sensitivity of sporophytes of U. pinnatifida to UVB and the lack of photoprotective role of phlorotannins suggests this species might have other strategies for success in the intertidal and might direct its energy mainly to growth and reproduction rather than to photoprotection and repair.  The response of the photosynthetic capacity and phlorotannins content to seasonal variations of light and UVB of U. pinnatifida was investigated. A clear seasonal trend in the photosynthetic capacity was observed in sporophytes that were correlated to PAR and UVB irradiances measured in the field. Phlorotannins were variable throughout the sampling period where soluble phlorotannins had seasonal and interannual variation, while there was no clear seasonal variation in cell wall phlorotannins concentration. No correlation between both phlorotannins and PAR and UVB was detected. The response of the photosynthetic apparatus to variations of light illustrates the capacity of this species to acclimate to ambient light conditions. Variation of phlorotannins throughout the year could be attributed to a combination of factors such as grazer and wound healing rather than only to the light conditions.  This research contributed to a better understanding of the tolerance of U. pinnatifida to environmental factors. This study showed that the tolerance and response to environmental factors is life stage specific. The major factor affecting U. pinnatifida negatively was UVB, while temperature had little impact on this species. The capacity of U. pinnatifida to inhabit a wide range of light and temperature conditions permits this species to succeed in coastal ecosystems, and these characteristics could permit this species to succeed under future climate change scenarios.</p>

scholarly journals The consumption of zooplankton by early life stages of fish in the North Sea

2007 ◽  
Vol 64 (9) ◽  
pp. 1650-1663 ◽  
Author(s):  
Michael R. Heath
Keyword(s):  
North Sea ◽  
Early Life ◽  
Life Stages ◽  
Early Life Stages ◽  
The North ◽  
The North Sea ◽  
Zooplankton Consumption ◽  
Zooplankton Production ◽  
Fish Early Life Stages

Abstract Heath, M. R. 2007. The consumption of zooplankton by early life stages of fish in the North Sea. – ICES Journal of Marine Science, 64: 1650–1663. Previous work has shown that during the 1970s, fish and carnivorous macrozooplankton together consumed ∼22 gC m−2 year−1 of mesozooplankton, principally copepods. Consumption declined to ∼17 gC m−2 year−1 during the 1990s, mainly because of a reduction in fish production. The zooplankton production required to meet this demand seems to be approximately accounted for by estimates of new primary production, but there are additional sinks for zooplankton production attributable to predation by, for example, gelatinous species. Additionally, the consumption of zooplankton by early life stages of fish is difficult to assess and could be larger than implied by the earlier analysis. Here, the role of fish early life stages in zooplankton consumption is re-assessed, and found to be approximately double that previously estimated. Some 28% of the zooplankton consumption by fish is now estimated to be attributable to early life stages, resulting in an estimate of zooplankton consumption by the fish community as a whole 14% higher. Taken overall, the consumption of zooplankton production by fish and other planktivorous predators is now estimated to be 19–25 gC m−2 year−1.

scholarly journals Potential role of sulfide and ammonia as confounding factors in elutriate toxicity bioassays with early life stages of sea urchins and bivalves

2007 ◽  
Vol 66 (2) ◽  
pp. 252-257 ◽  
Author(s):  
Chiara Losso ◽  
Alessandra Arizzi Novelli ◽  
Marco Picone ◽  
Davide Marchetto ◽  
Claudio Pantani ◽  
...  
Keyword(s):  
Early Life ◽  
Potential Role ◽  
Sea Urchins ◽  
Confounding Factors ◽  
Life Stages ◽  
Early Life Stages

scholarly journals Combined effects of low pH and low oxygen on the early-life stages of the barnacle Balanus amphitrite

2015 ◽  
Vol 73 (3) ◽  
pp. 791-802 ◽  
Author(s):  
Camilla Campanati ◽  
Stella Yip ◽  
Ackley Lane ◽  
Vengatesen Thiyagarajan
Keyword(s):  
Early Life ◽  
Interactive Effect ◽  
Low Ph ◽  
Limiting Factors ◽  
Lower Percentage ◽  
Life Stages ◽  
Balanus Amphitrite ◽  
Early Life Stages ◽  
Low Oxygen ◽  
Extreme Stress

Abstract Ocean acidification (OA) is anticipated to interact with the more frequently occurring hypoxic conditions in shallow coastal environments. These could exert extreme stress on the barnacle-dominated fouling communities. However, the interactive effect of these two emerging stressors on early-life stages of fouling organisms remains poorly studied. We investigated both the independent and interactive effect of low pH (7.6 vs. ambient 8.2) and low oxygen (LO; 3 mg l−1 vs. ambient 5 mg l−1) from larval development through settlement (attachment and metamorphosis) and juvenile growth of the widespread fouling barnacle, Balanus amphitrite. In particular, we focused on the critical transition between planktonic and benthic phases to examine potential limiting factors (i.e. larval energy storage and the ability to perceive cues) that may restrain barnacle recruitment under the interactive stressors. LO significantly slowed naupliar development, while the interaction with low pH (LO–LP) seemed to alleviate the negative effect. However, 20–50% of the larvae became cyprid within 4 d post-hatching, regardless of treatment. Under the two stressors interaction (LO–LP), the barnacle larvae increased their feeding rate, which may explain why their energy reserves at competency were not different from any other treatment. In the absence of a settlement-inducing cue, a significantly lower percentage of cyprids (∼15% lower) settled in LO and LO–LP. The presence of an inducing cue, however, elevated attachment up to 50–70% equally across all treatments. Post-metamorphic growth was not altered, although the condition index was different between LO and LO–LP treatments, potentially indicating that less and/or weaker calcified structures were developed when the two stressors were experienced simultaneously. LO was the major driver for the responses observed and its interaction with low pH should be considered in future studies to avoid underestimating the sensitivity of biofouling species to OA and associated climate change stressors.

scholarly journals Nestled in the city heat: urban nesting behavior enhances embryo development of an invasive lizard

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Sarin Tiatragul ◽  
Joshua M Hall ◽  
Daniel A Warner
Keyword(s):  
Embryo Development ◽  
Early Life ◽  
Environmental Changes ◽  
Abiotic Factors ◽  
Thermal Conditions ◽  
Population Persistence ◽  
Nesting Behavior ◽  
Life Stages ◽  
Early Life Stages ◽  
Suburban Site

Abstract Urbanization transforms many aspects of natural landscapes and poses many new challenges for individual survival and population persistence. Thus, urbanization provides an opportunity to examine how organisms deal with novel environmental change. Many studies provide evidence of phenotypic adaptation to urban environments, but few focus on responses during early life stages. Filling this information gap is important, because early life stages are particularly sensitive to abiotic factors, and no population is sustainable without successful embryo development. We tested the hypotheses that (i) embryos tolerate warmer temperature conditions of urbanized areas and (ii) maternal nesting behavior protects embryos from potentially lethal thermal conditions in urbanized habitats. We studied introduced populations of a subtropical lizard, Anolis cristatellus, in suburban and forested areas in Miami, Florida. In each habitat, we measured microenvironment variables for locations that females used for nesting vs. locations they did not use. We then incubated eggs from both populations under thermal conditions that mimicked used and unused sites. Nests in the suburban site were warmer than in the forest; however, in the suburban site, locations that females used were relatively cool compared with locations that were not used. We found no evidence that embryos are adapted to their respective suburban or forested thermal environments, but rather maternal nest-site choice enhanced embryo development in the suburban habitat. Maternal nesting behavior is likely an important factor for population persistence under major environmental changes, and a key contributor to the establishment and spread of invasive organisms across urbanized landscapes.

scholarly journals A multi-year experiment shows that lower precipitation predictability encourages plants’ early life stages and enhances population viability

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6443 ◽  
Author(s):  
Martí March-Salas ◽  
Patrick S. Fitze
Keyword(s):  
Population Growth ◽  
Early Life ◽  
Environmental Changes ◽  
Seedling Emergence ◽  
Temporal Correlation ◽  
Extreme Weather Events ◽  
Life Stages ◽  
Early Life Stages ◽  
Term Survival ◽  
Relevant Evidence

Climate change is a key factor that may cause the extinction of species. The associated reduced weather predictability may alter the survival of plants, especially during their early life stages, when individuals are most fragile. While it is expected that extreme weather events will be highly detrimental for species, the effects of more subtle environmental changes have been little considered. In a four-year experiment on two herbaceous plants, Papaver rhoeas and Onobrychis viciifolia, we manipulated the predictability of precipitation by changing the temporal correlation of precipitation events while maintaining average precipitation constant, leading to more and less predictable treatments. We assessed the effect of predictability on plant viability in terms of seedling emergence, survival, seed production, and population growth rate. We found greater seedling emergence, survival, and population growth for plants experiencing lower intra-seasonal predictability, but more so during early compared to late life stages. Since predictability levels were maintained across four generations, we have also tested whether descendants exhibited transgenerational responses to previous predictability conditions. In P. rhoeas, descendants had increased the seedling emergence compared to ancestors under both treatments, but more so under lower precipitation predictability. However, higher predictability in the late treatment induced higher survival in descendants, showing that these conditions may benefit long-term survival. This experiment highlights the ability of some plants to rapidly exploit environmental resources and increase their survival under less predictable conditions, especially during early life stages. Therefore, this study provides relevant evidence of the survival capacity of some species under current and future short-term environmental alterations.

Environmental factors impact the early life stages of Sargassum ilicifolium in laboratory

2021 ◽  
Vol 56 ◽  
pp. 102306
Author(s):  
Han-Yang Yeh ◽  
Mary Joy Libatique ◽  
Zhen-Hao Liao ◽  
Fan-Hua Nan ◽  
Meng-Chou Lee
Keyword(s):  
Environmental Factors ◽  
Early Life ◽  
Life Stages ◽  
Early Life Stages

Describing population dynamics for early life stages of rainbow trout (Oncorhynchus mykiss) using a stock synthesis model1This article is a companion to Korman et al. 2011, published this issue.

2011 ◽  
Vol 68 (6) ◽  
pp. 1110-1123 ◽  
Author(s):  
Josh Korman ◽  
S.J.D. Martell ◽  
Carl Walters
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Early Life ◽  
Survival Rates ◽  
Strong Support ◽  
Fold Increase ◽  
Life Stages ◽  
Early Life Stages ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Wide Range

A stock synthesis model was used to assess effects of experimental flows on early life stages of nonnative rainbow trout ( Oncorhynchus mykiss ) in the Colorado River below Glen Canyon Dam (Arizona, USA). The model estimated time-varying survival rates while correcting for entry of new recruits to the age-0 population and changes in vulnerability to capture associated with growth and ontogenetic habitat shifts. A controlled flood, designed in part to enhance native fish habitat, led to an 11-fold increase in early survival rates (fertilization to ~1 month from emergence) of weekly cohorts of trout fertilized after the flood. Effects of increased flow fluctuations during incubation, designed to reduce trout abundance, were not apparent. Age-0 mortality between August and September was over twofold higher in years when there was a 50% reduction in the minimum flow compared with years when flow was stable. There was strong support for models that simulated an ontogenetic shift to deeper habitat in four of five study years. The integration of detailed field information in a stock synthesis model to describe early life history dynamics is a valuable approach that can be applied in a wide range of systems.

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