Floating along marsh edges: The impact of invasive water hyacinth (Eichornia crassipes) on estuarine species assemblages and predation risk

Context. Potential mammalian prey commonly use the odours of their co-evolved predators to manage their risks of predation. But when the risk comes from an unknown source of predation, odours might not be perceived as dangerous, and anti-predator responses may fail, except possibly if the alien predator is of the same archetype as a native predator. Aims. In the present study we examined anti-predator behavioural responses of voles from the outer archipelagos of the Baltic Sea, south-western Finland, where they have had no resident mammalian predators in recent history. Methods. We investigated responses of field voles (Microtus agrestis) to odours of native least weasels (Mustela nivalis) and a recently invading alien predator, the American mink (Mustela vison), in laboratory. We also studied the short-term responses of free-ranging field voles and bank voles (Myodes glareolus) to simulated predation risk by alien mink on small islands in the outer archipelago of the Baltic Sea. Key results. In the laboratory, voles avoided odour cues of native weasel but not of alien mink. It is possible that the response to mink is a context dependent learned response which could not be induced in the laboratory, whereas the response to weasel is innate. In the field, however, voles reduced activity during their normal peak-activity times at night as a response to simulated alien-mink predation risk. No other shifts in space use or activity in safer microhabitats or denser vegetation were apparent. Conclusions. Voles appeared to recognise alien minks as predators from their odours in the wild. However, reduction in activity is likely to be only a short-term immediate response to mink presence, which is augmented by longer-term strategies of habitat shift. Because alien mink still strongly suppresses vole dynamics despite these anti-predator responses, we suggest that behavioural naiveté may be the primary factor in the impact of an alien predator on native prey. Implications. Prey naiveté has long been considered as the root cause of the devastating impacts of alien predators, whereby native prey simply fail to recognise and respond to the novel predation risk. Our results reveal a more complex form of naiveté whereby native prey appeared to recognise alien predators as a threat but their response is ultimately inadequate. Thus, recognition alone is unlikely to afford protection for native prey from alien-predator impacts. Thus, management strategies that, for example, train prey in recognition of novel threats must induce effective responses if they are expected to succeed.

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The cost of safety: Refuges increase the impact of predation risk in aquatic systems

Ecology ◽

10.1890/12-0502.1 ◽

2013 ◽

Vol 94 (3) ◽

pp. 573-579 ◽

Cited By ~ 75

Author(s):

John L. Orrock ◽

Evan L. Preisser ◽

Jonathan H. Grabowski ◽

Geoffrey C. Trussell

Keyword(s):

Predation Risk ◽

Aquatic Systems ◽

The Cost ◽

The Impact

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The impact of variable predation risk on stress in snowshoe hares over the cycle in North America’s boreal forest: adjusting to change

Oecologia ◽

10.1007/s00442-021-05019-1 ◽

2021 ◽

Author(s):

Sophia G. Lavergne ◽

Charles J. Krebs ◽

Alice J. Kenney ◽

Stan Boutin ◽

Dennis Murray ◽

...

Keyword(s):

Boreal Forest ◽

Predation Risk ◽

Snowshoe Hares ◽

The Impact

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Pengaruh Nitrat (NO3) Terhadap Pertumbuhan Alami Eceng Gondok (Eichornia crassipes Solms.) Berdasarkan Biomassa Basah Di Danau Batur, Kintamani, Bali

Journal of Marine and Aquatic Sciences ◽

10.24843/jmas.2017.v3.i02.215-222 ◽

2017 ◽

Vol 3 (2) ◽

pp. 215

Author(s):

Lisa Rosalia Prayuda ◽

I Wayan Arthana ◽

Ayu Putu Wiweka Krisna Dewi

Keyword(s):

Growth Rate ◽

Water Hyacinth ◽

High Fertility ◽

Natural Growth ◽

Initial Weight ◽

Daily Growth Rate ◽

Daily Growth ◽

Natural Lakes ◽

High Fertility Rate ◽

Eichornia Crassipes

Batur Lake is one of the natural lakes in the province of Bali where the activity of fishing, agriculture, tourism and housing available. This study aims to determine the effect of nitrate relation to the natural growth of the water hyacinth (Eichornia crassipes). Increased water hyacinth biomass in Songan station is the highest among the three other stations (Batur, Buahan, and Trunyan). At the end of the study (day 42 ), water hyacinth biomass of Songan station increased by 338.2 % from the initial weight, while at another station the increase weight ranges from 75 % -158 %. The highest daily growth rate in Trunyan station 3.68% / day, and the lowest in station Buahan which only reached 0.88% / day. At the Songan station where are many floating net which contribute to increase nitrate. There is a tendency of growth of water hyacinth faster at higher nitrate conditions. Nitrate conditions ranged from 0,35 to 0,62 m /l which shows that the waters of Batur Lake classified into waters that have a high fertility rate (eutrophic).

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Biogas Generation from Co-Digestion Waste Systems: The Role of Water Hyacinth

10.5772/intechopen.101568 ◽

2022 ◽

Author(s):

Adedeji A. Adelodun ◽

Temitope M. Olajire ◽

Ochuko Mary Ojo

Keyword(s):

Water Hyacinth ◽

Aquatic Macrophyte ◽

Biogas Production ◽

Scale Up ◽

Environmentally Benign ◽

Organic Loading Rate ◽

Eichornia Crassipes ◽

Poultry Droppings ◽

Pig Wastes

Using biomass as a renewable energy source has earned tremendous interest from researchers in recent decades, especially because the technology is environmentally benign. This article reviews the recent methods for generating biogas from water hyacinth (WH, Eichornia crassipes), arguably the world’s most evasive aquatic macrophyte. Therefore, various economic, environmentally benign, and renewable procedures that enhance biogas production from WH biomass are reviewed. WH has been co-digested with numerous waste types, including poultry droppings, municipal wastes, animal tissue wastes, pig wastes, cow dungs, etc., recording varying success degrees. Other studies focused on optimizing the operation parameters, such as mixing ratio, contact time, pH, temperature, organic loading rate, etc. We observed that most attempts to generate biogas from WH alone were not promising. However, when co-digested with other biomasses or wastes, WH either increases the process rate or improves the methane yield content. Also, the potential of WH as a phytoremdiator-cum-biogas source was investigated. This chapter provides mathematical models, scale-up installation models, and specific experimental results from various studies to guide future study plans toward optimizing CH4 generation from WH co-digestion.

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Assessment of sustainable vermiconversion of water hyacinth by Eudrilus eugeniae and Eisenia fetida

Journal of Applied and Natural Science ◽

10.31018/jans.v5i2.352 ◽

2013 ◽

Vol 5 (2) ◽

pp. 451-454

Author(s):

N. Kannadasan ◽

Nirmala Natarajan ◽

N. Anbusaravanan ◽

P. Sekar ◽

R. Krishnamoorthy

Keyword(s):

Water Hyacinth ◽

Eisenia Fetida ◽

Micrococcus Luteus ◽

Maximum Growth ◽

Garden Soil ◽

Cow Dung ◽

Aquatic Weed ◽

Eudrilus Eugeniae ◽

Toxic Heavy Metals ◽

Eichornia Crassipes

The present work has assessed sustainable vermiconversion of aquatic weed water hyacinth (Eichornia crassipes). The garden soil, water hyacinth and cow dung were taken in the following the combinations of 1: 2 : 1, 2: 1: 1 and 1 : 1: 2. Two species of earthworms Eudrilus eugeniae and Eisenia fetida was used for the experiment. The total nitrogen (0.18% in control and 1.68% in earthworm treated) and phosphate (0.63 % in control and 1.64 % in earthworm treated) levels were increased and toxic heavy metals zinc (7.66 ppm in control and 2.58 ppm in earthworm treated) and copper (6.68 ppm in control and 1.15 ppm in earthworm treated) were significantly decreased. The earthworm enriches the compost with various nutrients for plant and microbial growth. Plant growth studies were conducted in all the combination of water hyacinth, maximum growth of root length (8.9cm and 7.2 in control) and shoot length (21.6cm and 16.2 in control) observed compare to control. Gut microbial analysis revealed that Bacillus cereus, Micrococcus luteus were predominantly present in the earthworm. The study recommended that the aquatic weed compost was suitable of agricultural usage.

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The Impact of Wolf Reintroduction on the Foraging Efficency of Elk and Bison

The UW National Parks Service Research Station Annual Reports ◽

10.13001/uwnpsrc.1998.3363 ◽

1998 ◽

Vol 22 ◽

pp. 48-52

Author(s):

John Laundre

Keyword(s):

Predation Risk ◽

National Parks ◽

Cervus Elaphus ◽

The North ◽

Safety Research ◽

Conflicting Demands ◽

Before And After ◽

Quality Diet ◽

Long Term Impact ◽

The Impact

More and more, evidence indicates that nonÂlethal interactions between large mammalian ungulates and the predators that feed on them may play significant roles in ungulate population dynamics. Although predators such as wolves and mountain lions directly impact large ungulates like elk (Cervus elaphus) when they kill individuals, the fact that they scare their prey may actually have a greater long term impact on the population (Kotler and Hoyt 1989, Brown 1992, Brown and Alkon 1990 Brown et al. 1999). In response to predation risk, foraging animals are found balancing conflicting demands for food and safety. Research indicates they do this by two principal means: 1) when faced with higher predation risk, prey individuals will reduce feeding effort and/or increase vigilance compared to areas of lower risk (Sih 1980, Lima and Dill 1990), 2) they alter their use of habitat types to help reduce this predation risk. The major result is that reduced feeding efforts or selection of safer but possibly less productive habitat lead to a third prediction of a poorer quality diet as animals seek out safer areas but with likely lower quality forage. The reintroduction of wolves in Yellowstone National Parks offered a unique opportunity to test the impact of wolves on the feeding efficiency of elk and bison. After the wolves were reintroduced into Yellowstone Park in the spring of 1995, they quickly established themselves in specific locations, specifically in the Lamar Valley in the north end of the Park. This allowed us to collect data on areas with and without wolves for the first few years after their release. Additionally, as wolves have expanded their range in the Park, this has also provided an excellent opportunity to compare data on animals from the same areas before and after wolves have arrived. These comparisons then, would provide a critical test of the predictions that large predators can have a major non-lethal impact on their prey. To test these predictions, in 1996 we began a study of the foraging patterns of elk and bison in Yellowstone National Park. Here we report the results of the first four years of this study.

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