Distribution of Aquatic Vegetation as Measured by Line Intercept with Scuba

Schmid, William D.

doi:10.2307/1934014

Cited by 31 publications

(15 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The lake has a single basin, is 2.4 km long, and has a surface area of 66.5 ha and a volume of 7.63 ϫ 10 6 m 3 . The basin is symmetrical, relatively deep (maximum depth ϭ 24 m, mean depth ϭ 13 m), and has a small littoral zone (ϳ15% of lake surface area) (Schmid 1965). Its depth and simple morphometry make it ideal for acoustic analysis, and because interactions in the pelagic zone dominate the ecology of the lake, an understanding of the spatial distribution and abundance of Daphnia is especially relevant.…”

Section: Methodsmentioning

confidence: 99%

Seasonal and diel patchiness of a Daphnia population: An acoustic analysis

Hembre

Megard

2003

Limnology & Oceanography

View full text Add to dashboard Cite

Detailed information about the location and extent of zooplankton patches is fundamental to understand how abiotic and biotic forces interact to structure the spatial distribution of zooplankton. We mapped zooplankton patchiness in a Minnesota lake during spring, summer, and autumn with high-frequency (192-kHz) single-beam sonar. Conventional plankton samples of aggregations detected acoustically revealed that Daphnia pulicaria (mean body length 1.6 mm, mean target strength Ϫ120 dB) scattered most (ϳ63%) of the sound. Other taxa were smaller (Ͻ½ the length of D. pulicaria) and were usually less abundant and therefore scattered much less sound than D. pulicaria. Our acoustic estimates of Daphnia concentrations illustrate extreme patchiness, with concentrations varying by as much as four orders of magnitude over vertical distances of less than 1 m. Seasonal patterns of patchiness were related to predation by rainbow trout and to abiotic factors associated with stratification. Daphnia concentrations were highest from June to October in a deep-water ''refuge zone'' where oxygen concentrations were between 3 and 5 mg L Ϫ1 . These oxygen levels are suitable for Daphnia but are lower than those required by rainbow trout. Heterogeneity in Daphnia concentration along the lake's long axis was highest in May and June, when the population resided primarily in the oxic hypolimnion during the daytime. From July to October, as oxygen concentrations declined in the hypolimnion, the population became more metalimnetic and more uniformly distributed in the horizontal dimension. A diel study of the population in October indicated that the patchiness of population also changed dramatically between day and night. During the day the population aggregated densely in a thin layer (ϳ2 m thick) in the thermocline. After sunset the population dispersed into the epilimnion, where concentrations were ϳ100,000 m Ϫ3 less than they were during the day in the thermocline.Patchy spatial distributions and the low resolution of conventional sampling methods have impeded analyses of zooplankton populations. Zooplankton concentrations have been shown to vary by a factor of 1,000 within distances of meters horizontally or vertically, and the sampling resolution of conventional plankton nets and hoses is usually too coarse to identify the spatial limits of aggregations precisely (Coyle 2000). Variation in population density estimates due to sampling often cannot be distinguished from real changes of population density, and the effects of biological processes are difficult to distinguish from those of advective transport (Megard et al. 1997). Acoustic and optical plankton samplers developed during recent decades are major advances. They have very high sampling rates and spatial resolution, comparable to modern instruments (e.g., CTD profilers) used to measure environmental variables. Large numbers of plank-

show abstract

Section: Methodsmentioning

confidence: 99%

Seasonal and diel patchiness of a Daphnia population: An acoustic analysis

Hembre

Megard

2003

Limnology & Oceanography

View full text Add to dashboard Cite

show abstract

“…Other studies indicate that elodea is a species which grows in a wide range of water depths but finding it in water depths between 4 and 8 m was common (Wilson, 1941;Crum & Bachman, 1973;Chapman et al, 1974;and Schmid, 1965). Often the only species found at deeper locations in the lakes were macrophytic algae.…”

Section: Growth Patterns Of M Spicatummentioning

confidence: 97%

Ecological life histories of the three aquatic nuisance plants, Myriophyllum spicatum, Potamogeton crispus and Elodea canadensis

Nichols¹,

1986

View full text Add to dashboard Cite

The life histories of Myriophyllum spicatum L., Elodea canadensis Michx., and Potamogeton crispus L., serious aquatic nuisances in many regions of the world, are reviewed to provide insights into the life style of successful aquatic nuisance plants. Specifically, their distribution and spread in North America; their life cycle, productive and reproductive potential; and their ecosystem relationships are reviewed. Hopefully this review will improve a manager's ability to deal with aquatic nuisance problems. It also provides suggestions for basic research needed to develop more effective management practices.It was found that all three species possess a number of adaptations, including an ability to rapidly propagate vegetatively, an opportunistic nature for obtaining nutrients, a life cycle that favors cool weather, and a number of mechanisms which enhance photosynthetic efficiency, which allow them to proliferate.These three species do provide benefits to the ecosystem through their roles in materials cycling and energy flow. Therefore, management of these species should take an integrated approach which recognizes these benefits.The life history information available about the three species varies tremendously; however, a better understanding of resource gain and allocation is needed to manage all three species. Specifically, more research is needed to provide a better understanding of: 1) the role bicarbonate plays in photosynthesis, 2) the role roots play in supplying CO2 to the plants, 3) resource accumulation and allocation under different temperature and light regimes, 4) resource allocation on a seasonal basis, and 5) nutrient cycling under different management regimes.

show abstract

“…A picture of the study sites was taken using cannon 10X pixel camera along the western coast of the lake. In each of the four sites 15 plots were laid, each plot (quadrats) with a size of 0.5 × 0.5 m 2 and 25 meter apart from each other [12]. In the field, macrophytes were counted within each plot.…”

Section: Data Collectionmentioning

confidence: 99%

Invasion of Water Hyacinth (<i>Eichhornia crassipes</i>) Is Associated with Decline in Macrophyte Biodiversity in an Ethiopian Rift-Valley Lake—Abaya

Mengistu¹,

Unbushe²,

Abebe³

2017

OJE

View full text Add to dashboard Cite

Macrophytes play critical ecological role in inland water bodies, especially in shallow systems. Water hyacinth (Eichhornia crassipes) is an invasive plant species introduced to Ethiopian water bodies around the mid 20 th century with recently exacerbated devastating ecological and economic consequences. Here we report the impact of the invasive plant species on macrophyte species assemblage and biodiversity in Lake Abaya, southwestern Ethiopia. We compared four sites in Lake Abaya, two hyacinth infested and two non-infested, each site consisting of 15 plots. Our results showed that water hyacinth affects the macrophyte community composition, abundance and diversity negatively. Even though some macrophyte species from the Poaceae and Cyperaceae families appear to coexist with the alien plant, the invasive species has reduced macrophyte abundance and diversity at the infested sites, and in some cases changed the community to nearly monotypic flora. Our data affirm that water hyacinth has the potential to alter macrophyte composition, abundance and diversity in the wider Ethiopian aquatic ecosystems. A broad & closer, systematic and comprehensive look at the short and long term consequences of its expanding invasion within the framework of specific local environmental, ecological and societal conditions is long-overdue.

show abstract

Distribution of Aquatic Vegetation as Measured by Line Intercept with Scuba

Cited by 31 publications

References 9 publications

Seasonal and diel patchiness of a Daphnia population: An acoustic analysis

Seasonal and diel patchiness of a Daphnia population: An acoustic analysis

Ecological life histories of the three aquatic nuisance plants, Myriophyllum spicatum, Potamogeton crispus and Elodea canadensis

Invasion of Water Hyacinth (<i>Eichhornia crassipes</i>) Is Associated with Decline in Macrophyte Biodiversity in an Ethiopian Rift-Valley Lake—Abaya

Contact Info

Product

Resources

About

Distribution of Aquatic Vegetation as Measured by Line Intercept with Scuba

Cited by 31 publications

References 9 publications

Seasonal and diel patchiness of a Daphnia population: An acoustic analysis

Seasonal and diel patchiness of a Daphnia population: An acoustic analysis

Ecological life histories of the three aquatic nuisance plants, Myriophyllum spicatum, Potamogeton crispus and Elodea canadensis

Invasion of Water Hyacinth (&lt;i&gt;Eichhornia crassipes&lt;/i&gt;) Is Associated with Decline in Macrophyte Biodiversity in an Ethiopian Rift-Valley Lake—Abaya

Contact Info

Product

Resources

About

Invasion of Water Hyacinth (<i>Eichhornia crassipes</i>) Is Associated with Decline in Macrophyte Biodiversity in an Ethiopian Rift-Valley Lake—Abaya