Use of a quanta meter to measure attenuation and underwater reflectance of photosynthetically active radiation in some inland and coastal south-eastern Australian waters

1977 ◽  
Vol 28 (1) ◽  
pp. 9 ◽  
Author(s):  
JTO Kirk
Keyword(s):  
Attenuation Coefficient ◽  
Water Body ◽  
Coastal Waters ◽  
Photosynthetically Active Radiation ◽  
Inland Waters ◽  
Backscattering Coefficient ◽  
Active Radiation ◽  
South Eastern ◽  
Yellow Substance ◽  
Eastern Australia

The attenuation of total photosynthetically active radiation (PAR) in natural waters and its characterization by means of a vertical attenuation coefficient are briefly discussed. The factors determining underwater reflectance (ratio of upward to downward irradiance at a given depth) are considered, and a simple mathematical treatment is presented which leads to the conclusion that within that part of the water body where the asymptotic radiance distribution exists, if reflection from the bottom is negligible then the reflectance is equal to the asymptotic backscattering coefficient (defined in the text) divided by 2K, where K is the (natural logarithm) vertical attenuation coefficient. Data collected using a commercially available quantum irradiance meter over a 2-year period for various inland and coastal waters in south-eastern Australia are presented together with measure- ments of levels of yellow substance and phytoplankton. In the turbid inland waters attenuation of PAR closely follows an exponential law. In the much clearer coastal waters, by contrast, attenuation of PAR is approximately biphasic, the vertical attenuation coefficient in the upper few metres being noticeably higher than that at greater depths. Within any one water body the vertical attenuation coefficient was observed to vary up to four-fold during the 2-year period: nevertheless there were indications that the average attenuation of PAR tended to differ characteristically from one water body to another. In one of the inland waters, measurements at different times of day showed that the vertical attenuation coefficient was not strongly dependent on solar altitude. Underwater reflectance values in the inland waters were surprisingly high (0.04-0.21) compared to values in the literature: this is probably a consequence of the high turbidity of these waters. Calculated values of the asymptotic backscattering coefficient for the inland lakes are presented. It is suggested that measurements of yellow substance and phytoplankton, together with some estimate of light scattering, in parallel with measurements of attenuation of PAR would facilitate an understanding of the factors responsible for that attenuation.

Yellow substance (gelbstoff) and its contribution to the attenuation of photosynthetically active radiation in some inland and coastal south-eastern Australian waters

1976 ◽  
Vol 27 (1) ◽  
pp. 61 ◽  
Author(s):  
JTO Kirk
Keyword(s):  
Absorption Coefficient ◽  
Photosynthetically Active Radiation ◽  
Natural Waters ◽  
Sea Water ◽  
Light Attenuation ◽  
Active Radiation ◽  
South Eastern ◽  
Yellow Substance ◽  
Eastern Australia ◽  
Coastal Sea

The absorption spectra relative to distilled water of samples from various inland and coastal waters in south-eastern Australia (New South Wales and the Australian Capital Territory) have been measured. Amongst the freshwater samples the level of dissolved yellow substance (gelbstoff) was found to vary seven-fold (the base-10 logarithm absorption coefficient at 440 nm ranged from 0.42 to 2.90 m-1). In coastal sea water the concentration was much lower than in any of the freshwater samples (absorption coefficient 0.01-0.08 m-1 at 440 nm). Calculations have been carried out of the contribution made by yellow substance to attenuation of photosynthetically active radiation (PAR). In the inland waters yellow substance has a dominating influence on light attenuation, reducing the amount of PAR many-fold, and the blue region of the spectrum is abolished at quite moderate depths. In all cases except sea water it was calculated that most (60-80%) of the quanta captured are absorbed by yellow substance rather than by water. An alternative name, 'gilvin' (Latin, gilvus = pale yellow), for the yellow pigments in natural waters, to replace 'yellow substance' or 'gelbstoff ', is suggested.

Spectral Distribution of Photosynthetically Active Radiation in some South-eastern Australian Waters

1979 ◽  
Vol 30 (1) ◽  
pp. 81 ◽  
Author(s):  
JTO Kirk
Keyword(s):  
Blue Light ◽  
Photosynthetically Active Radiation ◽  
Spectral Distribution ◽  
Light Attenuation ◽  
Red Light ◽  
Extreme Case ◽  
Euphotic Zone ◽  
Active Radiation ◽  
South Eastern ◽  
Eastern Australia

The results are presented of a study of the spectral distribution of photosynthetically active radiation (PAR) in some inland, and one coastal, waters in south-eastern Australia, carried out with a submersible spectroradiometer. There is particularly rapid attenuation with depth of blue light in the 400-500-nm waveband, due to the yellow substances ('gilvin', 'gelbstoff') in the waters. Attenuation in the red region, due to absorption by water itself, is clearly evident but is generally much less steep than that in the blue. Within the rather shallow euphotic zone typical of these waters the available PAR is impoverished in blue light but still contains plenty of red (630-700-nm) light. At greater depths, in waters of moderate turbidity, a spectral distribution strongly peaked at about 580 nm, with a shoulder at about 630 nm, is obtained. Although the contribution of phytoplankton can be significant, in general in these turbid inland waters suspended soil particles contribute more to vertical light attenuation. This is partly due to the increased pathlength of the photons caused by scattering, but direct absorption of light, especially in the blue region, by the particulate inanimate 'tripton' is suggested by the data. Turbidity and dis- solved colour of the water tend to increase together: in particularly turbid, yellow waters the spectral distribution of PAR is shifted to longer wavelengths and in an extreme case consisted of quite a sharp peak at 700 nm. In the clear, comparatively colourIess coastal-estuarine waters of Batemans Bay (N.S.W.), blue light was attenuated less steeply than red light, so that the underwater spectral distribution, although peaked at about 570 nm, was (at 4 m) still quite rich in blue as well as red light.

Aggregates of particulate matter and aufwuchs on Elodea canadensis in irrigation waters, and inactivation of diquat

1982 ◽  
Vol 33 (3) ◽  
pp. 589 ◽  
Author(s):  
KH Browner
Keyword(s):  
Particulate Matter ◽  
Elodea Canadensis ◽  
Inland Waters ◽  
Surface Complex ◽  
South Eastern ◽  
Murray River ◽  
Eastern Australia ◽  
Aquatic Herbicides ◽  
High Concentrations ◽  
Irrigation Waters

In irrigation waters from the Murrumbidgee River and Murray River, south-eastern Australia. shoots of E. canadensis are heavily encrusted with a loosely attached complex of inorganic colloids with aufwuchs. Although 9,10-dihydro-8a,10a-diazoniaphenanthrene ion (diquat) is widely used overseas for the management of submerged weeds. it is often ineffective in Australian inland waters. Although several factors may be involved, measurements have shown that this surface complex would inactivate relatively high concentrations of diquat by adsorption. The activity of other aquatic herbicides may also be impaired.

Phytoplankton Bloom and Photosynthetically Active Radiation in Coastal Waters

2020 ◽  
Vol 86 (6) ◽  
pp. 1084-1091
Author(s):  
T. Ya. Churilova ◽  
V. V. Suslin ◽  
N. A. Moiseeva ◽  
T. V. Efimova
Keyword(s):  
Coastal Waters ◽  
Photosynthetically Active Radiation ◽  
Phytoplankton Bloom ◽  
Active Radiation

Some aspects of the ecology of Paratya australiensis (Crustacea : Decapoda : Atyidae)

1977 ◽  
Vol 28 (4) ◽  
pp. 403 ◽  
Author(s):  
WD Williams
Keyword(s):  
Breeding Season ◽  
Hydrological Regime ◽  
Early Summer ◽  
Inland Waters ◽  
Running Waters ◽  
Australian Species ◽  
South Eastern ◽  
Eastern Australia ◽  
Coastal Streams ◽  
Paratya Australiensis

Three Australian species of Paratya have been described. However, only one, P. australiensis, can be accepted. It occurs in Australia in a broad south-eastern arc, and in a wide variety of permanent inland waters (coastal streams, rivers, lakes, farm dams and ponds). In these it favours vegetated areas. Young hatch as free-floating larvae and hatching occurs mainly in early summer in southern Victoria. Females breed in their second summer. In south-eastern Australia, at least, this breeding season appears adapted to the hydrological regime of running waters.

Phosphate distribution in Bass Strait and south-eastern Australian coastal waters.

1980 ◽  
Vol 31 (2) ◽  
pp. 119 ◽  
Author(s):  
JD Smith ◽  
AR Longmore
Keyword(s):  
Coastal Waters ◽  
Inorganic Phosphate ◽  
South Eastern ◽  
Eastern Australia ◽  
Saline Waters ◽  
South Eastern Australia

Waters off south-eastern Australia, including Bass Strait, were analysed for dissolved phosphate. Concentrations in mid Bass Strait varied over the range 8.2-15.4 mg P m3. total dissolved phosphate, and 4.5-8.7 mg P m-3 dissolved inorganic phosphate. The effect of phosphate-rich Port Phillip Bay water was detectable for about 15 nautical miles offshore in Bass Strait. The warmer and less saline waters off the eastern Australian coast contained about half the levels of dissolved phosphate found in Bass Strait waters, and a greater proportion was present as dissolved inorganic phosphate.

The ecology and distribution of Halicarcinus lacustris (Brachyura: Hymeno-somatidae) in Australian inland waters

1969 ◽  
Vol 20 (2) ◽  
pp. 163 ◽  
Author(s):  
K Walker
Keyword(s):  
New Zealand ◽  
Ecological Factors ◽  
Salinity Range ◽  
Breeding Cycle ◽  
Inland Waters ◽  
South Eastern ◽  
Tasman Sea ◽  
Eastern Australia ◽  
Associated Species ◽  
South Eastern Australia

Halicarcinus lacustris is a small crab inhabiting inland waters in south-eastern Australia, New Zealand, and Lord Howe and Norfolk Islands. The Victorian distribution was investigated with reference to salinity. In the field the species occurs over a salinity range of 0.1-9.6‰ (although scarce in fresh waters), despite a tolerance of 0.0-36.3‰ shown by adults in the laboratory. This restricted distribution is attributed to physiological and ecological factors. Ecological notes are included on microhabitat, associated species, food, and the breeding cycle. Consideration is given also to the origins and overall distribution of the species. It is suggested that H. Lacustris rafted across the Tasman Sea, after having evolved in south-eastern Australia.

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