Here are some additional references for Wetlands/DOC... collection. The first seven are part of a symposium
collection that is not in the OSU or ORBIS consortium holdings. Any chance Mark S might have it? One of the coauthors of one of the papers (M. Bothwell) is at OSU, I will try to find out if maybe she has it. Otherwise I should
try to interlibrary loan the whole collection. Measurements of UV-B radiation in two freshwater lakes: An
instrument intercomparison Kirk, JTO; Hargreaves, BR; Morris, DP; Coffin, RB; David, B; Frederickson, D;
Karentz, D; Lean, DRS; Lesser, MPetal NOT AT OSU-ILL IMPACT OF UV-B RADIATION ON PELAGIC
FRESHWATER ECOSYSTEMS, SCHWEIZERBART'SCHE VERLAGSBUCHHANDL., STUTTGART (FRG),
1994, no. 43, pp. 71-99, Ergebnisse der Limnologie/Advances in limnology. Stuttgart [ERGEB. LIMNOL./ADV.
LIMNOL.], no. 43 Instruments and biological dosimeters were used to measure solar spectral irradiance in two
lakes, one clear and the other moderately coloured, with emphasis on the ozone-sensitive UV-B wavelengths. An
atmospheric model provided an approximate standard against which were compared commercial instruments from
Biospherical Instruments, Inc., International Light, Inc., LI-COR Inc., and Optronic Laboratories, Inc. Comparisons
of irradiance in air, and irradiance and attenuation coefficients at several depths, revealed differences in spectral
resolution, accuracy, sensitivity to low light energy, and convenience in generating depth-specific profiles.
Broadband instruments trade off resolution for simplicity and, in some cases, greater sensitivity, but are subject to
errors when the solar spectrum is modified by sun angle, atmospheric column ozone, and the inherent optical
properties of the water. For UV-B measurement in lakes, an ideal instrument should have a narrow bandwidth,
sensitive and temperature-stable light detector and wavelength filter/selector with high rejection of stray light, wellcharacterized cosine response and immersion coefficients in both air and water, and an integral sensor for precise
measurement of depth. None of the instruments tested matched the ideal, but each had useful characteristics as well
as limitations that in some cases could be minimized by coupling their use with an atmospheric model. Analysis of
results from bacterial and phage dosimeters using a new "biological attenuation coefficient", K*, yielded values
corresponding to instrument-derived attenuation coefficients in the range of 320-340 nm, suggesting that UV-B and
UV-A irradiance contributed to the damaging effects of sunlight. A several-fold reduction in mortality by Mylar
super( registered )-screening of dosimeters argues for a significant effect of UV-B light. Bacteria (DNA repairdefective) were consistently more susceptible to light than were phage under matched conditions. Karentz, D;
Bothwell, ML; Coffin, RB; Hanson, A; Herndl, GJ; Kilham, SS; Lesser, MP; Lindell, M; Moeller, RE; et al.
IMPACT OF UV-B RADIATION ON PELAGIC FRESHWATER ECOSYSTEMS, SCHWEIZERBART'SCHE
VERLAGSBUCHHANDL., STUTTGART (FRG), 1994, no. 43, pp. 31-69, Ergebnisse der Limnologie/Advances in
limnology. Stuttgart [ERGEB. LIMNOL./ADV. LIMNOL.], no. 43 NOT AT OSU-ILL Ultraviolet B (UV-B)
radiation has always been an important environmental factor. Recent global trends in stratospheric ozone depletion
could increase the amount of UV-B within aquatic environments and this has generated a growing interest in how
UV-B can affect aquatic ecosystems. While much has been learned about the UV photobiology and photochemistry
of natural waters, evaluating ecosystem responses is a very complex task. This report summarizes biological and
hydrological data related to UV-B exposure. Gaps in our knowledge are indicated and the potential effects of
increased UV-B on pelagic freshwater ecosystems are discussed. Appendices include an extensive bibliography
relating to the UV-photobiology of aquatic microorganisms and macroalgae. Optics of UV-B radiation in natural
waters Kirk, JTO IMPACT OF UV-B RADIATION ON PELAGIC FRESHWATER ECOSYSTEMS,
SCHWEIZERBART'SCHE VERLAGSBUCHHANDL., STUTTGART (FRG), 1994, no. 43, pp. 1-16, Ergebnisse
der Limnologie/Advances in limnology. Stuttgart [ERGEB. LIMNOL./ADV. LIMNOL.], no. 43 The solar
ultraviolet-B reaching the Earth's surface is almost entirely confined to the 300-320 nm waveband. Within the water
column, the UV-B flux undergoes absorption and scattering: absorption by water itself is negligible, and most of the
UV-B photons are absorbed by the dissolved and particulate yellow humic substances, present in all natural waters,
and originating mainly in the breakdown of terrestrial plant biomass in the soils of the catchments from which the
waters are derived. Light absorption by humic substances increases with decreasing wavelength in the visible region
and increases to even higher levels in the UV. Vertical attenuation of UV-B within water bodies can be either
measured directly with a suitable irradiance meter, or can be calculated from spectral absorption and scattering data
for the water concerned. Data are presented for penetration of UV-B into a range of marine and freshwater bodies.
The depth of water required to remove 90% of the solar radiation at 310 nm varies from about 20 m in the clearest
and most colourless ocean water to a few cm in brown humic lakes and rivers. With the exception of some highaltitude alpine lakes, inland waters, because of their higher humic content, attenuate UV-B more intensely than
marine waters. The attenuation of ultraviolet radiation in temperate lakes Scully, NM; Lean, DRS IMPACT OF UVB RADIATION ON PELAGIC FRESHWATER ECOSYSTEMS, SCHWEIZERBART'SCHE
VERLAGSBUCHHANDL., STUTTGART (FRG), 1994, no. 43, pp. 135-144, Ergebnisse der Limnologie/Advances
in limnology. Stuttgart [ERGEB. LIMNOL./ADV. LIMNOL.], no. 43 Downwelling spectral irradiance was
measured with depth in temperate lakes chosen to provide a gradient of dissolved organic carbon (DOC), particulate
organic carbon (POC) and chlorophyll a (CHLa). Downwelling diffuse UV-B attenuation coefficients (K sub(dI)B)
for radiation, integrated between 300 and 320 nm, could best be described as a power function of DOC(K sub(dI)B
= 0.415 DOC super(1.86), r super(2) = 0.97) and a linear function of DOC fluorescence (DOCFL) (K sub(dI)B =
0.0778 + 0.477 DOCFL, r super(2) = 0,96). Similarly, UV-A attenuation coefficients (K sub(dI)A) for radiation
integrated between 320 and 400 nm, were also a power function of DOC (K sub(dI)A = 0.299 DOC super(1.53), r
super(2) = 0,95) and a linear function of DOC fluorescence (DOCFL) (K sub(dI)A = 0.226 + 0.174 DOCFL, r
super(2) = 0.92). There was no significant correlation between UV-B or UV-A attenuation and CHLa, but there was
a weak correlation between both UV-B and UV-A attenuation and POC, largely due to correlation between POC and
DOC. Attenuation coefficients at 310 nm could be successfully predicted from the absorption coefficient (K
sub(a310)) determined by measuring the absorbance of filtered water in a UV-VIS spectrophotometer (K sub(d310)
= 0.237 + 1.23 K sub(a310), r super(2) = 0.98). Since wavelengths that are attenuated the most, are also the most
damaging, alternative ways of calculating attenuation coefficients to provide energy weighted values were provided.
Contribution of ultraviolet radiation (UV-A, UV-B) to photoinhibition of epilimnetic phytoplankton in lakes of
differing UV transparency Moeller, RE IMPACT OF UV-B RADIATION ON PELAGIC FRESHWATER
ECOSYSTEMS, SCHWEIZERBART'SCHE VERLAGSBUCHHANDL., STUTTGART (FRG), 1994, no. 43, pp.
157-170, Ergebnisse der Limnologie/Advances in limnology. Stuttgart [ERGEB. LIMNOL./ADV. LIMNOL.], no.
43 Epilimnetic algae from four Pennsylvania (USA) lakes of differing transparency to PAR and UV radiation were
all susceptible to photoinhibition of super(14)C uptake (82-95% reduction) and to photobleaching of chlorophyll-a
(57-79% reduction) when incubated at the lake surface. UV-A contributed strongly to the effect. UV-B effects were
difficult to separate from those of shorter UV-A, but UV-B apparently contributed to both photoinhibition of
photosynthesis and photobleaching of chlorophyll-a. Photoinhibition by UV-B as well as UV-A was resolved in a
natural population of a small green alga using super(14)C track autoradiography. Algae from the clearest lake were
somewhat less sensitive to PAR plus longer UV-A wavelengths than algae from the other lakes, but were equally
sensitive to shorter UV-A plus UV-B wavelengths. The absence of photoadaptation to the shorter UV region was
surprising, given the much higher ambient UV irradiances in the clearest lake (9-16% of subsurface UV-305 nm
irradiance at the base of the epilimnion compared to <1 x 10 super(-6) % in the other lakes). Daphnia responses to
UV-light Hessen, DO IMPACT OF UV-B RADIATION ON PELAGIC FRESHWATER ECOSYSTEMS,
SCHWEIZERBART'SCHE VERLAGSBUCHHANDL., STUTTGART (FRG), 1994, no. 43, pp. 185-195,
Ergebnisse der Limnologie/Advances in limnology. Stuttgart [ERGEB. LIMNOL./ADV. LIMNOL.], no. 43 The
tolerance and response of three different Daphnia pulex clones to UV sub(312) were assessed by laboratory studies.
The experimental data was compared with natural light levels and observed depth distribution. All three clones were
highly susceptible to UV sub(312) with somewhat higher tolerance in the arctic melanized clone relative to a
subarctic hyaline clone and the laboratory clone. Tolerance thresholds for UV in the laboratory relative to in situ
light levels suggest that Daphnia populations in clear ponds and lakes are exposed to natural UV-doses close to their
tolerance limits, and that an increased UV-stress could be detrimental to the most exposed populations. UV sub(312)
exposure also induced an immediate downward migration in all clones, demonstrating the ability to visually
perceive and avoid UV-light. A series of incubations of the laboratory clone at different food and light regimes did
not indicate that these animals significantly adjust their carotenoid levels to light. Carotenoids in Daphnia are largely
associated with pre-ovarial lipids and allocated into eggs. Challenges for an appraisal of UV-B effects upon
planktonic crustaceans under natural radiation conditions with a non-migrating (Daphnia pulex obtusa) and a
migrating cladoceran (Daphnia galeata) Siebeck, O; Boehm, U IMPACT OF UV-B RADIATION ON PELAGIC
FRESHWATER ECOSYSTEMS, SCHWEIZERBART'SCHE VERLAGSBUCHHANDL., STUTTGART (FRG),
1994, no. 43, pp. 197-206, Ergebnisse der Limnologie/Advances in limnology. Stuttgart [ERGEB. LIMNOL./ADV.
LIMNOL.], no. 43 The effects of UV-B radiation upon two species of Daphnia, the non-migrating Daphnia pulex
obtusa of a shallow, mountain pond, and the migrating Daphnia galeata of a freshwater lake, have been tested under
natural and artificial conditions. Results indicate that the mortality rate of Daphnia galeata during a cloudless June
day is 100% within one day, whereas that for Daphnia pulex amounted to around 10%. These and other results
provide the opportunity to verify and to discuss various properties of radiation and their importance for UV-B
tolerance. These are: the relative spectral effectiveness of UV-B radiation and recovery radiation, the dose and doserate of UV-B radiation and recovery radiation, and the relationship between the dose-rates of UV-B radiation and
recovery radiation. It will be shown that the results obtained by an experiment with an artificial radiation source and
one conducted out-of-doors under specific, natural radiation conditions, cannot readily be transferred to different
radiation conditions. An estimate of the effects of increasing UV-B radiation due to ozone depletion presupposes
that the minimal dose of UV-B radiation for lethal and sub-lethal effects upon zooplankton is known under a variety
of conditions. That will be possible only if the measuring techniques for both natural and simulated radiation in the
laboratory are improved. Effects of UV-radiation of humic water on primary and secondary production Hessen, DO;
Van Donk, E Water, Air, & Soil Pollution [WATER, AIR SOIL POLLUT.], vol. 75, no. 3-4, pp. 325-338, 1994
TD172 W3 Bioassays with UV-irradiated surface waters from two humic localities revealed a consistent pattern
with phytoplankton production being stimulated at moderate doses (1.1.-5.4 J cm super(-2), 312 nm), but with a
transition to severe growth inhibition at increasing doses (>10 J cm super(-2)). Phytoplankton (Selenastrum
capricornutum) was inoculated after the irradiation treatment, and the observed growth response gave support to the
hypothesis of long-lasting algicidal effects induced by UV-radiation. High UV-doses apparently also liberated
nutrients and metals (A1) complexed by humus. Since the applied UV sub(312)-doses corresponded to mid-summer
solar intensity, the results suggest both chemical and ecological implications, and that these effects have a non-linear
response on UV-dose. Conversely no effects were detected on dark respiration or during corresponding bioassays
with the crustacean zooplankton Daphnia magna. Gala W R. Giesy J P. EFFECTS OF ULTRAVIOLET
RADIATION ON THE PRIMARY PRODUCTION OF NATURAL PHYTOPLANKTON ASSEMBLAGES IN
LAKE MICHIGAN. Ecotoxicology & Environmental Safety 22 (3). 1991. 345-361. TD172 .E27 Inhibition of
primary production of offshore Lake Michigan phytoplankton assemblages by solar ultraviolet radiation (SUVR)
was observed from April to October in 1986 during in situ incubations in special Plexiglas chambers. Inhibition of
primary production by SUVR was observed to a depth of 6 m and at intensities which were approximately 1% of the
UV-B intensity at the lake surface. Significant inhibition of primary production by SUVR was restricted to the top
third of the euphotic zone. The order of relative sensitivities of offshore Lake Michigan phytoplankton assemblages
during different seasons to inhibition by SUVR were spring (ED50 = 17.6 kJ/m2 UV-B) > fall (ED50 = 30.5 kJ/m2
UV-B) > summer (ED50 = 131.6 kJ/m2 UV-B). A hazard assessment model predicted a significant reduction (13%)
in areal (total water column) primary production for offshore Lake Michigan due to current SUVR intensities.
Concern about possible increased reduction of primary production in the North American Great Lakes due to
depletion of the stratospheric ozone layer appears to be unwarranted.