20190397_Environmental Effect of CMA on Natural Phytoplankton Populations in Ten_20180810

ENVIRONMENTAL EFFECT OF CALCIUM MAGNESIUM ACETATE
QN NATURAL PHYTOPLANKTON POPULATIONS IN TEN
SIERRA NEVADA AND KLAMATH MOUNTAIN LAKES
Charles R Goldman
Frerl Lubnaw
James Etser
Division ofEnvironmental Studies
Universiry of Califomia
Davis, California 95616
�'
The damaging and corrosive effecu of road sait on cazs and highways, as well as
its impacts on terrestrial and aquatic ecosystems, have prompted investigations on a
variety of alternative deicing compounds. These studies have revealed that calcium
magnesium acetate (CMA) may prove to be a good alternative to sodium chioride.
Before C�1A ean be used on a large economic scale, however, investigations of iu
effects on various aquatic and terrestrial roadside environments are needed. As a
preliminary step in assessing the potential environmental impacu of CMA, a ten-lake
study was conducted in northem California. In this investigation, samples were taken
from each of the ten lakes and were then incubated in sit� with various concentrations
of CMA to determine if there are any effects on natural-lake phytoplankton growth.
Eight out of the ten lakes, including ultra-oligotrophic Lake Tahoe, showed no
significant response in algal biomass with tbe 0.1 to 10 mg pez liter �ppm)
concentrations of CMA used. Cedaz La7ce showed a weak stimulation in algal biomass
at the highest �,MA concentration of 10 mg liter'i, while L.ake Siskiyou showed an
inconsistent response, with an enhancement at the intermediate cancentration of i.d
mg liter 1. Within the scope of this investigation, CMA seems to have no or relauvely
smali effect on phytoplankton biomass.
INTRODUC'I'ION
Sodium and calcium chloride have been widely used as effecYive highvray
deieing compounds for many years. FIowever, over the past twenty years, data has
accumulated showing the detrimental ef£ects of these salts on both terrestrial and
aquatic ecosystems adjacent to treated roadways. Damage to roadside vegetation
(Lumis et �I. 1971; Hanes eC �I. 1976}, streams and lakes (Bubeck et al. 1971; Judd
1976; Hoffman et ai. i9$1; E-Iorner 19$3}, and soils and sediments (Judd 1916; Prior
and Berthoux 1976) have all been well documented, and contamination of groundwater
supplies is a further concem. it has also been well documented Ehat road salts do very
substantiai damage Co motorszed eehicl�s, Isridges, and buiidings through cc�rrosiv�
action {H an anc! Arlantes 1966}e
�

�ecause of these negative environmental and corrosive effects of road sait,
investigations have continued on alternative, less-harmful compounds (Dunn and
Schenk 1980). Of all thc deicers in questian, caicium magnesium acetate (CMA) is
thought by many to be the best alternative to road salt. It is an effective deicing
compound, has the potential for large-scale production, and has shown extremely low
levels of toaciciry to terrestrial and aquatic organisms (Dunn and Schenk 198d; Homer
1988). The following study deais only with aquatic systems.
'Tt�e effects of CMA on aquatic ecosystems have already been examined in a
number of studies {Horner 1983; LaPerriere and Rea 1989). However, the existing
data does not show how CMA may or may not affect a variety of limnetic systems.
Although lake systems may share many common physical, chemical and biological
factors, they are almost always unique systems with subtle but important differences. If
C?vLA is tc b� used an a large scale, additior,ai inf�nnation is needed on we effecu it
may have on a wider variety of aquatic ecasystems. Further, the mechanisms by which
CMA may impact aquatic communities are as yet not well understood. The results of
our studies are designed to assess the impacts of CMA on algal wmmunities in a wide
variety of Iakes, and to evaluate how interactions between algal and microbial
communities are influenced by CMA.
METHODS
Ten lakes in Northern California (five in the Klamath Mountain region af
Northern California, five in the Lake Tahoe region of the Sierra Nevada) were
selected for this 1989 study (Table i). 'The sampling and incubation procedures were
the same for all ten lakes. Subsurf�ce water was collected vrith a nonmetailic Yan-
Dom sampler and, in order to minimize grazing, was filtered through a$0-utn mesh
net ta remove crustacean zooglankton before being placed in acid-rinsed 250-m1 clear
PVC bntttes.
Four treatments were set up, each in ttiplicate. Contral hottles received no
CMA additions, while the other treatments received concentrations of 0.1, 1.0, and 10.0
mg liter"i of CMA. These concentrations of CMA are toward the lower range of the
predicted values from typicai annual spray and runoff additions af CIvSA onto a
highway (Horner 1988}. Finai concentrations in lakes receiving road runoff will vary
greatly according to their water valume, but are Iikely to be very low through dilution.
Incubations for Klamath Mountain region experiments were performed in Castle Lake;
while Tahoe region experiments were incubated in L.ake Tahoe. The botties were
incubated for four days at a d�pth of 5�3% ligh? penetratior. (Ie5 ::� for Castle Lake,
IS m for Tahoe}. The SQ% light level was determined with a PP.R met��. The dates of
e�geriments for each lake are shown in Table i.
The response of phytoplankton La varying concentrations of �M.4 ivas evaluated
by analysis of chlorophyli concentrations in ihe four treatmencs at the end of th�
incubation periad Chl�r€�phyll was d�t� 'ned by the fluorometric meLhcr� aft�r �cid
��J

Table 1: Ten lakes thac were sampled for the corngaradve study of che algal respoases to C:bIA.
Lake
Ciiff Lake
Castle Lake
Lake Siskiyou
Cedar Lake
Gumboof Lake
Lake Tahce
Donner L�ke
Fatlen-Leaf Lake
Cascade Lake
Martis Creek Res.
Date of
Aug. 3-7
Aug. 8-12
Sept. 5-1Q
Sepc ii-14
Brief Description
Klamath Mountain Lakcs
small (8 ha.) meso-oligoavphic cirque lake.
modezately-sized (20 ha.) meso-oli$otrophic
cirque lake at an elevarion of 1b57 m.
large (160 ha.) mesottophic impaundxnenc of the
Sacramento River, elevarion of 1000 m.
small, shallow lake wich macrophyte beds.
elevation of 1'700 m.
Sept. 12-15 small, shallow lake similaz to Cedar Lake,
elevadon at 1900 m.
Sierra Nevada :liountain Lakes
Aug. 23-27 very luge (500 km ), deep (505 m.} ultra-
o;igoerophie lake, eievation o£ I400 m.
Aug. 24-28 moderatel}�sized, otigotrophic lake,
elevation of 1970 m. adjacent to highway S0.
Ang. 25-29 moderately-sized, oligotrophic lake
elevation of 1944 cn.
Sept. 19-23 moderacely-sized, oligoaophic lake
elevarion oi 1970 m.
Sept. 19-23 small, shallow, eutrophic impoundment of
Marris Creek
■

correction for degradation groducts (Strickland and Parsons 1972}. ChlorophylI was
extracted from filtered material by soaking flters in methanol in the dark at b°C far
24 h(Marker et al. 1980).
THE EFFECTS OF CMA ON PFIYTOPLANKTON ASSEMBLAGES
OF TEN CALIFORNIA I.AKES
RESiILTS
Mean final chloraghyll concentrations (and 9S% co�dence limits an treatment
means} in the four treatments are shown in Figures 1-4. Results for eacfi Iake were
analyzed by analysis of variance and the outcome is presented in Table 2. A significant
staYistical vaiue was }udged to be at the 95�% confidence IeveI.
No significant effects of CMA on algai growth were observed in the eacperiments
performed on lakes in the Lake Tahoe region (Figures i-2, Table 2}. In Martis Creek
Reservoir, a small, shallow high-altitude impoundment, final chlorophyll
concentrations appeared to be lower in CMA treatments. However, due ta high
variability within treatments, this trend was not statisticaily significant at the 95%
confidence level.
Significant (p < 0.05) effects of Ci�A were observed in two of five lakes studied
in the Klamath Mountain region (Figures 3-4, Table 2). The significant effect observed
in the Cedar L,ake eacperiment reflected slightly higher algai growth in the two highest
CMA treatments {1.0 ppm and 10.0 ppm). While ANOVA detected a significant
treatment effect in the Lake Siskiyou experiment, treatment responses were not
consistent and the significant result largely resulted from high chlorophyll
cancentraeions in the intermediate �ft�iA treatment (1.0 pgm} relative to the contrals
and the towest (0.1 ppm} and highest (10 ppm) CaLS �reatmenis.
DISCUSSION
In eight out of ten lakes studied, no statistically signi�icant results were obserred
in response to CMA additions. Since algae tend not To use low concentrations of
arganic substrates such as acetate £or their metabolic processes, these results are not
surprising (Wetzel 1984; Wright and Hobbie 1966).
Additions of CM.4 appeared to have na significant effect on the aigal growth of
lakes in the L.ake Tahoe area (�'igures 1-'_, Table 2). Martis Creek Reservoir, Che most
eutrophic system examined of the ten lakes studied, had chlorophyll concentratians
that were Iawer in the �MA treatments. Even though thfs response was not
statistieally si�nifieant, 'se has �eea noeed by others ehat eutrapnie systems may snow
decreases in algal biomass in response to �MA asiditions �Horner 198L), Since
�utrophfc systems have fairly high concentrations of inorganic nuirYents, competation
betw�e�a algae and bacteria for these nutrients is grobably low. When ac�tate is added
to these nutrient-high waze�s, the groevth o� bacteri� may r,a Ionger be so lisnited by
12

Figure i. The mean chlorophyll concentrations of three lakes in the Tahoe
area, with 95Ye confidence limits on the treatment means. The four
treatments used in this study were controls (0.0 ppm), 0.1 ppm,
1.0 ppm, and 10.� ppm of CMA.
0.6
0.5
>,
s ^ 0.4
aa
� � 0.3
= V O.G
V 0.1
0.0
1.4
1.2
_ ,_, 1.0
o a 0.8
�=0.6
.a �" 0.4
V 0.2
0.4
2.0
a,
1.�
o.•, i.2
c�
o = 0.8
�V
J 0.4
Cascade Lake
Conttol 0.1 ppm 1.0 ppm 10 ppm
Donner Lake
Control 0.1 ppm 1.0 pgm 10 ppm
Fallen Leaf Lake
Contirol 0.1 ppm 1,0 ppm 10 ppm
13

Figure 2. The mean chlorophyll concentrations of two lakes in the Tahoe
area, with 95Y< confidence limits on the treatment means. The four
treatments used in this study were co�trols {0.0 ppm), 0.1 ppm,
1.0 ppm, and 10.0 ppm of CMA.
Martis Creek Reservoir
0.6
— 0.5
a,
Q � 0.4
L "' 0.3
o °D
� v �.2
v �.l
�.�
Controi 0.1 ppm 1.0 ppm 14 ppm
Lake Tahoe
Control 0.1 ppm t.4 ppm 10 ppm
s�

Figure 3. The mean chlorophylt concentrations of three lakes in the Mount
Shasta region, with 95q confidence limits o� the treatment means:
The four treatments used in this study were controls (0.0 ppm),
0.1 ppm, 1.0 ppm, and 10.0 ppm of CMA.
6
5
aa 4
L � 3
o dc 2
s °
U 1
0
— 2.0
a,
.c .-,
a,a
o�
`o m 1.0
.c °
U
0.0
2
Cast(e Lake
Controt 0.1 ppm 1.0 ppm 10 ppm
Cedar Lake
Clifi Lake
Control 0.1 pgm 1.0 ppm 10 ppm
�

Figure 4. The mean chlorophyll concentrations of two lakes in the Mount
Shasta region, with 95% canfidence limits on the treatment means.
7he four treatments used in this study were controls (0.0 ppm),
0.1 ppm, 1.0 ppm, and 10.0 ppm of CMA.
14
12
� ,.� 10
�,"a 8
o �-.
o = 6
.c "' 4
U 2
0
12
io
�a g
a
o� b
� �
o = �
sV
U 2
0
�ua�tsa�ot Lake
Coatrol 0.1 ppm 1.0 gpm 10 ppm
Lake Siskiyou
Conaol 0.1 pgm 1.0 pgm 10 ppm
,�

Table 2. Resulu of Analysis of Variance (ANOVA} of final chlorophyll concentrarions in
�-5 day bioassay experiments. Stadstical significance judged at rhe p< d.05 level.
Lake ANOVA Response
Result
Cascade
Donner
Fallen Leaf
'�farris Creek
Tahce
Castle
i.edar
Ciiff
Gumboot
Siskiyou
p>�.35
p > 0.40
p > 0.20
p>0.10
p > 0.99
p > 0.9?
ge�^v2'"
g a Q.QS
p > 0.05
p < 0.001 *
we:uc �si�ve sffec: at :ighest coa�er.�adons
inconsistent response; enhancement at intecmediate
concenttauon
1i

low concentrations of organic substrates and thus the bacteria may tend, at least in
culture experiments, to out-compete the algae far inorganic nutrients (Wright and
i�obbie 1)66).
In the HIamath Mountain region, two of five lake bioassays showed a significant
response to CMA additions (Figures 3-4, Table 2). In Cedar Lake, a shallow lake
abundant with macrop6ytes, chlorophyll concentrations decreased at the lowest CMA
concentraiion but increased slightly in the two highest CMA treatments. Other studies
have also shown slight increases in algal biomass with CMA additions {Horner 1988;
I.aPerriere and Rea 1989). This stimulation of algal biomass may be due to slight
heterotroghic ugtake of acetate by photosynthetic organisms, adding a little to their
growth increment (Droop 1974; Saunders 1972; Vincent and Goldman 1980}.
However, this situation is unlikely in the presence of naturalIy occurring bacteria that
are much more e�cient in ihe uptake c�f �rgar,ic substrates. A;z�re iikalp sxgl2na::on
is that inorganic nutrient contaminanu, such as phasphorus or nitrogen, contributed to
this increase in algal biomass in the CMA treatments (Horner 1988; LaPerriere and
Rea 1984).
Lake Siskiyou was the second lake that had a significant treatment effect.
However, the response was inconsistent, with chlorophyll increasing in the
intermediate CMA concentration of 1.0 ppm (Figure 4, Table 2}. Such a response is
difficult to interpret. The Lake Siskiyou experiment will be repeated during the
summer of 1990 to reevaluate the effect of CMA on the phytoplankton in this Iake.
Although eight out of the ten lakes examined here showed no staustically
significant response to CMA additions, some slight trends might still be seen. For
example, in Cliff L.ake (Figure 3) chlorophyll concentrations increased consistently,
albeit slightty, with ir,creasing car.centra?i�ns of CMA, Pven Lhough this trend was not
staristically significant. A high level of variability within the treatments contributed to
the lack of statistical significance in Cliff Lake and Martis Creek Reservoir. However,
it must be remembered that the variability in these fieid bioassays is similar to the
variability found in natural aquatic ecosystems, as opposed to more tightiy-controlled
laboratory bioassays (Homer 1988).
While these experiments indicate that CMA has negligible effects on atgal
grawih in the systems studi�d, more extensive ev�luations af the limnologicai effecu of
CMA are still desirable. Assessmeat of the efPects on bacterial biomass and
metabolism (and subsequent rates of nutrient mineralization) will be impa:tant ir.
understanding the direct impact of acetate as a bacterial growth substrate. In addition,
longer-term experiments (weeks, months) under realistie environmentai conditions will
pravide m�re cor,ctcsive results Lhan those fr�rm sh�rt-term bioassays such as thase
reported here. Tl?us, ?he resu�ts summarized in this report support the contention that
the impacts of CMA on aquatic ecosystems are small, bnt mare detailed anvestigations
which incr�ase our understandin$ of the effects of CMA in iakes will greatly enhance
onr confidence in th� environmerta] neutratity o£ CM.� as it becomes mor� widely�
usea as a road deicing agerat.
�

,
Bubeck, R.D., W.H. Diment, B.L. Peck, A.L. Baldwin, and S.D. Lipton. 1971. Runoff
of Deicing Salt: Effect on Irondequoit Bay, Rochester, New York. Science
172:1128-1132.
Dunn, S.A. and R.O. Schenk. 198Q. Alternatives to Sodium Chloride for Highway
Deicing. Transportation Research Record 776:12-15.
Droop, M.R. 1974. Heterotrophy of Carbon. In W.D.P. Stewart (ed.), A1gal
Physiology and Biochemistry. Univ. California Press, Berkeley. pp. 530-559.
Goldman, C.R. 19b3. The Measurement of Primary Productiviry and Limiting Factors
in Freshwater with C-14. In M.S. Doty (ad.), Conference on Primary Productivity
Mfeasurerient, Marine and �reshwater. Proceedings, US AEC TID-7633. pp.
203-113.
Goldman, C.R. and A. J. Horne. 1983. Limnology. McGraw-Hill Book C:ompany.
New York.
Hamman, W. and A.J. Mantes. 1966. Corrosive Effects of Deicing Salts. J. Am.
Water Works Assoc. 5&:11.
Hanes, R.E. 1976. Effects of Deicing Salts on Plant Biota and Soils - Experimental
Phase. NCHRP Report 170.
Hoffman, R.W., C.R. Goldman, S. Paulson, and G.R. Winters. 1981. Aquatic Impacts
of Deicing Salts in the Central Sierra Nevada Mountains, California. Water
Resources Bulletin 17280-285.
Horner, R.R. 1988. Environmental Monitoring and Evaluation of CMA.
Transportation Research Baard. Washington, D.C.
Judd, J.H. 1976. Lake Stratification Caused by Runoff from Street Deicing. Water
Research 4:521-532.
I.aPerriere, J.D. and C.L. Rea. 1989. Effects oi Calciu:n Magnesium Rcetate F?eicer
on Small Ponds in Interior Alaska. Lake and Reservoir Management 5(2):49-
57.
Lumis, G.P. 1911. Sa1t Damage to Roadside Plants. Ontario Ministry of Agriculture
and Food, Ottawa, Ontario, Canada.
Prior, G.A. and P.M. Berthouac. 147f. A Study of Salt Poliution af Saii by Highway
Salting. Highway Research Record P93. Hignway Research Board. Washington,
D.C.
Saunders, G.W. 1972. Fotential Heterotrophy in a Natural Populazion of Oscillatoria
ar�3hi var. is t rix Skuja. Limnol. Oceanogr. 17:704-711.
Strickland, J.I).H. and T.R. Parsons. 2972, A Practical Handbook of Seawater
Analysise T'he Alger Press Ltd.
Vincent, W.F. and C.R. Goldman. I980. Evidenee for rligai i-Ieteratroghy in L,ake
Tahoe, Califamia-t�Tevada. Liannel. Oceanogr, 27:&9-99.
Wetzel, R.G. 19$4e L.iannology. Saanders College �ubl. Philadeiphia, a'A.
�3dright,l2.'I°. and J.�,F. I-�obbie. 19(6. L7se of Giucase and Acvtate by �acceria and
Aigae in Aquatid �,�osystems. �coiogy 47;447-�b4.
�