METRIC CONVERSION FACTORS 

Multiply 

foot (ft) 

cubic yard (yd3 ) 

mile (mi) 

square mile (mi2 ) 

cubic foot per second (ft 3 /sec) 

By 

0.3048 

0.7646 

1.609 

2.590 

.02832 

To obtain 

meter (m) 

cubic meter (m3 ) 

kilometer (km) 

square kilometer (km 2 ) 

Cubic meter per ser;ond (m3 /s) 

105° 

120• 110' I 

~ 49• ------L 115' I -----------~ ~a" ------IT_j____________ \ ,_...) ' I I 

I ! . Spokane o ' \ I I , , ' ' MONTANA \ I ,\ , 

·Seattle 

I \ 

\ • Mount St Helens / ''->(, He~ena '1 

I ...--------.l_ ~'-:-------- '; (, \ Portland , ""\, ______ J 

~~ f \ ~-----------

/ ,, ---1'~ 1 ._,r- I 

I I [ 0 Boise \ 

I IDAHO \ 

OREGON 

! \ -------------~---------------~ 

0 100 200 300 MILES 

0 100 200 300 KILOMETERS 

COVER: North Fork Toutle River, June 30, 1980. Volcanic mud flow breccia 

and debris from the May 18, 1980 eruption of Mount St. Helens (in upper 

right) are as much as several hundred feet thick in the reach shown. 

Photograph by Austin Post, U.S. Geological Survey. 
Toxicity of Mount St. Helens 

Ash Leachate to a Blue-Green Alga 

By Diane M. McKnight, Gerald L. Feder, and Eric A. Stiles 

Hydrologic Effects of the Eruptions 

of Mount St. Helens, Washington, 1980 

GEOLOGICAL SURVEY CIRCULAR 850-F 

1981 
United States Department of the Interior 

JAMES G. WATT, Secretary 

Geological Survey 

Doyle G. Frederick, Acting Director 

Library of Congress catalog-card No. 81-600058 

Free on application to Distribution Branch, Text Products Section, 

U. S. Geological Survey, 604 South Pickett Street, Alexandria, VA 22304 
FOREWORD 

On May 18, 1980, after more than a month of earthquakes and eruptions, Mount St. Helens, in 

southwestern Washington, exploded in a volcanic eruption more violent than any in the conterminous 

United States during the 20th century. A lateral blast of hot gas and rock particles devastated an 

area of about 150 square miles on the northern side of the mountain knocking down trees to a 

distance of 15 miles. Several minutes later, a giant ash cloud rose to about 60,000 feet. Winds then 

carried the ash cloud across the United States, with heavy fallout and deposition in eastern 

Washington and parts of Idaho and Montana. Earlier, smaller eruptions deposited ash in western 

Washington and parts of Oregon and Canada. 

The hydrologic effects of the May 18 eruption have been both widespread and intense. During the 

eruption, a massive debris avalanche moved down the north flank of the volcano depositing about 3 

billion cubic yards of rock, ice, and other materials in the upper 17 miles of the North Fork Toutle 

River valley. The debris deposits are about 600 feet thick in the upper reaches of the valley. Following the avalanche, runoff from the melted glaciers and snow, and possible outflow from Spirit Lake, 

caused an extraordinary mudflow in the North Fork Toutle River. The mudflow shattered and 

uprooted thousands of trees, destroyed most of the local bridges, and deposited an estimated 25,000 

acre-feet of sediment in the Cowlitz River channel. A considerable amount of additional sediment was 

conveyed through the lower Cowlitz into the Columbia River where it deposited and formed a shoal 

that blocked the shipping channel. Mudflows also occurred in the South Fork Toutle River and in 

tributaries on the east flank of Mount St. Helens which enter Swift Reservoir. 

As part of a concerted Geological Survey effort to study the volcanic event and to identify potential 

hazards, Survey hydrologists have mounted an intensive program to document the hydrologic effects 

of the eruptions. The major initial hydrologic findings are reported in this circular series. Quick, 

useful assessment was made possible only because the Survey has long conducted extensive waterresources investigations in the affected areas of Washington, Oregon, and Idaho. Hence, there was a 

well-defined b~sis for identification and documentation of the types and magnitudes of hydrologic 

changes. 

The Geological Survey Circular 850, "Hydrologic Effects of the Eruptions of Mount St. Helens, 

Washington, 1980," consists of individually published short chapters that emphasize data collection 

activities, field observations, and initial comparisons of pre- and post-eruption conditions. The series 

will cover hydrologic events occurring on May 18 in the Toutle and Cowlitz River; physical alteration 

of the Toutle River system; the chemical and physical quality of precipitation, streams, and lakes 

affected by volcanic ash fall; ash-leaching studies; and Mount St. Helens glaciers. 

III 

Doyle G. Frederick 

Acting Director 

CONTENTS 

Page 

Foreword_____________________________________________________________________ III 

Abstract______________________________________________________________________ F1 

Introduction ------------------------------------------------------------------- 1 

Nlethods ---------------------------------------------------------------------- 4 

Background________________________________________________________________ 4 

Culture of Anabaena flos-aquae ------------------------------------------------ 5 

Leaching of volcanic ash ------------~----------------------------------------- 5 

Fractionation of leachate from volcanic ash -------------------------------------- 6 

Addition of leachate fractions to algal cultures ------------------------------------ 6 

Results----------------------------------------------------------------------- 7 

Leachate from volcanic ash collected at Richland ---------------------------------- 7 

Leachate from volcanic ash collected at Nloses Lake ------------------------------- 11 

Summary and conclusions -------------------------------------------------------- 11 

Glossary ---------------------------------------------------------------------- 13 

References____________________________________________________________________ 13 

ILLUSTRATIONS 

Page 

FIGURE 1. Nlap showing thickness of ash deposited from the Nlay 18, 1980, eruption of Nlount 

St. Helens ------------------------------------------------------- F2 

2. Generalized flow chart showing experimental design used to determine the general 

character of toxicants in leachate from volcanic ash ---------------------- 4 

3. Graph showing idealized growth curve for micro-organisms___________________ 5 

4. Graph showing growth of Anabaena flos-aquae exposed to different fractions of 

leachate from volcanic ash collected at Richland------------------------- 9 

5. Photomicrographs showing morphological differences between Anaba.ena flosaquae grown in cultures exposed to various concentrations of unfractionated 

leachate from volcanic ash collected at Richland------------------------- 10 

6. Graph showing growth of Anabaena flos-aquae exposed to different fractions of 

leachate from volcanic ash collected at Nloses Lake ---------------------- 12 

TABLES 

TABLE 1. Selected constituents and physical properties of water from (1) four lakes in ash 

fall area, central Washington; (2) synthetic freshwater; and (3) leachate from 

Page 

Nlount St. Helens volcanic ash collected at Richland and Nloses Lake, Wash__ F3 

2. Dissolved constituents in leachate from volcanic ash after passing through cationexchange resin column --------------------------------------------- 7 

3. Concentration of dissolved organic carbon and trace metals in cultures used for 

bioassay experiments with Anabaena flos-aquae ------------------------- 8 

4. Growth rates of duplicate Anabaenaflos-a.quae cultures exposed to different fractions of leachates from volcanic ash ----------------------------------- 11 

v 

HYDROLOGIC EFFECTS OF THE ERUPTIONS OF MOUNT ST. HELENS, WASHINGTON, 1980 

TOXICITY OF MOUNT ST. HELENS ASH LEACHATE 

TO A BLUE-GREEN ALGA 

By DIANE M. McKNIGHT, GERALD L. FEDER, and ERIC A. STILES 

ABSTRACT 

This report describes laboratory studies with volcanic ash intended to aid the assessment of the possible effects of ash 

presence on the blue-green algal populations in lakes. Bioassays 

using leachate from volcanic ash of the May 18, 1980, eruption 

of Mount St. Helens, Wash., indicate that leachate derived from 

ash collected at Richland, Washington, is toxic to the blue-green 

alga Anabaena flos-aquae, whereas leachate from ash collected 

at Moses Lake, Wash., is not. The difference in the toxicity of 

the two leachates may be attributable to differences in concentration of cationic-exchangeable, dissolved, organic compounds. 

Seventeen percent of the dissolved organic carbon from the 

leachate from ash collected at Richland was retained on a cationexchange column, whereas only six percent of the dissolved 

organic carbon from the leachate from ash collected at Moses 

Lake was retained. Anabaena flos-aquae cultures spiked with 

dilutions as large as 1 to 250 of leachate derived from volcanic 

ash collected at Richland showed toxic effects, whereas cultures 

spiked with a 1 to 25 dilution of leachate derived from ash collected at Moses Lake showed no toxic effects. 

The toxic components of the volcanic ash are nonuniformly 

distributed over the ash fall area. Preliminary data indicate that 

the toxic components may belong to one or more of the following classes of substances: (1) cationic organic compounds such 

as amines; (2) highly hydrophobic (sparingly soluble) organic 

compounds such as phenols that interact with and are retained 

by the cation-exchange-resin matrix; or (3) metal-organic complexes that are retained by interaction of the metal with the 

cation-exchange resin. 

INTRODUCTION 

The May 18, 1980, eruption of Mount St. Helens 

volcano in Southwestern Washington covered 

large areas of Washington, Idaho, and Montana 

with volcanic ash with accumulation of more than 

50 mm in parts of central Washington (fig. 1). To 

ascertain the possible effects of the ash on water 

quality, ash samples were collected from several 

locations for chemical analysis of their distilled 

water leachates. The results indicate that, relative 

to natural sur:face waters in tbe affected area, the 

leachates contain high concentrations of several 

F1 

potentially toxic trace elements, specifically 

manganese (Mn), zinc (Zn), copper (Cu), and cadmium (Cd) (table 1). 

In addition, the leachates contain large concentrations of important algal nutrients (phosphate, 

nitrate, ammonia) and as much as 200 milligrams 

of dissolved organic carbon per liter (mgC/L) 

(Taylor and Lichte, 1980). Chemical analyses of the 

organic compounds in volcanic ash collected at 

Richland, Washington, indicate that many of the 

identified components (for example, dicardoxylic 

acids, n-alkanes, 4-methaxybenzaldehyde, and 

trimethylphenanthrene) could have originated as 

breakdown products of pyrolized plant material 

(Pereira and others, 1980). These organic products 

may have formed during the eruption as a lateral 

blast of superheated gases and hot ash flattened 

about 40 square kilometers of coniferous forest. J. 

A. Leenheer (oral communication, 1980) of the 

U.S. Geological Survey reported that the concentration of organic compounds in leachate from ash 

varied with location, with higher concentrations 

near the periphery of the ash fall area than toward 

its center. In this context, Richland, Wash., is on 

the southern edge of the ash fall about 140 miles 

east of Mount St. Helens (fig. 1). 

Because of the large concentrations of trace 

elements and dissolved organic compounds in the 

leachates, concern arose over the possible effects 

of the ash on aquatic ecosystems, particularly in 

the many lakes of the area. Therefore, a 

preliminary bioassay experiment was conducted 

using volcanic ash leached with a synthetic solution 

simulating natural lake water. The organism 

selected for the test was Anabaena jlos-aquae, a 

common blue-green algae known to be sensitive to 

trace metals (McKnight and Morel, 1980). Results 

showed that leachate from volcanic ash collected in 
"1:j 

N 

123°W 

~N+ WASHINGTON 

• Seattle 

I MONTANA 

/ 

I 

/ ' 

/ ---~--- . / 

--- I --~ I 

- I ' -1.0 ' . 

10 I ...... ., 

• Kalispell 

:::0 -

Ritw ·11e . '\ J \.M'issoula • --) / 

0

• \ 

30 <:X§fJ _ __. 1 _.... __ s. "'--- ....- • - I _ _.. --- J ~ ke ....-.....- Mose 1 

• / ~ / 10 J.O--- I 

•Oiympoa ..o· / / S u•ow 

/ ___ 

// ;:._........- 30 ~ a Richland \ ', ( ' +46'N 

~ / ( \ ~~ · ft'fup L~k --- ---.::____ - oasco ---:::-:\ ) , _1 /\ 

\ ~_:::".:;... __ ..:=::--o- _,---- ~ =-O---'f IDAHO -v "'"'- Moun~ St Helens __ .r---·- OREGON 

\ ~ \ ,../'"'... ..... \ ,.,-·'-v.n '-..__ .. •Portland 

0 215 I 7

1

5 190 MILES 

I I I I I 

0 25 50 75 100 KILOMETERS 

OREGON IDAHO 

FIGli KE 1. Thickness of ash deposited from the May 18, 1980, eruption of Mount St. Helens, shown by lines of equal uncompacted thickness, in 

millimeters. (Adopted from Sarna-Wojicki and others, 1980. Areal distribution, thickness, and volume of downwind ash from the May 18, 1980, 

eruption of Mount St. Helens, U.S.G.S. Open File Report No. 80-1078.) 
~ C;.:) 

TABLE 1. -Selected constituents and phys1~cal properties of water from (1) four lakes in ash fall area, Central Washington.l(2) synthetic freshwatwr; and 

(3) leachate from Mount St. St. Helens volcanic ash collected at Richland and Moses Lake, Washi~gton. 

[NA, not added; ND. not determined] 

Lake Mount St. Helens volcanic ash collected at 

Synthetic 

Warden Moses Lenore freshwater Richland Moses Lah 

Concentration A Major cations mg/L mg/L mg/L mg/L mg/L 

Na ------------------------------ 1.11 ~!:J 11 200 :30 167 0.17 2G1 Ca ------------------------------ Ui fi.3 12 2.9 13 182 .21 2:34 

Mg ------------------------------ ,, !:1.4 fi.f:i G.3 5 3!:1 .04:l 48 Sr ------------------------------- .OO!:J .07 .O!:J .02 NA 1.2 .001 1.0 K ND ND ND 

Ma]c;r~~io-;s-====================== mg/L mg/L mg/L 

ND 4(added) ND ND 

mg/L mg/L(added) 

ND 

2.7 l!:J 7.fj 130 18 ND ND ND ~u ;)8 27 210 14.5 ND ND ND 

F ------------------------------- .2 .il .5 ~.fl NA ND ND ND N03 + N02 - N _____________________ .Oti 'J'J 

.dd .04 .01 14 ND ND ND 

P04 - P -------------------------- ND ND ND ND 1.5 ND ND ND Trace metals ______________________ l'g/L l'g/L l'g/L Mn ------------------------------ 2 2 I Zn ------------------------------ <3 <3 <;{ 

l'g/L l'g/L(arlded) "g/L l'g/L 

< 1 1.3 4.!:110 fi.l4 

<3 2.fi 303 .:l8 

l'g/L 

::>,170 

18 Li <4 G G 

Cu -============================== <10 <10 <10 

11 NA 17fi .22 

<10 .Ofi 103 .1:3 

246 

30 Ba 7 10 20 

Fe ============================== <10 <HI < 10 

10 NA 87 .11 

<10 G6 65 .081 

80 

24 

Co ------------------------------ <3 <:l <3 <3 .1G 2!:1 .036 4 

Cd ------------------------------ <1 <1 <2 <1 NA 17 .020 ~~ 

Mo < 10 <10 <10 Diss~lie_d_~~g~~~-c,;:-rb_o_n_============ mgC/L mg"C/L mgC/L 

< 10 .14 8 .010 

mgC/L rngC/L(added) mgC/L mgC/g 

31 

mgC/L .8 5.7 4.3 13.2 F 69 .08fi 5~ 

pH ------------------------------ ND 7.5 fi.G 8.7 8.0 7.1 7.4 Alkalinity in milliequivalents/L _______ .3 4.0 2.8 16.8 .3 Chlorophyll a in l'g/L _______________ .31 1.9 78.fi !:1.5 

1 Location of lakes shown in figure 1; lakes were samplerl on July 18, 1980. 

2 1 mgC/L obtained uy adding Biscayne fulvic acid (Thurman and Malcolm, written communication, 1!:180). 

0.1!:1 

.1!:1 

.0:37 

.001 

ND 

ND 

ND 

ND 

ND 

ND 

l'g/L 

2.77 

.Olfi 

.21 

.02fi 

.070 

.021 

.oo:> 

.008 

.027 

mgC/g 

.04fl 
the Richland, Wash., area was lethal to Anabaena 

flos-aquae at dilutions of up to 1~100. Even at 

weaker dilutions of up to 1:500, the ash leachate 

caused abnormal morphologies in the algal cells. 

These biological effects are particulary startling, 

because the noted laboratory dilutions approximate natural levels of chemical constituents that 

could be leached from volcanic ash; for example, a 

1:250 dilution corresponds to one centimeter of 

ash falling into a lake with a mixing depth of 2.5 

meters. 

The objectives of the present study are to: (1) 

determine whether trace elements, organic compounds, or both, are the toxic components in the 

leachate from volcanic ash deposited at Richland; 

(2) isolate and identify the trace metals or organic 

compounds causing the toxicity; and (3) determine 

if leachate from volcanic ash deposited near Moses 

Lake, Wash., is also toxic to blue-green algae. The 

Moses Lake region in central Washington has 

many lakes and received one of the thickest ash 

deposits (fig. 1). The hypothesis that the observed 

areal variations in organic and inorganic composition of the ash (Leenheer, oral communication, 

1980) would result in corresponding variations in 

toxicity of leachate from volcanic ash was also 

tested. 

To aid the reader, a glossary of technical terms is 

included at the end of this report. 

U nfractionated 

leachate 

METHODS 

BACKGROUND 

To assess the effects of the Mount St. Helens ash 

on blue-green algal populations in lakes, bioassay 

experiments were conducted with Anabaena flosaquae. The general approach in bioassay work is to 

study the interactions between organisms and 

their environment under known, controlled 

laboratory conditions where results can be more 

readily interpreted than under complex field conditions. The controlled conditions in the present 

study consisted of constant light and temperature, 

and a culture medium prepared from laboratory 

chemicals to simulate the natural aquatic environment. Several simultaneous bioassay experiments 

were conducted using different chemical fractions 

of the leachate from volcanic ash to determine the 

chemical characteristics of the toxic constituents. 

The flow chart in figure 2 shows the experimental 

design used in the experiments. Essentially, the 

experiment consisted of: (1) testing the toxicity of 

the unfractionated leachate; (2) passing the 

leachate through a cation-exchange resin;, and (3) 

testing the toxicity of the effluent from which most 

trace metals had been removed; and ( 4) testing the 

toxicity of the trace metals removed from the 

leachate by the cation-exchange resin. The specific 

methodologies are described below in the following 

No!) toxic* Toxic 

~ 

{

Cat_ion exch~nge 

resm removmg 

most metals and 

some organics TOXIC Nont~ 

Experiment 

continues 

TOXIC Noh ' toxic 

Conclusion: Acidic or 

2 neutral organic compounds 

are major toxicants 

*Experiment continues to compare fractionation with toxic 

leachates and to determine if any fraction stimulates growth. 

Experiment 

~ 

continues 

Conclusion: Cationic or 

hydrophobic organic 

4 compounds or metalorganic complexes 

are major toxicants 

FIGURE 2. -Generalized flow chart showing experimental design used to determine the general character of toxicants in leachate 

from volcanic ash. 

F4 
sequence: (1) culture of blue-green algae; (2) 

leaching of volcanic ash samples; (3) fractionation 

of leachates; and (4) addition of leachate fractions 

to algal cultures. 

CULTURE OF ANABAENA FLOS-AQUAE 

Anabaena .flos-aquae UTEX 1444 was grown in 

250 milliliters (ml) of synthetic freshwater culture 

medium (WC medium) in 500 ml polycarbonate 

Erlenmeyer flasks at 23°C under continuous light. 

Synthetic culture medium provides more optimal 

conditions than most natural waters, permitting 

Anabaena to grow faster, and providing for more 

reproducible and controlled experiments. Other 

reasons for using synthetic culture medium are the 

large variations in chemistry of lake waters in the 

study area (table 1) and the difficulty in transporting and preserving natural waters for laboratory 

study. Growth was monitored by measl1rernent of 

the concentration of chlorophyll a in the cultures 

every other day and by microscopic examination of 

the cultures. 

Increase of biomass in laboratory cultures of 

micro-organisms normally follows a sequence of 

slow growth (lag phase), rapid growth (exponential 

growth phase), and then no growth (stationary 

phase) (fig. 3). Toxicants may affect microorganisms in any growth phase; for example, the 

lag phase may increase in length as cells adapt to 

the stress, the growth rate during the exponential 

growth phase may decrease, or the maximum 

biomass reached during the stationary phase may 

be lowered, owing to inhibition of nutrient 

assimilation. 

LEACHING OF VOLCANIC ASH 

In the experiment with volcanic ash collected at 

Richland, leachate was eluted with WC medium 

from a column packed with 80 grams of ash and 

PHASE 

TIME 

FIGURE 3. -Idealized growth rurve for micro-organisms. 

F5 
saturated for 14 hours at 23oe with 100 ml of we 

medium (without trace metals orfulvic acid added). 

In the experiment with volcanic ash collected at 

Moses Lake, 172 grams of ash were leached with 

150 ml of We medium for 12 hours at 23°e and the 

leachate was eluted from the column with we 

medium. The amount of ash used in each experiment was governed by the amount of ash available 

for study. A Millipore1 HA 0.45~-tm filter, previously leached in we medium, was placed at the bottom of the column to retain particulate material. 

The leachates were stored in glass containers at 

4°e. 

In table 1, the dissolved chemical constituents of 

unaltered we medium and leachates from volcanic 

ash collected at Richland and Moses Lake are compared with those of four lakes in the ash fall area. 

The amounts of trace metals and organic material 

leached expressed as micrograms per gram of ash, 

are also shown. The analysis for major cations and 

trace metals was done by inductively coupled 

plasma emission spectroscopy and the dissolved 

organic carbon was determined with a Beckman 

915 carbon analyzer. Several of the measured constituents (Mn, eu, Zn, ed, and organic carbon) 

were present in concentrations high enough to be 

possibly toxic to algae (see Hutchinson, 1957; 

Bartlett and others, 1974). Both leachates have 

high concentrations of eu, ed, and Zn. Almost 

twice as much organic carbon was leached per 

gram of ash from the Richland sample, which is in 

accord with the trend reported by Leenheer (see 

page Fl) toward' highest organic contents in 

samples from the periphery of the ash fall area. 

FRACTIONATION OF LEACHATE FROM VOLCANIC' ASH 

In order to remove cationic trace metals and 

organic compounds, both the volcanic ash from 

leachates collected at Richland and Moses Lake 

were passed through a 30 ml column of sodiumsaturated cation-exchange resin previously extracted with methanol. Owing to the different 

amounts of leachate available from the previous 

step, different volumes were fractionated for the 

Richland and Moses Lake samples. 

A 25 ml sample of the leachate from the ash collected at Richland was applied to the column and 

50 ml of leachate and distilled water was eluted 

with distilled water. Only 67 percent of the organic 

1 The use of brand names in this report is for identification purposes only and does 

not imply endorsement by the U.S. Geological Survey. 

carbon in the leachate was recovered in the 50 ml. 

Another 50 ml of distilled water was passed 

through the column bringing the total recovery of 

dissolved organic carbon to 83 percent. These two 

50 ml effluent fractions were combined resulting in 

a fourfold dilution of the leachate. As shown in 

table 2, most of the trace metals were removed by 

the cation-exchange resin. 

A 50 ml sample of the leachate from ash collected 

at Moses Lake was applied to an identical column 

and eluted with distilled water and 100 ml of column effluent was collected. The recovery of 

dissolved organic carbon in the effluent was 93 percent, much higher than with the Richland leachate 

(table 2). Most of the trace metals in the Moses 

Lake leachate were retained by the cationexchange resin. 

ADDITION OF LEACHATE FRACTIONS TO ALGAL 

CULTURES 

The leachate fractions were filter sterilized and 

added to duplicate flasks of culture medium before 

inoculation with Anabaenaflos-aquae. Because the 

ash leachate from ash collected at Moses Lake had 

a lower concentration of dissolved organic carbon, 

the amounts of leachate added were scaled to approximate the concentrations of dissolved organic 

carbon in leachate from ash collected at Richland 

that were toxic in the preliminary experiment. In 

the two main experiments, a concentration of 2 

milligrams dissolved organic carbon per liter (mg 

e/L) was used to correspond to the 1:50 dilution 

that was completely inhibitory, and a concentration of 0.2 mg e/L was used to correspond to the 

1:500 dilution that caused abnormal cell morphologies, but did not inhibit growth. 

Table 3 presents the concentrations of trace 

metals and dissolved organic carbon obtained in 

the culture media by adding different volumes of 

unmodified leachate from volcanic ash, cationexchanged leachate, and synthetic trace metals. 

The synthetic trace-metal solutions were formulated to reproduce concentrations of trace 

metals in the leachates which might be toxic to 

algae at a 1:100 dilution. Manganese was highest 

in concentration among the trace metals in both 

leachates. However, even at the 1:25 dilution, the 

concentrations of manganese approximated those 

in natural waters of the affected area (compare 

table 3 to table 1). 

F6 
TABLE 2. -Dissolved constituents in leachate from volcanic ash after passing through cation-exchange resin column. 

Leachate from Mount St. Helens volcanic ash collected at Richland and Moses Lake 

Richland1 Moses Lake" 

pH ---------------- 7.0 6.2 

Major cations Concentration 

in mg/L Percent removed 

by exchange column 

Concentration 

in mg/L 

Percent removed 

by exchange column 

Na _______________ _ 

Ca _______________ _ 150 

.04 

<.04 

.6 

300 (increase) 

99 

352 

.01 

<.04 

<.04 

172 (increase) 

100 

Mg ---------------- 100 100 Sr ________________ _ 100 100 

Trace metals Percent removal J!g/L Percent removal 

Mn _______________ _ Zn _______________ _ Li ________________ _ 

Cu _______________ _ 

Ba _______________ _ 

Fe _______________ _ Co _______________ _ 

Cd _______________ _ 

Mo _______________ _ 

Dissolved organic 

carbon in 

<1 

5.9 

<4 

<10 

2.3 

<10 

<3 

1.3 

<10 

14.3 mgC/L 

100 

92 

100 

100 

89 

100 

100 

69 

100 

17 

<1 

.5 

<4 

1.9 

2.6 

<10 

<3 

.1 

<10 

24.3 p,g/L 

100 

94 

100 

87 

93 

100 

100 

98 

100 

6.5 

1 1:4 dilution was obtained by flushing cation-exchange column with 75 ml of distilled deionized water after passing 25 ml of lear hate from vnleanic a8h collerted at Richland 

through the column. 

' 1:2 dilution was obtained by flushing cation-exchange column with fiO ml of distilled deionized water after passing fiO ml of leachate from volcanic ash collected at Moses 

Lake through the column. 

RESULTS 

LEACHATE FROM VOLCANIC ASH COLLECTED AT 

RICHLAND 

Figure 4 shows the growth curves for the experiment with leachate from volcanic ash collected at 

Richland. The graphs show similar growth rates 

for the control, cation-exchanged leachate, and 

synthetic trace metal cultures (0.62, 0.64, and 0.58 

day- 1

, table 4). As in the preliminary experiment, 

the unfractionated leachate had a lethal effect on 

Anabaena flos-aquae at a concentration of 2 mg 

C/L of dissolved organic carbon (see table 3). The 

cultures exposed to the unfractionated leachate at 

a concentration of 0.27 mgC/L had a 7-day period 

of no net growth (lag phase), prior to an exponential growth phase with replicate growth rates of 

0.51 and 0.69 day- 1• In comparison, a 2-day lag 

phase had been observed at a concentration of 0.20 

mgC/L of leachate (1:500 dilution) in the 

preliminary experiment. 

The results of this experiment corresponds to the 

third possibility depicted in figure 2, wherein the 

leachate is toxic, but the cation-exchanged 

leachate and the synthetic trace metals are not. 

The most likely conclusion is that the toxicants are 

part of the 17 percent of organic carbon that was 

retained by the cation-exchange column. Several 

types of organic compounds could be retained: (1) 

cationic-organic compounds such as amines; (2) 

F7 

strongly hydrophobic (sparingly soluble) organic 

compounds such as phenols that interact with and 

are retained by the resin; or (3) metal-organic complexes that are retained by interaction of the metal 

with the cation-exchange resin. Further experiments are planned to distinguish between 

these possible types of organic compounds and to 

obtain a sufficiently large sample of toxicant for 

more detailed characterization. 

Photomicrographs (fig. 5) show Anabaena flosaquae filaments from the experiments with 

leachate from volcanic ash collected at Richland. 

Filaments from the cultures with cation-exchanged 

leachate and synthetic trace metals were similar in 

appearance to those in the control cultures. In the 

cultures with the higher concentration of unfractionated leachate, where no growth occurred, only 

short filaments ( < 5 cells/chain) having an aberrated morphology were observed. In the cultures 

with the lower concentration of unfractionated 

leachate, (that grew after a 7-day lag phase), the 

filaments were longer ( > 20 cells/chain), but still 

had an aberrated morphology. These abnormal 

cells were also observed in the cultures exposed to 

unfractionated leachate from volcanic ash collected at Richland in the preliminary experiment; 

they are characterized by greater width in the 

direction perpendicular to the filament and by a 

grainier appearance than normal cells. Heterocysts-the enlarged cells where nitrogen fixation 
a: 

\1) 

1-

::J 

a: 

\1) 

~ 

Vl 

~ a: 

a: 

8 

a: 

u 

~ 

0 

_J 

_J 

> ::r: 

~ 

0 

a: 

0 

_J 

::r: 

u 

300 

200 

150 

100 

75 

so 

40 

30 

20 

15 

10 

7.5 

5 

4 

e Controls 

3 D. 1:35 Dilution } Uriractionated 

X 1:250 Dilution Leachate 

2 01:35 Dilution yatioiH!lxchanged 

'\/1 :350 Dilution Leachate 

1.5 

o------~----~------~~----~~~~---

0 1 2 3 4 5 6 7 8 9 10 11 

DAYS 

FIGURE 4. -Growth of Anabaena flos-aquae exposed to different fractions of leachate from volcanic ash collected at Richland. 
"'%j 

<:.0 

TABLE 3. -Concentration of dissolved organic carbon and trace metals in cultures used for bioassay experiments with Anabaena flos-aquae. 

[N A not added, ND not detected] 

Leachate from Mount St. Helens volcanic ash collected at 

Richland 

Parameter 

Concentration in culture medium 

with unfractionated leachate 

added' 

Concentration in culture medium 

with cation-exchanged leachate 

added2 

Dilution 1:35 1:250 1:35 1:350 

Dissolved organic carbon (mg CIL) ____ 2.0 0.27 1.5 0.15 

Manganese (J.tgiL) ------------------ 139 19.6 ND ND 

Zinc (,..giL) ------------------------ 8.6 1.2 0.6 0.06 

Lithium (,..giL)--------------------- 5.0 .7 ND ND 

Copper (,..giL) --------------------- 2.9 .4 ND ND 

Barium (J.tgiL) --------------------- 2.5 .4 .2 .03 

Iron (,..giL)------------------------ 1.8 .3 ND ND 

Cobalt (,..giL)---------------------- .8 .12 ND ND 

Cadmium (,..giL) ------------------- .5 .07 .14 .01 

Molybdenum (,..giL) ---------------- .23 .03 ND ND 

1 The 1:35 dilution was obtained by adding 7.3 ml of unfractionated leachate to 250 ml of culture medium. 

The 1:250 dilution was obtained by adding 1 ml of unfractionated leachate to 250 ml of culture medium. 2 The 1:35 dilution was obtained by adding 29.2 ml of cation-exchanged leachate to 250 ml of culture medium. 

The 1:350 dilution was obtained by adding 2.9 ml of cation-exchanged leachate to 250 ml of culture medium. 

"The 1:25 dilution was obtained by adding 10 ml of unfractionated leachate to 250 ml of culture medium. 

The 1:250 dilution was obtained by adding 1 ml of unfractionated leachate to 250 ml of culture medium. 4 The 1:25 dilution was obtained by adding 20 ml of cation-exchanged leachate to 250 ml of culture medium. 

The 1:250 dilution was obtained by adding 2 ml of cation-exchange leachate to 250 ml of culture medium. 

Concentration in 

culture 

medium with 

synthetic 

metal solution 

added 

150 

8.6 

10.5 

3.1 

NA 

NA 

NA 

1.1 

.57 

Concentration in culture medium 

with unfractionated leachate 

added3 

1:25 1:250 

2.0 0.21 

122 12.6 

.7 .07 

9.5 .98 

1.1 .12 

3.1 .32 

.9 .10 

.15 .02 

.3 .04 

1.2 .12 

Moses Lake 

Concentration in culture medium 

with cation-exchanged leachate 

added4 

1:25 1:250 

1.8 0.19 

ND ND 0.04 0.004 

ND ND 

.14 .02 

.19 .02 

ND ND 

ND ND 

.01 .001 

ND ND 

Concentration in 

culture medium 

with synthetic 

metal solution 

added 

122 

NA 

9.5 

1.1 

NA 

NA 

NA 

.3 

1.2 
F IGURE 5. -Photomicrographs showing morphological differences between Anabaena 

flos-aquae grown in cultures exposed to various concentrations of unfractionated 

leachate from volcanic ash collected at Richland. A. Control cultures; B. Cultures 

exposed to a 1:36 dilution; C. Cultures exposed to a 1:250 dilution. (Enlargements of 

photomicrographs taken of unpreserved cultures with light microscope.) 

FlO 
TABLE 4. -Growth rates of duplicate Anabaena flos-aquae 

cultures exposed to different fract-ions of leachates from 

volca,nic ash. 1 

Leachate from volcanic ash collected at Richland 

Control cultures -------------------------

Growth rate, day-', computed 

from day 0 to day 5.1 

Culture 

0.64 

Duplicate 

culture 

0.64 

Unfractionated leachate (1:35 dilution) ______ no growth 

Unfractionated leachate (1:250 dilution)_____ 0.512 0.692 

Cation-exchanged leachate (1:35 dilution)____ .62 .62 

Cation-exchanged leachate (1:350 dilution)___ .62 .67 

Synthetic trace metals___________________ .58 .58 

Leachate from volcanic ash collected at Moses Lake 

Control cultures _________ __ _ __________ _ 

Growth rate, day-', computed 

from day 2 to day 4.4 

Culture 

0.71 

Duplicate 

culture 

0.83 

Unfractionated leachate (1:25 dilution)______ 0.69 0.74 

Unfractionated leachate (1:250 dilution)_____ .71 .69 

Cation-exchanged leachate (1:25 dilution)____ .69 .69 

Cation-exchanged leachate (1:250 dilution)___ . 74 . 71 

Synthetic trace metals___________________ .67 .69 

1 See table 3 for the content of dissolved organic carbon and selected trace metals in 

each culture. 2 Growth rate after 7-day lag phase. 

occurs in filamentous blue-green algae- were 

observed in all cultures, except those exposed to 

the unfractionated leachate from volcanic ash. 

Perhaps the toxicants act at the cell wall and interfere with nitrogen assimilation. 

Duplicate cultures of fresh, untreated WC 

medium were inoculated with abnormal Anabaena 

flos-aquae cells from the Richland experimental 

cultures. The cultures inoculated with Anabaena 

flos-aquae cells initially exposed to the lower concentration of leachate grew within a week, 

whereas the cultures innoculated with cells exposed 

to the higher leachate concentration grew after 

three weeks. No abnormal cells were observed in 

the final cultures, indicating that the effect of the 

toxicants on the morphology of the blue-green 

algal cells is reversible. 

LEACHATE FROM VOLCANIC ASH COLLECTED AT 

MOSES LAKE 

Figure 6 presents the growth curves from the experiment in which different fractions of leachate 

from volcanic ash collected at Moses Lake were 

added toAnabaenaflos-aquae cultures. None of the 

leachate additions had significant effects on 

growth or final biomass, nor caused changes in cell 

morphology. The data in table 4 shows no significant difference in growth rate computed from day 

2 to day 4.4 among the various cultures. 

The failure to observe any toxic effect of the 

leachate from volcanic ash collected at Moses Lake 

is not surprising given that (1) the toxicants in the 

leachate from volcanic ash collected at Richland 

were apparently part of the 17 percent of the 

dissolved organic carbon retained by the cationexchange column and (2) this fraction contributed 

only 7 percent of the total dissolved organic carbon 

to the leachate from volcanic ash collected at 

Moses Lake. The toxicants may not be present in 

the leachate or they may occur in relatively much 

lower concentrations. 

SUMMARY AND CONCLUSIONS 

The data reported here confirm that leachate 

from volcanic ash collected at Richland is toxic to 

Anabaenaflos-aquae at large dilutions. In addition, 

the results indicate the toxic substances are probably organic compounds retained on a cationexchange resin, rather than uncomplexed trace 

metals such as Mn, Zn, Cu, and Cd; or anionic or 

hydrophillic (readily soluble) organic compounds. 

The toxic constituents retained on the cationexchange resin could be one or more of the following types: (1) cationic-organic compounds such as 

amines; (2) strongly hydrophobic (sparingly soluble) organic compounds such as phenols that interact with and are retained by the resin; or (3) 

metal-organic complexes which are retained by interaction of the metal with the cation-exchange 

resin. Further experiments are being conducted to 

provide more specific identification of the toxic 

compounds. 

Results indicate that the leachate from ash collected at Moses Lake has neither an inhibitory nor 

stimulatory effect on the growth of Anabaenaflosaquae. This finding is consistent with the contrasting results from the experiment using leachate 

from volcanic ash collected at Richland, because 

the fraction of that leachate shown to be toxic occurs at a much lower concentration in the Moses 

Lake sample. The toxicants found in the leachate 

from the volcanic ash collected at Richland may 

either be absent or occur in much lower, nontoxic 

concentrations in the leachate from ash collected 

at Moses Lake. 

Visual observation and other data (Fruchter and 

others, 1980) have shown that the volcanic ash was 

fractionated (sorted by weight of particles) as it 

was carried eastward from Mount St. Helens. The 

lighter materials were carried farthest, and this 

distribution is reflected in data showing highest 

concentrations of dissolved organic carbon in 

Fll 
400 

300 

a: 

w 

1-- 200 ::::i 

a: 

w 

Q. 

~ cc 

a: 130 8 

a: 

u 

~ 100 

ai 

_J 

_J 

:::>- 75 ::I: 

Q. 

0 

a: 

0 

_J 

::I: 

u so 

30 

0 

• Controls 

6 1:25 Dilution } Urtractionated 

X 1:250 Dilution Leachate 

0 1:25 Dilution } Cation-exchanged 

\l 1:250 Dilution Leachate 

0 SVnthetic Trace Metal 

Solution 

1 2 3 4 5 6 7 

DAYS 

Frt;URE 6. -Growth of Anabaena jios-aquae exposed to different fractions of leachate 

from volcanic ash collected at Moses Lake. 

F12 

8 9 
samples from the periphery of the ash fall area 

(Taylor and Lichte, 1980; Pereira and others, 

1980). Delineation of the geographic distribution of 

the toxicants is planned for future study. This information will help identify lakes and streams most 

likely to be affected by volcanic ash deposition. Inh~bition of blue-green algal growth in Liberty 

Lake, Wash. (see fig. 1), which has a history of 

nuisance blue-green algal blooms, has already been 

reported (W. H. Funk, Washington State University, written communication, 1980). 

The failure to observe toxicity in laboratory experiments with leachate from volcanic ash collected at Moses Lake is consistent with field observations of algal populations in several lakes from 

the area. Soap Lake and Lake Lenore, northwest 

of the town of Moses Lake, have been studied for 

several decades and their summer phytoplankton 

assemblages during 1980 were similar to those in 

previous years (Walker, 1975; W. T. Edmondson, 

University of Washington, oral communication, 

1980). Moses Lake, itself, had the usual dense, 

blue-green algal bloom. In Warden Lake, south of 

the town of Moses Lake, the 1980 phytoplankton 

assemblage was dominated by diatoms and 

chysophytes, the same as reported (Dione and 

others, 1980) for previous years. 

GLOSSARY 

[Many definitions were obtained or modified from Rickert and others, 

1977] 

Alga, algae (n), algal (adj). Simple plants, many microscopic 

containing chlorophyll. Most algae are aquatic and are the 

primary food source in most lakes. 

Algal bloom (n). A large number of particular algal species, 

frequently amounting to 0.5 to 1 million cells per liter of 

water. Sometimes defined as a readily visible, concentrated 

growth or aggretation of algae. 

Algal filament (n). A chain of algal cells. 

Amines (n). Organic compounds which are amonia derivatives 

(R-NH2). 

Aquatic (adj). Pertaining to water; aquatic organisms such as 

algae or fish, live to water. 

Bioassay (n). The use of living organisms to test the effects of 

a substance on the organism. 

Biomass (n). The weight of living matter present in a unit 

area or volume of water at a given time. 

Blue-green algae (n). A group of algae that are similar to 

bacteria in cell structure. Members of this group are abundant in natural waters. 

Cation (n). A positively charged ion in solution. 

Cation-exchange resin (n). A resin that removes cations from 

solution by exchange with another cation, typically H +. 

Chlorophyll a (n). The major plant involved in photosynthesis. 

Dissolved organic carbon (n). Organic carbon that passes 

through a 0.45 ttm filter. 

F13 

Ecological (adj). Pertaining to the relation of organisms or 

groups of organisms to their environment. 

Ecosystem (n). A group of interacting organisms and their 

physical environment. 

Effluent (n). A solution that has passed through a 

chromatographic column. 

Fulvic acid (n). A class of organic compounds of high molecular 

weight that accounts for 30 to 60 percent of the dissolved 

organic carbon in natural waters. 

Growth rate (n). The rate at which organisms increase in 

number with time. 

Inoculum (n). The material used to make an inoculation. 

Leachate (n). A solution containing soluble constituents removed from ash, soil, or other natural material by percolation. 

Metal-organic complex (n). Chemical association of a metal ion 

with an organic compound. 

Morphology (n). The form and structure of an organism considered as a whole. 

Nitrogen fixation (n). The process of assimilating atmospheric 

nitrogen to form organic nitrogen compounds. 

Nutrient (n). Any chemical element, ion, or compound that is 

required by an organism for growth, for reproduction, or 

for other life processes. Trace nutrients are substances required by an organism in very small amounts. 

Organic (n). Pertaining or relating to a compound containing 

carbon. 

Organism (n). Any living entity. 

pH (n). The reciprocal of the logarithm (to the base 10) of the 

hydrogen ion activity in water. Th'e pH value of water is a 

measure of the degree of its acidity or alkalinity. 

Phenols (n). Aromatic organic compounds having at least one 

hydroxyl group attached to a benzene ring. 

Phytoplankton (n). The plant organisms (mainly algae) that 

drift passively with water currents. 

Pyrolized (adj). Pertaining to the subjection of organic compounds to very high temperature. 

Synthetic medium (n). A solution made from chemical 

reagents. 

Toxic (adj), toxicity (n), toxicant (n). Having the effect of a 

poison. 

Trace metal (n). A metal generally found in small quantities 

in the environment. 

REFERENCES 

Bartlett, Larry, Rabe, F. W., and Funk, W. H., 1974, Effects of 

copper, zinc, and cadmium on Selanastrum capricornutum: 

Water Research, v. 8, p. 179-185. 

Dione, N. P., Bortleson, G. C., and Innes, J. K., 1980, Data on 

selected lakes in Washington: Washington State Department of Ecology, Water-Supply Bulletin 42, Part 6, 125 p. 

Fruchter, J. S.,and others, 1980, Mount St. Helens ash from the 

May 18, 1980, eruption: chemical, physical, mineralogical, 

and biological properties: Science, v. 209, p. 1116-1125. 

Hutchison, G. E., 1957, A Treatise on Limnology, v. I. Geography, Physics, and Chemistry: New York, John Wiley and 

Sons, 1014 p. 

McKnight, D. M., and Morel, F. M. M., 1980, Copper complexation by siderophores from filamentous blue-green algae: 

Limnology and Oceanography, v. 25, p. 62-71. 

Pereira, W. E., Rostad, C. E., and Taylor, H. E., 1980, Mt. 

St. Helens, Washington, 1980 volcanic eruption: 

characterization of organic compounds in ash samples: 

Geophy~ical Research Letters, vol. 7., no. 11, p. 953-954. 
Rickert, D. A .. Peterson, R. R., McKenzie, S. W., Hines, W. G., 

and Wille, S. A., 1977, Algal conditions and the potential for 

future algal problems in the Willamette River, Oregon, U.S. 

Geological Survey Circular 715-G. 

Sarna-Wojicki, and others, 1980, Areal distribution, thickness, 

and volume of downwind ash from the May 18, 1980, eruption of Mount St. Helens: U.S. Geological Survey Open-File 

Report 80-1078. 

Stein, J. R., 1973, Growth measurement, Chapter IV of Handbook of Phycological Methods, Culture Methods and Growth 

Measurements: Cambridge, England, Cambridge University Press. 

Taylor, H. E., and F. E. Lichte, 1980, Chemical composition 

of Mount St. Helens volcanic ash: Geophysical Research 

Letters, vol. 7, no. 11, p. 949-952. 

Walker, K. F., 1975, The seasonal phytoplankton cycles of two 

saline lakes in central Washington: Limnology and 

Oceanography, v. 20, p. 40-53. 

-(:(U.S. GOVERNMENT PRINTING OFFICE: 1981-341-6141191 

F14