RODUCI
1s
ie Crove, in Fonterey County, California,
fapproximately 15,000 people which disposes of abou
one and one-half million gallons of primary treated sewage
The sewage outfall is located intertidally on
ach day
rocks of Point Pinos, which demarcates the southern
xtremity of Nonterey Bay.
The primary treated sewage
which is subject to heavy chlorination, is discharged
et from the base of Point Pinos in a rocky intertide
feet
rea at a tidal height of about mean lower-low water (0.
preliminary examination of this area showed several inter-
dal organisms to have distributions which appearedt
That
the presence of the nearby outfall.
these organisms had very sparce distributions for as
nuch as 100 feet around the outfall pipe, but showed increase
bundance with increased distance from the outfall.
The
organism selected for this project, Anthopleura elegantissima
one of those originally seen to have such a distribution.
nce little is known concerning the effects of primary
reated effluent on intertidal organisms it was decide
nat the best approach would be to first quantify the distri
tion of anemones in the area around the outfall and
try to relate the pattern of distribution to local curren
systems and the flow of primary effluent into the area.
dition, an attempt would be made to determine more
36
the outfall was indeed inf
ily whether the presence of
isolating the
neing whether the animals were living by
us inluded laboratory experiments t
ctors involved
ibe tolerances in various dilutions of sewage and th
o's in such dilutions
TTHODS AND FATERIAI
urrent studies were made in early April, 1970 by utiliging
These
e packets containing twenty grams of fluorescein dye
vere thrown into the water from the rocky precipice directly
5, and 35 feet
behind the outfall and at distances of 5, 15, 2:
Because it is difficult te
low
mthe end of the pipe.
dri
bottles were also
packets in heavy surf
ing the same pattern of distribution as de
light-weight color-coded plastic bottles whi
nad been half-filled with fresh water so that they wo
The packets and bottles were followed
remain buoyant.
Low tide on that
0630 to 1830 on a single day, Apri
ay was at 1130.
uring the same period studies were made of the distr
butional pattern of salinity, chlorine, and phosphort
study area. Chlorine and phosphorus were use
as
the
use they are known to be presen
the sewage fiel
be
cific Grove primary effluent.
high concentrations in Pa
tests are outlined in Standar
proceures use
thes
Salinity measurements
lethods (Strickland
and Parsons
ractometer calibrat
were likewise made with an Ac
against known dilutions of standard Copenhagen water
of the above tests were made 1-2 times daily for a
period of five days at a series of six stations (see figure 2
tation 1 was located in the middle of the valley which
urrounds the base of the outfall pipe. Station 2 is
ocated approximately 10 feet north of the outfal
tation 3 is in a tidepool in the channel area. Station
is about 50 feet from the pipe in a wave-swept area.
Station 5 is in a tidepool which is 110 feet from the
pe and only swept by polluted water at rising tide
and station 6 is across the channel, which is apparently
mntouched by effluent.
The initial population survey was made by cursory
examination of the area and was later confirmed quantita-
ively by first dividing the study area into four sections
and counting ten to fifteen isolated populations in each
these sections. In addition the surface area cover
each of these populations was measured
or both field and laboratory studies, anemones were
taken from under the canneries in nearby Cannery Row, an
rea free from sewage pollution. All individuals utilize
were taken from the same clone in order to minimize indivi-
The anemone
variability due to genetic heterogeneity.
d in the field study were first marked by sewing bead
through one side of their columns, a technique which i
escribed by Buchsbaum (1968). After being marked the
were allowed to resettle on granite boulders in tanks o
took about a week
running sea water. This proces.
he utmost care had to be taken to keep water flowing
at a gentle rate because anemones react to excess distur
bance by not adhering to the substrate. Six granite
oulders to which about 15 anemones each were attache-
were placed in the field, as shown in figure!
The
were left in the field for five weeks and observed every
our days.
determine the LTgo, anemones in groups of ten
were placed in gallon jars with various concentrations
Pacific Grove (chlorinated) and Monterey (unchlorinated
ewage
following concentrations were used: 1007
The 100% sewage was corrected
509
and
20
337
or osmotic difference by adding 35 grams of Wards Instant
A sea water control and a 50% freshwater
cean per liter.
control for possible osmotic effects were also utilized.
or each of the jugs, the water was changed every day and
aerated, and the bottles were submerged in running
sea water so that the temperature would remain at a constant
14 degrees Centrigrade.
isolate the effects of chlorine from other possib.
oxic constituents in Pacific Grove sewage, a third seri-
Anemones wer
laboratory experiments was initiated
laced in both chlorinated and unchlorinated Pacific Grove
described
ewage and set out under the same conditions as
above
ESULT
Figurei illustrates the relationship of Foint Pinos
Monterey Bay and shows the exact location of the stud,
area at Point Pinos. The study area itself lies about
300 feet from the base of Point Pinos and is about 100
feet by 50 feet. For convenience it has been divided
into four subareas, as shown in figure i
igure2 demonstrates the relationship of current
atterns to salinity and concentrations of phosphates
and chlorine at five stations in the study area. Station
not swept by waves carrying sewage effleunt. Not
mexpectedly levels here are similar to those expected
or normal seawater. Stations 2,3, and 4 are inshore
om the outfall in rocky areas where currents tend to
weep the effluent at both high and low tides. Here levels
f chlorine and phosphorus are greater. Note that there is
gradient from station 2 (highest concentrations of effluent
through station 4 to station 3. Station 5 is swept by
olluted water only during the rising tide and has therefore
orrespondingly lower values. This area for the most par-
continually flushed with fresh seawater which tends
legate the effect of any effluent carried into it.
ote that the above results justify the division of
the study area into four sections shown in figures 1 and 4.
includes stations 2 and 4 which appear to continuall.
Area 2 includes
have high concentrations of effluent.
tation 3 and is slightly less polluted. Area 3 includes
station 5 and appears to be very little affected by sewage
Area
t6
fluent, and area 4 appears to be virtually normal
results of the distribution study, as shown ir
3 and 4 indicate that Anthopleura elegantissima is distri
in a pattern not unlike that described above for
ite
nutrients and chlorine. That is, there are no anemones
in area 1, some in area 2, and more still in areas 3 and 4
e mean number of anemones per square foot is 70 in area
124 in area 3, and 153 in area
During the course of this field study it was notice
that in the large tidepool in area 2 the anemones were
overed with a peculiar sheath of mucous-like materia
x weeks after the studies were initiated this same popu-
lation had progressed to a stage where individuals were
They also appeared te
y to pry off their substrates.
e in the process of everting their gastro-vascular cavities
iving the anemones a bloated appearance. At the conclusion
the study these anemones were all dead
norder to more precisely relate the natural distributior
f the anemones to the direct effects of the sewage field
granite boulders with approximately 15 anemones attached
e of these
were put out at six stations (see figure 5
were positioned at stations 1,2,3,5, and 6, which had earlier
been used for chemical analysis, and the sixth was placed in
tidepool on the north side of the point which, on the
basis of chemical analysis, appeared to be normal. The rock
were checked every four days and it was observed (figure:
that the anemones tended to leave the rocks at a rate dependen
on 1) wave action and 2) amount of exposure to sewage-lader
The influence of these two factors is especially
water
shown by the rocks placed at stations 2 and 6. Both of
these areas are subjected to heavy wave action. Anemones
on the rocks placed immediately behind the outfall became
etached within four days, whereas those at the wave-action
control (station 6) stayed for a much longer period, almost
half of them migrating to the protected side of the rock
before becoming detached. The other rocks were placed
idepool areas less affected by wave action and it was
ound that in every case the anemones in pools with higk
hosphate and chlorine concentrations left more quickly than
those in pools with normal seawater concentrations,
o better judge the variables involved in the detachment
anemones, laboratory experiments to test toxicity were
run with va rious dilutions of both Pacific Grove and Fontere
orimary treated effluent. One very noticeable difference
petween the two sources of sewage is that the sewage from
Wonterey was unchlorinated. The results of these experiment
figures6) were very graphic in that Pacific Grove sewage
a much morr rapid effect at all concentrations than
had
le Monterey sewage did. For instance, the LTgo in 1004
ewage was 14 days in Pacific Grove effluent while anemones
in Wonterey effluent at a similar concentration showe
an LT50 of 6 days
At this point it would be easy to conclude that chlorine
was responsible for the greater toxicity of Pacific Grove
sewage. However the results of an experiment designed
to test the relative toxicity of chlorinated and unchlorinate
In unchlorinated
sewage were not at all conclusive (figure 12)
Pacific Grove sewage at a concentration of 50%, the anemones
are only slightly better than those in an equal concentra-
ion of chlorinated effluent. Thus chlorine may be some-
what toxic to A. elegantissima, but it cannot be considere
to be the sole factor responsible for the toxicity of
cific Grove sewage
ne results show that in the study area.Anthopleura
alegantissima is distributed in a definite gradient from
the outfall. In the immediate area of the outfall no
anemones can be found while as one moves farther away, the
This suggests that there
populations increase in size.
is a relationship between sewage effluent and the distri-
This suggestion is consistent with
bution of anemones.
the results of the field studies where rocks with resettle-
anemones were placed out in the field: the anemones detache
at a rate dependent on distance from the outfall. Also,
chemical analysis of the area demonstrates the same trend
in the distribution of chlorine, phosphorus, and salinit,
Thus it appears that sewage is responsible fpr the distri-
However, laborator
bution of anemones in the outfall area.
ets show toxicity only at high concentrations, concentra-
Further.
ons greater than those occurring in the field
pre, there appears to be no negative reaction to lesser
we must look into what variables mi
ution.
ught about this discrepancy. One very obviou
that chlorine decomposes very rapidly in the
esence of air, and therefore is only active for short
eriods of time during the laboratory experiments.
field, on the other hand, the concentrations of chlorine
bserved are fairly constant because of the relativel
steady flow of fresh effluent. Wave action may be another
actor contributing to this discrepancy between laborator
In the lab the only water movement the
and field work.
nemones had to cope with was that brought about by gentle
aeration. Some constituent in the sewage could be weakenir
ne attachment apparatus, but this might be noticeable or
der the stress of continual water surge. Thus in th
ld the effects of sewage effluent might not brin-
about death, as it does in the laboratory, but rather i
might seriously interfere with the ability of the anemone
In this case, the
emain attached to their substrate.
tached anemones would not have very good chances fo
urv
ond most interesting fact uncovered during the
perimentation was the obvious difference in viability
the anemones when tested in Monterey and Pacific Grov
could not be isolated as the sole factor
sewa
Chlorine
causing the greater toxicity in Pacific Grove sewage, a
so some other factor must be responsible. It is possibl
hat there is wore organic matter in Pacific Grove sewag
or that it is more concentrated, because these dilutions
had a large amount of frothing with the aeration than
However, further research i
id those from Monterey.
oing to have to be done in this area before any conclusions
san be made.
A third point that came up during the investigatior
as the possibility that the sewage was having an effec
the algal symbionts, zooxanthellae, usually present ir
Anthopleura elegantissima. The symbionts are known to
be ejected upon treatment of the host with various chemicals
r heat (Buchsbaum, 1968). This ejection could be influencing
arvival because zooxanthellae produce oxygen which could
make up for oxygen deficiencies in the polluted water
sit was thought that the presence of zooxanthellae
ould very well influence the distribution of anemone
the study area. While populations of anemones around
stations 3 and 5 were found to be quite variable in respect
to whether or not they contained zooxanthellae, no correla
Furthermore, anemones
on with pollution could be made.
that had been in high concentrations of Pacific Crove
sewage did not eject their zooxanthellae at any time
45
SUNNA
Anthopleura elegantissima is distributed around the
putfall according to a gradient which parallels gradients
physical and chemical properties related to the presence
fsewage effluent.
Anemones placed in the field become detached from their
ubstrates more frequently as they approach the outfall.
LTso's of animals placed in Monterey sewage were longer
than those tested in unchlorinated Pacific Grove effluent
hese in turn were longer still than those tested in
orinated Pacific Grove sewage
Concentrations of sewage necessary to produce toxicit
n the laboratory were far greater than the effective
concentrations of sewage experienced by the anemones
the field
Observations of the reactions of anemones to concentra
observations suggested that fie
sewage and to field
pulations were being directly affected by the primar
ffluent.
All of the evidence from this study suggests that sewage
responsible for the peculiar distribution of anemones
the study area around the outfall
IOGRA
Vicki Mabel (1968) Behavioral
bau
iologi
on
to Light by the Sea Anemone Anthopleura
leganti
sima.
tation
(196
Manue
rickland, J.D.H., Parsons
sheri
arc.
Water Analys
Canada.
Bull
KNOWLEDGE
npart by the Undergraduat
k was supported
Program of the National Science
searc
Participation
tion Grant GY-436.
also like to especi-
unda
patience and enthusiasm
ted
hank Di
Welton Lee for
ring
the cour
juring
ending
countless hou
at Hopkins
smat
who made
more entertaining
it much
gure
ure 2.
gure 3.
ure
ure
gure
igure
Numbers ind
e study area
general mar
e subareas.
Study area showing currents and chemical concentra
Phosphorus readings a
tions at various stations.
gram atoms phosphorus per liter and chlorine
Blacked-in arrows indicate
s inparts per
illion
clear arrows show movement ai
rrents at le
ising
1
umbers indicat
Distributional study of the are
anemones per square foot
Analysis of the distributional study of the area
Wean is mean number of anemones per square foot
total is the sum of all anemones in the indivdua
opulations in that area, total area is the sum
of the areas of the indivdual populations, deviation
efers to standa
deviation.
Blacked
of anemones placed in the field.
Succe
in columns represent the first day in the field
the fifth, striped ones the ninth, and
otted one
olumns with broken lines the thirteenth.
Mortelity in 100% Pacific Grove and Monterey sewage
ific Grove is on the top half of the page for
next five graphs
Pacific Grove and Nonterey sewage.
Norta
in
34 Pacific Grove and Monterey sewage
Mortality in
acific Grove and Nonterey sewage
Mortalit
freshwater and in seawater
Th
4
ture
gure 12.
grapt
watt
on the top half of the page
nated and unchlorinated Pacii
wage and
es
in Monterey sewage
urvival in 50% chlorinated and unchlorinat
fic Grove sewage. Blacked-in columns sho
columns with broken lines indicate weakn
columns indicate no evidence of
dama
60
4
STUDY AREA
antacas
Monterey
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