Effects of Guano
Page 2
Abstract
Gigartina papillata (Rhodophyta) cultured in high con-
centrations of NO, NH, and guano for 10 days showed the
same changes in R-phycoerythrin for all three conditions.
G. papillata from an area with high guano exposure off China
Point on the Monterey Peninsula showed significantly (p.01)
more phycoerythrin and significantly (pc.05) less carrageenan
than control sites with little guano exposure. G. papillata
was also shown to be significantly (p£.01) thicker in distal
branches than in control sites. Endocladia muricata (Rhodophyta)
and G. papillata from high guano density areas were shown
significantly (p£.01) shorter and had significantly (p.01)
less branching than did the same species in control sites.
Effects of Guano
Page 3
Introduction
In coastal waters, there are various types of con¬
centrated sites of animal waste of which several examples
are seal and sea lion rookeries, human sewage outfalls and
guano deposits produced by birds. Algal marine communities
effected by seal excrement has been investigated (Hanson,
Judy 1971: Hanson, John 1972). Although the bulk of most
research is on sewage effluent produced by humans, there
has been some mention in the literature on the effect of
shore bird guano. Guano has been implicated in enhancing
the production of phytoplankton as well as enhancing the
production of fish (Wheeler 1945). But on the whole,
there have been no systematic attempts to détermine what
the consequences of this excretory product are. Questions
such as does this nitrogen and phosphorous rich compound produce
a favorable environment for local organisms? or does this
substance act more as a pollutant than as a nutrient? or
are there no effects at all? have never been adequately
answered.
In this paper, I discuss the differences in Gigartina
papillata and Endocladia muricata between areas with intense
guano exposure and guano free areas and I present experimental
evidence which implicates guano as a factor in causing
some of these differences.
Effects of Guano
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Materials and Methods
The study site consisted of a group of rocks approx¬
imately fifty meters off China Point on the Monterey Penin-
sula (see figure 1.) At the time of the study, these rocks
supported a large population of seagulls, approximately
twenty cormorants, two oyster catchers, and a few transient
pelicans. All sampling within the study site was done
along a 20 meter transect, running parallel to the coast-
line, on the protected side of Bird Rock. The control sites
with relatively little guano exposure consisted of areas
1 and 2 in figure 1.
Random numbers were generated corresponding to a
20 meter transect and at each point samples of algae were
obtained from the control site and from the study site.
Samples were taken from approximately three feet above the
mean lower tide level. Length is the distance between the
frond origin at the holdfast to the tip. Branching is
the number of branch points radiating from the stipe.
Thickness for G. papillata only, was determined by measur-
ing the mid portion, with a micrometer, of the most distal
branch of the holdfast origin.
R-phycoerythrin was extracted from G. papillata
samples in 6 ml. of .025 Tris-HCl per .4 g. ground dry
algae sample. Each sample was extracted for four hours
at five degrees after which maximum absorption at 565 nm.
(Siegelman et al. 1978) using a model DU Beckman spectrometer.
Effects of Guano
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Total carrageenan content was determined by a method
recommended by E. L. McCandless in personal communication
and modified by Huskins (personal communication). The algae
used were male or sterile G. papillata from the study site and
from the control sites. Each sample was dried, ground in a
ball mill, and then weighed portions of about 1.5 g. were added
to 200 ml. of distilled water with 5 ml. of 2% NaOH.
After extraction at 80-90 degrees centigrade for 18 to
22 hours, the samples were filtered with celite and the fil¬
trate was added to 2.5 times its volume of isopropyl alcho¬
hol to precipitate the carrageenans which were subsequently
filtered, dried and weighed.
Guano and non-guano G. papillata were cultured in various
concentrations NH,, NO., PO, and guano. Refer to table 1.
Solutions were changed every three days and were under constant
aeriation and were grown outside in constant day/night cycles.
The temperature was kept constant in a constantly circulating
seawater bath. A portion of the plant was used to est-
ablish initial phycoerythrin levels. Ten days later at the
termination of the experiment final absorption was determined.
Results
Figures 2A and 2B show the differences in length and
the amount of branching between the study site and control
site 2 in E. muricata and G. papillata. Using the student's
t-test, the guano plants were found to be significantly
(pc.01) shorter and have significantly (p£01) less branching.
Effects of Guano
Page 6
Figure 3A depicts the differences between G. papillata
distal frond thickness from guano and non-guano areas.
Guano G. papillata were shown to be significantly (p£.01)
thicker than non-guano G.papillata.
Figure 3B depicts the differences in R-phycoerythrin
content between guano and non-guano plants. Guano G. papillata
were found tohave significantly (p2.01) more phycoerythrin.
Figure 4 depicts the carrageenan content as a percentage
of dry weight in guano and non-guano G. papillata. Non-
guano algae were shown to have signifieantly (p7.05) more
carregeenan than guano algae.
The results of the growth experiment are presented
in figure 5. No appreciable increase in phycoerythrin
was exhibited in any of the conditions. NH, and guano
both had the same effect in decreasing the phycoerythrin
content in the study site plants. However, the control
and PO, condition decreased the absorption to a greater
extent than guano or NH,. In the non-guano algae, NH,,
NO, and guano had the same effect in maintaining the phy¬
coerythrin content constant. In the control condition, the
phycoerythrin content decreased.
Discussion
High guano exposure does produce quantifiable dif¬
ferences in algae growth as demonstrated by the data.
Shacklock, et al. (1975) have shown that carrageenan
production is inversely related to the amount of available
Effects of Guano
Page 7
nitrogen. In the presence of nitrogen, proteins are prefer¬
entially produced. As the nitrogen levels drop, protein
production is suppressed and the excess carbons are stored in
the form of such polysacharrides as carregeenans. The low
levels of carregeenan in the guano area algae indicates
that there has been nitrogen enrichment.
Phycorythrin is a protein bound accesory photopigment
primarily responsible for the color of red algae (Abbott, Hol¬
lenberg 1976). The high phycoerythrin in plants near guano
(see figure 3B) was sufficient to make them obviously darker
in color. Pigment concentration increases with increasing
nitrogen levels (Eocha 1965); the high levels of this pig-
ment in the study site relative to the control site indicate
a high nitrogen concentration.
There were deviations from what was expected. Study site
plants when grown in guano and NH, decreased in pigment content
instead of staying the same or increasing; appreciable increases
did not occur in control site algae grown in NH,, NO, or guano.
These discrepancies could be attributed to a nitrogen defficiency
in all conditions and particularily in the ambient and
phosphate situations. Or more concievably, the environment
in an erlenmeyer flask is not ideal for optimal growth.
There is a positive correlation between the amount
of carrageenan and the ability to resist desiccation (Huskins
1979). If carrageenan is instrumental in preventing desic¬
cation in the high intertidal zone of the study site, G. papil-
lata containing small amounts of carrageenan would seem to be
maladapted for survival.
Effects of Guano
Page 8
The guano plants have a smaller surface to volume
ratio than the carrageenan rich control plants being
shorter, thicker and less branched. These morphological
traits may have developed as a means of compensating for
a relative lack of carrageenan in combatting a deadly
desiccation at low tide.
Conclusions
(1) This study showed that there were quantifiable differences
between guano and non-guano areas and that these
differences could be attributed to guano.
(2) Figure 8 summarizes the conclusions that can be drawn
from this study. As nitrogen and guano levels increase
phycoerythrin content rises while carrageenan con¬
centrations drop.
This investigation underscores the ability of biological
(3)
organisms to adapt to a variety of environmental conditions.
Through their morphological changes, plants residing
in high guano exposed areas have been able to respond
successfully to an environmental stress.
Effects of Guano
Page 9
Literature Cited
Abbott, I. A. and Hollenberg, G.J. 1976. Marine Algae
of California. Stanford University Press, Stanford
Hanson, John 1972. Marine algal nutrient regeneration:
the enrichment of water surrounding Ano Nuevo Island
California by pinnipeds. Masters Thesis, Fresno
State College, 47 pp.
Hanson, Judy 1971. Effects of pinniped excreta on marine
benthic algae of Ano Nuevo Island California. Masters
Thesis, Fresno State College, 74 pp.
Huskins, C. 1979. The relation of carrageenan content
and dessication resistance to tidal height in Gigar-
tina papillata. Unpublished. Hopkins Marine Station,
Pacific Grove, California.
O hEocha, C. 1965. Chemistry and biochemistry of plant
pigments. In: Lewin (editor), Physiology and Bio¬
chemistry of Algae. Academic Press, London, pp. 421-435.
Provasoli, L., McLaughlin, J. J. A., and Droop, M. R. 1957.
The development of artificial media for marine algae.
Arch. Mikrobiol. 25: 392-428
Shacklock, P. F., Robson, D. R., and Simpson, F. J. 1975
Vegetative propagation of Chondrus crispus (Irish Moss)
in tanks. Technical Report No. 21 of the Atlantic
Regional Laboratory, National Research Council of
Canada, Halifax, N. S.
Siegelman, W., and Kycin, J. H. 1978. Algal biliproteins.
In: Hellebust and Craigie (editors), Hand Book of
Effects of Guano
Page 10
Phycological Methods, Cambridge University Press,
London, pp. 72-78
Wheeler, W. M. 1945. Plant nutrients in the sea. Nature,
Vol. 155, pp. 731-732
Page 11
Effects of Guano
Acknowlegements
I would like to express sincere gratitude for the
effort and time William Magruder spent on minenand every¬
one else's projects. I would also like to thank Judy
Hanson for her insights and suggestions. Special apprecia¬
tion goes to Robin Burnett for showing me that Biology
in the field could be as exciting as Biology in the class¬
room.
Effects of Guano
Page 12
Figure Legends
Figure 1: China Point on the Monterey Peninsula. Study
site and control sites 1 and 2 are shown.
Figure 24: Differences in length between guano and non-guano
algae. Standard errors are shown by the vertical bars.
Figure 2B: Differences in the number of branches between
guano and non-guano algae.
Figure 3A: Frond thickness for G. papillata between guano
and non-guano areas. Vertical bars show standard errors.
Figure 3B: Changes in absorption between guano and non-guano
G. papillata. Vertical bars show standard errors.
Figure 4: Differences in carrageenan content as a percentage
of dry wieght between guano and non-guano G. papillata.
Figure 5: Results showing initial and final absorption of
G. papillata grown in various nutrient concentrations.
Figure 6: Percentage of initial phycoerythrin after ten days
growth in various nutrient conditions in guano and non¬
guano G. papillata.
Figure 7: The relationship between nitrogen, guano, phycoery-
thrin and carrageenan is depicted.
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Effects of Guano
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Effects of Guano
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Effects of Guano
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Effects of Guano
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