Kelsey Friemoth
November 2, 2011
Diseases Harbored in Aquatic Systems
Objective
Discuss and outline how diseases are spread in aquatic systems and highlight botulism, a disease found
in Lake Erie starting in 1999 (Pe´rez-Fuentetaja, 2006).
Introduction
 Human impacts have caused changes in ecosystems through agriculture, aquaculture, ballast
water, among many other sources (Peeler, 2011).
 Diseases found in fish of aquaculture are often common due to population homogeneity. If
these fish are accidentally or purposefully (or carelessly) released into the wild, the fish of the
area are affected (Peeler, 2011).
 Agriculture runoff affects lakes with great magnitude and causes severe nutrient loading
(leading to increased primary production). This can cause introductions of invasive species
(especially of species from areas that have high productivity and respond to high amounts of
nutrients and food) that may carry new diseases (Peeler, 2011).
 Ballast water can spread non-native species of fish and invertebrates from one area to another
very quickly. This moves pathogens to new ecosystems quicker than species in these areas can
acclimate to them (Peeler, 2011).
 Changes in water flow such as by dams change sedimentation and in these new ecosystems
snails are prevalent (snails often carry parasites and vectors) causing an introduction or vectors
and diseases to a new area (Naiman, 2010).
Selected Publication
Influence of limnological conditions on Clostridium botulinum type E presence in Eastern Lake Erie
Sediments by Alicia Pe´rez-Fuentetaja and many other authors is about the fish and bird kills of 1999 and
forward and linking the kills to phenomenon of certain climate and weather occurrences that promote
the growth of Clostridium botulinum type E. In the eastern basin of Lake Erie anoxic conditions occur
during late summer more and more often due to eutrophication. Eutrophication causes sedimentation
of the lake, nutrient loading which leads to high primary production, and then high amounts of dead
organic matter settling to the bottom of the lake (which when dissolved causes low oxygen levels). The
combination of all of these factors creates an environment that is good for the growth of the bacteria
that causes botulism.
Glossary
Botulism – caused by Clostridium botulinum type E, a bacteria that produces a strong toxin that blocks
impulses from nerves to muscles among other symptoms (Pe´rez-Fuentetaja, 2006).
Conclusion
Diseases are spread through aquatic systems because human impacts have created (indirectly and
directly) environments that promote their production and dispersal.
References
Naiman, Robert J. and Dudgeon, David. The Ecological Society of Japan, 2010. Global alteration of
freshwaters: influences on human and environmental well-being. Retrieved from
http://journals.ohiolink.edu/ejc/pdf.cgi/Naiman_Robert_J.pdf?issn=09123814&issue=v26i0005&article=865_gaofioh
aew on October 25, 2011.
Peeler, Edmund J . and Feist, Stephen W.. Freshwater Biology, 2011. Human intervention in freshwater
ecosystems drives disease emergence. Retrieved from http://journals.ohiolink.edu/ejc/pdf.cgi/
PEELER_EDMUND_J.pdf?issn=00465070&issue=v56i0004&article=705_hiifedde
on October 25, 2011.
Pe´rez-Fuentetaja, Alicia, et al. Hydrobiologia, 2006. Influence of limnological conditions on Clostridium
botulinum type E presence in Eastern Lake Erie Sediments (Great Lakes, USA). Retrieved from http://p8331xlib1.ohiolink.edu.proxy.ohiolink.edu:9099/V/GPD8EFRPLTH7ULN3ETFET779NE D9GDJA2QHUDCQLQ5GAL6U6VC11421?func=quick-3&short-format=002&set_number=0010
27&set_entry=000004&format=999 on November 1, 2011.