The Food Chain: Bioaccumulation and Biomagnification (Part 1)

Just last week I came across this saying on a bookmark: “the Earth does not belong to Man; Man belongs to Earth,” which I later found out was by Chief Seattle, a Native American Indian from the Duwamish tribe during his 1854 speech.

Basically speaking, I interpreted it in my own way as Man, being inhabitants of planet Earth, have the great responsibility of taking care of it and its resources within; and should rid the mindset of everything on Earth as our entitlement. In light of this statement, and today’s environmental problems, the many developments of Man have been at the expense of the Earth’s resources – think environment (water, air, land…). However, the nature of Man is innately competitive; while attempting to outdo each other and achieve great progress in our own ways, have we forgotten that we are still inhabitants of Earth, subject to and potentially vulnerable to the blowback effects of what has been done to the environment during all these pursuits?

So how does this apply to the water pollution discussion?
When pollutants are released into the environment through human-related activities (in addition to those already released naturally), something happens within the food chain.

BIOACCUMULATION
What?
The “accumulation of chemicals in the tissue of organisms…” OR “progressive increase in the amount of a substance in an organism or part of an organism.”

How?
“Through any route including respiration, ingestion, or direct contact with contaminated water, sediment, and pore water in the sediment.”

Why?
“Because the rate of intake exceeds the organism’s ability to remove the substance from the body.”

… and BIOMAGNIFICATION
What?
The “sequence of processes in an ecosystem by which higher concentrations of a particular chemical, such as the pesticide DDT, are reached in organisms higher up the food chain.” OR simply, when “tissue concentrations of a contaminant increase as it passes up the food chain.”

How?
“Generally through a series of prey-predator relationships,” and this is “through two or more trophic levels.”
(A trophic level is a “group of organisms united by obtaining their energy from the same part of the food web of a biological community.” – Orlans, 1995)

Thus, “bioaccumulation refers to how pollutants enter a food chain; (and) biomagnification refers to the tendency of pollutants to concentrate as they move from one trophic level to the next.”

Bioaccumulation and Biomagnification (Photo: Sustainable Nano)

I shall leave you with these definitions for now, stay tuned for a second part where I share more about the pollutants involved in food chain bioaccumulation and biomagnification!

Resources:
“Bioaccumulation and Biomagnification” (2002). Based on Mader, Sylvia S. 1996. Biology – 5th Ed. WBC and Cox, G.W. 1997. Conservation Biology – 2nd Ed. WCB. Retrieved from: http://www.marietta.edu/~biol/102/2bioma95.html (Definitions above-mentioned are taken from this source)

Don Shepard. “Food Chains and How They Are Affected by Water Pollution.” Retrieved from: http://classroom.synonym.com/food-chains-affected-water-pollution-7712.html

United States Geological Survey (2014). “Environmental Health – Toxic Substances.” Retrieved from: http://toxics.usgs.gov/definitions/bioaccumulation.html

Orians, G.H., 1995, “Ecology, aggregate variables”, in Neiremberg, W.A., ed., Encyclopedia of Environmental Biology: San Diego Calif., Academic Press, v. 1, p. 581-588.

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s