In 2011 my parents decided to convert their pool into a pond
and started adding different species of fish, including Koi. Until recently I
was taking care of the pond and its inhabitants, and noted the Koi reproducing
these last two years. This spring, black racer snakes took a swim in the
pool-pond and some sort of turtle made itself at home in it. We also end up
with hundreds of tadpoles several times throughout the year.
During one of his visits, my dad built plant islands with Styrofoam
bases; after heavy storms, bits of Styrofoam float on the surface. I have seen
the older Koi (about 1 foot long and thicker than my wrist) accidentally
sucking these pieces in but then spitting them right back out. Recently one of
the Koi born this spring was sluggish, didn’t submerge more than two to three
inches, seemed blind, and kept rapidly moving its mouth. I pulled it out, fed
it by hand, and then placed it into a temporary habitat for observation, but it
perished overnight. Based on my recent experience in the OCE1001 lab, I decided
to check the stomach for Styrofoam.
First of all, I had to choose between a butter and a steak
knife; turns out a steak knife is not the ideal tool since I did more sawing
than cutting. During last week’s lab, Samm (one of the current students) mentioned
reading about plastic microbeads getting caught in fishes’ gills, thus I
checked the gills for Styrofoam particles but did not see any with my bare eye.
Guess what, there wasn’t any Styrofoam in the stomach either because
apparently, to my surprise, Koi do not have stomachs! In my confusion I thought
maybe it died because its stomach shrunk or due to inbreeding it was born
without this vital organ and finally succumbed to this defect. After some googling
I learned carp (Koi is a type of carp) do not have stomachs but the food is
digested directly in the intestine on its way out.
Are you searching for a certain type of plastic or are you just looking for plastic in general? The reason I ask is because based on the research I have done recently on cigarette butts is their filters are made out of a plastic and are regularly are eaten by fish and birds. Maybe try fishing in an inclosed pond that has noticeable plastic debris and see if those fish are consuming the debris.
ReplyDeleteI wrote a "response post" to your question. Last spring semester I wrote a post about the plastic in cigarettes and was hoping someone would find it interesting and maybe do an individual research project on the topic. So, I'm VERY excited you discovered this problem and are possibly considering further researching it!
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