Last week, my computer class and I went to a workshop in Drew Gardens on the wildlife in the Bronx River area taught by a man named Brendan. As a prelude to the activities and an illustration of the evolutionary process, Brendan showed us wild animals he had obtained from various places around the world. He began with two different species of turtle obtained from local markets that sold them for food. One of these species, a southern painted turtle, came from areas in the southern United States. In order to dramatically illustrate the results of a long evolution, he showed us a pufferfish, whose spines served as tiny hypodermic needles carrying deadly neurotoxins. At this point, Brendan broke us into two groups, one to fish using a dragnet or Seine net and the other to dig for worms and snakes. I joined the first group of kids and went to the back of the garden.
My group went to an unoccupied plot at the back of the garden and spent about half an hour digging. We found four or five worms, but the soil was too dry for very many to show up. After that we went down to the riverbank to hut and, alas, found nothing. At that point, Heidi called us over to the north end of the garden and we went out to wait for waders to enter the river. During that waiting period I went out to the area right by the bridge and found a way to access the tunnel that carried the river under East Tremont Avenue. That grew old relatively quickly when someone found a homeless man hiding under the bridge and began harassing him. Soon after that unfortunate incident, my little sister and I got hold of some waders and we went fishing with the net. Our rather zealous behavior ended us up soaked yet grinning despite the fact that we caught nothing.
Two weeks ago, I went to the first in a series of workshops in Drew Gardens on the environment as part of my computer class. That time the class learned about the watershed principle, and from this were taught why pollutants on the street can do severe damage to the river. The teacher, Mrs. Jennifer Plewka, opened by giving a short talk on the watershed principle. The essential idea is that the river runs along the bottom of a slope and thus gravity will pull liquid pollutants through the soil into the river. Solid pollutants will only directly enter the river if they are intentionally deposited, but any high rain has the potential to wash them in.
Jennifer then told us about problems with the Bronx’s municipal sewer system that have led to severe pollution over the last few decades. First of all, the system has a relatively low maximum capacity because it was built over a century ago. Back then, the Bronx was a mainly suburban and rural community and generated only low to moderate amounts of waste. As a result, the system was built with that capacity in mind and the additions built to serve the modern low-income housing projects, public facilities, and industrial facilities have a relatively low margin of safety. According to Jennifer, the end result of this rather haphazard building process is a sewer system that backs up every time it rains at a faster rate than one inch per hour. The other pressing problem with the sewer system is that it empties directly into the river through combined sewer outlets or CSOs when it gets backed up. After pointing out the CSO behind us, Jennifer told us that, during one particularly bad rain, it turned the river a sickly pea-soup green all the way up to Tremont Avenue, a full block upriver.
From there Jennifer explained that the various pollutants on the street would do all kinds of damage to the Bronx River ecosystem. Motor oil, soap, drain opener, and similar caustic chemicals can poison the fish and other wildlife. Untreated sewage from homes causes additional problems, as it feeds algae and similar organisms to the point where they deoxygenate the river. Solid pollutants cause a variety of problems depending on the specific nature of the litter. Containers such as bags and bottles usually carry residue of their former contents, and this residue may be toxic to animals. Exposure to water dislodges the residue and releases it into the river. Certain bottles can also trap fish and small marine life. Also, certain plastic rings such as those holding together sixpacks of soda and beer can strangle animals unlucky enough to get caught.
Afterwards, Jennifer had us participate in an activity to demonstrate the watershed principle. She had us crumple up a sheet of wax paper so as to create random high and low points, and then mark the high and low points with different colored markers. To make the exercise more relevant, she then had us mark off landmarks around the West Farms community and the major roads. Finally, Jennifer had us take a spray bottle and squirt the paper with water to simulate the effects of a rain. As expected, the markers bled and produced multicolored puddles in all the low points, simulating the path of pollutants along the lowest possible ground.
