The Ethical Culture Fieldston School will be taking a trip down the Bronx River in October as a part of their interdisciplinary Bronx River 
Biography unit. One section will look into the health of the river, and in preparation, my son and I got out and placed leaf packs into a couple of different places along the Bronx River. The expectation is that macroinvertebrates will make their home out of the leaf packs and we will be able to remove them, count and classify them before replacing them in their old neighborhood. The group will be supported by Bob Ward, and part of the hope is that such studies will become a regular monitoring procedure upon the river.
September 19th, 2009
The Water Pod has arrived at Concrete Plant Park helping to mark the return of public access to
this incredible site. It quickly has become a normal feature of the area, harkening back the original function of the site that gives the park its name. But while the pod might spark memories for past employees, the monarch butterflies that are migrating through the Bronx River Corridor have quickly decided that the plants aboard the pod are a good choice of nourishment. several pupae have also attached themselves to plants on board.
Did I mention the parrots? Yes, several pairs are nesting at CCP in what I believe is a choke cherry bush. I first heard there call a couple of weeks ago, and then my daugther and I were greeted by them this morning as we left CCP.
Rocking the Boat and Pete Seeger…
September 5th, 2009
While one way to prove an understanding of environment and environmental education may be a multiple choice exam, the real proof lies in action. In the early days of July the young people that attend the Tremont United Methodist Church Summer Program visited the Bronx River at the Mitsubishi River Walk adjacent to the Bronx Zoo. The goal was to get in a canoe in the Bronx River and learn the basics of paddling. Forty-five youth, thier counselors and their director, Cheryl Holtz Andrews, met their goal with flying colors, paddling until their armswere ready to fall off. But this was just the beginning. Two young lady’s looked around at the river and were not quite satisfied with the experience of canoeing for the first time in their lives.
“Damian, we should do something about all of these plastic bottles floating in the river,” said one.
“Yeah, they could all be recycled,” said the other. And from their they set about making it happen.
Today, after almost two months of convincing their director that it was a necessary event, the two returned with 12 other program participants and once again paddled the river. This time, however, the focus was the removal of any floatable garbage that they could reach safely from their canoes. With dilligence and care (and no lack of joyful enthusiasm) the youth spent over an hour paddling to distinct areas of the river between the Bronx Zoo and The New York Botanical Garden and removing plastic bottles, plastic bags and one large plastic triangle once used as part of a traffic blockade. It was impressive to see the pride with which each successive 
canoe came up on to the bank to show off what they had found in the river, what they had done to improve the environment that surrounds them. If there is a test to discover just what has been internalized from a lesson, this was it.
August 24th, 2009
On a visit to Hunts Point Riverside Park, I decided to try my luck in the water with a seine net. I could see the small fish flashing along under the surface, but I was not sure that I would be able to sample any since they seemed to sense my presence well before I approached the river’s edge. But one short walk parallel with the shore brought up the bounty of the sea.
These silversides (maybe Rough Silversides?), also known as sand smelt, are one of the most abundant fishes in our coastal waters. As Tarleton Hoffman Bean in his 1903 work Catalogue of the fishes of New York writes, these fish are not of great importance as a human food source, but they are a food source for the larger fish that inhabit local waters, as well as the wading birds that are regular visitors.
Silversides begin to spawn in May and, after a gestation period of just eight days, their young begin feeding on zooplankton before graduating to detritus, algae and even small fish and insects. The schools follow the tides up the river to feed in the salt marshes or other protected river banks, swimming in tight shoals that serve as a form of protection against predators. Over the summer the populations swell, creating a migrating energy source that will move out to deeper water in the fall, sharing the productivity of the estuary and the salt marsh with the greater oceans.
Unfortunately the picture below did not turn out as planned, but the jellyfish shown, most likely a comb jelly, also came up in my net. One of 90 species in phylum Ctenophora, some are able to glow with a slight phosphorescence as this example shows. The color that appears in the photo was not visible to my eye at the park, but appeared when I cropped the shot. Comb jellies are all carnivores and, though they have no tentacles, have tremendous mouths under their bell and can even eat prey larger than themselves.
August 11th, 2009
Thinking about beavers does not conjure up images of urban areas. Quite to the contrary, as a matter of fact, and people do not often associate the Bronx with beavers, but we do have one: at least one.
Since the first bite marks were noticed over two years ago, the now named Jose the Beaver has been little seen but his presence has been noticed. In the section of the Bronx River that stretches between the New York Botanical Garden and the Bronx Zoo, trees ave been gnawed and felled, and two lodges and a burrow have been identified has beaver housing. Being largely nocturnal, Jose works while the two establishments are closed and he (she?) is out of sight of the casual passersby. Photographs were taken with trip cameras by WCS, and a writer for Outdoor Magazine claims to have infrared photos but nobody has seen them. A staffer at the Bronx Zoo did see Jose one morning and placed Jose among the biggest beavers he had ever seen. Running between 30 and 70 lbs, the guesstimate weighs him in around 50 lbs.
If you put yourself on the list of those who have not seen Jose The Bronx River Beaver, you may now remove yourself from that list. On the morning of June 12, 2009 Jose put in an appearance at Drew Gardens as the participants in Bronx River Crossing made preparations to launch their watershed representation. Chris Kannon was able 
to take a series of shots as Jose swam leisurely upstream before lumbering out of the water to walk under East Tremont Ave. Some of us noted that he seemed sluggish or even disoriented. Of course, having never seen a beaver, maybe they always look that way. On more than one occasion the same has been said about me. Maybe it was the salty water where he was swimming? Drew gardens is at the top of the estuary and has been found to have levels of salinity up to 8 parts per thousand (oceans are 30-35 ppt and freshwater is usually < 0.5 ppt) When the dying beaver was found last year in the East River on the day of the pope’s visit, it was reported that, while that beaver had already been sick, it was probably the brackish waters of the East River that finally did him in. Could Jose be on his way to a similar fate? Could the stresses of life in the zoo and the garden be such that he is being chased down stream and into a perilous situation?
Jose came up again in a discussion that our Executive Director had with a local fisherman on Saturday in River Park, just south of the last dam on the river and the zoo. When she mentioned the beaver having been seen just to the south, the fisherman nonchalantly replied, “Oh yeah, I see that beaver all the time down here.” Could it be that Jose is putting himself in danger on a regular basis? Why would he chance forays into brackish water unless he has a death wish or is suffering from dementia?
In May of this year, W. Gregory Hood, Ph.D. of the Skagit System Cooperative published a research paper entitled The Overlooked Ecosystem. Dr. Hood had set out to study the distribution of Sweetgale (myrica gale) in the estuarine section of the Skagit River in Seattle. While he did find the sweetgale, he also found that the estuary was frequented by beaver from the fresh water section of the river. Dr. Hood explains that beavers are known to make use of estuarine areas with salinity levels as high as 10 ppt. Being true vegetarians, they are in search of those trees that will fulfill their appetite while providing the needed nutrients. If the trees in question are along the banks of brackish water, the beaver is prepared to go there. Beavers rarely forage more than 100 yards from the stream they call home which makes upstream and downstream travelling the normal event. Jose is probably in search of food and a quiet place. In most land conflict events, beaver will look for new foraging areas. This explains Jose’s “bizarre” behavior. It was our lack of understanding of normal behavior that made his acts seem bizarre.
But Dr. Hood also raises some questions that are pertinent to our river. Hood makes the connection between the salmon that use the river for spawning and the beaver that rework the habitat in the estuary and beyond. Being tidal, some estuary sections can become quite shallow at low tide. While the beaver may be in the area to forage, an effort may also be made to dam up small areas, causing tidal pools that will provide safe harbor when the tide runs out. Perhaps coincidentally, these tidal pools also provide a safe zone for salmonids in the area. Being that the beavers prefer somewhat deeper water, the pools are deeper than the areas where wading birds generally will hunt. By providing for personal needs, the beaver helps a multitude of other organisms. While we do not have salmon on the Bronx River, the return of the alewife herring and the catadromous eels fill a similar niche. Both would benefit from a tidal hideout at low tide.
And just what is Jose feeding on in the estuary? It will mean some kicking about in the area, but while beavers preference is for aspen and poplar, they will go for whatever is available when necessary. In that area there are willow trees which are always a part of the diet, but perhaps this new understanding of the range of the beaver and its possible utility can become a part of th present converstation about the soon-to-begin construction in Starlight Park, just south of the Cross Bronx Expressway. From drew Gardens south, the river is armored on both sides with rip rap, leaving the banks barren and lifeless. Dr. Hoods research found that trees growing along the banks of the river did so above the tidal zone, though they did not grow in soil. Instead the trees were able to take root in the woody debris that washed down from upstream and became lodged on the bank at high tide. Perhaps a consideration in the lower Bronx River would be to provide such woody debris. At the present time most woody debris cannot make it down stream due to the dams that block the river at certain point. In some upstream areas, logs have been cabled to the banks as a form of bank stabilization. The Section of the river between Drew Gardens and the south end of Starlight Park needs little bank stabilization due to the rip rap, but taking the same simple idea may provide a landing zone for seeds that can then provide a food source for beaver and create habitats for other unexpected guests.
DG
Cool links:
http://books.google.com/books?id=-xQalfqP7BcC&pg=PA295&lpg=PA295&dq=beaver+favored+diet&source=bl&ots=XOlaFu5796&sig=kBq_s3ePD5K2dJ2eg1exkObBNUE&h
l=es&ei=IdRKSufeIofCNu7v4KoB&sa=X&oi=book_result&ct=result&resnum=1
http://www.wildlife.state.nh.us/Wildlife/Wildlife_PDFs/Beaver_control.pdf
http://www.skagitwatershed.org/rpapers_overlooked.html
July 6th, 2009
On July 18, 2008, the Bronx River Alliance placed more than 350 stormdrain markers (above) in Bronx River sewersheds, HP-007, HP-004, HP-009 and HP-008. Support, in the form of funding and ten energetic volunteers, for this project was provided by Goldman Sachs. Thank you to all of the staff from both the Alliance and Goldman Sachs who braved the extreme heat in the name of stormwater education! The Alliance aims to have a total of 500 markers placed by the end of August. Please visit the Storm Water Infrastructure Matters Discussion Forum to discuss stormdrain marking in more detail.
July 28th, 2008
When my father would tell me that I was dense, I did not take it as a compliment, but I did not quite understand the insult either. It did not occur to me that what he meant to tell me was that I was incapable of learning, stupid, even, because I knew that for my father, to be dense was to be a jackass: stubborn. But density is oh so much more. There is a certain power in density, mass divided by volume, in certain circumstances that my father may have, in some askew manner, been actually keying me in on.
In the world of our river, density comes mostly in to play in the interplay between salt water and fresh. If you just consider the comparison between a glass of fresh water, and a glass of water of the same volume into which a table spoon of salt has been added, it is plain that the added salt would make the water weigh more and, therefore, be more dense than the glass of fresh water. But water is water right? So when salt water meets fresh, they should mix and find some medium between the two, right? This is true, but the mixing is not instantaneous. The variables of density, temperature and flow affect the time that it takes for the solution to find this medium point.
There is a fun way to test this effect. You will need four glasses, two of which are filled with water, blue and yellow food coloring and ½ cup of salt. One glass of water will remain as is, but into the other you should add the ½ cup of salt. Should the salt not dissolve entirely upon stirring, you can heat the water slightly in a microwave, stirring occasionally until dissolved. Add 4 drops of yellow food coloring to the fresh water, and 4 drops of blue to the salty water. Pour half of each color into one of the empty glasses so that you know have a two half glasses of yellow (fresh) water and two half glasses of blue (salty) water at approximately the same temperature. Slowly add the salty water to the fresh and ved versa and compare how the two mix and become another color or find where you can see where the two remain separate. If you have tries the experiment, or perhaps if you have not, you will note that the salty water tends to stay towards the bottom of the glass. The same happens in a tidal estuary such as in the Soundview area and farther upstream, only instead of water being added from above, you have two walls of water moving towards one another. The salt water is carried upstream by the tides and the fresh water is carried downstream by gravity. There is a point where these two meet and it is called the salt wedge. The Denser salt water pushes under the fresh water, settling towards the bottom, as the lighter fresh water floats over the top.
This wedge can stretch for miles as it does in the Hudson, or it can be much more vertical if the flow of the river is equally matched by the rise of the tide. In the case of the Hudson, the salt wedge is carefully watched since Poughkeepsie gets much of its drinking water directly from the Hudson. If the salt wedge runs too far north, the flow is increased to push it back down south. Sampling the water at different depths will show the differing salinities.
Fresh water means less than .5 parts per thousand (ppt) of salt, while brackish water is between .5 ppt and 17ppt, and oceans average 35 ppt. Most estuaries, like the Bronx River Estuary, are brackish. At our last monitoring of Drew Gardens miles above the mouth, Sally found2-3 ppt salinity from a surface sample. As a I walked upstream to get a few pictures of The Phipps Youth Employment Program students that were being introduced to water quality monitoring, I saw a nice size blue crab crawling across the bottom of the river in an area were the flow was quite slow.
I thought that the water would be dangerously low in salt for this creature which thrives 10ppt-25ppt but there could be mitigating factors. One is that the test we had done was surface which means that towards the bottom it could have been a little more salty. There is also an interesting study from 2005(POSEY Martin H. (1) ; ALPHIN Troy D. (1) ; HARWELL Heather (1) ; ALLEN Bryan (1) ) that discusses the tendency for juvenile blue crabs to seek areas of lower salinity(3ppt) in the summer and the fall. The theory put forward by the authors is that they are actually looking for waters safer from predators since salinity and predators were positively related. In any case, it shows the river’s improvement and, should this crab not be atypical, demonstrates the importance of this part of the estuary to all waters down river.
Dad may have been right about my being dense, but now I know that density can also have its advantages.
DG
July 21st, 2008
