the [inter]relations

"Three hundred trout are needed to support one man for a year. The trout, in turn, must consume 90,000 frogs, that must consume 27 million grasshoppers that live off of 1,000 tons of grass."
-- G. Tyler Miller, Jr., American Chemist (1971)

This is a reoccurring quote when measuring an ecosystem's health, which refers to the transference of nutrients, or energy, through trophic relations. The bottom line is that man, or any widespread carnivorous mammal, although not directly dependent on sunlight for energy, can trace any food source to a primary source,or the primary production, in all cases to the sun.
At a simplified glance, a plant requires sunlight, carbon dioxide, water, and nutrients, and through photosynthesis produces reduced carbon compounds and oxygen.(1) This simply stated process, in theory, allows the energy-devouring plants to develop further, thus increasing the potential for more plant life from their prospective offspring, and thus increasing an environment's relative 'biomass'.
The measure of the environment's primary production serves as an accurate way of measuring the complexity of a region because all other forms of life will be dependent on plant life in both direct and indirect ways.
An abundance of plant life serves for an abundance of nutrient availability for all other forms of life, through an interweaving web of digestive connections; eg. through herbivore species, followed through to carnivorous species. The increase of plant biomass within the environment can even satiate the region's detrivore populations with the addition of decomposing materials(2).
This dependent relation is of primary production is at the heart of any healthy river system. It can be well assumed that urbanization in the northern east coast has altered these primary production levels among the Delaware River. The introduction of toxins to the water can disrupt natural processes. Even waste pollution, as simple as a discarded paper cup, can out-compete biotic species in oxygen through its decomposition. That single cup may serve as a fatal final-blow, if it drifts upon an ecosystem that already faces a continuing battle with dissolved oxygen levels-a struggle that originated with a reduction in of primary production.
One of the key factors in primary production among aquatic ecosystems is nutrient availability, and human disturbances continue to have an increasing effect on the natural nutrient recycling processes by contributing foreign chemicals and toxins. The environmental symbiosis between terrestrial runoff and aquatic health is highly sensitive. Human development disrupts natural occurrences that have spent eras in accordance of geological perfection. The sensitivity of such environmental symbiosis was observed in a case study in Ontario, Canada, where the conversion of forested land for agricultural use increased phosphorus runoff by 4x, and Urban conditions contribute 9x more phosphorus than forest land with vegetative buffered zones(2, 450-451).

As observed from the chart above, although the Delaware River is said to be of the healthiest in the nation, it's primary production rate is lower in comparison to other U.S. rivers that are not as severely affected by urban patterns.

River biota, like all life, seem to operate in these intricate bio/geo/chemical associations with all other species within their shared region. Influencing one missing link in a food web may affect the status of many species.
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1.) http://www.physicalgeography.net
2.) Molles, Manuel C. Ecology: Concepts and Applications, McGrawHill 2008

est.u.ary

Although the focus of my blog is on the freshwater 'non-tidal' portion of the river, I want to briefly examine the Delaware Estuary system, for it serves a vital aspect of the river system. Estuaries are said to be one of the most biologically productive ecosystems on Earth, serving as spawning and feeding grounds for a variety of , as well as migratory routes for many recreational and commercial fish. Once waters of the Delaware River drift past Trenton, the freshwater begins to mix with saltwater from the Delaware Bay, a transition of eco-conditions merge to create the Delaware Estuary, New Jersey's largest estuarine system. The transition boundary of the fresh and salt waters is variable because it is dependent on regional rainfall. In conditions of drought, the brackish water can travel upstream.
The estuarine biotic systems are in the constant pressure of this changing environmental physiology, which makes them more susceptible to the alterations that we add with our development. Although the estuary is protected in the National Estuary Program, the lower Delaware Basin, of which it lies, is highly urbanized, both residential and commercial. According to a US House of Representative report, in 2005 the Delaware River ports generates $19 billion in annual economic activity(DRBC). This regional prosperity is unarguably the product of a well-developed river system, for any environment's quality is a reflection of the quality of its water system.
However, it can be observed in the past that any exponentially expanding urbanization pattern against a naturally flowing environment will ultimately have disastrous effects on native biota. The estuary is visited by a number of migratory waterfowl, as well a super-highway for migratory fish to the freshwater spawning ground the northern Delaware River. Although there are numerous efforts to alleviate human pressures upon the estuary, the tidal-water flow does not receive the intense protection as its headwaters, which may lead it to further degradation through the continuing years advancing urbanization.

[atmos.pH.eric] threats

Since the Clean Water Act of 1970 and its following amendments, industrial and municipal discharges along the Delaware River have been dramatic reduced, and regions of special protection have shown biotic improvement. With point-sources of pollution at focus, we cannot neglect the not-so-locatable sources of ecological toxins. The Delaware Watershed faces non-point pollution from all regions of development, from urban to rural; pollutants such as lead or mercury deposits, accumulated from urban runoff, enter the river and mingle with other toxic wastes such as sewage discharge, or DDT and other agricultural pesticides. Besides runoff sources, one should also consider the effects from airborne pollutants, as stated by the IPCC, most of the ecological effects on freshwater systems depend on "hydrological responses to climatic change" (IPCC).
This climatic change is not only applied to a large scale such as global warming, but regional changes due to alterations in natural landscapes. It is commonly noted that urban development is a significant contributor of environmental pollution and as displayed on the map below, the result of this contrbution is very visible.




A major non-point contributor to the Delaware River Basin is acid rain, which is the result of atmospheric accumulation of harmful airborne pollutants from urban and industrial smog. Acid rain is usually associated with highly urbanized regions, and the northern headwaters of the Delaware Basin lies downwind of New York City, as well being among influential boundaries of other densely populated cities along the river borders such as Stroudsburg, Easton, Trenton, Philadelphia, and Wilmington.
The ecological threat begins when the chemical concoction begins its decent to the Earth's surface as precipitation. Like a sort of reverse atmospheric acupuncture, each droplet of contaminated rain delivers a multitude of toxins to be leached into the freshwater systems.
Rocky mountainous terrains such as the Catskills, from which the Delaware River draws it's headwaters, can prove to be as impervious as an urban city street, and high periods of precipitation can inundate the biotic communities with PCBs, mercury, dioxin, DDT and other wastes. This airborne pollutant is practically unavoidable. Policies such as the Clean Air Act, have helped lessen it impact, but the release of inorganic pollutants into the atmosphere is a continuing effect development.

To think that the Delaware River Basin faces such a continuing harmful threat, one would assume that the aquatic life would have been entirely eradicated by now, however biotic communities continue to thrive in these conditions. Shown on the left is a chart common to most biology textbooks. Various species of fish, more notably the Rainbow and Brook trout, thrive in these mildly acidic waters, but still can only thrive within a small range pH, a sensitivity common to most aquatic organisms.

A successful freshwater ecosystem is able to maintain sustainability of water conditions with the presence of a vegetative buffer, refered to as the riparian zone.

Plant life within this riparian boundary create a botanical bio-filter, which strain the influx of harmful chemicals, interrupting their entrance into our water systems in such heavy periods of inundation, but rather in a slow release in order to maintain suitable biotic living conditions for aquatic organisms. The importance of this environmental symbiosis between forest regions and river quality was demonstrated in a USGS assessment, which analyzed the effects of 'chronic episodic acidification' periods within the Catskill Moutains.

During the spring and fall seasons of 1989, the USGS conducted an analysis of fish mortality in relation to heavy acidic rain innundation. Juvenile brook trout were subjected to various acidic magnitiudes in varying increments, mimicking the upstream buffering conditions of the upstream Delaware River.
Although the climatic conditions of the Catskill experiences both extremes in summer and winter, precipitaiton is high year-round. There is a vicious cycle of pollutants interrelating through the atmospheric and hydrologic systems of the mountain region.
The degree of fish mortality was positively related to the riparian buffer zones which surrounded the Delaware River. The condition of a poorly buffered river under an acidic precipitation episode proved to be 100% deadly to fish communities.
The assessment implied that indirect environmental effects maybe be more disastrous to biotic communities than direct sources, and recognized the specific chemical culprits associated with the fish mortality(in order of importance), 1. inorganic monomeric aluminum, 2. dissolved carbon, 3. calcium, and 4. chloride.
Further examinations showed that the inorganic Aluminum concencrations, alone, could account for 76-85% of the variability within brook trout mortality(1). The effects of the acidic episodes among the rivers with a more densely vegetative riparian buffering zones yielded shorter durations and lower magnitudes of the acidification process(1).
The results of this assessment not only identified the specific airborne chemicals that are environmentally harmful, but also clearly demonstrates the importance of a preserved vegetated buffer zone along the river banks. Although the vast forested regions of the upper Delaware River is under constant threat of acidic rain, the densely forested river booundary are a necessity at maintaining the river's biotic conditions.
The isopleth map below represents the average annual pH of atmospheric precipitation. The highly urbanized northern east coast of our country has a visibly different influences to the quality of our waters compared to the rest of the country. The threat of non-point pollution is significant perhaps for its broad stretch and silent omniscience that is a part of all forms of human development, patiently wavering above our heads in the disguise of a beautiful cloud-filled sky.



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1.) Effects of Forest Harvesting on Ecosystem Health in the Headwaters of the New York City Water Supply, Catskill Mountains, New York

By Michael R. McHale, Peter S. Murdoch, Douglas A. Burns, and Barry P. Baldigo

invasive

invasive species always peaked my interest, as horribly devastating as they may be. highlighted as invasive



species in the Delaware River valley.



number one of the most unwanted on the list is the flathead catfish.
they are most notable for their ferocious eating habits, and hey are known to
grow over 160 lbs! The image is to give a reference, it is listed as a 154 lb flathead catfish caught in Santee Cooper Reservoir in Pineville, South Carolina in 2004.

forest_footprint

Its hard to envision the heavily urbanized regions of our country as they once were before their colonization. From historical hindsight, the negative relation of urban patterns against pristine natural landscapes is easily visible; and development and deforestation are two ever-related concepts. Today, boundless forested horizons rarely stretch uninterrupted without the occasional pulse of human development.Although the Delaware River Basin lies between two of the most heavily populated regions on the East Coast, it remains primarily forest. By 1700, much of the lower region of the water basin had been developed into an urban environment.


[photo-Delaware River @ Philadelphia 1928]


Although the Delaware River catered to an influx of new colonizers, it never fell victim to any extreme ecological alterations. The Delaware River distinguishes itself by remaining the only undammed river east of the Mississippi, despite multiple attempts. In the 1960s, extensive efforts were placed in the preservation of the river, but had little effect on the long-lived legacy of industrial pollution that plagued the downstream basin region. Around this time, the quality of the river around the Philadelphia/Camden region was so considerably altered, that the entire tidal-water portion of the river(Trenton to estuary) was completely deprived of oxygen, creating a biological blockade for migratory fish breeding patterns(2). It was not until the Clean Water Act of 1970, with over a million dollars in funding from the Government, that the river would show considerable positive changes in over-all quality. Despite the lingering remnants, like PCBs, mercury, lead, DDT, that still litter its downstream river beds, the the Delaware is now considered one of the healthiest rivers in the continental United States(3). As of 1992, it was national recognized in the Scenic and Wild Rivers Systems, which assuredly promises the continued preservation of the river.

plan_philly

PlanPhilly was created in 2006 to cover the Central Delaware Riverfront Visioning project. One of their main goals is preserving the riparian life within Philadelphia's waterfront.
"Many cities proclaimed their waterfronts to be dead for any development other than industry and decided to plan around them, building overbearing highways along their banks and cutting off public access to what has now become a great urban resource"
This is exactly what seems to be the case for much of Philadelphia; besides Penn's Landing and Penn's Treaty Park, a large portion of the downtown river access is mostly municipal or industrial.

Philadelphia waterfront has been shown an increasing amount of attention with the casino controversy... Current issues are...

biotic_integrity

Monitoring water quality in river systems vary regionally, this makes it unfeasible to have a constant standard of which all rivers are measured. In this case, the EPA proposed the Index of Biotic Integrity(IBI), to serve as a continuing assessment of our nation's water systems, by which our impact on environments could be identified, comparatively, through the years.
The IBI is a measure of an ecosystem's "ability to support and maintain a balanced, integrated, and adaptive community of organisms...having a species composition, diversity and functional organization comparable to those of natural habitats within a region"(Karr, J. R. and D. R. Dudley).
Biotic integrity could be equated to environmental prosperity, measured through the complexity and diversity of the native biotic populations.


The major determinates of the IBI level are human-induced, as illustrated by and IBI's standard, the Biological Condition Gradient(BCG). The BCG offers classification for measuring freshwater biota in response to human disturbance. The extreme alterations in an ecosystem yield extreme alterations in populations densities. Nearly all rivers and streams have been influenced or 'modified by direct and indirect human activity' (Baron, Jill S.)

As defined by the USGS:
"Direct activities that have altered aquatic ecosystems include: habitat destruction and fragmentation; dams, diversions, channelizations, and groundwater pumping that alter flow patterns, erosion activities, thermal regimes, and species migration routes; point and non-point introduction of a wide array of organic chemicals, toxic metals, and fertilizers such nitrogen and phosphorous; alteration of thermal regimes through damming, point source inputs of hot water, or riparian vegetation alteration; introduction of non-native plant and animal species; and over-harvesting.
Indirect effects occur from land use change within watersheds, and long-range transport and deposition of acid and metal pollutants."