10 Emily

Our UTF, Alison, and our group (Team 7) had discussed the viability of various plans especially in regards to disparities in economic ability to pay. We had thrown around the idea of creating regional caucuses that would be "in charge" of an area of regional water as a collective, so that the more economically stable countries can provide some of the capital in exchange for abidance of rules by the developing countries; ideally, this will pair resources with need so that everyone has a better fish population in general. Furthermore, we felt it addressed the differences in management as required by area. The International group probably has a better idea of the feasibility of this idea, but I just wanted to throw it out there.

9 Emily A. Moberg (Team 7) Nov. 2nd   Riparian Buffers

Importance:

                Riparian buffers provide various important stream functions.

(1)    Leaves that fall into the water provide energy for headwaters (i.e. a food source).

(2)    Branches and roots provide shelter for in-stream organisms.

(3)    Overhead leaf cover shades water and keeps it cool, by as much as 10° in summertime (Great Fishing).

(4)    Roots hold stream banks in place and prevent erosion.

(5)    Vegetation slows water velocity, thus reducing run-off induced erosion and also allows particulates (including many water contaminants) to settle out.

(6)    Soils and root systems filter nutrients and pollutants (especially from agriculture and residential areas) before they reach surface areas from groundwater (Haberstock).

These functions are not only important to the biota that lives in these regions year round, but also to anadromous species that come to spawn. For example, salmon require clean gravel for spawning; if silt settles over the gravel, it not only destroys suitable spawning substrate, but it can also smother eggs and the invertebrates that juveniles feed upon (Haberstock). Haberstock also reports that branches and other woody structures provide places for invertebrate prey to live, as well as structural habitat and varied flow patterns that are important for salmon. The improved water quality provided by riparian buffers and the cooling effect they provide are also critical (Haberstock).

Solution:

Riparian buffers should be established along rivers; the width should be determined based on various criteria as detailed below. To implement this, focus should be placed on education of farmers to take up these measures voluntarily. Governments and agencies that can afford to provide funds to help establish these buffers, offer tax incentives, or to rent land to take it out of production should do so.

The width of the buffer depends on many factors, especially the slope of the land (steeper slopes require wider buffers), the permeability of the soil (less permeable soils require wider buffers because water takes longer to infiltrate), and the presence of overland water sources--like intermittent streams or gullies-which can render small buffers ineffective (Haberstock). The type of vegetation-such as wooded or ground level vegetation--as well as factors such as duff height can influence buffer efficacy (Haberstock). Buffer width is measured from the end of alluvial soils (floodplain edge) (Haberstock). Haberstock also notes that wetlands in these areas should be preserved, because they function more effectively in nitrogen-fixation and retention of contaminants and sediments.

Zone 1: 35 feet

For other width determinations, see the method outlined in Haberstock pages 8-14.

8 Emily A. Moberg (Team 7) Nov. 2nd

DAMS

I.                    Solutions: (I have lots of reasons why dams are a problem, but I didn't include them for reading ease)

For dams that have not yet been built there are many steps that can be taken to minimize the impacts. First, efforts should be extended to maximize energy and water efficiency as much as possible; in the past, increases in technological efficiency, recycling, enforcement of environmental legislation, and industrial minimization of intensive water use resulted in a water consumption rate increase much lower than the population demand pressure (WCD). This can be seen as a cost effective method, considering that large-scale dam projects require an incredible amount of capital and are usually both over budget and are completed late (WCD). However, if a dam is definitively needed, research should be thoroughly conducted to determine the environmental impacts. The World Commission on Dams reports that many of the negative impacts from dam construction resulted from complications that were unforeseen; it predicts that use of environmental impact assessments could significantly lower these effects (WCD). Furthermore, proper placement of dams (such as on tributaries rather than on a main branch) and the use of minimal numbers of dams on a given river (because multiple dams can have cumulative effects, such as the dams leading to the Aral sea, which decreased water flow to such an extent that an increase in salinity and pollutants caused the entire fishery to collapse at a cost of approximately $1.25-2.5 billion per year) should be legislated by governments as these restrictions can minimize the large-scale negative impacts of large dams (WCD). Once these data are collected, the dam planning may begin; in this way, the dam design can take into account such features as gates that allow managed flood releases on a scale that can mitigate effects to the ecosystem. The use of such managed floods in Kenya has been economically favorable by maintaining sectors of the economy that relied upon flows that would have been blocked entirely by damming (WCD). These floods help to release nutrients and sediments and help lessen the impact of the dam overall (WCD). These managed floods should be tailored to a specific river, as flood cycles are highly unique. It is important, however, that all such planning occurs before dam construction, as post-construction mitigation techniques have not been shown to be effective; the WCD reports rates of 20% effectiveness.

In terms of fish passage, fish passes have a very low success rate currently. In Norway, fish passes report a 26% rate of "good efficiency" and 32% of no success at all (WCD). In many parts of the world, fish passes are not used at all. Also, even with fish passes, fish often suffer from a lack of environmental cues (like currents) that help them find their spawning site (WCD). However, properly designed fish passes (specific to each dam and species of intended use) do hold promise; in Pennsylvania, fish passes were ineffective until tailored to the American shad, at which point they became very helpful in shad restoration (Richardson). Fish hatcheries and stocking may also be required to augment populations until the spawning routine is re-established with the dam in place; successful restoration of American shad and striped bass required such measures (Richardson), and these methods are likewise advocated by the WCD. The creation of artificial wetlands around shallow dam can also help mitigate dam impact by providing new habitat (WCD).

For developed countries with large budgets and effective environmental legislation (such as France and the United States) decommissioning dams is a solution for aiding fish in special habitats (especially salmon) (WCD). While short-term effects of dam removal include large-scale sediment flushing, over relatively short time scales fish will return and spawn in those areas. However, dam removal is costly and must be studied beforehand; in many cases, toxins and chemicals can build up behind dams and the effects of these toxins washing downstream can be severe (Francisco).