home

=SWEET SPRINGS POND RESTORATION =

**Problem Statement**
The ponds at Sweet Springs Nature Preserve (located in Los Osos, CA) have become increasingly anaerobic over the years due to a large amount of overhanging eucalyptus debris that falls and decomposes in the water. As a result, survival has become challenging for inhabiting organisms at all levels of the food chain. Of particular concern is the welfare of the resident southwestern pond turtles, which have been classified as a species of special concern by the California Department of Fish and Game. Additionally, it is suspected that effluent from the septic systems of surrounding developments has been finding its way into the pond, resulting in excessive levels of nitrogen in the water.

media type="googlemap" key="http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=Sweet+Springs+Nature+Preserve,+Los+Osos,+CA&aq=&sll=35.321752,-120.841048&sspn=0.003672,0.004823&vpsrc=0&ie=UTF8&hq=Sweet+Springs+Nature+Preserve,&hnear=Los+Osos,+Baywood-Los+Osos,+San+Luis+Obispo,+California&t=h&ll=35.321408,-120.843389&spn=0.006295,0.027202&output=embed" align="center" width="672" height="559"

Background
The Sweet Springs Pond Restoration project was originally introduced by Holly Sletteland, a Preserve Manager working for the Morro Coast Audubon Society (MCAS), which is based in Morro Bay, CA. She expressed a desire in finding a team of volunteers who would be willing to work on a project to help clarify the ponds at Sweet Springs Nature Preserve in hopes of improving the habitat for both resident and visiting wildlife. More specifically, the long term goal as she explained was to incorporate a design utilizing bioremediation techniques to accomplish the task.

Objective
The objective of this project, per Morro Coast Audubon Society's wishes, is to design and construct an ecological water treatment system utilizing bioremediation techniques to help reduce excessive levels of nitrogen while simultaneously increasing the dissolved oxygen content of the pond.

Literature Review
The western pond turtle (//Clemmys marmorata//) formally ranged from northwest British Columbia to northern Baja, California. It is a small turtle, with few distinct markings and a relatively low carapace. While there are thought to be many genetic variations of the western pond turtle, two subspecies are recognized: the northwestern variety (//Clemmys marmorata marmorata//), ranging from San Francisco to eastern Nevada, and the southwestern variety (//Clemmys marmorata pallida//), ranging from south of San Francisco throughout coastal and central California. Sweet Springs Nature Preserve in Los Osos, California is host to the southwestern pond turtle. Due to the similarities in species, habitat, and problems with population decline, analysis of the entire //Clemmys maramorata// species provides a more in depth understanding of the problem, and possible solutions. The pond in Sweet Springs Nature Preserve is a suitable habitat for the southwestern pond turtle, although some issues exist preventing it from being ideal. Lovich writes that “optimal habitat seems to be characterized by the presence of adequate emergent basking sites, emergent vegetation, and the presence of suitable refugia in the form of undercut banks, submerged vegetation, mud, rocks and logs (Holland, 1994).” While there are many of these characteristics at Sweet Springs, there is a severe lack of sunlight reaching the pond due to overhanging eucalyptus trees shading the area. In addition, the pedestrian trails in the area may limit the necessary habitat for the species, as “the availability of suitable terrestrial shelter sites is necessary to provide protection from predators and thermal extremes,” (Lovich, 1999). Nests are usually located along pond margins, but may be over 100m away from the water on hillsides or 2 km downstream if suitable nesting areas are not available. Typical nests of the species are in open, grassy areas with southern exposure (Holland, 1994). Population decline of the western pond turtle has been sudden, and steep. In 1960, southern California hosted 87 known localities of the species, by 1970, this was reduced to 57. In 1987, 53population locations were identified, but only 10 were thought to contain reproductively viable populations (Brattstrom, 1988; Brattstrom and Messer, 1988). In 1992, the Fish and Wildlife Service stated “The greatest single threat to this species is habitat destruction. Over 90 percent of the wetland habitats within the historic range of the species in California alone have been eliminated due to agricultural development, flood control and water diversion projects, and urbanization.” Other threats include invasion of exotic pests and non-native turtles such as the red-eared sliders and painted turtles. These animals out compete the native western pond turtle for food and habitat. Predation from bullfrogs, especially from birth until full maturity, has been shown to limit population of the species (Overtree and Collings, 1997).
 * The Southwestern Pond Turtle**

Sources Brattstrom, B. H. 1988. Habitat destruction on California with special reference to //Clemmys marmorata//: a perspective. pp. 13-24. //In:// H. F. DeLisle, P. R. Brown, B. Kaufman and B. M. McGurty (eds.), Proceedings of the Conference on California Herpetology. Southwestern Herpetological Society, Van Nuys, California.

Brattstrom, B.H. and D.F. Messer. 1988. Current status of the southwestern pond turtle, Clemmys marmorata pallida, in southern California. Final Report for California Department of Fish and Game, Contract C-2044. 47 pp. + xii.

Fish and Wildlife Service. 1992. Endangered and threatened wildlife and plants; 90-day finding and commencement of status reviews for a petition to list the western pond turtle and California red-legged frog. Fed. Reg. 57:45761-45762.

Holland, D.C. 1994. The western pond turtle: habitat and history. U.S. Department of Energy, Bonneville Power Administration, Portland, Oregon. 11 chapters + appendices.

Lovich, Jeff. Western Pond Turtle. Rep. United States Geological Survey, UC Davis, 1999. 

Overtree, L.; Collings, G. 1997. Western pond turtles in the Kern Valley region. The Tortuga Gazette 33:1-2.

Chanu, L., & C., M. S. (n.d.). //Concepts of Bioremediation and its Application in Aquaculture//. Retrieved 01 20, 2012, from Aquafind: http://aquafind.com/articles/BioremediationInAquaculture.php

Eco-Impact Bioremediation and Mould Experts. (2003, April). //Bioremediation of Pond Water, Wastewater and Hydrocarbons//. Retrieved January 21, 2012, from http://www.bioremediate.com/index.html

United States Environmental Protection Agency. (n.d.). //About Nitrogen and Phosphorus Pollution: The Problem//. Retrieved 01 21, 2012, from http://water.epa.gov/scitech/swguidance/standards/criteria/nutrients/problem.cfm

Wikipedia. (n.d.). //Bioremediation//. Retrieved January 19, 2012, from http://en.wikipedia.org/wiki/Bioremediation

Sustainable Wastewater Treatment and Reuse in Urban Areas of the Developing World

Q & A with Holly Sletteland
//**Why is there a need for a living machine in the pond(s) at Sweet Springs Nature Preserve? Have any other solutions been considered?**//

The ponds have become very anaerobic over the years due to the large amount of eucalyptus debris that falls from trees overhead and decomposes in the water. This makes it very difficult for freshwater organisms to survive at all levels of the food chain. Dredging the pond would certainly be another option, but it would be extremely expensive. It would also require pulling out existing fencing to get large equipment in, and would likely cause extensive damage to trails and vegetation. It is also unlikely that we could get permits to do it that way as threatened and endangered animals would be put at risk.

//**What species of animals inhabit the pond, and why are the turtles significant?**//

The southwestern pond turtle is the only freshwater turtle found in the State of California. It is currently considered a species of special concern by the CA Dept of Fish & Game. We are seeing little recruitment of young turtles at Sweet Springs. Although we have not done a comprehensive analysis to determine the causes, there are likely many factors at work – predation from native & nonnative species (e.g. raccoons, water fowl, bullfrogs, etc.), insufficient sun/warmth from shading, insufficient food from poor water quality and illegal collecting. We have not done recent wildlife surveys to identify all of the animal species that inhabit the ponds, but historically there are a wide array of bird species and a limited number of frogs, fish and macro invertebrates.

//**How deep is the pond and how much does the water level fluctuate throughout the year?**//

We haven’t taken any recent depth measurements and it is filling up with sedimentation. There is one relatively deep channel in the center that is 4-5 feet. Most of the pond is relatively shallow – less than 3 feet. It fluctuates considerably during low and high tides. I think we would probably want to take some new depth measurements before we get started.

//**Does the pond have an outflow, or does it remain stagnant most of the time?**//

The pond does have both inflows and outflow through the salt marsh. Originally 2 ponds were dug – one large and one small. The small pond was dug to about 8 feet deep as I understand it and was intended to prevent salt water from moving into the large pond by capturing it. It has since filled in so some salt water is making it in to the large ponds, but they are still predominantly fresh. The mouth of the outflow gets clogged sometimes and the pond does start to stagnate, but part of my job is to make sure that gets cleared out when that happens.

//**Who are the stakeholders of this project? (i.e. Who has a say and stands to benefit from the final product)**//

The primary stakeholder is Morro Coast Audubon Society, but other parties likely to be involved are CA Dept of Fish & Game, Morro Bay National Estuary Program and TooSLO (an organization dedicated to turtle & tortoise conservation). Environmental benefits, should the project succeed, will accrue to the community as a whole and to state and national efforts to preserve biodiversity.

//**Are there any other students/groups/individuals working on this project as well?**//

Currently, I do have 2 Cal Poly students doing water quality monitoring in the ponds who will be doing this for a couple more quarters. This is fortunate, because we now have good baseline data to measure improvement against.

Prototype Building Process
media type="youtube" key="LyT8rtZKDmg" width="425" height="350" This is a video we took that tested the way the water flows through each component. We used coffee to see the way the water flows (we did not have any dye on hand). We found that the water went straight through without circulating in each box. This means that we will have to install some type of baffles to create better circulation. These are pictures of our process of cutting and connecting the pvc pipes, drilling holes in the containers, and fitting it all together.

Group Members
//Environmental Engineering Graduate Student// awwright@calpoly.edu 541.301.8642
 * Andrew Wright**

//Industrial Engineering Graduate Student// jyuan@calpoly.edu 415.812.5301
 * Jeffrey Yuan**

//Landscape Architecture// charla.kaul@gmail.com 916.316.5605
 * Charla Kaul**

**Project Affiliates**

 * Morro Coast Audubon Society**

Related News

 * Cal Poly Partners with Energy Commission to Launch Algae-Based Wastewater Treatment Plant**

Glossary
bioremediation

phytoremediation

mycoremediation

effluent

blackwater

graywater

biofilm