Marsh Study

Abstract:

The purpose of this lab was to collect information and data regarding the differences between a natural and artificial lake in Orange County, California. The lakes used in this study are a man-made lake in William R. Mason Regional Park, and a natural lake located in Laguna Canyon, Barbara's Lake. The two lakes will be tested for the same elements and compared to each other. The hypothesis to be tested is to determine if artificial lakes have higher amounts of the growth-limiting nutrients phosphorous and nitrogen. The two lakes will be tested during the same time period and date, maintain different compositions in terms of dissolved oxygen, NO3 and PO4 concentrations, temperature, salinity, and conductance. The artificial lake, as opposed to the natural lake, will differ in natural vegetation, native and local wildlife, productivity, and water quality.

Introduction:

Lakes can be categorized into artificial and natural lakes. An artificial lake is one that was created by human engineering, which can be due to flooding or deliberate excavation for example. A natural lake is a body of water that occurs on the surface through natural environmental processes. There are many examples of these types of lakes in the state of California. Two examples used for the scope of this study were a human-created lake in William R. Mason Regional Park and a natural lake in Laguna Canyon, Barbara's Lake.

William R. Mason Regional Park is a 345 acre park that was created in Irvine, California in 1978. The 9.2 acre lake is approximately 270 m wide and 240 m long, (OC Parks, 2011). The lake resides at 0ft elevation at sea level and is enclosed by a cement wall. The lake is typically used by migratory birds and local wildlife and there are restrictions for human activity and entry into the lake. Common wildlife include non-native species such as the red-eared slider, and local avian species such as mallard ducks, Canadian geese, and Egyptian geese and invertebrate species such as physid snails, (Professor Bowler, personal communication, August 2011). There is no riparian vegetation, however western sycamore and white alder exist in the surrounding areas.

Barbara's Lake is a 12-acre ground-water depression wetland and is a natural lake located in James Dilley Preserve in Laguna Canyon at an elevation of 325 ft above sea level (Needham, 1924). The dominant riparian vegetation is California bulrush (S. californicus) and broad-leaved cattails (Typha latifolia). Other dominant vegetation is coastal sage scrub, laurel sumac, ragweed, mulefat, mugwort, black willow, and saltgrass. Common wildlife include freshwater shrimp, leeches, ramshorn snails, and mosquito fish. Other common insect species include damselflies and dragonflies. Avian species that inhabit the area are American coots, mallard ducks, and grebes, (Professor Bowler, personal communication, August 2011).

The purpose of this study is to compare a natural lake and an artificial lake using observational and experimental research to determine differences in abiotic and biotic conditions. The objective of this paper displays that artificial lakes are more abundant in the growth-limiting nutrients phosphorous and nitrogen.

Materials and Methods:

On August 15, 2011 and August 17, 2011 data was collected at each lake between 12:30 and 3:00 p.m. A visual survey was completed at each lake. The temperature and representation of fauna and the surrounding vegetation was noted. A five gallons of water was collected at random to note any species collected. A collection of organisms was also collected with a net approximately 3ft in depth and 5ft from the waters edge. To measure the Orthophosphate and Nitrate levels in each lake we used a HACH Test Kit (0-10 mg/l, Model NI-14) to measure NO3 (nitrate), and a HACH Test Kit (0 - 50 mg/l, Model PO-19) to measure PO4. A YSI 55 Dissolved Oxygen meter was used to measure dissolved oxygen in mg/l and % DO saturation at both surface level and deep level. A YSI 30 meter and an ExStik was