Mike Hiatt
Sophomore Project
Final Project
10/12/04
Wood River Restoration Project: Fish Species Assemblage
Wood River Wetland Restoration Project: Fish Species Assemblage
Introduction:
Wetlands support a wide variety of plants and animals that have adapted to the fluctuating conditions and water levels (South Dakota FSW 2003). A wetland is defined as: land or areas (as tidal flats or swamps) containing much soil moisture (M-W, 2004). Wetlands in the United States have undergone degradation for farmland, housing complexes, golf courses, and many other reasons for hundreds of years. For instance, in the Puget Sound, European settlement in the 1800s and 1900s led to the conversion of intertidal wetlands to human use by diking and filling (Tanner et al., 2002). Today the Washington Department of Fish and Wildlife has reclaimed some of this land and restored it for the use of the various birds, fish, and other wildlife species in the area.
Wetland restoration is not an easy task and usually involves a collaborative effort from several different agencies including federal, public, and private, all of which share a common goal in the restoration process (Oregon Trout, 2003). Along with the restoration of the wetlands studies are conducted on the biological species that inhibit the wetland areas. When the construction starts, base line data is gathered, and over the course of the construction, and well after the construction is completed, studies are conducted to compare with the previous years data.
Fish are among the species of interest in some of the wetland restoration areas. This is just one of the many aquatic species that rely on the wetlands for survival. Statistical data is gathered on the various fish species and is usually repeated each year for several years. Trends are then discovered that can answer some of the questions regarding a particular species. In some cases the fish species within a wetland region may be endangered or on the brink of extinction. This is one of the main reasons that some wetlands are restored.
Background:
The Wood River wetland area is located about 20 miles north of Klamath Falls, Oregon, on the north shore of the Agency Lake. In 1992, a local citizens group (Klamath Basin Water Resources Advisory Committee) proposed federal acquisition of this property for the purpose of wetland restoration. During 1992 and 1993, Congress appropriated $2.4 million for the BLM to purchase the 3,200 acre Wood River Ranch property (BLM, 2003). The main goals of the project were to improve the water quality that is entering Agency Lake and to improve habitat for the endangered shortnosed sucker (Chasmistes brevirostris) and the Lost River sucker (Deltistes luxatus) (BLM, 2003).
One of the phases of the restoration projects was aimed at returning the stream channel back to its original meandering state. This restoration project is said to be one of the largest of its kind in the United States. This project headed by Oregon Trout took the combined effort of, the Bureau of Land Management, the Bureau of Reclamation, the U.S. Fish and Wildlife Service, the Klamath Tribes, the Oregon Department of Fish and Wildlife, and a team of experienced stream restoration consultants. Total cost of this phase was over one million dollars and took five years to complete. However, this is just one phase of the restoration project (Oregon Trout, 2003).
In correlation with the restoration project several studies have been conducted on many of the species within the wetland. In 1995 some base line data were collected on the various species of fish within the wetland area using two different methods of capture, trap nets for deeper water habitats and electro-shocking for shallow water habitats. The fish species that were monitored at this time were as follows: brown bullhead (Ameiurus nebulosus), tui chub (Gila bicolor spp.), pumpkinseed (Lepomis gibbosus), yellow perch (Perca flavescens), speckled dace (Rhinichthys osculus), and fathead minnow (Pimephales promelas), most of which are non-native species. Twelve sites were sampled in total and all of the sample sites were located within the series of canal channels that run through the property. The drainage canals sampled were approximately four to six feet deep. These canals run NW/SE and are spaced approximately 100 meters apart over the entire length of the property. Six of the twelve sites were sampled several times in 1995 by the use of trap nets. The trap nets generally catch fish over 50 mm (Monitoring Report, 1995).
Since 1995, there has been no attempt to assess the fish species assemblage within the Wood River restoration area. However, in July of 2004 this study was conducted to reassess the fish species along with the size and populations of those species within the wetland area. This study was looking at how the species assemblage numbers compare to the assemblage data that was collected in 1995. Size distribution classes were set for all of the species that were sampled and this also was compared to the 1995 data. This study proposed to answer the following questions. How does the assemblage numbers of 2004, compare to the assemblage numbers from the base line study in 1995? What are the size distributions of the species that are present?
Methods and Materials:
In this study six sites throughout the restoration area were sampled. These six sites were selected within the main channel areas of the wetland and were selected for accessibility and depth, in order to deploy trapping devices. Each site was sampled one to two times depending on number of fish trapped. These six sites are recorded on a Global Positioning System (GPS) unit and placed into a Geographic Information System (GIS). The six sites were added to a Digital Ortho Quad (DOQ) within the GIS program and displayed on an aerial view of the property.
Trap nets were used to capture the fish and the nets were left in the water over night for approximately seventeen to twenty hours. Trap net mesh sizes are either 6.4 or 12.5 mm bar mesh. Trap nets consist of a lead (1.2 m deep x 30.5 m long) followed by a rectangular frame (1.2 m x 1.8 m x 1 m). The trap frame leads into four circular hoops (1m diameter, 1 m apart), which contain three internal fykes (Hamilton, personal communication, February 2004) (See image 1). All fish species were identified, measured to the fork in the tail, and released (Monitoring Report, 1995). A standard metric measuring device was used to determine the length of the fish and, Keys to Oregon Freshwater Fishes, by Carl E. Bond, professor Emeritus of Fisheries, Southern Oregon University, was used to identify the fish. Pictures were taken of some of the species and fish biologist Andy Hamilton was there to provide quality assurance and to help identify the species trapped in the net. Data such as date, time of day, weather conditions, and water temperature was also recorded. A sheet for recording data was obtained from the fish biologist and was used for all of the sampling sites. All data was then placed into the following tables and graphs in the results section to be analyzed.
Results:
The species that were captured in the nets include brown bullhead, pumpkinseed, tui chub, yellow perch, and the fathead minnow. The two most productive of the six sites sampled were at opposite ends of the wetland, one located to the far north of the property, and one located to the far south of the property. The more productive of the two was the one to the north. Two of the six sites sampled yielded no fish at all. It should be noted that a number of bullfrogs were trapped at the most productive site at the north end of the wetland and a muskrat was also captured at this site. The bull frog numbers were recorded but the length or size of the species was not determined. There were also a large number of water beetles caught at all sites but there was a substantial number of about 50 captured at one of the six sites in particular. The water beetles and the muskrat have been omitted from the data. Individual trap station results are outlined in Table 1, which is located on the following page.
Table 1, species type and number of fish by species at each site. Hours fished were approximately the same for each station fished.
Relative species abundance is outlined in Figure 2. This is the total species abundance for all six sites that were sampled.
Figure 2, Relative species abundance in all sites sampled.
Size class distributions are also included in Figures 3-7, bull frogs were omitted from these figures because their size was not determined.
Figure 3, Size class distribution (brown bullhead). Figure 4, Size class distribution (tui chub).
Figure 5, Size class distribution (pumpkinseed). Figure 6, Size class distribution (yellow perch).
Figure 7, Size class distribution (fathead minnow).
These figures represent the total number of fish throughout the six sites that were sampled. From the figures it is indicated that the brown bullhead and the pumpkinseed are two most abundant species within the wetland. However, data was only collected from six sites which may or may not be enough data to discuss abundance trends. The six sites that were sampled are outlined in figure 8.
Figure 8, Trap Net Sites, Wood River Wetland.
Discussion:
In this study it was expected that a larger amount of fish would be trapped because of the longer period of time that the nets were fished in this study as opposed to the study conducted in 1995. The numbers in the individual trap station results are much larger than those of the study conducted in 1995. There were two sites that were sampled in 2004 that were also sampled in 1995. Station 20 produced more fish in 1995 than it did in 2004, in fact, in 2004 station 20 produced only 5 brown bullhead. This was surprising because the 1995 numbers include three other species besides the brown bullhead. Station 25 was also sampled in 1995 and again in 2004. The 2004 sample of station 25 produced no fish of any species. Again fish were present in 1995 and no fish were trapped in 2004. In addition to these two sites, four other sites were sampled in 2004 that were not sampled in 1995. Station 5 was sampled two times and each time there were no fish in the net. Station 28 was also sampled two times and this is where a vast majority of the fish captured were recorded. Station 28 produced five different species of fish, brown bullhead, pumpkinseed, tui chub, yellow perch, fathead minnows, and a large number of bullfrogs were also observed at station 28. Station 20A, which is one canal over from station 20, produced brown bullhead, tui chub, and pumpkinseed but the numbers were not that large. Station 26 was the last station sampled and there were several fish trapped at this station. The fish trapped at station 26 include all of the five species listed above. Station 26 was the second most productive station that was sampled in the study. Station 26 also produced the largest fish measured in the study, which was a brown bullhead that was 320mm in length.
The size distributions of the fish throughout the wetland are very similar to the ones that were measured in 1995. There were a few interesting trends that was noticed here. For instance, in 1995 a majority of the pumpkinseed captured were in the 90mm range and in 2004 the majority were in the 60mm range. A similar trend was noticed with the brown bullhead as well. In 1995 the majority of the brown bullhead were in the 210mm and 220mm ranges with the largest one recorded at 260mm. In 2004 the majority of the brown bullhead captured were in the 90mm range with the largest at 320mm. There are similar trends to be noticed in the tui chub and yellow perch species but the fathead minnow was not included in 1995.
The populations and size distributions are random within the wetland. The main factor driving the distribution of fish about the wetland appears to be a correlation between water temperature and fish distribution. The two places that yielded the most fish had the lowest surface water temperatures. Station 28 was recorded at 76o F the first day and 80o F the second day it was sampled, and station 26 was recorded at 84o F the only day it was sampled. The two stations that did not produce any fish had very high surface temperatures. Station 5 had a surface water temperature of 94o F both days it was sampled and station 25 had a surface water temperature of 92o F the only day it was sampled. These were some of the highest temperatures recorded of all the sites that had the temperature recorded. Not all of the sites had the temperature recorded in this study so the correlation between water temperature and fish distribution could not be added. The water temperature could be attributable to the large amounts of rich black organic matter that is dispersed in the water. Places where water is standing still and does not have any flow seems to be where the warmest water is found. Station 26 had the same organic matter in the water but there was a large outlet which allowed water to flow freely which was close to the sample site.
Conclusion:
The study conducted at the Wood River wetland was conducted between July 1st and July 9th of 2004. A previous study had been conducted on the wetland in July of 1995. The purpose of this study is to compare the base line data collected in 1995 to the data collected in 2004. In the new study six sites were sampled for fish species. A trap net was used to trap the fish and the net was left in the water over night. The net was then pulled from the water and the species were identified and measured to the fork in the tail and released. The species that were trapped throughout the wetland include brown bullhead (Ameiurus nebulosus), tui chub (Gila bicolor spp.), pumpkinseed (Lepomis gibbosus), yellow perch (Perca flavescens), and fathead minnow (Pimephales promelas). Four of the six sites sampled produced fish of at least one of the species classes mentioned above. Two of the six sites sampled produced no fish at all. This study concludes that there are still fish within the wetland area and the numbers are comparable to the data collected in 1995. Further studies could be conducted to answer the following questions. Does surface water temperature effect the distribution of fish species throughout the wetland? If so, is this a direct function of water quality such as, pH, turbidity, DO, nitrates, and phosphates, due to the temperature?