By David Ernes – Lake Management Committee

The 2023 season turned out to be a season of unusual weather coupled with unexpected observations. Despite this, for the third straight year, we ended the season with no algal toxin levels exceeding the EPA Advisory limit. We also added over 400 pounds of feeder fish to enhance the excellent fishery. This document includes a review of the issues we faced and the conclusions from the reports from our consultants.

The report from EnviroScience related to the in-lake conditions found that, on a whole lake basis, the algaecide treatments were successful at maintaining the recreational use of the lake. Selected areas did observe issues but overall, the lake has seen an improvement since 2021. In August, algae populations increased primarily in the north, which was surprising, prompting the second partial algaecide treatment. The nitrogen levels were elevated above that seen in prior years. The report does encourage efforts being done to control the nutrients by seeking financial assistance.

The AquaDoc report, measuring the conditions south of the lake, showed phosphorus levels similar to last year. The increase in nitrogen levels primarily for nitrate, appeared at the end of June and originated in Whetstone Creek. It appeared as the weather shifted from a drought to heavy rain events. It slowly returned to normal as the summer progressed. While the source is unknown, the elevated nitrogen level is felt to be responsible for some of the unusual observations this season.

Throughout the course of the year, we have been in communication with our consultants to try to understand the unusual situations we experienced. The consensus opinions are briefly described below.

Filamentous Algal Mats. As has been discussed both at Board Meetings and e-blasts, an increase in non-toxic green, filamentous algae is expected as we work to control the more toxic blue-green algae. In addition, the increase in nitrogen (in the form of nitrates) entering the lake likely acted as a ‘fertilizer’ for the filamentous algae, increasing the magnitude of the problem, especially in the south.

Floating snails. At the end of June, an increased number of floating snails were observed. These snails, likely Mystery Snails, are invasive to our area. They seemed to originate in the south (observations in September found them to proliferate south of the lake) with the shells floating north with the current. The complicating factor is that these snails can float and still be alive. Observations by our consultants and the author have confirmed this. While there are several possibilities to explain why they behaved as they did, it is not clear which factor (or some combination of factors) was responsible. The fact that this was unique to this season suggests the nitrate level increase as a likely contributing factor.

Odor in the South.  Around September 22, a sewer-like odor was observed in the south end of the lake, extending upstream of the bridge. This was found to be due to a condition called hypoxia, where the oxygen level in the lake was depleted. When this happens, odor-causing chemicals are released as the aquatic vegetation and algae die off at that time of year, consuming dissolved oxygen in the water. Normally the fall rain brings in freshly oxygenated water, but the unusually dry September prevented this, so the normal processes occurring in the lake were again disturbed. In addition, the high level of filamentous algae, and the excessive vegetation in the lake below Spanish Cove and extending south of the Route 6 bridge added to the load. This drop in oxygen also adversely affected the fish (and snail) population in this area. With artificial aeration and returning rainfall, the situation was corrected.

Overall, this year we saw that factors beyond our control acted against our efforts to improve conditions in the lake. Until we find a Bond villain with a weather control machine, we will have to do our best to adapt. As in the past, we will use lessons learned this season to direct our plans moving forward. Because, as always, we all must do our best to…

Be Lake Responsible

Dave Ernes – Lake Management Committee

A Fish Survey was conducted on Lake Roaming Rock on September 12-13, 2022 by Jones Fish. Briefly, boats equipped with electrofishing apparatus travel throughout the lake. At each location sampled, the fish are stunned, collected, and assessed by measuring the length and weight. The fish are then returned to the lake unharmed. This process is done in as many areas as is feasible but is not intended to determine the population throughout the entire lake, especially one the size of our lake. This snapshot will give us an unbiased assessment of the current condition of the fishery. It should be noted that the survey was conducted two days after the Bass Tournament and the effect on the survey was expected to be minimal.

Based on the report, Jones Fish believes the overall condition of the fishery is very good. The largemouth bass (bass), the most often sought species, were found to be healthy. The overall food web including both predator and prey species is said to be diverse. The only issue identified is a low number of bass in the 5–9-inch range, representing fish 2-3 years old. The fish representing year-one were found to be good. This gap was not noted for the other species identified in the lake. The cause of this gap has not been fully defined but was speculated to be related to weather conditions during the spring spawning seasons. A link to the full report can be found at the end of this report.

            In addition to the specialists from Jones Fish, a member of the Lake Management Committee was also present for the survey. Their input, as well as follow-up questions submitted to the author, were used to evaluate the results.

            The health of the bass is measured by a Relative Weight Index. This compares the weight of each fish greater than ten inches in length to one that is considered normal. A value of 100% indicates that the bass are of normal size. The average for our lake was 97.5, which indicates that the bass are of average size with no indications of malnutrition. Another measurement of the bass population is Proportional Stock Density, which is a ratio of the number of “quality” fish versus “stock” fish. This was not presented in the report but was calculated by the author from the data submitted. For bass, a PSD of 40-70 is considered well-balanced, with our lake showed a value of 65.

            One other parameter discussed was the distribution of the various fish species throughout the lake. In general, a more significant distribution of fish was observed in the two major coves (Plum, Sugar), and in some of the small coves north of Sugar Creek and along the eastern shoreline. There appeared to be an inverse correlation with the number of fish caught and the density of the vegetation. For example, fewer fish were collected in the southern areas where the weeds tend to be thicker and those that were collected were considered non-prime species (i.e. suckers, catfish).

            One area that the report discusses is the level of “structure”, representing features such as submerged logs, that the fish will use for spawning and to avoid predators. They felt the level of structure in the shallow areas was good, but that the deeper areas may benefit with additional structure. (Please note that anyone who considers adding structure on their own would be violating the rules of the Association and can incur fines starting at $1000.)

            The LMC and the Board will continue to monitor the fishery as we move forwards and will evaluate adding structures and stocking suggestions as time and budget considerations warrant.

Be Lake Responsible

Dave Ernes – Lake Management Committee

Understanding how our lake behaves is paramount in any effort to improve it. During the 2021 recreational season, data was collected for our lake. This data has been compiled in the 2021 Water Quality Report recently received. It is one of the most comprehensive evaluations of our lake and its tributaries in recent years. This article gives a brief overview of this report. It should be noted that most of the data involved monitoring for sources of nutrients, the main driving force behind algal blooms.
 
The Executive Summary states that our lake continues to be eutrophic, a classification that our lake has had since at least 1978. If you are unfamiliar with this term, it is based on what is known as the Trophic State Index (TSI). As lakes age, they become more “productive” regarding algae, aquatic plants, etc. and the TSI is a way to measure this. It is impacted by many factors including location, weather, and other external factors and has varied from year to year. The good news is that the application of VodaGuard C this past year reduced the chlorophyll level below the EPA criteria, with a resultant TSI at the low end of the eutrophic range.
 
Nutrients enter our lake both from internal sources (sediment) and external (watershed) sources. The first set of data was collected to evaluate the internal source. It shows that our lake continues to be stratified into an oxygen-rich top layer and an oxygen poor lower layer (think of a Black and Tan). As a consequence of this, over the course of the summer, the sediment at the bottom releases nutrients into the water. If this stratification is strong enough, it prevents the migration of the nutrients to the surface until the fall turnover. What we found was that the turbulence from the rains of July resulted in the lake becoming less stratified, allowing the nutrients to mix with the water at the surface. This may help explain why the VodaGuard treatment started to lose its effectiveness towards the later part of the summer. Luckily, the stratification was re-established in August.
 
The other source of nutrient entering the lake is from the watershed. Our watershed is large, and one of the ways it enters the lake is via the tributaries. The data collected from the five main tributaries showed that, not surprisingly, Rock Creek is the worst offender regarding nutrients. One interesting finding was that Fisherman’s Cove exhibited the second largest phosphorous concentration, and an elevated bacteria level.
 
The last section of the report details some potential mitigation strategies to further improve the lake, like aeration and nutrient inactivation. Each is correlated with the likelihood that it would be effective for our lake. Many of these will be further evaluated in our 2022 Management Plan.
 
One of those strategies is for us to do our part. It is true that no single individual can have the same effect as a storm, but collectively we certainly do. What we do on our property regarding fertilizer, mowing practices, and even landscaping design can have positive or negative effect.  Many articles have been written detailing Best Practices. So, as we move forwards with our efforts to improve the quality of our lake, each of us can do their part, so please …  

Be Lake Responsible

The Water Quality Monitoring Report can be found on the Lake Management Page of the RRA Website under Lake Surveys and Studies.

By David Ernes – Lake Management Committee

As we have stated before, reducing algal blooms is the primary focus of the LMC in this phase of our overall Management Plan. The two common ways to do this are either through the use of algicides or though the reduction of nutrients. Chemical algicides are effective and fast, and are being investigated but they are a band aid and are not a long term solution. And they have some drawbacks that must be understood. The best solution is the control of excess nutrients. Nutrients come into the lake from several sources such as the legacy sediment deposited on the lake bottom over the 50+ years of its life, or from the watershed (via run-off from yard fertilizers and agricultural operations or the streams and tributaries).  With a  Nutrient Budget or Water Quality Model we will establish the percentage that each source contributes to the overall nutrient load for the lake. And from that information we can focus on the mitigation practices that have the best chance of success. (A Budget is also one of the common features one sees in any successful Lake Management Plan.)

The RRA Board has approved the requisiton of a Budget for our lake. At the same time, the LMC is researching various mitigation techniques that address the algae blooms. Once the Budget is completed, we can select those techniques that will have the greatest impact both short-term and long-term while being financially responsible. And once the nutrients are better controlled, we can then move on to other issues such as aquatic vegetation control.

As we wait for the results, we are also looking at simple changes that can impact our lake. One such change approved by the Board was a combined effort by the LMC, the EAC and the RRA maintenance department to alter the mowing practices of the RL lots. In those areas adjacent to the water’s edge or bordering the neighboring farmland, the native vegetation will be allowed to grow unimpeeded, creating a Buffer Zone to absorb nutrient runoff.  This does not cost anything to implement and will actually help the maintenance department. Creation of Buffer Zones is a practice we have often suggested that homeowners can adopt where feasible. Therefore, it is suggested again that you examine your lot and see where you could incorporate a similar practice. Several recent articles have addressed this option. The search for other  “quick hit” options will continue.

 We are moving forwards, and with everyone’s help and patience, we all will continue to…

BE LAKE RESPONSIBLE

Background: The US Environmental Protection Agency (USEPA) is conducting an investigation of methane dynamics in reservoirs. Methane is a potent greenhouse gas that is produced by microorganisms in reservoir sediments. The USEPA is supporting research to estimate the magnitude of methane emissions from reservoirs in the United States.

Lake Roaming Rock Work Plan: The USEPA will measure methane emissions from 32 reservoirs in Ohio, including Lake Roaming Rock, during the summer of 2016. Methane emissions will be measured from 15 locations in each lake using a device which captures methane rich bubbles as they rise through the water column toward the atmosphere (Fig 1). One device will be suspended from an orange buoy (11 x 15 inch) at each site. Buoys will be deployed on Sept 4th and will be removed within 24 hours.

In addition to methane emissions, many other indicators of lake water quality will be measured. These are listed in the table below (Table 1). The USEPA has stated that they would be happy to share the results of these measurements with the Lake Roaming Rock Board in the form of a written report.

If you see these buoys in the lake, please do not disturb them.

Figure 1: Methane bubble collectors. One collector will be deployed below each buoy.

Table 1: Additional water quality measurements

water temperature
specific conductivity
dissolved oxygen
pH
redox potential
turbidity
chlorophyll
total nitrogen
total phosphorus
dissolved organic carbon (DOC)
total organic carbon (TOC)
dissolved greenhouse gases