WROC HABs Team – Executive Summary

Executive Summary

Throughout the United States, Harmful Algal Blooms (HABs) have started to appear more frequently in lakes and ponds and have become a concern for many cities and towns. These blooms are formed by cyanobacteria and can grow at a very rapid pace, resulting in large algae-contaminated regions within the lakes. When they develop into large masses, they absorb a lot of the oxygen from the water, which can reduce the amount of oxygen getting to the other surrounding organisms, potentially killing them. When the cyanobacteria cells die or get ruptured, they can release cyanotoxins into the water. These cyanotoxins can cause health problems with animals and humans ranging from very mild effects all the way to death. When these blooms form in the city’s water bodies, the city is forced to shut down recreation in the lake to protect the public’s health. Closing the water body is very frustrating for the residents as they rely on these water bodies for recreation and to relax.

The City of Worcester, MA has also experienced cyanobacteria blooms in a number of its lakes and ponds, and has been working to prevent and manage them more effectively. The City’s goal is to be able to keep the city’s water bodies open as much as possible while at the same time keeping the public safe. The city has focused a lot of time on researching the causes of their blooms and has found some very good information that they will be able to use to hopefully reduce the frequency of bloom occurrences. The city currently performs frequent water tests to monitor the growth of these blooms and will treat the water if possible to try and prevent the blooms from occurring. If the bloom is already too big to treat, the water body will be closed until the bloom has gone away.

For this project, we are working with the Department of Public Works and Parks to help them research monitoring, prevention, and treatment techniques that they can use to improve their current harmful algal bloom management strategy. The goal of our IQP was to provide the Worcester DPW&P with research and recommendations on their current management plan to prevent premature and unnecessary closure of the local water bodies during the summer and fall seasons. We accomplished this goal by pursuing the following objectives:

1)  Understand the current procedures that the Worcester DPW&P use for monitoring their water bodies.

2)   Acquire information from research scientists and universities to better understand cyanotoxins and testing procedures for these toxins.

3)  Compare and contrast researchers’ preventive methods to current Worcester DPW&P preventive methods.

4)  Provide recommendations and alterations to the current monitoring techniques and testing procedures.

The approach to meet these objectives included archival research, data analysis, and interviews with researchers and scientists. We conducted archival research to get a better understanding of cyanobacteria and cyanotoxins. We then analyzed the data of water tests that have been conducted on water bodies in Worcester to better understand the cyanobacteria that they are experiencing and also the cyanotoxins that are being produced. Finally we conducted interviews with researchers and scientists that focus a lot of their work on harmful algal blooms. This helped us to see the methods used in other parts of the country as well as the techniques that have been the most effective in combating harmful algal blooms.

Once we collected all of our information from conducting archival research, data analysis, and interviews with researchers and scientists, we started to analyse it by breaking it down into separate sections. We broke the information down into monitoring, prevention and treatment so that we could analyze each section individually. We found common trends and found which methods within each section that would work the best for the issues occurring in Worcester as well as the resources available for harmful algal bloom management. 

The common trends that we found within our research and interviews was that frequent water tests are common practice to monitor the nutrient levels in water bodies as well as the amount of cyanobacteria present. The cell density threshold for cyanobacteria used by most of our interviewees was in the 70,000 – 100,000 cells/mL range and this was also the range that we found in our research. Treatment of blooms is always a last resort and is something that is not practiced very often due to the potential negative effects on the surrounding ecosystems. Everyone agreed that prevention was the most important part of their management strategy. Their main goal was to prevent excess nutrients from reaching the water bodies. This can be done in a variety of ways.

After finding these trends and analysing Worcester’s current management strategy, we were able to provide a few recommendations to help them improve their already proactive management strategy. We recommended adding testing for saxitoxins and anatoxins, recommending looking into raising Worcester’s cyanobacteria threshold to 100,000 cells/mL, and to continue their effective prevention methods. We hope that these recommendations will help the city of Worcester improve their harmful algal bloom management strategy to keep recreation open as long as possible for residents while also keeping everyone safe.