A Protocol for Evaluating Lighting Practices and Light Pollution in Coastal Locations

team LP #2Sponsoring organization: Departamento de Recursos Naturales y Ambientales

Team members: Felicia Gabriel (Electrical and Computer Engineering ’16), Benjamin Greenbaum (Mechanical Engineering ’16), Cody Holmes (Chemical Engineering ’16), Noelle Ouellette (Management ’16)

Download the full report.

Executive Summary: Excess artificial lighting has become a growing problem around the world. There are many benefits to artificial lighting, but if good lighting practices are not applied a serious problem may arise, and this is referred to as light pollution. High levels of artificial light result in adverse effects, including sky glow, glare, light trespass and light clutter. Sky glow is caused by the accumulation of light from many fixtures that each emits a portion of light directly upward into the sky where light scatters and cumulatively increases nighttime illumination. Light trespass refers to light that spills over its necessary boundaries into areas where light is unwanted or needed (Longcore & Rich, 2004).

Organizations around the world are beginning to take steps to assess and improve lighting habits. In Puerto Rico, light pollution is a main concern due to the coast’s ability to support sea turtle nesting. Under Puerto Rico regulations, there should be no light trespass on a potential sea turtle nesting beach. Two organizations, the Departamento de Recursos Naturales y Ambientales (Department of Natural and Environmental Resources) and the Junta de Calidad Ambiental (Environmental Quality Board), are developing a protocol to measure coastal light levels in order to evaluate lighting practices in coastal regions of Puerto Rico.

The goal of this project is to assist the Departamento de Recursos Naturales y Ambientales and the Junta de Calidad Ambiental in developing a program to measure light levels and evaluate lighting practices for coastal communities in Puerto Rico. The program will involve a protocol for measuring light levels, creating an inventory of current light fixtures, and a survey to gauge the perspectives of community members on light pollution and its impacts on these communities. Our protocol is in part a modification of an existing protocol (Devries et. al, 2013) used by the JCA which we adapted for coastal conditions, but also includes additional measurements that were not present in the existing protocol. Our work will allow the DRNA and JCA to develop, promote and perform other projects around the coast using this protocol.

team LP #1The first step in creating the protocol was to develop a system for measuring sky glow and light trespass. This required careful selection of a sampling schedule so as to accurately measure the brightness of the sky without interference. Our protocol uses a GIS program to select data points. To develop our protocol for measuring light trespass, we started with the existing protocol developed for the JCA by a past IQP group (Devries et. al., 2013) for measuring light trespass in urban and rural locations. As our protocol was intended specifically for coastal locations, we used trial and error to determine what changes needed to be made for this protocol to yield the desired data in coastal regions. We began by testing the 10×10 meter square quadrant system used to take readings. The process of initial preparation and perimeter set up was completed in the field. The second part of the protocol involved creating daytime and nighttime site assessments which include geographical and observational data. To evaluate the daytime and nighttime assessment protocols, we visited the site both at daytime and nighttime hours to pilot test the initial system and note any changes that needed to be made. To create a method for collecting light trespass measurements along the coast, our team tested the protocol to see if any problems or limitations arose. To complete this, our team went to the coast and completed the process multiple times for multiple points and noted any changes that needed to be made. As a new element for measuring light pollution, our team added a system of taking sky glow measurements. Another item added to the protocol was a system to create an inventory of all the lights located along the coast. The last addition to the protocol was a survey intended to gain insight into the degree to which community members understand the potential ecological impacts of light pollution in their neighborhood. It will also provide information on the opinions of community members on the lighting practices currently in place. This is a critical part of any assessment of coastal light pollution because without knowing the motivation behind community member lighting practices it will be difficult to enact change.

Our final Coastal Light Level Measuring Protocol consists of six chapters designed to allow the DRNA and JCA to study lighting practices in any coastal location. The protocol includes the following chapters:

  1. Using the Photometer: This chapter outlines how to use a photometer to measure light trespass. This includes calibration methods, standard units of measurement, and instructions on how to take light level readings.
  2. Quadrant System: This chapter describes the process of selecting data points every 100 meters using a Geographic Information System. These points serve as anchors for a 10×10 meter quadrant system used to take light trespass and sky glow measurements.
  3. Daytime and Nighttime Assessments: This chapter provides instructions on how to complete daytime and nighttime assessments at each point, using a Site Assessment Sheet to document geographic information including photographs and observations of each quadrant.
  4. Performing Nighttime Measurements: This chapter provides detailed instructions for how and when to take light trespass and sky glow measurements and record the data using a Data Collection Sheet.
  5. Creating an Inventory of Coastal Lights: This chapter outlines how to complete an inventory of coastal lights by assessing location, lighting use, shield type, bulb type, and type of shut off.
  6. Survey to Gauge Perspectives of Community Members: This chapter provides a survey to be distributed in the studies location in order to gauge the perspectives of community members on light pollution and its impacts on these communities.

Our second objective was to use the protocol in the coastal community of Isla Verde to evaluate their current lighting practices. We measured sky glow and light trespass, completed an inventory of light fixtures along the coast, and administered a survey to the residents of Isla Verde.

First, we created a schedule of possible dates and times to complete our measurements, and six days were selected in November. The Management Program of the Coastal Zone of the Department of Natural and Environmental Resources identified points for our study using a GIS program to create an aerial map of Isla Verde. After taking our sky glow measurements the data was compared to a classification scheme for sky glow readings. Due to Isla Verde’s location, our team hypothesized that the sky glow readings for the coast of Isla Verde would be consistent with typical readings of an urban neighborhood or bright suburb. Light trespass measurements were taken to determine if the levels were within acceptable range of a turtle nesting site, below 0.005 footcandles. The inventory was completed to make conclusions about lighting practices in Isla Verde and whether or not they effected light trespass measurements. The last step involved administering the survey using Qualtrics, an online survey platform, and in person to individuals in the area.

The sky glow measurements along the coast of Isla Verde had readings that all fell within the range that is typical of bright suburbs or urban areas where there is too much light for the Milky Way to be seen. There was a significant amount of variability in the light trespass data between quadrants as well as variability among the points of each quadrant. This was attributed to the practice of using a single or small set of luminaires to illuminate a very confined area around paths and for security. We found that only one out of 29 total quadrants had mean levels of illumination below the 0.005 foot-candle limit that is the maximum acceptable light for sea-turtle beaches. Even though the mean was below the 0.005 foot-candle limit, several points within the quadrant were above the limit. This was attributed to lights from hotels which were several hundred yards away.

After completing the inventory of the coast our team wanted to determine if there was any correlation in our data between coastal lighting practices and light trespass levels. We recorded a total of 336 lights. The number of lights per site ranged from 0-45 with the average number of lights per quadrant being 11.2. From the data, our team concluded that there was a positive correlation between number of lights surrounding a site and levels of light trespass. There was also a positive correlation between poor levels of shielding on a light and levels of light trespass. Fully shielded lighting resulted in lower levels of light trespass while areas with high levels of light trespass were surrounded by lighting with mostly partial, improper, or no shielding. After analyzing all of the classification data our team concluded that each property type requires lighting for different purposes and that lighting used for security and patio lighting were the most likely to have no shielding. Our final conclusion was that lighting habits have a direct effect on light trespass levels on the coast.

For our survey, although we had a large number of potential respondents, very few actually completed the survey. Due to the poor response rate, we concluded that the residents had an apparent lack of concern towards light pollution. While conducting surveys in person, many residents voiced concerns about safety and given the choice, would like to have more lights along the beach. The exception to this was a building administrator who had received education from the DRNA on the effects of light pollution and better lighting practices.

Our protocol results clearly indicated that Isla Verde has a light pollution problem, and that this stems directly from the area’s poor lighting habits. Our team created technical recommendations to improve the protocol for future applications. In order to address poor lighting practices, our team decided to focus our efforts on creating community outreach programs to educate community members and help get them involved in making positive changes in Isla Verde. The programs are designed to be implemented in any region in order to promote discussion about lighting practices and get the community involved in making better lighting choices.

After applying the protocol in the coastal community of Isla Verde, our team was able to recommend improvements to certain aspects of the protocol. These protocol recommendations are designed to make the protocol more effective and allow greater critical analysis.

After concluding that the coast of Isla Verde has high light levels and low levels of concern for changing lighting practices, our team created a system to get community attention. While enforcement of local and state level regulation is pending for next year, the next best step is to hand out official notices to promote voluntary cooperation. We created a prototype for a Light Fixture Notice for recommendations on how to improve lighting habits. It does not include any legal repercussions if the light fixture recommendation is not completed.

The second part of our outreach plan includes a brochure that the DRNA and JCA can distribute to coastal regions in Puerto Rico to promote voluntary cooperation. The brochure provides information about the program as well as personalized data about a regions lighting practices and potential impacts on the ecosystem.

We also recommend that the DRNA and JCA coordinate a community outreach program in the form of a stargazing trip. The trip will include two components, an educational information session focusing on local lighting practices and a night sky tour. This program is intended for all community members in any coastal region where the protocol is carried out. However, the night sky tour will take place in a different location where it is dark and the light levels are not high enough to affect the appearance of the night sky. This tour will be used to attract the community members to participate in the program and used to help participants appreciate the result of a night sky in a dark location.

Lastly, we created a feedback form to allow community members to describe problematic light fixtures in their area and to request change. This is an excellent way for two-way communication to give the community members a voice in the process of changing lighting habits. The form will allow the DRNA and JCA to understand how community members feel about any bothersome light fixture and what their personal recommendations for improvement would be.