NOAA Great Lakes Environmental Research Laboratory

The latest news and information about NOAA research in and around the Great Lakes


Leave a comment

Ron Muzzi: An inquisitive mind opens the door for a career in marine engineering at NOAA GLERL

Profiler Deployment Aug 1999

A profiler, deployed in August 1999, was designed by Ron Muzzi, to autonomously climb up and down a mooring cable in Lake Michigan. The profiler (above) carried a CTD sensor providing water quality measurements on conductivity, temperature and density throughout the water column.

Ron Muzzi has led the life of a marine engineer at NOAA’s Great Lakes Environmental Research Laboratory (GLERL) since 1979.  Throughout his career, Ron has worked to extend the reach of technology to study the Great Lakes. In leading GLERL’s Marine Instrumentation Laboratory (MIL) team of engineers, he has worked on the development of instrumentation and equipment to monitor the physical, chemical, and biological changes of our freshwater lakes. Some of these monitoring tools have been invented by Ron and his MIL team and others adapted from oceanographic equipment to large freshwater lake use.

So what would lead a 19 year old electrical engineering student at the University of Michigan (UM) to pursue a life-long career as a marine engineer? Ron, a self-professed tinkerer, thinks it’s probably his keen sense of curiosity.  Ron recalls that from a young age, “I was constantly experimenting—taking things apart and then putting them back together in the process of fixing things.” He actually built his own computer (known as the COSMAC ELF) while still in high school.  It was programmed with a hex keyboard and display, but would also play simple video games programmed by Ron.

Ron launched his career at GLERL as a part time engineering aid when he was a college freshman. In the process of completing his college education while working at lab, he followed the advice of his supervisor by taking courses that built broad foundation in math, science, physics, chemistry, and thermodynamics. This foundation has served Ron well as an electronics engineer, a position that later transitioned into MIL team lead for GLERL.

In doing the job of a marine engineer, Ron describes himself as being a ‘jack of all trades’ as he manages the front lines in delivering real time data from the Great Lakes back to the lab for analysis and modeling. Speaking from many years of experience, Ron stresses that our monitoring systems must be designed and built to stand up to the rugged environment of the Great Lakes. These monitoring systems— made up of integrated electrical and mechanical components—must not only survive working in the water, but also reliably provide accurate data. He identifies one of the most challenging aspects of his job is “knowing what to do when things go wrong in the field and how to solve those problems, including when problem solving needs to be diagnosed remotely from the lab.”

CurrentMeters_Circa_1980-90s

Current meters instruments used from the 1970s to 1990s that measured current velocity and direction on a cassette tape that was transferred to a main frame computer.

In looking back to the mid-1980s, early on in Ron’s career, lake hydrology was one of the focuses of GLERL research. In a project to predict the fluctuating Great Lakes water levels, measurements were taken in real time of the flow rate (velocity) of the Detroit River. To accomplish this, Ron and his team deployed an Acoustic Doppler Current Profiler (ADCP) (left). Ron recounts one of his experiences using the ADCP: “During a strong wind event, the ADCP accurately measured a temporary river flow reversal that occurred throughout the water column. Up until that time, this had never been measured before. The event was observed to occur after a strong south wind pushed the water in Lake St. Clair to the north, making the level of the south end lower and then shifted to a strong east wind that pushed water into the western end of Lake Erie making the level of that lake higher. So until it could re-balance itself, the water level at the source of the Detroit River was lower than the water level at the mouth of the Detroit River, causing the river to flow upstream.  For about an hour the Detroit River was actually flowing north!”

Ron recognizes the importance of listening carefully to the scientists to make sure he understands what they are trying to learn about the Great Lakes in their research pursuits. In doing so, Ron is better able to configure the tools needed to monitor changes in the lakes to meet GLERL’s research goals and objectives. Frequently, this involves designing a new instrument or adapting an existing one designed for the ocean for freshwater use.

Ron compares the challenges in his work as a marine engineer to solving puzzles, as he expresses, “I am really inspired by the creative process of designing and putting together innovative monitoring tools that are efficient, reliable, economical, and functional in rugged conditions. Being reliable in the harsh environment of the Great Lakes is especially critical. If our desktop computer crashes, we can easily reboot it, but that’s not an option when the computer is located inside a buoy a few miles from shore on a stormy day.” Ron is also inspired by working as a team in MIL as he knows all too well, “no one person can do this type of work on their own— it takes a team effort, always.”

One important development that Ron has helped advance is NOAA GLERL’s Real-Time Environmental Coastal Observation Network (ReCON) buoys, expanding GLERL’s capacity to monitor the Great Lakes. In working with the MIL team, Ron helped build and maintain the ReCON network—a system of wireless Internet observation buoys positioned at coastal locations around the Great Lakes covering approximately 800 square miles. The system of buoys, powered by solar energy, collects meteorological (Met) data and also provides sub-surface measurements of chemical, biological, and physical conditions. ReCON buoys obtain on the water data in real-time that is accessible to the public and ensures the safety of user groups going out on the water, such as surfers, anglers and boaters, duck hunters, sailors, as well as researchers.  See slide show below for ReCON related images.

Muzzi on ReCON_-EMUTour-2013

Muzzi explains how the ReCON system is used to track meteorological conditions around the Great Lakes basin with real-time meteorological data, animations, and photographs available for each met station shown on the Great Lakes map above.  

Ron identifies one of the ongoing challenges in doing research on the Great Lakes is monitoring the five-lake system—massive in scope, covering  a surface area of 94,250 square miles with a volume of 5,439 cubic miles. While acknowledging this as a steep challenge, Ron discussed how newly developed technology, such as the Autonomous Unmanned Vehicles (AUVs), has increased GLERL’s capacity to monitor larger areas of the lakes more efficiently. GLERL also does more with cameras images and videos taken from aircrafts to increase monitoring capacity. Ron is optimistic that as robotics and imagery improves, we can continue to expand the scope of our research monitoring work.

Ron’s advice for young people interested in marine engineering harkens back to how he spent his childhood. “Young people need to experiment on their own, play around with science and technology kits, and get a good foundation in the basic sciences and mathematics. You may even consider exploring music.”  Ron plays the piano and organ as well as directing his church choir and strongly believes that his musical pursuits have transferred over to strengthening his engineering skills. “Designing requires a creative spirit which should be explored at a young age.” 

Lesson_Circuitry_Muzzi

Muzzi teaches a lesson to a group of elementary students visiting GLERL on electrical circuitry which included a group challenge exercise for our next generation of scientists/marine engineers.

Applyicaiton_Circuitry_Muzzi

In looking to the future of Great Lakes research, Ron believes that one of the most significant challenges we face is getting the research done with limited resources as well as keeping the focus to a manageable number of projects. He hopes that the pioneering spirit of GLERL’s scientists and engineers continues in the spirit of developing innovative instrumentation to monitor the Great Lakes. And as a society, we all must take responsibility in being good stewards of the lakes for generations to come.

This slideshow requires JavaScript.


Leave a comment

A message from the director: A global community convenes on the shores of Lake Geneva, France to share lessons learned on large lakes

I had the pleasure of attending the European Large Lakes Symposium (ELLS) – International Association of Great Lakes Research (IAGLR) 2018 international conference entitled “Big Lakes, Small World” during the week of September 23-28, 2018 in Evian, France on the shores of Lake Geneva.  

IMG_6688

The ELLS-IAGLR symposium drew scientists studying large lakes systems from around the world to the shores of Lake Geneva in Evian, France.

This symposium was notable for many reasons, including being the first IAGLR meeting held outside of North America, in conjunction with the 5th European Large Lakes Symposium. I was impressed with the strong Great Lakes presence at ELLS. In addition to myself and Philip Chu representing the NOAA Great Lakes Environmental Research Laboratory (GLERL), colleagues from the Cooperative Institute for Great Lakes Research (CIGLR)—Tom Johengen, Dmitry and Raisa Beletsky—also attended. There were also a number of our Laurentian Great Lakes partners from around the basin participating in the symposium.

Like French cuisine, the conference “menu” was jam-packed with scientific gourmet entrees, which we gorged on each day from 8:45 in the morning until after the poster session concluding at 7:00 each evening.  The conference was held in the historic Palais Lumiere (below), formerly a bathhouse, circa 1902, converted into a convention and cultural center in 2006—where better to hold a conference focused on water?

IMG_6698

The symposium was held at the historic Palais Lumiere  formerly a bathhouse, circa 1902, converted into a convention and cultural center in 2006.

Presentations featured an array of topics, including the chemical, physical, and biological aspects of lakes exotic as the Amazonian floodplain lakes and Russia’s Lake Peipsi, as well as those large lakes familiar to us, such as the Great Lakes, Lake Champlain, and Lake Tahoe. Common issues of concern raised during the symposium involved the dynamic changes caused by multiple stressors, namely, increasing temperature, human populations, invasive species, and harmful algal blooms. One observation that I’m excited to report is the number of times NOAA data, products, and services were referenced in talks—a telltale sign that scientists worldwide are relying on NOAA expertise. Items ranged from a Great Lakes sticker on monitoring equipment to the use of graphics like NOAA global surface temperature maps and GLERL food web charts (twice!).  I also spotted a quote pulled from our 5-year science review and even one from our venerable Craig Stow (see image below). I counted at least 18 presentations that cited a connection to NOAA.

As a Great Lakes stakeholder attending this international symposium, I would like to convey to our Great Lakes partners from around the region that we, as a community, can take pride and satisfaction that our daily work results in global impact on large lakes—small world!

IMG_6709

Michelle Selzer, Lake Coordinator with the Michigan Office of the Great Lakes, quotes GLERL’s Craig Stow on the topic of establishing phosphorus load targets in Lake Erie: “Going forward, our willingness and ability to monitor, evaluate, and update the targets will be more important than the original targets.”

IMG_0324

Philip Chu with Ph.D candidate Theo Baracchini and Dr. Shubham Krishna of Physics and Aquatic Systems Laboratory, Swiss Federal Institute of Technology.

IMG_0321

CIGLR scientist, Dmitry Beletsky, presents at ELLS on a CIGLR/GLERL research project to advance hypoxia forecasting.

 


Leave a comment

A message from the Director: Great Lakes research highlighted at the 2018 World Environmental and Water Resources Congress

cris-surbeck-sri-kamojjala-deborah-lee

(Left to right) Cristiane Surbeck, PE, D.WRE,  EWRI President (2018), Associate Professor, Department of Civil Engineering, University of Mississippi; Sridhar Kamojjala, PE, D.WRE, EWRI 2018 Conference Chair, Las Vegas Valley Water District; Deborah H. Lee, PE, D.WRE, Past President American Academy of Water Resources Engineers, NOAA GLERL Director

By Deborah H. Lee, Director, NOAA Great Lakes Environmental Research Laboratory

Recently, I had the opportunity to bring NOAA in the Great Lakes to the 2018 World Environmental and Water Resources Congress. The conference, held in Minneapolis the first week of June, brought together of several hundred civil engineers and members of the Environmental Water Resources Institute (EWRI). The Institute is the largest of the American Society of Civil Engineers’ 9 technical institutes, with about 20,000 members serving as the world’s premier community of practice for environmental and water-related issues.

As the invited keynote luncheon speaker, I presented, “Keeping the Great Lakes Great: Using Stewardship and Science to Accelerate Restoration.” In keeping with this year’s theme of “Protecting and Securing Water and the Environment for Future Generations,” my focus was NOAA’s science and restoration success stories, highlighting the many accomplishments of the Great Lakes Restoration Initiative.

I took the audience on a virtual tour of NOAA’s most exciting and innovative projects. Among those discussed were Areas of Concern, preventing and controlling invasive species, reducing nutrient runoff that contributes to harmful/ nuisance algal blooms, restoring habitat to protect native species, and generating ground-breaking science. 

I purposefully took a multimedia approach in reaching out to the EWRI community, recognizing that not all may be familiar with the Great Lakes and NOAA’s role in the region. To keep the audience engaged and entertained, several short videos were integrated throughout my talk, including the Telly award-winning “NOAA in the Great Lakes” and the short animation “How Great are the Great Lakes?” Three video clips on Great Lakes Restoration Initiative projects that highlighted the positive environmental and economic impacts of NOAA’s work were also incorporated.

Overall, I see my participation in this high profile conference as a great opportunity to raise awareness on the Great Lakes and NOAA’s mission, and was very pleased with the interest and enthusiastic response to my presentation. In looking ahead, I will be serving as EWRI’s next vice-president beginning this October and then sequentially as president-elect, president and past president in the following years. I look forward to continuing to work as steward for Great Lakes issues and advancing NOAA’s work in the region.


Leave a comment

Photo story: Taking a closer look at how invasive mussels are changing the Great Lakes food web

The invasion of zebra and quagga mussels in the Great Lakes is taking a toll on the ecosystem. To investigate these ecological changes, scientists from GLERL and the Cooperative Institute for Great Lakes Research (CIGLR) are doing experimentation on how quagga mussels affect the lower food web by filtering large amounts of phytoplankton out of the water.  Scientists are also investigating how mussel feeding and excretion of nutrients drive harmful algal blooms (HABs) in growth stimulation, extent, location, and toxicity.

The following experimental activities are being conducted under controlled conditions to look for changes in living and nonliving things in the water before and after quagga mussel feeding.

photo of small quagga mussels

Scientists are using quagga mussels captured from Lakes Michigan and Erie to understand how invasive mussels impact the lower food web. Prior to experimentation, the mussels are housed in cages where they graze on phytoplankton in water kept at the same temperature as the lakes. This helps acclimate them to natural lake conditions.

male and female scientists doing research at lab tables

The research team, led GLERL’s Hank Vanderploeg (front right), coordinates the different phases of the experiment. By filtering water before and after quagga mussel feeding, team members learn about the effect of these mussels on levels of phytoplankton (as measured by chlorophyll), nutrients (phosphorus and nitrogen), particulate matter, carbon, bacteria, and genetic material.

scientists pouring water into large buckets

CIGLR research associates, Glenn Carter and Paul Glyshaw, pour lake water into sample bottles for processing at different stages of the experiment.

female scientist pouring water into small container

GLERL’s, Joann Cavaletto, pours lake water from the graduated cylinder into the filter funnel. She is filtering for particulate phosphorus samples. She also measures total chlorophyll and fractionated chlorophyll based on 3 size fractions; >20 µm, between 20 µm and 2 µm, and between 2 µm and 0.7 µm.

male researcher using instrument next to computer screen

GLERL’s Dave Fanslow, operates the FluoroProbe displaying the level of pigments from different phytoplankton throughout the feeding experiment: pre-feeding of quagga mussel, progression of feeding on an hourly basis, and final measurements at the end of the experiment. The FluoroProbe measurements determine the concentration of pigments, such as chlorophyll, that quagga mussels filter out of the water throughout the experiment.

zoom in of computer screen showing lines and data

The FluoroProbe emits highly specific wavelengths of light using an LED array, which then trigger a fluorescence response in algae pigments and allow the immediate classification of green and blue green algae, cryptomonads, and diatoms.

male scientists filtering water

University of Michigan scientists, Vincent Denef (left and upper right, kneeling in bottom right) and Nikesh Dahal (standing in bottom right), filter water before and after quagga mussel feeding. They are looking at changes in the bacterial community based on the genetic composition of groups, focusing on the variability of toxic production in cyanobacteria in harmful algal blooms. Following the filtration phase of the experiment, they will conduct DNA and RNA sequencing for toxicity gene expression in the cyanobacteria.


3 Comments

Casting a high tech sampling net to learn more about the Great Lakes ecosystem

9.JPG

Researchers at GLERL are using a new tool, a MOCNESS, to study the Great Lakes.

In the Great Lakes, communities of plants and animals vary depending on where and when you look. They are dispersed up and down and all around in the water, making it tricky to collect them for research studies. To answer questions about these organisms and how they interact in the Great Lakes ecosystem, scientists from NOAA’s Great Lakes Environmental Research Laboratory (GLERL) and CIGLR (Cooperative Institute for Great Lakes Research) are using a new high tech sampling tool called a MOCNESS (Multiple Opening and Closing Net and Environmental Sensing System).

GLERL’s MOCNESS is the first of its kind to be used in a freshwater system. Scientists are hopeful that this technology will lead to new discoveries about the Great Lake ecosystem, such as where plankton (microscopic aquatic plants and animals) live and what causes their distributions to change over space and time. The MOCNESS will also help scientists learn more about predator-prey interactions that involve zooplankton (microscopic aquatic animals), phytoplankton (microscopic aquatic plants), and larval and juvenile fishes.

MOCNESS_FullScale

A closer look the MOCNESS (Multiple Opening and Closing Net and Environmental Sensing System)

Keeping track of changes in plant and animal communities in the Great Lakes over time is important, especially with changes in climate, the onslaught of invasive species, and land use practices causing increased nutrient runoff into the lakes.

The MOCNESS is a big improvement over the traditional single mesh sized sample collection nets. The sampling system provided by this new tool has a series of nets of different mesh sizes to collect different sized organisms (see a few examples in the gallery below). The operator can remotely open and close these nets, much like an accordion. At the heart of the system is a set of sensors that measure depth, temperature, oxygen, light levels, and the green pigment found in algae, Chlorophyll-a. Because this data can be viewed in real time on the vessel, the operator can better determine what is going on below the water surface and choose where and when to sample different sized organisms.

Here are some of the key questions that the scientists hope to answer using this advanced technology:

  • How do plankton and larval fish respond to environmental gradients (water temperature, dissolved oxygen, UV radiation) over the course of the day, season, and across years?
  • What are the major causes for changing distributions of the animals across space and over time (long-term, seasonal, 24-hour cycle)?
  • How do these changes in affect reproduction, survival, and growth of individuals and their communities?

The MOCNESS has been tested in the waters of lakes Michigan and Huron for the past three years. The team, led by Dr. Ed Rutherford, is supporting GLERL’s long term study of the Great Lakes food webs and fisheries. “The MOCNESS will enhance the ability of our scientists to more effectively observe the dynamics of Great Lakes ecosystem over space and time—a critical research investment that will pay off for years to come,” says Rutherford.

This year, the team is actively processing samples that were collected in the spring and will continue to collect more samples through the fall. The MOCNESS will support ongoing ecological research on the Great Lakes and the results will be shared with others around the region who are working to make decisions about how to manage Great Lakes fisheries and other water resources.

This slideshow requires JavaScript.


1 Comment

Leading the way toward solutions to flooding issues in Lake Champlain and Richelieu River System

A project update from GLERL Deputy Director, Jesse Feyen

GLERL has a long track record for modeling and predicting circulation and levels for our Great Lakes waters. Now we are working to apply this expertise in Lake Champlain, a large lake system that is shared with Canada. The lake lies along the New York/Vermont border and flows north into Quebec via the Richelieu River. In 2011, this lake-river system experienced significant precipitation and wind events that raised the levels of Lake Champlain to record levels and caused extensive flooding and damage around the lake and along the Richelieu River.

As a cross-border boundary water, management of the Lake Champlain/Richelieu River system is subject to the International Boundary Waters Treaty. In responding to a reference from the governments of the United States and Canada, the binational International Joint Commission (IJC) is conducting a study exploring the causes, impacts, risks, and solutions to flooding in the basin like during 2011.

The IJC has tapped GLERL to play a lead role in the study given our expertise in modeling the hydrology and hydrodynamics of the Great Lakes and experience working with Canadian partners. As a key expert in the IJC’s Upper Great Lakes Study and the Lake Ontario-St. Lawrence River Study, GLERL Director Deborah Lee was invited to serve as a U.S. member of the project’s Study Board, which provides the overall guidance and direction for the project. Deborah nominated Deputy Director Jesse Feyen to head up the U.S. portion of the study’s Hydraulics, Hydrology, and Mapping Technical Working Group, or HHM TWG.

A GLERL-led team of research partners is building solutions to these flooding issues in Lake Champlain and Richelieu River System. In addition to Lee and Feyen, team members include Integrated Physical and Ecological Modeling and Forecasting (IPEMF) Philip Chu, Drew Gronewold, and Eric Anderson; Cooperative Institute for Great Lakes Research (CIGLR) Dima Beletsky, Haoguo Hu, and Andy Xiao, with support from Lacey Mason; and the Northeast River Forecast Center’s Bill Saunders.

The two priorities of the study are to determine what flood mitigation measures can be implemented in the basin, and to create new flood forecast tools for the system. Current flood models operated by the National Weather Service (NWS) cannot account for the effects of winds and waves on Lake Champlain water levels, which can increase water level by several feet, significantly impacting flooding.

The modeling approach used in this study mirrors GLERL’s work in the Great Lakes. In Lake Champlain, a 3D FVCOM is being built to model water levels, temperature, and circulation; a WAVEWATCH III wave model will be coupled to FVCOM model to predict wave conditions; a WRF-Hydro (Weather Research and Forecasting) distributed hydrologic model will predict streamflow and runoff into the basin. This approach relies on models that are in use at NOAA and can readily be transferred to operations by the NWS and National Ocean Service, both of which have been participating in planning throughout the project.

While flooding issues in the Lake Champlain and Richelieu River system pose steep challenges on both sides of the border, GLERL brings the leadership, technical expertise as well as a “One NOAA” approach that are all essential for leveraging progress.


1 Comment

Sounds of the storm and coral reef recovery following Hurricanes Irma and Maria in Puerto Rico

By Dr. Doran Mason (NOAA Great Lakes Environmental Research Laboratory) and Felix Martinez (National Centers for Coastal Ocean Science)

2017-10-23-PHOTO-50

University of Puerto Rico grad students servicing a hydrophone at the Weinberg site at La Parguera Natural Reserve on the southwest coast of Puerto Rico.  Photo Credit:  Rebecca Becicka, Ph.D. student at University of Puerto Rico, Mayagüez

Researchers at NOAA’s Great Lakes Environmental Research Laboratory (GLERL) are exploring the use of sound to monitor and assess the health of coastal ecosystems, most recently focusing on the soundscape created by Hurricanes Irma and Maria in Puerto Rico. In collaboration with the University of Puerto Rico at Mayagüez, Purdue University (a partner university in the Cooperative Institute for Great Lakes Research consortium), and the National Centers for Coastal Science (NCCOS), GLERL has launched a pilot study on developing the long-term use of soundscape. To implement this new approach to monitoring, hydrophones, an instrument in measuring sound, are used to track the response of ecosystems to natural (e.g., tropical storms) and human-induced (e.g., stressors such as excess nutrients, sedimentation, fishing pressure, climate change) disturbances.

In this pilot project, hydrophones have been in place for six months at three sites (see below for Google Earth Map of Magueyes Island, La Parguera, Puerto Rico) at La Parguera Natural Reserve on the southwest coast of Puerto Rico prior to and during the two category 4 hurricanes that pummeled the island. Miraculously, the recorders and data survived the storms and were recovered, providing us with a unique opportunity to listen to the hurricanes and to evaluate how quickly reefs recover from a natural disaster.  

What is a soundscape?  Soundscapes are created by the aggregation of sounds produced by living organisms (invertebrates, fish, marine mammals), non-biological natural sounds (waves, rain, movement of the earth), and sounds produced by humans (boats, coastal roads). Changes in the biological portion of soundscape can provide us with the quantitative data to assess the health of the ecosystem in response to natural and human-induced disturbance.  Thus, our overall goal is to develop quantitative indices of coastal ecosystem health, based on the soundscape to assess the state of the environment, and to understand and predict changes, with application towards ecosystem restoration and conservation efforts. The utility of this approach is the use of a low-cost, remote autonomous technology that holds potential in expanding NOAA’s long-term observational capacity to monitor and assess coastal habitats.

Why GLERL?  As part of a long history of monitoring and research in the Great Lakes, GLERL scientists have cultivated a unique expertise in the development of autonomous remote sensing technology. In the last two decades, Purdue University (a CIGLR partner) has been one of the leaders in the development of terrestrial soundscapes as a critical tool to monitor ecosystem change. More recently, interest has grown in expanding this approach into the aquatic realm.  Building on our relationship with Purdue, GLERL and partners are well positioned to advance use of soundscape ecology to meet NOAA’s mission to protect, restore, and manage the use of coastal and ocean resources. In addition to the pilot study, GLERL is partnering with NCCOS to reach out to other NOAA Line Office programs in efforts to formalize the use of soundscapes within NOAA as a scientific program.  For example, efforts are underway to plan an international workshop to establish the foundational principles and identify research and technology gaps for the use of soundscape ecology.

Why Puerto Rico? Original support for this pilot study came from a congressional allocation for enhancing relationships with the cooperative institutes for the benefit of coral reef restoration and conservation. Given the scientific knowledge accrued from NCCOS’ prior investments in La Parguera, GLERL and its NCCOS partner recognized that Puerto Rico would be a prime location to test and develop the use of soundscapes technology to track and quantify the health of coastal ecosystems.

Google Earth Map-MagueyesIsland-PR

Google Earth Map of Magueyes Island, La Parguera, Puerto Rico showing coral reef locations where the hydrophones were deployed at different depths: Weinberg (shelf-edge) – 75′; Media Luna (mid-shelf) – 45′; Pelotas (inner-shelf) – 35′.  Provided by: Prof. Richard Appeldoorn, University of Puerto Rico, Mayagüez

IMG_3548

Colleagues from Purdue University and University of Puerto Rico deploy Media Luna reef site hydrophone for the first time.  Photo credit: Steve Ruberg, NOAA GLERL

IMG_3539

View of La Parguera from Media Luna reef site. Photo credit: Steve Ruberg, NOAA GLERL