Research - Guam EPSCoR

January 15, 2025January 16, 2025

UOG workshop reveals findings on tackling crown-of-thorns outbreaks

Dr. Ciemon Caballes, a senior research associate at the University of Guam's NSF EPSCoR and assistant professor at the UOG Marine Lab, presented findings from a study during the "Guam Crown-of-Thorns Starfish Outbreak Response Strategy" workshop in December at the UOG Marine Lab.

Insights into reproductive trends, predation patterns, and climatic triggers observed before a crown-of-thorns (COTS) outbreak are crucial for developing effective mitigation strategies to protect coral reefs, according to Ciemon Caballes, Ph.D., a senior research associate at the University of Guam’s NSF EPSCoR and assistant professor at the UOG Marine Lab.

Caballes shared his insights during the “Guam Crown-of-Thorns Starfish Outbreak Response Strategy” workshop in December at the UOG Marine Lab.

COTS are marine invertebrates known for their predation on corals. They can cause devastating impacts on coral reefs by depleting coral populations. They are found in reefs across the Indo-Pacific region.

Caballes’ research, supported by a grant from the National Fish and Wildlife Foundation, in collaboration with UOG’s NSF EPSCoR and Sea Grant, and other local and federal resource management agencies, focuses on understanding and mitigating these outbreaks.

“When we try to catch a serial predator, like the crown-of-thorns starfish, we need to build a profile,” Caballes said noting that understanding COTS and the trends leading to an outbreak is crucial for an effective mitigation strategy.

Caballes outlined several hypotheses regarding the formation of COTS outbreaks. The first suggests that outbreaks are a natural biological predisposition, given the species’ high fertilization rates.

According to Caballes, even a single mating pair can initiate a population surge. He said a female starfish could potentially produce over 100 million eggs in one spawning season while a male can produce around 50 billion sperm.

Surprisingly, he pointed out that, despite a male-skewed sex ratio, crown-of-thorns starfish maintain high fertilization rates, achieving up to 30% success even when separated by significant distances.

The second hypothesis links outbreaks to the overfishing of natural predators, leading to the release of COTS from predatory pressure and triggering a trophic cascade.

He also discussed the nutrient hypothesis, which posits that elevated nutrient levels from river runoff result in increased phytoplankton densities. Since phytoplankton provide a source of food for COTS larvae, the spike improves their survival and development rates. However, he also said recent findings indicate that excessive phytoplankton might lead to overfeeding, affecting larvae survival negatively.

Caballes also recalled several significant outbreaks, particularly one in 2009, and noted the possible influence of temperature and strong El Niño-Southern Oscillation (ENSO) events on COTS populations. He illustrated the correlation between high precipitation and river discharge events, such as those in 2003 and 2004, and subsequent COTS outbreaks in 2006 and 2007.

Caballes noted, “With back-to-back coral bleaching events compounded by COTS outbreaks, corals are struggling to recover.” He emphasized the need for effective management strategies to address these dual threats.

“This workshop is the culmination of our work since 2022. The project began in March of that year to assess the crown-of-thorns starfish populations around Guam and explore the feasibility of coral rehabilitation in these reef areas.” Caballes stated.

Caballes described their research efforts, which included testing various plots to determine if culling crown-of-thorns starfish would enhance the survival of transplanted corals.

Input from workshop participants have been integrated into the Guam COTS Outbreak Strategic Management Plan, which will be available to the public and distributed to all local and federal partners.

Fran Castro, associate director for operations and development at the UOG Center for Island Sustainability and Sea Grant, highlighted the significance of the project in addressing COTS. She described multi-agency efforts that involved training local agencies and coordinating monitoring efforts.

December 6, 2024December 6, 2024

Graduate research assistants continue to make impact

Grace McDermott displays coral samples at the Mote Marine Lab in Sarasota, Florida. Photo courtesy of Grace McDermott.

As the year 2024 reaches its end, four former Guam NSF EPSCoR Graduate Research Assistants (GRA) share where they are now, and how their time at the University of Guam helped them get there.

The Guam NSF EPSCoR Graduate Research Assistantship (GRA) is a 3-year program that allows graduate students with a Bachelor of Science in Biology or related studies the chance to fully immerse themselves in their fields. Within the program, GRA student researchers can engage in fieldwork and utilize various oceanographic research instruments to investigate coral reefs and further develop research for their theses.

Carlos Tramonte studied under Bastian Bentlage, PhD, from 2020 to 2023, focusing on coral species replacements on the island’s reef flats. More specifically, Tramonte spent much of his time investigating coral-associated Symbiodiniaceae and their response to environmental stressors. Currently residing in Oahu, Hawaii, Tramonte is in his second year of the University of Hawaii’s Institute of Marine Biology PhD program.

EPSCoR 241031 CarlosTramonte 2 — *Carlos Tramonte conducting coral reef field work in Oahu, Hawaii. Photo courtesy of Carlos Tramonte.*

“My time at UOG laid a lot of the groundwork for everything I do today. The skills I developed in project design, data analysis, and environmental science, along with my first real experience in Pacific reef ecosystems as a graduate student, have been essential”, says Tramonte. “UOG’s programs helped solidify my commitment to Pacific conservation and gave me the tools to pursue complex projects, such as this current research on reef biodiversity.”

Now an official member of the Guam NSF EPSCoR Biodepository team, Kelsie Ebeling-Whited, initially did research on the spawning of sixbar wrasse fish under project director Terry Donaldson, PhD from 2017 to 2020.

Regarding her academic stint in the EPSCoR Biodepository, Whited describes that it “helped me discover my interest in historical collections and museum work.” Her transition to a full-time role with the team allowed her to continue the work she started as a GRA student researcher.

Therese Miller also studied under Bentlage for her 2020-2023 GRA experience, in which she investigated bacterial communities living within staghorn coral, most specifically Acropora pulchra. She also studied communities of bacteria living in Porites cylindrica and Porites lobata as part of an Guam NSF EPSCoR-funded project, which included transplantation experiments and coral monitoring/sampling.

Miller now resides in Nelson, New Zealand and is working towards her PhD in Marine Science through the University of Auckland. Her current research involves following migration routes of two freshwater eel species native to New Zealand: Anguilla dieffenbachii and Anguilla australis schmidtii.

EPSCoR 241203 ThereseMiller — *Therese Miller (front middle) and her colleagues at sea in New Zealand. Photo courtesy of Therese Miller.*

Miller had just recently completed a five-week long research voyage in her and her peers collected seawater samples from Wellington to New Caledonia.

“I’m about to start lab-work with the samples I collected from my time at sea, and the molecular biology I learned at UOG has given me plenty of experience for the amount of work I am now expected to do,” Miller explains.

“I also learned other valuable skills during my master’s, such as how to conduct literature reviews, how to organize and prepare my samples, how to work on a team of other researchers, and what the structure of a research-based degree is like.”

Under the guidance of UOG Marine Lab Director Laurie Raymundo, PhD, Grace McDermott studied the phenotypic differences in coral during her GRA program ending in 2023. These days, she works as a biologist and laboratory manager at the Mote Marine Laboratory in Sarasota, Florida, while also preparing to apply for PhD programs.

EPSCoR 241118 GraceMcDermott 2 — *Grace McDermott poses for a selfie in the lab at Mote Marine Lab, Florida. Photo courtesy of Grace McDermott.*

“My time at the UOG Marine Lab helped me cultivate experience organizing and leading experiments in the field and in the lab testing the resilience of corals to stress,” McDermott details. “The accessibility of Guam’s coral reefs provided me with the opportunity to explore my interest in the impacts of future climate change scenarios on marine ecosystems.”

As the year 2024 reaches its end, four former Guam NSF EPSCoR graduate research assistants share where they are now, and how their time at the University of Guam helped them get there.

Now an official member of the Guam NSF EPSCoR Biorepository team, Kelsie Ebeling-Whited, initially did research on the spawning of sixbar wrasse fish under project director Terry Donaldson, PhD from 2017 to 2020.

Regarding her academic stint in the Guam NSF EPSCoR Biorepository, Whited describes that it “helped me discover my interest in historical collections and museum work.” Her transition to a full-time role with the team allowed her to continue the work she started as a GRA student researcher.

Miller had just recently completed a five-week long research voyage in her and her peers collected seawater samples from Wellington to New Caledonia.

Her current research includes running experiments to identify coral species candidates for Mote’s coral restoration and reproduction programs, as well as studying situ coral disease dynamics and novel antibiotic-free treatment efficacy.

“My time at the UOG Marine Lab helped me cultivate experience organizing and leading experiments in the field and in the lab testing the resilience of corals to stress,” McDermott details. “The accessibility of Guam’s coral reefs provided me with the opportunity to explore my interest in the impacts of future climate change scenarios on marine ecosystems.”

November 25, 2024January 15, 2025

UOG-hosted town hall explores ocean energy for aquaculture, island power-source

Bastian Bentlage, associate professor of Bioinformatics at the UOG Marine Lab and one of the leads from UOG, speaks at the November town hall meeting, 'Ocean Energy Systems to Power Guam Aquaculture.' Bentlage states that UOG'd primary role in the project is to provide insights into site-specific considerations for evaluating the feasibility of deploying ocean energy systems.

While ocean energy system technologies are still in the development stage, their potential as a renewable energy source is promising, according to a technical report from a study developed by a team from the University of Guam, Pacific Northwest National Laboratory (PNNL), and Sandia National Laboratory.

The findings presented at a November town hall meeting, “Ocean Energy Systems to Power Guam Aquaculture,” focused on utilizing ocean thermal energy conversion (OTEC) and wave energy conversion (WEC) technologies to power a proposed Guam Aquaculture Innovation Center and, potentially, as a renewable power source for Guam.

UOG hosted the town hall with the support of Guam NSF EPSCoR and the Center for Island Sustainability and Sea Grant, during which PNNL, the lead entity for the project, presented the findings and gathered feedback from community participants to inform future research.

Since the performance of OTEC and WEC systems is site-specific, they examined two potential locations for the proposed aquaculture center: Tanguisson on the west side of Guam and an area near the UOG Marine Lab on the east side, according to Bastian Bentlage, associate professor of Bioinformatics at the UOG Marine Lab.

“One of the questions we asked is what are the options for powering an aquaculture facility using renewable energy that harvest the power of waves or thermal gradients between surface and deep-sea waters,” Bentlage said.

Bentlage explained that UOG’s primary role in the project was to provide insights into site-specific considerations for evaluating the feasibility of deploying these ocean energy systems. He emphasized the importance of including team members familiar with Guam’s unique landscape and marine environments.

Bentlage and David Crisostomo, an aquaculture specialist with the UOG Sea Grant Program, are leading the research at UOG for this project.

Crisostomo described the proposed aquaculture center as a potential game-changer for Guam’s aquaculture industry. He stated that the center will serve as a research hub for cultivating local species. Additionally, it could provide a business incubator setup for individuals interested in entering the aquaculture industry.

At the town hall, the project leads presented the benefits as well as the infrastructure, environmental, and economic impacts of OTEC and WEC.

In her presentation, Fleur de Peralta, senior advisor with the Risk & Environmental Assessment Group at PNNL, highlighted the benefits and challenges of ocean energy systems for Guam. She stated that OTEC can provide baseload power, which helps stabilize the grid and supports black start capabilities. The ocean’s depth near Guam is ideal for the technology, and the consistently warm surface temperatures ensure an adequate temperature differential. Additionally, OTEC, once deployed, will create jobs in installation and maintenance, among others.

However, there are challenges to consider. For OTEC, further research is needed to assess water temperatures and depths accurately, and environmental protection requires additional study. The permitting process remains unclear among various agencies, and shore-based plants must be designed to withstand natural hazards.

Regarding WEC, de Peralta presented assessments by Sandia that indicate Guam possesses substantial wave resources. However, ensuring a reliable survival strategy for installations is essential, and deployment can be costly, necessitating a careful balance of cabling and mooring expenses with location choices.

De Peralta noted, “Outreach engagements with the Guam community and stakeholders is an important part of our project to gain insights on the use of marine energy systems as a clean energy power source and considerations on the potential impact on the island, environment, culture, and livelihood of the island’s communities.”

Peralta, who grew up in Guam, said that the information shared during the town hall discussions will inform further assessments and the development of ocean energy systems.”

Meanwhile, Charles Gunzel, a program manager at PNNL, also emphasized the importance of community feedback, which ocean energy system designers should consider.

“It’s extremely satisfying to engage with the residents of Guam, learning their unique concerns, so these can be made known to the planners, designers, and manufacturers of tomorrow’s ocean energy systems,” Gunzel said.

According to Bentlage, a significant outcome of this project is the strengthened partnership between UOG and the two National Laboratories that lead in renewable energy research and development.

“We intend to build on this relationship to enhance research capacity in this area, supporting informed decision-making as Guam works to diversify its economy and transition to renewable energy,” Bentlage stated.

The project commenced in early 2023 after receiving funding from the US Department of Energy Water Power Technologies Office (WPTO).

Charles Gunzel, a program manager at Pacific Northwest National Laboratory, highlights the importance of community feedback in designing and developing ocean energy systems. Gunzel participated in the "Ocean Energy Systems to Power Guam Aquaculture" town hall meeting in November.

At the “Ocean Energy Systems to Power Guam Aquaculture” town hall meeting in November, presenters shared findings on ocean energy systems from a technical report by the University of Guam, Pacific Northwest National Laboratory, and Sandia National Laboratory. The focus was on OTEC and WEC technologies to power the proposed Guam Aquaculture Innovation Center and support renewable energy efforts for Guam. They also gathered feedback from members of the community.

David Crisostomo, aquaculture specialist at UOG Sea Grant, describes the proposed aquaculture center as a potential game-changer for Guam’s aquaculture industry at the November town hall meeting, "Ocean Energy Systems to Power Guam Aquaculture."

Fleur de Peralta, senior advisor with the Risk & Environmental Assessment Group at the Pacific Northwest National Laboratory, presents the benefits and challenges of ocean energy systems for Guam. De Peralta is one of the presenters at the “Ocean Energy Systems to Power Guam Aquaculture” town hall meeting in November.

October 31, 2024December 6, 2024

Dr. Terry Donaldson: From cold Lake Michigan to sunny Guam

Everyone knows that Terry Donaldson, PhD, is the principal investigator and project director of Guam NSF EPSCoR, but not everyone is aware of his journey as an ichthyologist. When did this interest in marine biology begin?

For Donaldson, it began as a child growing up by the cold lakes of Michigan and following the adventures of Jacques Cousteau through books and television series. It was no surprise that he developed an admiration for fish, having spent a great deal of his childhood snorkeling to find them or catching them with his grandfather.

Donaldson earned his doctorate in Ichthyology which led to him studying various species around the world including New Zealand, Japan, French Polynesia, the Solomon Islands and Guam, where he has been serving the University of Guam’s Marine Lab for over many years.

“Fish can be really beautiful to look at,” said Donaldson, noting that he can enjoy just watching and observing the sea creatures, from physical characteristics to their behaviors. Astounded by the sheer diversity – thousands of species, that we know of – he finds fulfillment in the discovery of new species as well as new observations on existing ones.

One of his most recent publications details the communication behaviors of squirrelfish, which reflects his interest in bio acoustics that stems from undergraduate studies at Michigan State University.

The paper, titled “Production of sounds by squirrelfish during symbiotic relationships with cleaner wrasses,” observes nine species of Holocentridae (squirrelfish) and how they use acoustic signals to communicate in their interactions with cleaner wrasses.

Throughout this life-long journey in Ichthyology and marine biology, Donaldson has also ended up in several leadership positions including principal investigator and project director of Guam NSF ESPCOR and the former head of UOG’s Marine Laboratory.

Most recently, he was elected as President of the National Association of Marine Laboratories in January of this year.

With decades of experience in research and leadership, he subscribes to the belief that learning is a lifelong endeavor.

“Every day I come through the door and I learn something new. Often people in this building teach me or just (through) interacting with other people, I learn something new,” he said nothing that Guam NSF EPSCoR’s successes are not just from his leadership but because he has a talented team working with him.

“Don’t be afraid to get your feet wet!” Donaldson said, offering a piece of advice to those just starting their careers.

He believes in the importance of trying new activities and cultivating interests that can be useful years down the line. This belief has certainly proven true for this scientist, whose love for marine animals started well before his own career took off.

October 29, 2024November 8, 2024

Bioblitz survey finds false spider crab in Guam

Among over a thousand species that were found during the University of Guam’s first Bioblitz is the Elamena castanea, a type of false spider crab.

While the Elamena castanea superficially looks like one, this species is not actually a spider crab and belongs to the Hymenosomatoidea superfamily which means they aren’t even related to true spider crabs.

Originally discovered in the Philippines, this is the first time that the species has been observed here in Guam even though the area has been sampled numerous times through the decades.

Since this discovery, several more crab specimens have been found on the reef flat behind the UOG Marine Lab.

“It shows you how much diversity there is out there,” said Robert Lasley, PhD, UOG Biorepository crustacea curator. “Elamena castanea specimens were collected under rocks or in seaweed in shallow depths – usually less than 1-2 meters.”

Lasley notes that even after the three-week biological survey, there are still hundreds, possibly even thousands, of marine species that remain undocumented in the waters off Guam.

“Honestly, though, we find new records all the time, often without noticing it,” he said. “It takes a lot of work at the microscope and digging through literature to confirm if something is a new species or new record.”

Along with the Elamena castanea, other findings included new records of different species of isopods, nudibranchs, nemerteans, gobies, and shrimps.

It has been estimated that between 10 to 15 percent of the specimens collected during the BioBlitz are either new records or entirely new species.

Since February, the Biorepository team has been developing and cataloging the specimens and uploading the specimen data to the Biorepository database.

Soon, they will be able to loan out specimens to researchers so that they can be further examined and new information can be reported.

The team is also planning future biological surveys with more targeted searches for specific organisms, using the information collected during this first Bioblitz.

In addition, they intend to organize surveys in other places throughout the region, such as Palau and the Marshall Islands.

Through these surveys, researchers will be able to learn more about what organisms call the vast ocean home, including the Elamena castanea, which will also help the community learn how to preserve and protect them.

October 26, 2024November 25, 2024

Collaborative study yields new research instrument

After a detour to Alabama following the 28th NSF EPSCoR National Conference in Nebraska, Bastian Bentlage, PhD, Associate Professor of Bioinformatics, brought home a newly developed scientific instrument to aid in coral research.

Bentlage, with accompanying graduate research assistant Nikko Galanto, made the journey out to the Dauphin Island Sea Lab, located on Alabama’s Gulf Coast. The lab has been developing the build and circuitry of a new scientific research instrument, as well as the computer models and programs needed to run it. This instrument measures the performance of a coral’s photosystem under heat stress using fluorescent light.

“If you shoot a blue light at a chloroplast, like let’s say an algal cell, not all of the energy from the light is actually seamlessly converted right into making sugars and by extension energy,” Bentlage explained. “So, you can actually measure the amount of fluorescence that is produced and by extension then can make some inferences about the underlying health of the chloroplast.”

With this new method, the researchers hope the instrument will help to identify corals that are most resilient to increasing sea surface temperatures so they may be prioritized for reef restoration.

This particular research project is conducted in collaboration with Kenneth Hoadley, Ph.D., from the University of Alabama and Mark Warner, Ph.D., from the University of Delaware, with Bentlage and Marine Lab director Laurie Raymundo, Ph.D., representing the University of Guam.

The connection stemmed from another proponent of the research project Victor Bonito, Ph.D., director of Fiji-based non-profit Reef Explore Fiji, Ltd. The universities first approached Bonito to write a grant to help expand their existing research. As a graduate of the UOG Marine Lab, it was through Bonito’s recommendation that the UOG Marine Lab be sought out for collaboration.

“It was really interesting for me to visit, to see a different approach to science,” Bentlage mentioned. “I’ve never really thought about, or didn’t know really where you would start to work with someone who was actually in that space where, ‘hey, we’re actually developing the technology to measure certain things.’”

The two universities plan to visit Guam next year to see what results the instrument has found, as well as to conduct their own research and experiments.

October 10, 2024October 11, 2024

Lasley ready to bring crab education to students on Guam in latest CHalan Deskubre

Crabs have always had a special place in Robert Lasley’s heart, and now he is sharing that love to help educate students on Guam.

As a part of the placed-based educational magazine CHalan Deskubre, which is supported by Guam NSF EPSCoR, Lasley has lent his “crab genius” so the children of the island may learn more about the crustaceans and what they do for our ecosystem.

According to CHalan Deskubre Editorial Coordinator Maria Louella Losinio, who also works on the EPSCoR Science Communication Team, Lasley’s gift for conveying science in an easily digestable way makes him a great fit for the magazine.

“The target audience for this magazine is school aged people from kinder through twelve grade and something we can all agree on is the intrigue they all share about animals around Guam,” said Losinio. “Dr. Lasley is able to bring information about the crabs to them in ways that they not only learn from, but are entertained by too.”

Lasley will be featured in the second issue of the magazine, which focuses on Sustainable Development Goal #14 – Life Below Water.

The issue is set to launch this month and will be available to students all around Guam.

September 10, 2024October 10, 2024

Coral research could have big implications for Guam’s future

Research by Reilly Kleven at the University of Guam (UOG) has revealed the remarkable growth potential of branching Lithophyllum coralline algae, a vital component of Guam’s coral reefs.

Kleven is a Graduate Research Assistant with the Guam National Science Foundation’s (NSF) Established Program to Stimulate Competitive Research (EPSCoR) at UOG.

Kleven’s research, conducted under the guidance of Tom Schils, Ph.D. of the UOG Marine Labratory, focused on quantifying the growth rates of these algae in various reef habitats around the island. By utilizing advanced 3D scanning techniques, Kleven was able to measure the growth of individual algae samples over an extended period.

“Nongeniculate coralline algae are one of the most abundant calcifiers on Guam’s reef. They provide a variety of ecosystem services for reef environments. They help build and stabilize reef framework by depositing calcium carbonate in the form of magnesium calcite skeletons,” explained Kleven. “They act as important binders, decreasing the likelihood of structural collapse by reinforcing caves and cavities. Their skeletons further contribute to the resilience and recovery potential of reefs, providing protection from disturbances such as bio erosion and tsunamis.”

One of the most significant findings of the study was the exceptional growth rates observed in Lithophyllum algae from Pago Bay, Guam. These algae demonstrated remarkable resilience, growing at a rate that far exceeded previous estimates for coralline algae in tropical regions.

Kleven’s research also highlighted the importance of environmental conditions on algal growth. While Pago Bay offered optimal conditions for Lithophyllum growth, factors such as nutrient levels, sediment output, and water temperature were found to significantly influence growth rates in other areas, such as Togcha Bay.

These findings have significant implications for understanding the resilience of Guam’s coral reefs and their ability to recover from disturbances. As climate change continues to threaten coral ecosystems, the growth potential of lLithophyllum algae offers hope for future reef conservation efforts.

“As coral bleaching events become more frequent and severe the significance of coralline algae increases. These algae are likely to play a crucial role in preserving tropical reef carbonate structures as environmental change continues,” added Kleven.

Kleven’s research marks a significant contribution to the field of marine biology and provides valuable insights into the complex dynamics of coral reef ecosystems at a time when many see the importance of the protection of our reefs.

July 24, 2024July 24, 2024

Guam NSF EPSCoR supports sustainable fisheries through fish maturity workshop

From May 28 to June 14, 2024, graduate students from the University of Guam as well as scientists from Saipan attended a workshop called Jungle Histology: Fish Gonad Analysis at the UOG Marine Laboratory to learn how to determine the sex and maturity of reef fishes.

“At the most basic level, one of the things that people seem to understand is that it’s a good idea not to catch a fish and eat it until it’s had the chance to reproduce,” said Ken Longenecker, Ph.D., an associate researcher at Bishop Museum and one of the workshop’s facilitators. “But we don’t know the size at which fish reach maturity for about 83 percent of exploited species worldwide.”

Histology is a discipline of biology that examines the microscopic anatomy of biological tissues. In the case of fish histology, the gonads of a specimen are extracted, processed, and then examined with a microscope.

“There are resources here I don’t have back home, so I look forward to learn what I can at these workshops and bring this knowledge back and teach the people there,” said Naomi Billimon, a student at the Northern Marianas college in Saipan and an intern at the CNMI Division of Fish and Wildlife.

From May 28 to June 14, 2024, graduate students from the University of Guam as well as scientists from Saipan attended a workshop called Jungle Histology: Fish Gonad Analysis at the UOG Marine Laboratory to learn how to determine the sex and maturity of reef fishes.

This workshop was the final segment of the two-part, weeklong Fish Life History Workshop series funded by Guam NSF EPSCoR to enhance regional research capacity within Micronesia and improve the management of fisheries within the Pacific.

Three visiting scientists from Hawai’i facilitated the session: Ken Longenecker, Ph.D., an associate researcher at Bishop Museum; Ross Langston, Ph.D., a professor of biology at Windward Community College; and Erik Franklin, Ph.D., an associate research professor at the Hawai’i Institute of Marine Biology at the University of Hawai’i at Manoa.

According to Longenecker, knowing whether a fish is mature is essential to the sustainability of fisheries.

“At the most basic level, one of the things that people seem to understand is that it’s a good idea not to catch a fish and eat it until it’s had the chance to reproduce,” said Longenecker. “But we don’t know the size at which fish reach maturity for about 83 percent of exploited species worldwide.”

Histology is a discipline of biology that examines the microscopic anatomy of biological tissues. In the case of fish histology, the gonads of a specimen are extracted, processed, and then examined with a microscope.

Typically, histological practices require working in a laboratory with specialized equipment, but according to Langston, the method of jungle histology is unique because its needs are minimal.

“We can do this work with just a few batteries, so we don’t need much in the way of infrastructure,” said Langston.

Bolstering regional research capacity
Workshops like this one are crucial in supporting communities within the Pacific who rely on their fisheries for sustenance.

“For a lot of places like Saipan and Guam and other areas in the Pacific, fish are the primary or even the only source of protein that some people have in their diets, so it’s extremely important that we are able to give them data so that they can confidently manage their harvest year after year without depleting their stocks,” said Franklin.

Improving regional research capacity allows scientists to answer questions so that they can serve the interests of their communities and even teach other researchers skills that they have learned.

“There are resources here I don’t have back home, so I look forward to learn what I can at these workshops and bring this knowledge back and teach the people there,” said Naomi Billimon, a student at the Northern Marianas college in Saipan and an intern with the CNMI Division of Fish and Wildlife.

July 24, 2024July 24, 2024

Guam NSF EPSCoR bolsters regional research capacity through fish ageing workshop

On Monday, May 21, 2024, University of Guam graduate students, members of the Guam Green Growth Conservation Corps, as well as visiting scientists from Saipan, Palau, and Hawai’i convened at the UOG Marine Laboratory to learn how to determine the age of fish.

To determine a fish’s age, scientists extract a bonelike structure called an otolith within its ear and count its growth rings.

“Otoliths grow throughout time just like a tree. If you cut one in half, you can count the rings that are being laid down every single year,” said Brett Taylor, Ph.D., the workshop facilitator and an assistant professor of fisheries ecology at UOG.

Many of the participants, such as Christina Muller-Karanassos, a researcher from the Palau International Coral Reef Center, had varying levels of experience regarding extracting, processing, and reading otoliths. “I hope I can use this information in the future because we want to collect life history information for more fish species,” said Muller-Karanassos. “Nobody where I work really does any fisheries work, so I hope I’ll be able to pass on the knowledge to some people there.”

On Monday, May 21, 2024, University of Guam graduate students, members of the Guam Green Growth Conservation Corps, as well as visiting scientists from Saipan, Palau, and Hawai’i convened at the UOG Marine Laboratory to learn how to determine the age of fish.

The fish ageing component was the first segment of the two-part, weeklong Fish Life History Workshop Series funded by Guam NSF EPSCoR to improve regional research capacity within Micronesia.

To determine the age of a fish, scientists extract a bonelike structure called an otolith from its ear and study its growth rings.

“Otoliths grow throughout time just like a tree. If you cut one in half, you can count the rings that are being laid down every single year,” said Brett Taylor, Ph.D., the workshop facilitator and an assistant professor of fisheries ecology at UOG. “In the hottest part of the year, these rings are growing the fastest, and in the coldest part of the year, they’re growing slower and creating a denser profile along the banded structures.”

According to Taylor, around 300 fish species are harvested in Guam. Knowing how to ascertain the age of a fish is vital to habitat conservation, fisheries management, and maintaining the perpetuation of local fishing practices and culture.

Many of the participants, such as Christina Muller-Karanassos, a researcher from the Palau International Coral Reef Center, had varying levels of experience regarding extracting, processing, and reading otoliths.

“I hope I can use this information in the future because we want to collect life history information for more fish species,” said Muller-Karanassos. “Nobody where I work really does any fisheries work, so I hope I’ll be able to pass on the knowledge to some people there.”

As part of the workshop, participants gained experience extracting otoliths from a variety of reef fish species at different life stages to hone their skills.

“The next part, which will be taught by our colleagues from Hawaii, will cover the histology of fish gonads. These workshops are putting together the two data pillars of life history information which are how old the fish are and what their maturity status is. When you put those two elements together, you can piece together the biology of the species,” said Taylor.