Study challenges estimates used to guide Atlantic menhaden fishing

Reanalysis of a historic tagging study could help managers better balance commercial harvests with the needs of coastal food webs

University of Miami Rosenstiel School of Marine, Atmospheric, and Earth Science

Facebook

XLinkedIn
MessageWhatsAppEmail

image: 

Atlantic menhaden (Brevoortia tyrannus) form large schools in the Atlantic Ocean and bay areas. Photo: NOAA Fisheries

view more 

Credit: NOAA Fisheries

Virginia Key, Fl. — Atlantic menhaden (Brevoortia tyrannus) supports a major commercial fishery along the U.S. East Coast and serves as essential prey for fishes, seabirds, and marine mammals, may be less able to sustain fishing pressure than some assessments suggest. A new study finds that a key estimate of deaths from natural causes was substantially overstated, potentially making the population appear more productive than its biology supports.

Led by Jerald Ault, professor emeritus at the University of Miami Rosenstiel School of Marine, Atmospheric, and Earth Science, with co-author Jiangang Luo, a scientist at the Rosenstiel School’s Cooperative Institute for Marine and Atmospheric Studies, the study revisits a landmark federal tagging experiment. The research, published in the journal Fisheries Research, examines how historical records and assumptions about tag recovery influence estimates used to guide fisheries management.

Why it matters

Managers rely on population assessments to determine how much fishing a species can sustain. A central input is natural mortality, the rate at which fish die from causes other than fishing. Setting that rate too high can underestimate fishing’s impact and overestimate the size of the breeding population, leading to overly optimistic harvest advice.

“Getting this number right matters for both the fishery and the coastal ecosystems that depend on menhaden,” said Ault. “If natural mortality is set too high, the population can appear able to support more fishing than its biology allows.”

The researchers estimated a natural mortality rate of 0.50 per year, less than half the 1.17 estimate reported in a 2019 reanalysis by Liljestrand et al., which was incorporated into the SEDAR 69 benchmark stock assessment by the Atlantic States Marine Fisheries Commission. The new result was also substantially below the corrected value of 0.92 adopted in a 2025 stock assessment update.

Ault and Luo returned to original records from a federal tagging program conducted from 1966 through 1971 along the Atlantic coast, from Massachusetts to Florida. The experiment involved more than 1 million tagged menhaden and more than 100,000 recovered tags.

Over approximately three years, they reconstructed two versions of the historical data, checked release and recovery counts, rebuilt fishing-effort records and examined how tags were detected at fish-processing plants.

“Our investigation identified discrepancies involving the numbers of released and recovered tagged fish, reconstruction of historical fishing effort, treatment of tag-detection efficiency at processing plants, and aspects of the statistical model,” said Ault.

A critical issue was the performance of magnets used to recover metal tags from harvested fish. Detection varied widely among plants and over time. After correcting the underlying records, the researchers found that accounting for this variation was the principal reason their mortality estimate differed from earlier analyses.

Models that allowed tag-detection efficiency to vary by location and month better matched the recovery records. Both reconstructed datasets produced natural mortality estimates near 0.50 per year. Additional computer simulations tested uncertainty in the assumptions, with the best-fitting results consistently supporting a similar value.

The estimate also aligned with earlier research and biological evidence showing that Atlantic menhaden historically lived at least 10 years.

The findings concern a historical estimate, rather than a newly observed change in survival. The authors recommend that future assessments evaluate natural mortality values centered at 0.50 per year while accounting for uncertainty. The study does not establish a new catch limit.

“If natural mortality is high, fishing appears to account for a smaller share of population change. If it is closer to 0.5, as this study and earlier historical estimates suggest, fishing may account for a larger share of the losses,” added Ault. “For a species that is both heavily harvested and ecologically central, that distinction matters not only to the menhaden fishery but to the many managed predators that rely on menhaden.”

The study titled “Investigation of Atlantic menhaden mortality rates” was published on September 16, 2026 in the journal Fisheries Research. The authors are Jerald S. Ault and Jiangang Luo of the University of Miami Rosenstiel School.

About the University of Miami and Rosenstiel School of Marine, Atmospheric and Earth Science

 The University of Miami is a private research university and academic health system with a distinct geographic capacity to connect institutions, individuals, and ideas across the hemisphere and around the world. The University’s vibrant academic community comprises 12 schools and colleges serving more than 19,000 undergraduate and graduate students in more than 180 majors and programs. Located within one of the most dynamic and multicultural cities in the world, the University is building new bridges across geographic, cultural, and intellectual borders, bringing a passion for scholarly excellence, a spirit of innovation, and a commitment to tackling the challenges facing our world. The University of Miami is a member of the prestigious Association of American Universities (AAU).

 Founded in 1943, the Rosenstiel School of Marine, Atmospheric, and Earth Science is one of the world’s premier research institutions in the continental United States. The School’s basic and applied research programs seek to improve understanding and prediction of Earth’s geological, oceanic, and atmospheric systems by focusing on four key pillars:

*Saving lives through better forecasting of extreme weather and seismic events. 

*Feeding the world by developing sustainable wild fisheries and aquaculture programs. 

*Unlocking ocean secrets through research on climate, weather, energy and medicine. 

*Preserving marine species, including endangered sharks and other fish, as well as protecting and restoring threatened coral reefs. www.earth.miami.edu.

 

---

Journal

Fisheries Research

DOI

10.1016/j.fishres.2026.107865

Method of Research

Data/statistical analysis

Subject of Research

Animals

Article Title

Investigation of Atlantic menhaden mortality rates

Article Publication Date

16-Sep-2026

 

The depths of the ocean aren’t immune to human debris

A survey of the never-before-seen sea floor of a submarine canyon found plastic and other waste, indicating that it is not as distant as it may seem

PLOS

Facebook

XLinkedInWeChatBlueskyMessageWhatsAppEmail

image: 

Examples of deep-sea litter found in the Mar del Plata Submarine Canyon. (A) Medium-sized plastic wrapper, 2,109 m. (B) Rubber boot, 2,598 m. (C) Food wrapper, 1,920 m. (D) Snack wrapper, 3,231 m. (E) Tissue paper wrapper, 3,814 m. (F) Sediment-filled plastic bag, 3,739 m. (G) Highly degraded plastic fragment, 3,709 m. (H) Nylon cord with a hook, 1,949 m. (I) White plastic cup and bag (arrows), 3,243 m. Scale bars: 10 cm. All images courtesy of Schmidt Ocean Institute/ ROV SuBastian (CC BY 4.0), expedition FKt250712.

view more 

Credit: Teso et al., 2026, PLOS One, CC-BY 4.0 (https://creativecommons.org/licenses/by/4.0/)

It’s no secret that plastic and other human trash are a problem for marine life, but our understanding has long focused on the ocean’s surface. Now, a more complete picture is coming into focus, revealing that even some of our planet’s greatest depths have become home to our debris. As described in a study published on September 16, 2026 in the open access journal PLOS One, an international team led by Dr. Daniel Lauretta of Argentina’s natural science museum surveyed the Mar Del Plata Submarine Canyon in the southwestern Atlantic, finding that our trash has accumulated in a part of the planet we typically consider pristine.

The ocean’s depths remain one of Earth’s greatest unknowns, but­ as the fish swims—or as the debris sinks—the sea floor is not all that distant. On average, our oceans are just a few miles deep, and thus, not so far from human influence. This study, which took place in summer of 2025, marked the first time scientists had taken images of the seafloor within the Mar Del Plata Submarine Canyon. They documented approximately 40 species that may be new to science but also some more familiar sights.

Across 10 of the 17 dives with a remotely operated submersible, the researchers saw 29 identifiably manmade objects. The vast majority were plastic, along with a few rubber items. They ranged from fishing gear to plastic bags and food wrappers and even a boot. Some were buried in the sediment, while others were trapped in rocks or still drifting. The researchers observed more litter inside the canyon compared to the surrounding area, suggesting the geography and currents funneled these items into the fissure.

Researchers observed some animals also interacted with the waste. Mobile creatures like crustaceans had transient interactions while more stationary creatures—like starfish  and corals—had attached to some debris, often partially subsumed plastic packaging and fishing ropes. Though life was present, the team cautioned that we can’t assume these objects are suitable habitats.

This is not the only time scientists have found traces of our trash so far below the surface. Just a few months before the expeditions in the Mar Del Plata Submarine Canyon, a plastic bag was found in the Mariana Trench, the planet’s deepest fissure. The sinking of organic material is essential to life beyond the reaches of sunlight, but this new study adds to emerging evidence that nutrients aren’t the only matter pulled to the ocean floor.

The authors add: "Unveiling a species previously unknown to science in the endless darkness of the deep sea may be one of the most extraordinary experiences a marine biologist can have."

 

 

Author interview: https://plos.io/4ys71Nz

In your coverage, please use this URL to provide access to the freely available article in PLOS One: https://plos.io/3UwaXhS

Citation: Teso V, Urteaga D, Bozzano G, Bigatti G, Brogger MI, Brusa F, et al. (2026) Out of sight, hidden into the deep: Marine litter in the Mar del Plata Submarine Canyon (southwestern Atlantic) revealed by ROV survey. PLoS One 21(9): e0357098. https://doi.org/10.1371/journal.pone.0357098

Author countries: Argentina, Ecuador, USA.

Funding: The oceanographic expedition FKt250712 was funded by the Schmidt Ocean Institute (SOI), the Nippon Foundation-Nekton Ocean Census Programme (https://oceancensus.org/), CORDAP Coral Accelerator Program under Award No. CAP-2023–1502, and the AZARA Foundation. Funding was also provided by PICT 2020-1169 (Agencia I+D+I), PICT 2020-1215 (Agencia I+D+I), PIBAA 2022-0410 (CONICET), PIBAA 2022-0433 (CONICET), PIP 2022-0277 (CONICET), and Fundación ProyectoSub. All funders have no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Faunal interactions with anthropogenic litter in the Mar del Plata Submarine Canyon (MPSC). (A) Degraded black plastic sheet, partially buried, with arthropods including Tetrachaelasma southwardi and an octocoral, 2,108 m. (B) Plastic bag with the asteroid Smilasterias sp., 3,243 m. (C) Fishing rope with tubicolous polychaetes, 2,054 m. (D) Nylon filament (probably fishing line) with Anthozoa polyp indet., 1,616 m. (E) White plastic container, partially buried, with the brittle star Ophioplinthus sp. and probable ascidian, 1,764 m. All images courtesy of Schmidt Ocean Institute/ ROV SuBastian (CC BY 4.0), expedition FKt250712.

Credit

Teso et al., 2026, PLOS One, CC-BY 4.0 (https://creativecommons.org/licenses/by/4.0/)

---

Journal

PLOS One

DOI

10.1371/journal.pone.0357098

Method of Research

Observational study

Subject of Research

People

Article Title

Out of sight, hidden into the deep: Marine litter in the Mar del Plata Submarine Canyon (southwestern Atlantic) revealed by ROV survey

Article Publication Date

16-Sep-2026

 

Harvesting hot electrons could break solar panel barrier

University of Groningen

Facebook

XLinkedInWeChatBlueskyMessageWhatsAppEmail

image: 

The visual abstract of the paper in ACS Energy Letters, showing how two synergetic effects create a delay in the loss of energy from hot electrons:

1) The Hot Phonon Bottleneck

2) Band-filling, resulting in the Burnstein-Moss effect

 

view more 

Credit: ACS Energy Letters

Physics predicts that no more than 33 percent of the solar energy that falls on a solar panel can be converted into electricity. However, experiments and simulations by scientists at the University of Groningen (the Netherlands) revealed a way to harvest extra energy from ‘hot electrons’, which could break this barrier.

When light falls on a solar panel, the energy of the photons brings electrons in the solar cell material into an excited state, thus transferring the energy to them. This reaction can free an electron from the solar cell material and create a voltage.

However, very energetic photons give the electrons extra energy, producing ‘hot electrons’. In theory, the extra energy these hot electrons carry could increase the voltage. In practice, the extra energy is lost as heat in a matter of picoseconds (0,000000000001 second). ‘This means that the energy is lost before the hot electron exits the solar cell material’, says Jan Anton Koster, Professor of Physics of Novel Semiconductors and Devices at the University of Groningen.

Scepticism about the claims

However, in an experimental setup, his colleague Maria Antonietta Loi, professor of Photophysics and Optoelectronics, managed to produce a delay in heat loss by hot electrons. She created a solar cell material called tin-based perovskite, and observed that the loss of extra energy is slowed down to nanoseconds, roughly a factor of 1,000. ‘The measurements were clear, but we didn’t understand the physics behind this’, says Koster. This led others in the field to question this claim. ‘We even started to doubt the measurements ourselves’, he admits.

In order to solve this conundrum, Koster and his PhD student Tim Faber used simulations to study the physics of this energy loss. They found that in perovskite solar cells, two different mechanisms combine to extend the time it takes hot electrons to lose the extra energy.

Nanosecond range

When energy is lost as heat, the environment surrounding the electrons will become warmer. Koster and Faber realised that this lingering heat can be reabsorbed by the electrons. ‘When we added this well-known process called Hot Phonon Bottleneck to the simulations, it slowed the loss of energy, but not enough to explain our measurements.’ This required adding a second mechanism to the simulation.

The extra energy of hot electrons can bring them into a number of excited states. Energy loss means that the excited state is reduced to a lower energy level in discrete steps. However, when the different steps in this process are already occupied, the way down to the lowest energy level is more difficult and takes more time. This is called the Burstein-Moss effect. Koster: ‘When we added this process to the simulation as well, we saw that energy loss was now in the nanosecond range, as seen in the experiments by Maria Loi.’

As both of these processes are present in tin-based perovskite solar cells, Koster and his team finally understood why the energy loss of hot electrons was slowed down. There are many other questions that still need answers, but in theory, this discovery could allow the creation of more efficient solar cells, beyond the theoretical limit of 33 percent.

Reference: Tim Faber et al.: The Physics of Ultra-Long Cooling Times in Metal Halide Perovskites. ACS Energy Letters, 11 September 2026.

---

Journal

ACS Energy Letters

DOI

10.1021/acsenergylett.6c00547

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

The Physics of Ultra-Long Cooling Times in Metal Halide Perovskites

Article Publication Date

17-Aug-2026

 

Conserving just 35% of U.S. waterways could sustain freshwater biodiversity

Study evaluated resilience and protected status of rivers and streams across the contiguous US

PLOS

Facebook

XLinkedInWeChatBlueskyMessageWhatsAppEmail

image: 

The Ashuelot River in New Hampshire drains over 400 square miles of mostly forest and forested wetlands before meeting the Connecticut River.

view more 

Credit: Jerry Monkman/ Ecophotography, CC-BY 4.0 (https://creativecommons.org/licenses/by/4.0/)

By evaluating the health of waterways across the US, researchers have identified about one-third of rivers and streams that, if conserved and restored, could sustain the nation’s freshwater biodiversity in the face of habitat degradation and climate change. Mark Anderson of the Nature Conservancy, US, led the new study, published September 16, 2026, in the open access journal PLOS One.

During the past century, streams and lakes in the US have deteriorated, as more than 150,000 dams have fragmented river networks, and changes to the landscape and groundwater usage have altered how and where the water flows. Many freshwater species are now in rapid decline, exacerbated by the impacts of climate change.

To address this crisis, The Nature Conservancy worked with 66 freshwater con­servationists to map out freshwater networks in the contiguous US and evaluate their resilience to degradation. Each watershed was scored based on its connectivity, condition, water availability and naturalness of flow, and checked against local surveys of freshwater biodiversity. They put together a patchwork of rivers and streams – named the Freshwater Resilient and Connected Network – that covers 35% of the lower 48 states but could preserve our freshwater biodiversity. Conserving this network will be challenging, however, as currently, only 6% of the area is both protected and resilient, and 14% needs both protection and restoration.

The analysis also showed that of the 5.2 million miles of rivers and streams in the contiguous US, 33% rated as above-average for resilience. While rivers that are above average should continue to support similar patterns of biodiversity in the future, those just above average may still require restoration. These networks are concentrated in the Pacific Coast, the Northern Rocky Mountains, Great Lake areas in Wisconsin and Minnesota, Northern Maine and coastal regions along the southeastern US and the Gulf of Mexico. Vulnerable or below-average river networks made up 15% of those miles and were concentrated in the Southwest deserts, lower New England, the shortgrass prairie east of the Rocky Mountains and the agricultural lands of the midwestern states.

The study provides a solid foundation for conservation efforts to sustain biodiversity in freshwater systems and provides a clear picture of the challenges ahead. Researchers said the analysis has already been used to identify dams for removal, prioritize land protection in key headwaters and improve conditions in river systems that need restoration. The team acknowledges the maps do not take into account human needs, but data representing human dimensions could be combined with this analysis to identify them.

The authors add: “Resilience to climate changes adds important context to our efforts to conserve freshwater biodiversity. We hope our study will help our state, federal, Tribal and other conservation partners make investments where they have the greatest chance to succeed into the future.”

 

 

In your coverage, please use this URL to provide access to the freely available article in PLOS One: https://plos.io/4Ae7W6j

Citation: Anderson MG, Olivero AP, Barnett AR, Khoury ML, Martin EH (2026) A freshwater resilient and connected network to sustain biodiversity under a changing climate. PLoS One 21(9): e0351782. https://doi.org/10.1371/journal.pone.0351782

Author countries: USA.

Funding: Anonymous Donor, Volgenau Foundation, Kia America, and Enterprise Mobility Fund. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

The Lower Pecos River is fed by a regional aquifer sustaining a unique and biodiverse ecosystem and critical inflows to the lower Rio Grande basin.

Credit

Ryan Smith, CC-BY 4.0 (https://creativecommons.org/licenses/by/4.0/)

Components and results of the analysis. A. Climatic Regions, B. Freshwater Resilience, C. Freshwater Recognized Biodiversity Value. D. Freshwater Opportunity Map. D. Freshwater Conservation Status. F. FRCN Conservation Status. G. Freshwater Resilient and Connected Network (FRCN). These maps were created with ArcGIS Pro 3.5.2 (ESRI, Redlands, CA). Hillshade used in Figures A-F from World Hillshade (Sources: Esri, Airbus DS, USGS, NGA, NASA, CGIAR, N Robinson, NCEAS, NLS, OS, NMA, Geodatastyrelsen, Rijkswaterstaat, GSA, Geoland, FEMA, Intermap, and the GIS User Community) [75]. Hillshade used in Figure G from Herwig G. Schutzler, 1965, Shaded Relief Archive, https://shadedreliefarchive.com/usa-schutzler.html. 

Credit

Anderson et al., 2026, PLOS One, CC-BY 4.0 (https://creativecommons.org/licenses/by/4.0/)

---

Journal

PLOS One

DOI

10.1371/journal.pone.0351782

Method of Research

Observational study

Article Title

A freshwater resilient and connected network to sustain biodiversity under a changing climate

Article Publication Date

16-Sep-2026