Still standing but mostly dead: Recovery of dying coral reef in Moorea stalls

Dead branches of Pocillopora coral on the outer reef of Moorea were killed by bleaching in 2019. The dead branches are coated in algae and the broken ends expose the hollow interior that is described in a new study.
Photo Credit: Kathryn Scafidi

Scientific Frontline: "At a Glance" Summary: Coral Reef Recovery Stalls in Moorea

• Main Discovery: Dead coral branches in Moorea are being hollowed out internally by marine organisms like mussels and fungi, while their exteriors are simultaneously fortified by encrusting algae, creating durable but dead structures that prevent new coral from growing.
• Methodology: Researchers collected long-term ecological field data via scuba surveys and utilized high-resolution microscopy to analyze the structural integrity, porosity, and biological composition of the intact but hollowed-out coral skeletons.
• Key Data: A 2019 marine heat wave triggered a severe bleaching event that reduced live coral coverage on the affected Moorea reef from approximately 75% to less than 17% within a single year.
• Significance: The unprecedented structural stabilization of dead coral by the alga Lobophora variegata disrupts the natural cycle of reef regeneration, as the enduring skeletons fail to break away and thereby occupy the essential physical space required for juvenile corals to settle and recolonize.
• Future Application: These findings will refine predictive ecological models regarding coral reef degradation and inform targeted marine intervention strategies to facilitate reef recovery in environments facing chronic warming and acute marine heat waves.
• Branch of Science: Marine Biology, Earth Science, and Environmental Ecology.
• Additional Detail: The structural integrity provided by the encrusting algae allowed the dead coral skeletons to successfully withstand a 2024 tropical storm that would have typically cleared the debris to make room for new growth.

Understanding how “marine snow” acts as a carbon sink

Hitchhiking bacteria dissolve essential ballast in “marine snow” particles, which could counteract the ocean’s ability to sequester carbon, according to a new study.
Photo Credit: MIT News; iStock
(CC BY-NC-ND 3.0)

Scientific Frontline: Extended "At a Glance" Summary: Marine Snow and Carbon Sequestration

The Core Concept: Marine snow is a continuous shower of organic dust and detritus that falls from the upper layers of the ocean to the seafloor, acting as a vital "biological pump" that transports and stores atmospheric carbon in the deep ocean.

Key Distinction/Mechanism: While it was previously assumed that the calcium carbonate ballast weighing down marine snow remained intact until reaching profound depths, recent findings reveal a microscale disruption. Bacteria hitchhiking on these sinking particles consume organic material and excrete acidic waste, which dissolves the calcium carbonate ballast, slowing the particles' descent and prematurely releasing carbon dioxide back into the shallow ocean.

Major Frameworks/Components: 

• The Biological Pump: The overarching macroscale process by which phytoplankton absorb atmospheric carbon dioxide and convert it into sinking organic matter and calcium carbonate.
• Microbial Dissolution Feedback: The microscale localized chemical reaction where bacterial metabolic waste creates an acidic environment that erodes inorganic calcium carbonate.
• Sinking "Sweet Spot" Dynamics: A hydrodynamic framework demonstrating that dissolution peaks at intermediate sinking speeds, where bacteria remain sufficiently oxygenated but their acidic waste is not flushed away too rapidly by surrounding currents.
  

New study finds deep ocean microbes already prepared to tackle climate change

A research group co-led by the University of Illinois Urbana-Champaign predicts that a surprisingly adaptable species of marine archaea will play an important role in reshaping biodiversity in the planet’s oceans as the climate changes.
Photo Credit: Fred Zwicky

Scientific Frontline: Extended "At a Glance" Summary: Deep Ocean Ammonia-Oxidizing Archaea

The Core Concept: Nitrosopumilus maritimus is a highly adaptable species of marine archaea that accounts for approximately 30% of the marine microbial plankton population and plays a vital role in regulating the ocean's biological and chemical balance amid climate change.

Key Distinction/Mechanism: While it was previously thought that deep-ocean environments (1,000 meters or deeper) were insulated from surface warming, these iron-dependent microbes actively adapt to rising temperatures and decreased nutrient availability by lowering their iron requirements and significantly increasing their physiological iron-use efficiency.

Major Frameworks/Components: 

• Ammonia Oxidation: The metabolic process by which these archaea alter the forms of nitrogen available in seawater.
• Nutrient Cycling: The biogeochemical mechanism through which microbes control nitrogen and trace metal availability to sustain primary production.
• Iron-Use Efficiency: The physiological adaptation allowing marine microbes to survive and maintain chemical reactions under high-temperature and low-iron stress.
• Global Ocean Biogeochemical Modeling: The computational framework used to project how deep-ocean archaeal communities will maintain their ecological roles across iron-limited regions.

What Is: Abyssopelagic Zone

A master of abyssopelagic survival, the anglerfish overcomes absolute darkness and sparse food supplies with a specialized, light-producing appendage designed to mimic prey.
Image Credit: Scientific Frontline

Scientific Frontline: Extended "At a Glance" Summary: Abyssopelagic Zone

The Core Concept: The abyssopelagic zone, derived from the Ancient Greek word for "bottomless," is a massive deep-water layer of the pelagic ocean located between 4,000 and 6,000 meters (approximately 13,100 to 19,700 feet) below the sea surface. Covering approximately 83 percent of the total global ocean area, it constitutes the largest single continuous ecosystem on Earth, characterized by near-freezing temperatures, extreme hydrostatic pressures, and the total absence of sunlight.

Key Distinction/Mechanism: Unlike sunlit upper ocean layers, the abyssopelagic zone is completely devoid of solar radiation and autotrophic photosynthesis. Instead, its ecosystem and metabolic processes rely entirely on the downwelling of cold, oxygenated surface waters via global circulation patterns, and the influx of sinking particulate organic carbon (known as "marine snow") falling from the euphotic zone above.

Origin/History: During the foundational oceanographic voyages of the HMS Challenger in the late 19th century, this region was historically conceptualized as a dark, static, and barren wasteland. Modern deep-sea research and long-term sensor mooring have fundamentally reclassified the abyss as an extraordinarily complex, highly dynamic biome.

50 years after whaling, behavioural effects linger

A breaching humpback whale.
Photo Credit: Mike Doherty

Scientific Frontline: "At a Glance" Summary: Behavioral Effects of Whaling on Humpback Whales

• Main Discovery: Female humpback whales in Oceania continue to show significant shifts in mate selection patterns 50 years after commercial whaling severely reduced their population size.
• Methodology: Researchers analyzed epigenetic data from 485 male humpback whales during long-term monitoring at a breeding ground in New Caledonia between 2000 and 2018.
• Key Data: The Oceanic humpback population was reduced to fewer than 200 individuals in the 1970s, causing a severe demographic bottleneck.
• Significance: The findings reveal that as the population recovers and ages, females are increasingly selecting older males for breeding, a shift from the immediate post-whaling period when younger males bred more frequently to maintain genetic diversity.
• Future Application: The data emphasizes the necessity for continuous, long-term monitoring of previously exploited marine populations to accurately manage their ongoing recovery and understand shifting behavioral dynamics.
• Branch of Science: Marine Biology, Behavioral Ecology, and Epigenetics.

Smaller fish and changing food webs – even where species numbers stay the same

"Beyond the Numbers"
The hidden transition from ecosystems ruled by apex predators to those crowded by smaller, mid-level feeders.
Image Credit: Scientific Frontline

Scientific Frontline: Extended "At a Glance" Summary: Reorganization of Global Fish Food Webs

The Core Concept: Long-term global data indicates a widespread restructuring of marine and freshwater fish food webs, characterized by a shift toward smaller-bodied species and altered feeding relationships, even in ecosystems where overall species richness remains stable.

Key Distinction/Mechanism: Unlike traditional biodiversity metrics that rely primarily on species counts (richness), this ecological shift highlights underlying structural changes. Because the size of predators and prey governs feeding rules, the decline of large top predators and the rise of mid-level, generalist feeders create denser, more highly connected food webs. Ecosystem degradation is occurring via shifting biological traits and interactions rather than direct species loss.

Origin/History: The phenomenon was detailed in a massive global synthesis led by researchers from the German Centre for Integrative Biodiversity Research (iDiv), Martin Luther University Halle-Wittenberg (MLU), and Friedrich Schiller University Jena. By analyzing time-series data spanning up to 70 years across nearly 15,000 fish communities, the research team formally published their findings in Science Advances on February 24, 2026.

Marine Plastic Pollution Alters Octopus Predator-Prey Encounters

Madelyn A. Hair returns an octopus to its capture site after participating in the study.
Photo Credit: Courtesy of Florida Atlantic University

Scientific Frontline: Extended "At a Glance" Summary: Marine Plastic Pollution and Predator-Prey Dynamics

The Core Concept: Marine plastic pollution leaches bioactive chemicals, such as the industrial lubricant oleamide, into the ocean, mimicking natural biological signals and fundamentally altering the behaviors and interactions of marine predators, like octopuses, and their prey.

Key Distinction/Mechanism: While traditional plastic pollution impact focuses on physical hazards like ingestion and entanglement, this phenomenon highlights chemical sensory disruption. Oleamide acts as a sensory decoy; it causes crustacean prey to mistake the chemical for natural foraging cues (such as oleic acid), leading them to abandon predator-avoidance behaviors. Simultaneously, it confuses the waterborne and contact chemosensory abilities of octopuses, resulting in increased exploratory grasping but fewer successful hunts.

Major Frameworks/Components:

• Chemical Mimicry: Oleamide, widely used in polyethylene and polypropylene plastics, leaks into the water as the plastic degrades and actively mimics natural marine pheromones and scavenging cues.
• Behavioral Tracking: Researchers analyzed over 31,500 observations of the common South Florida octopus (Octopus vulgaris) and its native prey (hermit crabs, free-living crabs, snails, and clams) to quantify shifts in prey preference and proximity.
• Interaction Dynamics: The study differentiated between consumptive (successful predation) and non-consumptive (failed attempts and brief grasps) encounters, noting a significant spike in non-consumptive interactions during chemical exposure.
• Lingering Ecotoxicity: The observed behavioral disruptions—including altered prey choice and reduced caution in prey—persisted for at least three days after the chemical was removed from the environment.

Twilight fish study reveals unique hybrid eye cells

Two pearlside species that have hybrid photoreceptors in their eyes as larvae and adults, Maurolicus muelleri  and Maurolicus mucronatus.
Photo credit: Dr Wen-Sung Chung

Scientific Frontline: Extended "At a Glance" Summary

The Core Concept: A newly discovered type of visual cell found in deep-sea fish larvae that challenges the traditional biological dichotomy of rod and cone photoreceptors. These cells are specifically adapted to optimize vision in "twilight" or gloom-light conditions found at intermediate ocean depths.

Key Distinction/Mechanism: While vertebrate vision is historically categorized into cones (for bright light) and rods (for dim light), this hybrid cell functions as a bridge between the two. It uniquely combines the molecular machinery and genetic profile of cones with the physical shape and form of rods to maximize efficiency in half-light environments.

Origin/History: The discovery was announced in February 2026 by researchers at The University of Queensland, following marine exploration voyages in the Red Sea. The findings overturn approximately 150 years of established scientific consensus regarding vertebrate visual systems.

Major Frameworks/Components:

• Hybrid Morphology: Cells exhibiting the structural rod shape for sensitivity but utilizing cone-specific genes for processing.
• Developmental Adaptation: Found in larvae inhabiting depths of 20 to 200 meters, serving as a transitional visual system before the fish descend to deep-sea habitats (up to 1km) as adults.
• Twilight Optimization: A specialized biological design for low-light environments that balances sensitivity and detection better than standard rods or cones alone.

Tiny marine animal reveals bacterial origin of animal defence mechanisms

Glass plates to catch the model organism Trichoplax in its natural habitat, warm coastal waters. Scientists at Kiel University use the tiny placozoan for evolutionary research.
Photo Credit: © Harald Gruber-Vodicka, Kiel University

Scientific Frontline: "At a Glance" Summary

• Main Discovery: The simple marine animal Trichoplax utilizes an ancient, bacteria-derived lysozyme for acidic extracellular digestion, proving that essential animal immune mechanisms evolved from early digestive processes.
• Methodology: Scientists characterized the enzyme in Trichoplax sp. H2 using proteomics and Western blotting, monitored in situ pH levels with fluorescence reporters, and reconstructed the enzyme's evolutionary history via structure-based phylogenetics.
• Key Data: The research identified a glycoside hydrolase family 23 (GH23) lysozyme that exhibits peak activity at pH 5.0, precisely matching the acidic environment generated within the animal's temporary feeding grooves during nutrient uptake.
• Significance: This study provides the first evidence that metazoan GH23 lysozymes originated from a horizontal gene transfer event from bacteria to a pre-bilaterian ancestor, functioning simultaneously in nutrition and pathogen defense.
• Future Application: Elucidating these ancient dual-use mechanisms clarifies the evolutionary trajectory of the innate immune system and may inform the development of bio-inspired antimicrobial agents.
• Branch of Science: Evolutionary Biology, Immunology, and Marine Biology
• Additional Detail: The lysozyme features a unique N-terminal cysteine-rich domain that stabilizes the protein during transport but is cleaved off to maximize enzymatic potency at the site of action.

Deep-sea Microbes Get Unexpected Energy Boost

New discovery overturns long held assumptions that the deep ocean is a “nutrient desert”, reshapes our understanding of the ocean’s carbon cycle
Image Credit: Scientific Frontline

Scientific Frontline: "At a Glance" Summary

• Main Discovery: Intense hydrostatic pressure at ocean depths of 2–6 kilometers causes sinking "marine snow" particles to leak substantial amounts of dissolved organic carbon and nitrogen, effectively feeding deep-sea microbes.
• Methodology: Researchers synthesized marine snow from diatoms (microalgae) and subjected the aggregates to simulated deep-sea pressure in specialized rotating tanks, allowing them to measure chemical leakage while keeping particles in suspension.
• Key Data: The study revealed that sinking particles lose up to 50% of their initial carbon and 58–63% of their nitrogen content, triggering a 30-fold increase in bacterial abundance within just two days.
• Significance: This finding reshapes the global carbon cycle model by suggesting that less carbon is buried in deep-sea sediments for geological storage, while more remains dissolved in the deep water column for centuries to millennia.
• Future Application: These insights will be used to refine climate models regarding oceanic carbon sequestration and will guide an upcoming verification expedition to the Arctic aboard the research vessel Polarstern.
• Branch of Science: Marine Biogeochemistry and Microbiology.
• Additional Detail: The hydrostatic pressure functions like a "giant juicer," forcing out proteins and carbohydrates that provide an immediate, high-quality energy source for deep-ocean bacteria previously thought to inhabit a nutrient desert.

Shrinking Shellfish? Risks of Acidic Water in the Indian River Lagoon

FAU researchers measured aragonite saturation – a key indicator of water’s ability to support calcifying organisms like clams and oysters – throughout the Indian River Lagoon.
Photo Credit: Courtesy of Florida Atlantic University

Scientific Frontline: "At a Glance" Summary

• Main Discovery: Elevated nutrient runoff, freshwater discharges, and harmful algal blooms are accelerating coastal acidification in Florida's Indian River Lagoon, resulting in critically low levels of aragonite saturation necessary for shell-building organisms to survive.
• Methodology: Researchers performed a comprehensive spatial survey of the entire lagoon alongside weekly monitoring at three distinct central sites—an urban canal, a river mouth, and a natural reference area—between 2016 and 2017 to measure water chemistry and correlate aragonite saturation (\(\Omega_{arag}\)) with environmental stressors.
• Key Data: The study established a strong positive correlation between aragonite saturation and salinity, with data showing that nutrient-dense northern regions and freshwater-impacted southern areas consistently exhibited saturation levels insufficient for healthy shell development.
• Significance: Depleted aragonite levels inhibit the growth and structural integrity of calcifying species like oysters and clams, making them more vulnerable to predation and disease, which threatens the stability of the entire estuarine food web and local economy.
• Future Application: These findings provide a baseline for new ecosystem management strategies focused on controlling nutrient inputs and freshwater flows, supported by real-time pH and \(\mathrm{CO_2}\) monitoring via the upgraded Indian River Lagoon Observatory Network of Environmental Sensors (IRLON).
• Branch of Science: Marine Biogeochemistry and Estuarine Ecology
• Additional Detail: This research represents the first complete documentation of aragonite saturation distribution across the entire Indian River Lagoon, identifying specific "hotspots" where local anthropogenic pressures amplify global ocean acidification trends.

Tests uncover unexpected humpback sensitivity to high-frequency noise

Photo Credit: Mike Doherty

Scientific Frontline: "At a Glance" Summary

• Main Discovery: Humpback whales demonstrate unexpected sensitivity to high-frequency sounds, reacting to frequencies significantly higher than prior anatomical predictions suggested.
• Methodology: Researchers employed behavioural observation audiometry (BOA) over four migration seasons, broadcasting frequency-modulated upsweeps to migrating groups and recording behavioral changes such as course deviation or speed adjustment.
• Key Data: The study confirmed a hearing range extending from 80 Hz to 22 kHz, with specific reactions at the 22 kHz threshold proving sensitivity at the upper end of the human hearing range.
• Significance: This finding overturns the long-held assumption that baleen whales are exclusively low-frequency specialists and validates that wild-setting experiments can match the precision of captive studies.
• Future Application: These insights will refine strategies for mitigating human-induced noise pollution along migration routes, thereby enhancing conservation and protection protocols.
• Branch of Science: Marine Biology and Environmental Science.
• Additional Detail: The research generated the first data-driven audiogram for humpback whales, visually mapping their sensitivity across the tested frequency spectrum.

Silky Shark Study Reveals Deadly Gaps in Marine Protected Areas

The Silky Shark (Carcharhinus falciformis)
Photo Credit: Alex Chernikh
(CC BY-SA 4.0)

Scientific Frontline: "At a Glance" Summary

• Main Discovery: Silky sharks predominantly migrate west and northwest from the Galápagos Marine Reserve into unprotected high-seas corridors, exposing them to industrial fishing fleets despite the existence of nearby Marine Protected Areas.
• Methodology: Researchers deployed fin-mounted satellite tags on 40 adult silky sharks (33 females and 7 males) off Wolf and Darwin Islands, tracking their movements and residence times within protected versus unprotected zones for up to 1.75 years.
• Key Data: The tagged sharks spent more than 50% of the study duration outside Marine Protected Areas, with one individual traveling a record 27,666 kilometers; global populations of the species have declined by 47% to 54% in the last 40 years.
• Significance: The study reveals a critical misalignment between current conservation boundaries and shark behavior, as the animals rarely use the recently established eastern protected areas, preferring instead to travel into high-risk fishing zones.
• Future Application: Conservation planners can utilize this migration data to shift or expand Marine Protected Areas toward the west and northwest to cover the actual pelagic pathways used by the species.
• Branch of Science: Marine Ecology and Conservation Biology
• Additional Detail: Silky sharks are the second-most common species found in the international fin trade, driving their classification as vulnerable with a high risk of extinction.

Arctic seas are getting louder as ice melts, posing risks

Photo Credit: Наталья Коллегова

Scientific Frontline: "At a Glance" Summary

• Main Discovery: Current international regulatory frameworks for monitoring Arctic underwater noise are insufficient as they rely on narrow low-frequency "shipping bands" that miss modern, higher-frequency noise sources like snowmobiles and small vessels.
• Methodology: Researchers analyzed over a decade of acoustic measurements from a community observatory in Cambridge Bay, Nunavut, correlating soundscapes with seasonal ice dynamics to evaluate noise pollution beyond standard satellite tracking.
• Key Data: The study utilized 10 years of continuous data and highlights that the Arctic is warming three times faster than the global average, necessitating region-specific rather than generic European open-water noise models.
• Significance: Inadequate monitoring poses severe risks to marine wildlife that rely on sound for navigation and communication, while also threatening the subsistence hunting practices of Indigenous communities by making prey harder to locate.
• Future Application: International bodies must revise environmental policy frameworks to monitor a wider range of sound frequencies and incorporate seasonal ice cover variables into noise regulation thresholds.
• Branch of Science: Underwater Acoustics and Environmental Physics
• Additional Detail: The research demonstrates that "satellite-invisible" human activities, such as small boat traffic, generate distinct acoustic signatures that significantly alter the soundscape but remain undetected by current tracking systems.

Study finds fisheries management—not predator recovery—drives catch levels in the North Sea

Harbour seals (Phoca vitulina) basking on a rocky shore. Recent data shows these charismatic marine mammals have surged in the past few decades. However, new research suggests this increased population size remains compatible with sustainable fisheries.
Photo Credit: Jeremy Kiszka, Ph.D., Florida International University.

Scientific Frontline: "At a Glance" Summary

• Main Discovery: Anthropogenic fishing effort, driven by management decisions, serves as the primary determinant of fishery yields in the North Sea rather than predation pressure from recovering large marine mammal populations.
• Methodology: Researchers constructed a comprehensive ecosystem model of the southern North Sea and eastern English Channel, integrating data from 12 commercial fishing fleets and the complete marine food web, ranging from microscopic plankton to apex predators like gray seals and harbor porpoises.
• Key Data: The model synthesized extensive real-world datasets, including predator diet studies, fish stock assessments, and historical fisheries catch records, to accurately simulate the interplay between ecological dynamics and human harvest rates.
• Significance: This analysis demonstrates that the conservation of protected predator species is compatible with sustainable seafood production, challenging the prevailing assumption that recovering predator populations inevitably compromise commercial fishery viability.
• Future Application: Findings support the broader implementation of ecosystem-based fisheries management (EBFM) strategies that prioritize regulating human fishing pressure to balance economic objectives with ecological recovery.
• Branch of Science: Marine Ecology and Fisheries Management.
• Additional Detail: Published in the Canadian Journal of Fisheries and Aquatic Sciences, the study indicates that while total consumption by predators increased alongside their population growth, its impact on fish stocks remained subordinate to the volume of biomass removed by commercial fleets.

Positive Interactions Dominate Among Marine Microbes, Six-Year Study Reveals

Lead study author Ewa Merz conducting maintenance on a pump below the Scripps Pier, which brings seawater to the surface for sampling.
Photo Credit: Riley Hale

Scientific Frontline: "At a Glance" Summary

• Main Discovery: Marine microbial communities are driven primarily by positive, mutually beneficial interactions rather than competition, a trend that intensifies during periods of elevated ocean temperature.
• Methodology: Scientists utilized a six-year time series of high-frequency seawater sampling from Scripps Pier combined with DNA sequencing and computational analysis to map interactions among 162 abundant microbial taxa.
• Key Data: Analysis revealed that 78% of microbial associations were positive; specifically, warmer waters caused a 33% drop in total interactions but drove an 11% shift toward facilitation among the remaining connections.
• Significance: These findings challenge the traditional ecological emphasis on competition and predation, suggesting that cooperative networks are critical for microbiome stability and ecosystem function.
• Future Application: Integrating these positive interaction dynamics into climate models will enhance the accuracy of predictions regarding carbon cycling and food web stability in warming oceans.
• Branch of Science: Marine Microbial Ecology
• Additional Detail: The study identified specific "keystone" microbes that disproportionately influence community structure, noting that the identity of these critical species shifts in response to temperature changes.

Seawater microbes offer new, non-invasive way to detect coral disease

This brain coral shows the effects of stony coral tissue loss disease. The brown areas are healthy, the white areas are newly dead from the disease, and the light yellow areas are dead and colonized by endolithic algae.
Photo Credit: Amy Apprill ©WHOI

Scientific Frontline: "At a Glance" Summary

• Main Discovery: Microorganisms in seawater immediately surrounding corals act as superior, non-invasive biomarkers for detecting diseases like Stony Coral Tissue Loss Disease (SCTLD) compared to microbes within the coral tissue.
• Methodology: Researchers performed a four-year longitudinal analysis (2020–2024) of brain coral (Colpophyllia natans) in the U.S. Virgin Islands, using genetic sequencing to compare microbial shifts in coral tissue versus adjacent seawater throughout a disease outbreak.
• Key Data: Microbial communities in seawater remained stable near healthy corals but shifted dramatically during disease infection, whereas internal coral tissue microbiomes varied inconsistently regardless of health status.
• Significance: This approach overcomes the limitations of traditional visual assessments by enabling non-destructive, presymptomatic detection of reef health declines, allowing for timely intervention.
• Future Application: Development of automated, rapid genetic monitoring systems to provide early warning signals for reef managers to mitigate disease spread.
• Branch of Science: Marine Microbiology and Coral Ecology.
• Additional Detail: The study, published in Cell Reports Sustainability, suggests seawater microbes respond to specific materials released by diseased corals, offering a clear signal even before visual lesions appear.

Bristol scientists discover early sponges were soft

Xestospongia muta, the barrel sponge, may live for 100 years and grow to over 6 feet tall. While populations have declined at sites throughout the Caribbean, they appear to be quite healthy on Little Cayman Island. Caribbean Sea, Cayman Islands.
Photo Credit: NOAA
(Public Domain)

Sponges are among earth’s most ancient animals, but exactly when they evolved have long puzzled scientists. Genetic information from living sponges, as well as chemical signals from ancient rocks, suggests that sponges evolved at least 650 million years ago. 

This evidence has proved highly controversial as it predates the fossil record of sponges by a minimum of 100 million years. Now an international team of scientists led by Dr M. Eleonora Rossi, from the University of Bristol’s School of Biological Sciences, has solved this conflict by examining the evolution of sponge skeletons.  The research was published in Science Advances. 

Living sponges have skeletons composed of millions of microscopic glass-like needles called spicules. These spicules also have an extremely good fossil record, dating back to around 543 million years ago in the late Ediacaran Period. Their absence from older rocks has led some scientists to question whether earlier estimates for the origin of sponges are accurate. 

A molecular switch that controls transitions between single-celled and multicellular forms

The marine yeast Hortaea werneckii switches between unicellular and multicellular forms depending on food availability. These microscope images show (left to right): individual cells dividing on their own, fully connected multicellular chains that develop directly from single cells, and multicellular forms transitioning back by producing unicellular offspring. This flexibility helps the yeast adapt to changing ocean conditions.
Image Credit: Gakuho Kurita, Sugashima Marine Biological Laboratory, Nagoya University

How did multicellular life evolve from single cells? Nagoya University researchers have identified genes in marine yeast that may help answer this fundamental question. 

Scientists at Nagoya University in Japan have identified the genes that allow an organism to switch between living as single cells and forming multicellular structures. This ability to alternate between life forms provides new insights into how multicellular life may have evolved from single-celled ancestors and eventually led to complex organisms like animals and plants. 

Published in Nature, the study represents an exceptionally detailed molecular explanation of how clonal multicellularity, where all cells descend from a single ancestor, can be achieved and controlled at the genetic level. 

Manta rays create mobile ecosystems

Juvenile Atlantic manta ray swimming over sandflat with remora symbionts in South Florida. 
Photo Credit: Bryant Turffs

A new study from the University of Miami Rosenstiel School of Marine, Atmospheric, and Earth Science and the Marine Megafauna Foundation finds that young Caribbean manta rays (Mobula yarae) often swim with groups of other fish, creating small, moving ecosystems that support a variety of marine species.

South Florida—particularly along Palm Beach County—serves as a nursery for juvenile manta rays. For nearly a decade, the Marine Megafauna Foundation has been studying these rays and documenting the challenges they face from human activities near the coast, such as boat strikes and entanglement in fishing gear, which can pose significant threats to juvenile mantas