Biologist Finds Answers to Origins of Most Diverse Fish Fauna on Earth
Recent research by Dr. James Albert, professor of ecology and evolution in our biology department, and three collaborators sought to understand the origins of the megadiversity of freshwater fish fauna in South America.
Albert his colleagues discovered that abrupt increases of species evolution coincided in time and place with major mountain uplifts and river re-arrangements.
The research by Prof. Albert and colleagues across the country was published earlier this month in the journal: Proceedings of the National Academy of Sciences. They integrated an unprecedented dataset of about 5,000 species with a newly complied, time-calibrated evolutionary tree of South American freshwater fishes - the most species-rich continental vertebrate fauna on Earth – to track the evolutionary processes associated with river and sea events over 100 million years.
“The effects of river network re-arrangements on dispersal and lineage diversification were poorly understood,” said Albert. “Our results support the hypothesis that landscape dynamics, which shaped the history of drainage basin connections, strongly affected the assembly and diversification of basin-wide fish faunas.
“Species in the Western Amazonia originated faster and persisted longer than those in other regions, substantially enhancing the exceptional diversity of aquatic organisms across the whole continent,” he added.
The study used the most complete datasets of geographic distributions and evolutionary relationships of South American fishes to date, to track the influence of the geological history on the origins, extinctions, and interchanges of these fishes over the past 100 million years.
Findings note that five abrupt shifts in diversification rates occurred during the Paleogene and Miocene periods – between 30 and 7 million years ago – in association with major landscape evolution events. These events include the formation of several mountain ranges in South America: Serra do Mar, Serra da Mantiqueira, and the Andes.
Read the full paper here: Landscape dynamics and diversification of the megadiverse South American freshwater fish fauna.
Biologist heads $14 million effort to produce more resilient oysters
Dr. Beth Stauffer, of our Biology Department, heading a $14 million, three-year research initiative to develop oyster broodstock capable of survival in low-salinity environments. Leveraging Opportunities and Strategic Partnerships to Advance Tolerant Oysters for Restoration, or LO-SPAT, is designed to help sustain populations of the shellfish and support the seafood industry. The Louisiana Department of Wildlife and Fisheries is funding the project.
Stauffer, a phytoplankton ecologist, and other UL Lafayette researchers are collaborating with scientists from the LSU AgCenter and the University of Maryland Center for Environmental Science Horn Point Laboratory. Spat-Tech, a Mississippi-based oyster aquaculture company, is the private sector partner. “The objective is to examine low-salinity tolerant populations of oysters. We’re researching how low salinity – and other environmental stressors – factor in, and identifying heritable traits that make some oysters hardier than others,” Stauffer said. The LO-SPAT team is pooling its expertise in coastal and restoration ecology, environmental monitoring, organismal and molecular biology, economics, and aquaculture and oyster husbandry. Researchers are collectively examining the entire oyster life cycle, from larvae and broodstock to juveniles that can be deployed in nurseries and, ultimately, at restored reef sites. Creating sustainable breeding operations starts with collecting wild oysters, then introducing them to stressors; the next step is using modern molecular tools to determine which oysters prove capable of growing in unfavorable conditions. “Those oysters are then bred over multiple generations through a process known as selective breeding, which allows producers to build a better oyster using their natural genetic diversity,” Stauffer explained.
It’s important work. Louisiana is one of the nation’s major oyster-producing states. Declining production, however, has created ecological and economic consequences. Increases in rainfall and flooding in Louisiana and along the Gulf Coast in recent years have introduced high amounts of freshwater into oyster habitats and reefs. That’s problematic, since the shellfish need at least some salt to live and more to grow and reproduce. Jack Montoucet, secretary of the Louisiana Department of Wildlife and Fisheries, said the LO-SPAT initiative provides “a comprehensive approach to addressing a state, regional and national problem, and we’re excited play a role in that.” “Developing an oyster that can tolerate low salinity for an extended period of time – which we don’t have now – is important to maintaining the industry as we know it. And with all of the research capabilities that exist today, we should be able to do that.” Oysters are essential to coastal ecosystem health. They filter massive volumes of water and build reefs that provide habitat for fish and other marine life. The shellfish are also vital to the economy and provide thousands of jobs. The Gulf of Mexico produces 46% of the oysters in the United States, and the regional oyster industry has an annual value of $66 million. It’s why pursuing initiatives – such as LO-SPAT – that will ensure a vibrant oyster industry has become a priority in Louisiana. Promoting sustainable ecosystems and providing habitats for commercial industries is a primary goal of the Coastal Protection and Restoration Authority’s Coastal Master Plan.
Findings generated as a result of the LO-SPAT initiative are integral to that effort. So, too, are UL Lafayette research laboratories, including at its 50-acre Ecology Center. The center has a 15,000-square-foot building that houses spaces for a broodstock facility and laboratory. Construction and operations of broodstock facilities at the Ecology Center is being overseen by a team of staff members. In addition to innovations in oyster broodstock, researchers will conduct field sampling using sensors deployed in estuaries to characterize the environments oysters are experiencing and acoustic monitoring to quantify oyster reef health.
Other key LO-SPAT researchers include Dr. Megan La Peyre, a research biologist for the U.S. Geological Survey Louisiana Fish and Wildlife Cooperative Research Unit at the LSU AgCenter; Dr. Louis Plough, an associate professor and geneticist at the University of Maryland Center for Environmental Science Horn Point Laboratory; Dr. Durga Poudel, a geosciences professor in UL Lafayette's Ray P. Authement College of Sciences; Dr. Natalia Sidorovskaia, a professor who heads UL Lafayette’s Department of Physics; and Dr. Geoffrey Stewart, an associate professor in UL Lafayette’s B.I. Moody III College of Business Administration;
Giant tsunami from dino-killing asteroid impact revealed in fossilized ‘megaripples’
Dr. Gary Kinsland of our School of Geosciences is featured in a Science Magazine article from 12 July 2021. Dr. Kinsland found that a meteor responsible for dinosaurs' demise triggered a tsunami that left large-scale subsurface ripples — and his research revealed those ripples are fossilized here in Louisiana.
A Tectonic Shift in Analytics and Computing Is Coming
Dr. Gabriele Morra of our Department of Physics and the School of Geosciences just published an overview of the opportunities and challenges in Machine Learning and Supercomputing in the Geosciences in a journal of the American Geophysical Union.
Artificial intelligence combined with high-performance computing could trigger a fundamental change in how geoscientists extract knowledge from large volumes of data. Check out the details in the article A Tectonic Shift in Analytics and Computing Is Coming .
Flukes and hazards: Geologists map hot spots in Louisiana's coastal zone
(UL Lafayette news item: Wed, 07/25/2018)
Two researchers at the University of Louisiana at Lafayette are contributors to an atlas focused on coastal Louisiana's complicated – and at times, hazardous – relationship with geology. But don't be fooled by the name. The Louisiana Coastal Geohazards Atlas is more than a collection of maps. It's an encyclopedia, too. It will combine information about geologic conditions – such as flooding, faulting and subsidence that can affect land use in the coastal zones – into a first-of-its-kind authoritative resource. Learn more about this project.
University biologist suggests rough sailing for planned river diversions
(UL Lafayette news item: Mon, 07/23/2018)
The fate of fish in a New England estuary could predict what's ahead for Louisiana marsh life should the state activate a cornerstone of its coastal restoration plan. That's according to Dr. James A. Nelson, a University of Louisiana at Lafayette biologist. Nelson and other researchers introduced nutrient-enriched seawater into three watersheds in Plum Island Estuary, an area of tidal marshes and interconnected creek channels in northeastern Massachusetts. The team's goal was to determine how nutrients such as phosphate and nitrate affected the estuary's food web, the relationship between predator and prey in nature. Learn more about this project.
Researchers discover hidden biosphere after 2010 oil spill wiped out marine life
(UL Lafayette news item: Mon, 07/02/2018)
The Gulf of Mexico resembled an aquatic desert. It was a barren landscape with little to no life left after the 2010 Deepwater Horizon oil spill polluted the waters and masked any-and-everything in a thick layer of dark sludge. Although the spill was a devastation to coastal communities and local wildlife, it transformed and expanded the way the scientific population viewed the area. Without the accident, Drs. Suzanne Fredericq and Sherry Krayesky-Self may not have made the breakthrough that could potentially affect all levels of the planet's food chain. "What we've learned will revolutionize the way we look at the ocean and at life," said Fredericq, a University of Louisiana at Lafayette biology professor. Learn more about this project.
What makes tick-born pathogens tick?
(UL Lafayette news item: Tue, 12/05/2017)
The battle against pesky ticks during what could already be considered the unbearable Louisiana heat rages on in a new research study. Dr. Scott Duke-Sylvester, an associate professor of biology at the University of Louisiana at Lafayette, has joined a team of researchers to analyze how transmitted diseases born from pathogens - microorganisms that cause illnesses - found in the small arachnids will affect human health. "We are hoping to have a better understanding of where the disease is distributed in different parts of the country, if there's any change in that distribution and which tick species are responsible," he said. Learn more about this project.
'Earthzine' features doctoral student's marsh study
Samantha Hauser and Paul LeBerg
UL Lafayette doctoral fellow Samantha Hauser was near Brigantine, N.J., the day before Hurricane Sandy made landfall there on Oct. 29, 2012. She had been conducting research in a marsh on the coast of the Atlantic Ocean. "I was about to leave and the marsh was covered with saltwater already," she told La Louisiane. A New Jersey native, Hauser was pursuing a bachelor's degree in ecology and natural resources at Rutgers University at the time. "We were at least an hour or two inland and we were still completely flooded from the saltwater coming into the Raritan River," she said. Learn more about this project.
Studies show which snakes strike fastest, including the monster Titanoboa
Dr. David Penning photo by Doug Dugas
University researchers are shedding light on snakes and their behavior, from venom-injecting vipers to a prehistoric constrictor called Titanoboa, an almost 50-foot-long giant too thick to squeeze through a modern doorway. In one case, research conducted by Dr. Brad Moon, an associate professor of biology; Dr. David Penning, a former UL Lafayette doctoral student; and Baxter Sawvel, a graduate student, took the fangs out of the widespread misconception that venomous snakes, such as rattlesnakes and cottonmouths, strike faster than nonvenomous snakes. Learn more about this project.
Dolphins, beaked whales and endangered sperm whales in the Gulf of Mexico have a lot to say about their deepwater environment. Some University of Louisiana at Lafayette scientists were part of a multidisciplinary group that spent 10 days listening to them this summer. Learn more about this project.
Second Chance: Plant's return to space yields clues about how they sense gravity
Dr. Karl Hasenstein hopes some of the answers to the scientific riddle of why plants grow up, while their roots grow down, rest in the palm of his hand. He's holding an amber-colored "plug" about the size and shape of a pencil eraser. Encapsulated inside the plug, which is composed primarily of resin, is a tiny root tip of Brassica rapa, or field mustard plant. The sliver of root, which resembles the stinger of a honey bee, is on of 80 such roots of a biology experiment that took place aboard the International Space Station earlier this year. Learn more about this project.
Growing Opportunity: Research team develops trademarked line of native seeds, plants
There is a rule of thumb among native plant growers: The first year, it sleeps. The second, it creeps. And the third year, it leaps. Reintroducing native varieties takes time, but the effort pays off handsomely. Once these long-lived plants are established, they're essentially maintenance free. They don't require fertilizer, because they're adapted to native soils. And they don't require pesticides, because they're adapted to native insects. They're almost impervious to drought and can even survive fire. Learn more about this project.