Tag Archives: species

Rethinking oyster reef restoration and coastal community resilience: The use of biomimicry and outreach to offset the growing risk of invasive species

“I like to think of them as the corals of estuaries,” says Megan Considine as she describes the role that oysters play in coastal systems all over the world. Megan is a first-year Marine Resource Management Masters student who is working on a project to map the distribution of an invasive mud worm (Polydora websteri) that infects native shellfish such as the commercially grown Pacific oyster (Crassostrea gigas) and wild populations of Olympia oysters (Ostrea lurida).

Oyster transplant project in the Lynnhaven River, a tributary to the Chesapeake Bay where Megan worked prior to coming to OSU. Photo courtesy of Megan Considine.

Megan explains that these tiny worms don’t make the oyster meat inedible, as infected populations can still be harvested and sold for canning, but they do become unmarketable on the half shell. This is because the worms crawl between the inner shell surfaces, and the oyster then grows new shell material over it to wall off the invader. The worm then deposits muddy material or debris into the shell pocket and essentially creates a blister. Although these blisters are not known to negatively impact the oysters themselves, they are not exactly aesthetically pleasing to the consumer. This is what is really hurting the multi-million dollar industry and the main reason stakeholders from Alaska, Washington, Oregon and California are all working together to detect and prevent further spread of the worms. 

A Pacific oyster infected by the invasive mudworm, showing blisters that have been opened up to try and extract the worm. Photo courtesy of Megan Considine.

Dr. Steve Rumrill is the Shellfish Program Leader at the Oregon Department of Fish and Wildlife (ODFW) and as courtesy faculty of Hatfield Marine Science Center is Megan’s primary advisor. Working with ODFW, Megan visits shellfish farms located in estuaries along the Oregon coast and picks up oysters which are inspected for worms. If found, samples are then sent to a lab in Washington for genetic analysis to confirm infestation. Megan says that farmers may not even know their oysters are infected and she hopes to expand her work beyond just ecological sampling to outreach and mitigating an emergent problem.

“I want to create an education piece in Spanish and English, so that farmers can be aware of when their oysters are infected.”

Megan’s passion for education goes far beyond aquaculture. Getting back to her coral analogy, oysters are not just important to aquaculture here in the Pacific Northwest. Ecologically, they are incredibly valuable wherever they occur both when living, for example, filtering the water column, but also after they die. Their calcium carbonate shells provide the foundational habitat that supports an incredible diversity of estuarine life. 

For a long time in oyster restoration efforts, it’s been understood that substrate is a primary limiting factor in supporting this reef-building capacity of oysters. According to Megan, in the PNW, they were just completely overharvested during the Gold Rush era. In addition to her work on invasive mud worms in oyster farms, Megan is also a part of efforts to restore natural oyster populations in Oregon, specifically at Yaquina Head. And this is an area of research Megan has been passionate about for some time. 

Megan getting ready to snorkel assist with coral restoration in the Florida Keys working with Mote Marine Laboratory. Photo courtesy of Megan Considine.

Originally from Virginia Beach, Megan recalls her time as an elementary school student being tasked along with her classmates to monitor the growth of a bag of oysters donated by a local non-profit. Along with studying their entrusted specimens, she says that they would also engage in other activities about estuarine ecology surrounding oysters in the Chesapeake Bay. This hands-on experience would come full circle when after completing her undergraduate studies at the University of South Carolina, Megan had the opportunity to intern with the same organization, Oyster Reef Keepers, that sponsored the oyster education program in several schools, leading kids through many of the same activities that sparked her early fascination with estuary ecosystems and marine science.  

Although a more well-known issue on the East coast, Megan explains that oyster habitat degradation is a world-wide problem and she came to Oregon State to expand her knowledge of its effects in other places. She says that oyster restoration hasn’t had as much momentum here in the West because aquaculture has been the focus, but it’s gaining traction. Concern over threats like climate change to coastal ecosystems have supported this trend. Although oysters are  less sensitive to climate change impacts like ocean acidification than corals are known to be, it still may compromise their ability to cope with other direct threats, such as invasive species. 

At Yaquina Head, Megan is working with an artist from the East coast named Evelyn Tickle who makes concrete tiles to be used in oyster reef restoration that are designed to mimic natural oyster beds. These one square foot tiles differ from the cinder block structures that have been used to provide substrate for the oysters to grow on in the past by providing a more complex structure made of compounds like calcium carbonate. Overall, the tiles give oysters a better chance to establish amidst other stressors. 

Megan has been so inspired by Evelyn’s work that she has begun working with two other OSU students, Chad Sullivan and Nicolás Gómez-Andújar, to develop other biomimicry concrete structures for future restoration efforts that support the erosion and storm mitigation services that both oysters and corals provide to coastal systems. They are calling themselves the Urban Reef Lab. 

Megan on one of many coastal trips taken since Megan moved to Oregon; exploring the West coast is one of her favorite pastime’s. Photo courtesy of Megan Considine.

“The idea is that instead of using simple and smooth breakwater structures or sea walls, we can incorporate textures and shapes that are designed for specific organisms. So, working with nature rather than against. For instance, if the goal is oyster settlement we would use the appropriate texture such as crevices and pits. The designs can also be used as hard substrate for coral outplants or for oyster restoration efforts, like the Yaquina Bay project.”

To learn more about Megan’s research and outreach goals beyond her graduate work, tune in to KBVR 88.7 FM or stream online April 19, 2020 at 7 P.M. 

Core Strategies for Conservation of Greater Sage-Grouse

Greater sage-grouse (GRSG) is a North American bird species that nests exclusively in sagebrush habitat. In the last century, natural populations of this species have significantly declined largely due to human influenced habitat loss and fragmentation. This has prompted multiple petitions to the U.S. Fish and Wildlife Service (USFWS) to list GRSG under the Endangered Species Act (ESA), which would require mandatory restrictions on critical sagebrush habitat. This means that land managers of sagebrush areas would face land use restrictions for natural resource extraction and development, the bulk of the economy in Wyoming.

Wyoming Basin study site with associated GRSG Core Areas in blue. These Core Areas were designated as part of the GRSG Core Area Protection Act, Wyoming’s GRSG conservation policy aimed at protecting at least 67% of male GRSG attending leks. This policy is focused on directing development outside of these areas by setting strict conservation measures inside the Core Areas. Overall, the policy has remained effective in protecting at least 2/3 of GRSG habitat and has been identified as having the highest conservation value to maintaining sustainable GRSG populations.

 

Scent station and associated trail camera set-up in Natrona County, WY. Scent stations were randomly placed throughout the study site along roads and stratified between Core and Non-Core Areas. Mammalian predators are known to use roads for easy travel. These scent stations will help gather occupancy data of mammalian predators (Photo Credit: Eliana Moustakas).

Wyoming is a stronghold for GRSG, with the most birds, the most leks (male mating display grounds), and the largest contiguous sagebrush habitat in North America. Since GRSG declines have led to its possible endangered listing, Wyoming Governor Dave Freudenthal launched an effort in 2007 to develop stronger policies for GRSG that would protect the species and its habitat while also sustaining the state’s economy. A public forum followed, including representatives from state and federal agencies, non-governmental organizations, and industries, and in 2008 a conservation policy called the Greater Sage-Grouse Core Area Protection Strategy was developed to maintain and restore suitable habitat and active breeding GRSG pairs. The plan aims to protect at least 67% of male GRSG attending leks, and is focused on directing development outside of Core Areas by setting strict conservation measures inside Core Areas. By protecting sagebrush habitat and allowing development and mining in Non-Core Areas, Wyoming can continue to expand its natural resource economy and play a critical role in GRSG conservation.

In 2010, the USFWS concluded that GRSG were warranted protection but left them off the ESA list because threats were moderate and did not occur equally across their range. The status of GRSG was reevaluated in 2015 and the USFWS determined that GRSG did not warrant protection, claiming that the Core Area Strategy was sound framework for a policy by which to conserve GRSG in WY. However, recent monitoring of GRSG has shown that populations are still in decline in some Core Areas and in populations across their range. Our guest this week, Claire Revekant, a second year Master’s student in the Department of Animal and Rangeland Science, is trying to understand if avian and mammalian predator abundance differs between Core and Non-Core Areas.

Golden eagle using a utility pole to perch. Raptors and corvids are known to use  structures to perch and nest.

 

Working under Dr. Jonathan Dinkins, Claire estimates associations between human influence areas and habitat variables on the abundance of predatory birds and occupancy of mammalian predators. For example, raptors and corvids have been documented to perch and nest on fences and other human structures, and roads have been found to be used as travel paths for mammalian predators. Claire’s hypothesis is that predatory animals will be higher in Non-Core Areas where human-influenced environments serves as areas of food subsidies. Identifying areas of predator abundance and relating those areas to human features and habitat variables may help policy makers prioritize plans to mitigate human influence and protect sagebrush habitat.

Badger captured by trail camera at scent station in Lincoln County.

While her research is focused on predators of GRSG, Claire’s work for GRSG conservation contributes to the conservation of other sagebrush-obligate species (species that relay on sagebrush for all or some parts of their life cycle). By protecting the ecosystem for one “umbrella” species, other species may also benefit. Throughout her career as a wildlife biologist, Claire has been involved with numerous projects where she has handled and monitored several species. From learning to band raptors as a child to monitoring seabird productivity as an intern at the Monomoy National Wildlife Refuge, Claire has developed a passion for research. She told us that she can’t remember a time when she had a different dream job. Tune in tonight Sunday November, 11 at 7 to hear more about Claire’s research and her journey to graduate school on 88.7 FM KBVR Corvallis, or stream the show live.

Beetle-Seq: Inferring the Phylogeny of Clivinini

We humans are far outnumbered by organisms that are much smaller and “less complex” than ourselves. The cartoon above depicts representatives of major groups of organisms, and each organism is drawn such that its size reflects the number of species contained within its group. The bird, the fish, and the trees look as expected, but you may notice the enormous beetle. No, beetles are not generally larger than trees or elephants, but there are more species of beetles than any other group of organisms. Beetles are a wonderful representative of the biodiversity of the earth because they can be found in almost every terrestrial and non-marine aquatic environment!

Examples of carabid beetles of the tribe Clivinini (top row; photos with ‘HG’ – Henri Goulet, otherwise – David Maddison). Male genitalia of a clivinine species, Ardistomis obliquata, with possible ‘copulatory weapons’ (right) and several examples of clivinine female genitalia (bottom row) modified from Zookeys 2012;(210):19-67 shared under CC BY 3.0.

Our guest this week, Antonio Gomez from the Department of Integrative Biology, studies a group of beetles called clivinines (pronounced kliv-i-nīnz) which has 1,200 species, and potentially more that have yet to be discovered. Antonio is also particularly interested in the morphological diversity and evolution of clivinine beetle sperm. Antonio wants to know: What is the evolutionary history of clivinine beetles? What is the pattern of morphological diversity of sperm in clivinine beetles, and how are sperm traits evolving? The objective is to collect beetles, study their form, sequence their DNA, and understand their diversification.

Several examples of sperm conjugates (cases where two or more sperm are physically joined and travel together) in carabid beetles. Conjugation is considered rare, but in carabid beetles, it’s the rule and not the exception to it. In many carabids, sperm leave the testis but do not individualize. Instead, they remain together and swim as a team.

This is no small task, but Antonio is well equipped with microscopes to dissect and describe beetle anatomy, a brain geared to pattern recognition, and some fresh tools for genome sequencing. All of this is used to build an evolutionary tree for beetles. This is kind of like a family tree, but with species instead of siblings or cousins. Antonio and other students in the lab of David Maddison are adding knowledge to the vastness of the beetle unknown, bit by bit, antenna by antenna, gene by gene.

Antonio Gomez collecting beetles near a really bright light (a mercury vapor light trap) near Patagonia, Arizona.

Like many of our graduate students at Oregon State, a group of great mentors can make all the difference. Before working with Dr. Kelly Miller at University of New Mexico, he never knew beetle phylogenetics meant exploring exotic locations around the world to collect and potentially discover new species. As an undergraduate, Antonio even named a species of water beetle, Prionohydrus marc, after the undergraduate research program that go him started as a beetle systematist, the Minority Access to Research Careers (MARC) program. Pretty amazing. That was not his first or last research project with insects before he joined ranks at Oregon State, he also was participated in a Research Experience for Undergraduate program at the California Academy of Sciences and completed a Master’s at University of Arizona. Now he has ample experience working with beetles and is maybe a little overwhelmed but still excited by the unknown beetle tree of life. Next on his list of questions: did the ancestor of all clivinines likely have sperm conjugation?

You’ll have to tune in on Sunday April, 16 at 7 pm to hear more about that evolutionary arms race!
Not in Corvallis? No sweat! Stream the show live.

Can’t get enough? Follow this link to learn about Stygoprous oregonensis, a blind subterranean diving beetle that had not been seen in 30 years. Recently, a team of researchers that included Antonio Gomez reported the discovery of more specimens, which allowed them to place Stygoporus in an evolutionary tree.