Tag Archives: fish

Finicky Fish: Investigating the impact of dams on the John Day White Sturgeon

This week we have a Fisheries and Wildlife Master’s student and ODFW employee, Gabriella Brill, joining us to discuss her research investigating the impact of dams on the movement and reproduction habits of the White Sturgeon here in Oregon. Much like humans, these fish can live up to 100 years and can take 25 years to fully mature. But the similarities stop there, as they can also grow up to 10 ft long, haven’t evolved much in 200 million years, and can lay millions of eggs at a time (makes the Duggar family’s 19 Kids and Counting not seem so bad).   

Despite being able to lay millions of eggs at a time, the White Sturgeon will only do so if the conditions are right. This fish Goldilocks’ its way through the river systems, looking for a river bed that’s just right. If it doesn’t like what it sees, the fish can just choose not to lay the eggs and will wait for another year. When the fish don’t find places they want to lay their eggs, it can cause drastic changes to the overall population size. This can be a problem for people whose lives are intertwined with these fish: such as fishermen and local Tribal Nations (and graduate students).

The white sturgeon was once a prolific fish in the Columbia River and holds ceremonial significance to local Tribal Nations, however, post-colonialization a fishery was established in 1888 that collapsed the population just four years later in 1892. Due to the long lifespan of these fish, the effects of that fishery are something today’s populations have still not fully recovered from.

Image of white sturgeon in a river. It is a large bluish grey fish. The river is a murkey dark green color.
White Sturgeon

Can you hear me now

Gabriella uses sound transmitters to track the white sturgeon’s movements. Essentially, the fish get a small sound-emitting implant that is picked up by a series of receivers – as long the receivers don’t get washed away by a strong current. By monitoring the fish’s journey through the river systems, she can then determine if the man-made dams are impacting their ability to find a desirable place to lay eggs. 

Journey to researching a sturgeon’s journey

Gabriella always gravitated towards ecology due to the ways it blends many different sciences and ideas – and Fish are a great system for studying ecology. She started with studying Salmon in undergrad which eventually led to a position with the ODFW. Working with the ODFW inspired her to get a Master’s degree so that she could gain the necessary experience and credentials to be a more effective advocate for changes in conservation efforts that are being made. One way to get clout in the fish world: study a highly picky fish with a long life cycle. Challenge accepted.

Gabriella Brill holding a smaller sturgeon while on a boat.

To hear more about these finicky fish be sure to listen live on Sunday February 26th at 7PM on 88.7FM, or download the podcast.

Are Microplastics the New Fish Food?

Geologists have considered an entirely new geologic era as a result of the impact humans are having on the planet. Some plastic material in our oceans near Hawaii along are hot magma vents and is being cemented together with sand, shells, fishing nets and forming never before existing material — Plastiglomerates. This new rock is a geologic marker providing evidence of our impact that will last centuries. Although rocks seem inert, that same plastic material floating around our oceans is constantly being eaten, purposefully and accidentally, by ocean creatures from as small as plankton to as large as whales and we’re just beginning to understand the ubiquity of microplastics in our oceans and food webs that humans depend on.  

Our guest this evening is Katherine Lasdin, a Masters student in the Fisheries and Wildlife Department, and she has to go through extraordinary steps in her lab to measure the quantity and accumulation of plastics in fish. Her work focuses on the area off the coast of Oregon, where she is collecting black rockfish near Oregon Marine Reserves and far away from those protected areas. These Marine Reserves are “living laboratory” zones that do not allow any fishing or development so that long-term monitoring and research can occur to better understand natural ecosystems. Due to the protected nature of these zones, fish may be able to live longer lives compared to fish who are not accessing this reserve. The paradox is whether fish leading longer lives could also allow them to bioaccumulate more plastics in their system compared to fish outside these reserves. But why would fish be eating plastics in the first place? 

These are the locations of Oregon’s Marine Reserves. The sampling for juveniles and adult black rockfish is occurring at Cape Foulweather which is between the Cascade head and Otter Rock Reserves. PC:
Black rockfish are a common fish off the Oregon coast and due to their abundance it’s a great study species for this research.

Plastic bottles, straws, and fishing equipment all eventually degrade into smaller pieces. Either through photodegradation from the sun rays, by wave action physically ripping holes in bottles, or abrasion with rocks as they churn on our beaches. The bottle that was once your laundry detergent  is now a million tiny fragments, some you can see but many you cannot. And they’re not just in our oceans either. As the plastics degrade into even tinier pieces, they can become small enough that, just like dust off a farm field, these microplastics can become airborne where we breathe them in! Microplastics are as large as 5mm (about the height of a pencil eraser) and they are hoping to find them as small as 45 micrometers (about the width of a human hair). To a juvenile fish their first few meals is critical to their survival and growth, but with such a variety of sizes and colors of plastics floating in the water column it’s often mistaken for food and ingested. In addition to the plastic pieces we can see with our eyes there is a background level of plastics even in the air we breathe that we can’t see, but they could show up in our analytical observations so Katherine has a unique system to keep everything clean. 

In order to quantify the amount of plastics in fish, you have to digest some of the fish guts. PC: Katherine Lasdin

Katherine is co-advised by Dr. Susanne Brander who’s lab studies microplastics in marine ecosystems. In order to keep plastics out of their samples, they need to carefully monitor the air flow in the lab. A HEPA filtration laminar flow hood blows purified air towards samples they’re working with in the lab and pushes that clean air out into the rest of the lab. There is a multi-staged glassware washing procedure requiring multiple ethanol rinses, soap wash, deionized water rinses, a chemical solvents rinse, another ethanol, and a final combustion of the glass in a furnace at 350°C for 12-hours to get rid of any last bit of contamination. And everyday that someone in Dr. Brander’s lab works in the building they know exactly what they’re wearing; not to look cool, but to minimize any polyester clothing and maximize cotton clothing so there is even less daily contamination of plastic fibers. These steps are taken because plastics are everywhere, and Katherine is determined to find out just big the problem may be for Oregon’s fish.  

Katherine Lasdin working in the laminar flow hood that blows purified air towards the samples in Dr. Brander’s lab. PC: Cheyenne Pozar

Be sure to listen to the interview Sunday 7PM, either on the radio 88.7KBVR FM or live-stream, to learn how Katherine is conducting her research off the coast of Oregon to better understand our ocean ecosystems in the age of humans.

Listen to the podcast episode!

On this episode at the 16:00 mark we described how every time you wash clothing you will loose some microfibers; and how a different student was looking at this material under microscopes. That person is Sam Athey, a PhD student at the University of Toronto who also studies microplastics.

Crabby and Stressed Out: Ocean Acidification and the Dungeness Crab

One of the many consequences associated with climate change is ocean acidification. This process occurs when high atmospheric carbon dioxide dissolves into the ocean lowering ocean pH. Concern about ocean acidification has increased recently with the majority of scientific publications about ocean acidification being released in the last 5 years. Despite this uptick in attention, much is still unknown about the effects of ocean acidification on marine organisms.

Close-up of a Dungeness crab megalopae

Our guest this week, Hannah Gossner, a second year Master’s student in the Marine Resource Management Program, is investigating the physiological effects of ocean acidification on Dungeness crab (Metacarcinus magister) with the help of advisor Francis Chan. Most folks in Oregon recognize the Dungeness crab as a critter than ends up on their plate. Dungeness crab harvest is a multimillion dollar industry because of its culinary use, but Dungeness crab also play an important role in the ocean ecosystem. Due to their prevalence and life cycle, they are important both as scavengers and as a food source to other animals.

Hannah pulling seawater samples from a CTD Carrousel on the R/V Oceanus off the coast of Oregon

To study the effect of ocean acidification on Dungeness crab, Hannah simulates a variety of ocean conditions in sealed chamber where she can control oxygen and carbon dioxide levels. Then by measuring the respiration of an individual crab she can better understand the organism’s stress response to a range of oxygen and carbon dioxide ratios. Hannah hopes that her work will provide a template for measuring the tolerance of other animals to changes in ocean chemistry. She is also interested in the interplay between science, management, and policy, and plans to share her results with local managers and decision makers.

Hannah working the night shift on the R/V Oceanus

Growing up in Connecticut, Hannah spent a lot of time on the water in her dad’s boat, and developed an interest in marine science. Hannah majored in Marine Science at Boston University where she participated in a research project which used stable isotope analysis to monitor changes in food webs involving ctenophores and forage fish. Hannah also did a SEA Semester (not to be confused with a Semester at Sea) where she worked on a boat and studied sustainability in Polynesian island cultures and ecosystems.  Hannah knew early on that she wanted to go to graduate school, and after a brief adventure monitoring coral reefs off the coast of Africa, she secured her current position at Oregon State.

Tune in Sunday June, 17 at 7 pm PST to learn more about Hannah’s research and journey to graduate school. Not a local listener? Stream the show live or catch the episode on our podcast.

Hannah enjoying her favorite past time, diving!