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By Virginia Rose Whalen

Podcast Transcript

When you look deep into the ocean, the world you will see is colder, darker, and slower.

The species who live there have to adapt to these harsh environments by moving in slow motion. Their metabolism slows down, and their growth – even slower. They live a life so different from our own, it’s almost unimaginable.

Living the slow life can also mean surviving for a really long time. Take the Greenland Shark (Somniosus microcephalus) for example. This species resides deep in arctic waters, typically reaching more than 13 feet in length. A 2016 study discovered that these sharks can live to be a whopping 400 years old, and don’t reach reproductive maturity until at least 150. The authors of the study used radiocarbon dating on the eye lenses of deceased specimens in order to determine their age. It was also estimated that the sharks grow less than a centimeter a year, which contributes to their longevity.

Despite being so slow and so old, Greenland Sharks are considered to be the top predators of their food chain. Though they were long assumed to only scavenge for things that have already died, a 2013 study found that they are actually capable of catching live prey. They eat things like Atlantic cod, wolffish, and even harbor seals.

We still have a lot to learn about how deep sea fish like the Greenland Shark live. With most of the ocean left unexplored, there are almost certainly more fascinating species out there.

Sources

Nielsen, J., Hedeholm, R. B., Heinemeier, J., Bushnell, P. G., Christiansen, J. S., Olsen, J., Ramsey, C. B., Brill, R. W., Simon, M., Steffensen, K. F., & Steffensen, J. F. (2016). Eye lens radiocarbon reveals centuries of longevity in the Greenland shark (Somniosus microcephalus). Science 353(6300), 702-704.

Nielsen, J., Hedeholm, R. B., Simon, M., & Steffensen, J. F. (2013). Distribution and feeding ecology of the Greenland shark (Somniosus microcephalus) in Greenland waters. Polar Biology 2014(37), 37-46.

Prior to European colonization, the indigenous communities of the Pacific Northwest practiced sustainable fishing techniques for thousands of years. A recent collaboration between scientists at Simon Fraser University and the Tsleil-Waututh nation revealed how these Coast Salish peoples maintained a sustainable chum salmon (Onocorhynchus keta) fishery 2,000 years ago (Robitzski 2021).

A team of scientists and archeologists from the university designed this project for the Tsleil-Waututh nation to validate historical records from the Port of Vancouver. Using PCR techniques, scientists were able to extract the DNA from salmon bone samples (Figure 1)  that had been collected from four different historical sites along the northeast coast of Vancouver (Morin et al 2021). They discovered that at two of the four sites, the bones were overwhelmingly male. The other two sites had a more balanced mix of male and female salmon remains.

With just the raw DNA data, it was at first unclear whether this uneven distribution of sexes was intentional or not. So, the university scientists then turned to members of the Tsleil-Waututh Nation to better understand the nation’s historic fishing practices. These members confirmed that the Coast Salish inhabitants did prefer male salmon, because they were larger and provided more food (Robitzski 2021). Furthermore, these fishermen could easily distinguish between the sexes due to the coloration and large front teeth of males (Figure 2).

Together, the scientists and Tsleil-Wauthuth nation concluded that this data suggests male salmon were also selected because of the sustainable benefits. It is likely fishermen realized that male fish can fertilize the eggs of multiple females, so fishing selectively for males would not deplete the overall salmon population. Therefore, the Coast Salish peoples were able to sustain a healthy chub salmon fishery.

With the current world human population on the never-ending rise, overfishing continues to become a pressing issue. It is key that we continue studies like this one in order to learn from the sustainable practices of our ancestors.

Citations

Morin, J., Royle, T.C.A., Zhang, H. et al. Indigenous sex-selective salmon harvesting demonstrates pre-contact marine resource management in Burrard Inlet, British Columbia, Canada. Sci Rep 11, 21160 (2021). https://doi.org/10.1038/s41598-021-00154-4 

Robitzski, Dan. (2021, November 29). 2,000-year-old salmon DNA reveals secret to sustainable fisheries. The Scientist Magazine®. Retrieved November 30, 2021, from https://www.the-scientist.com/news-opinion/2000-year-old-salmon-dna-reveals-secret-to-sustainable-fisheries-69466.  

The delta smelt is a species that lives in California’s Delta, where half of California’s fresh water is moved through and used for agriculture, industry, and residents.  The delta smelt is sensitive to changes in it’s habitat and it’s decline in the delta is a concern for the smelt and the overall health of the California Delta.  The delta smelt is a concern because the delta smelt is a keystone species in the delta and it’s decline is an indicator on the overall health of the delta.  Many other fish that have been introduced in the delta and are native are also declining in the delta as well.  It is likely that the smelt is decline is due to a combination of factors such as the loss of freshwater flowing, water diversion, introduces species, and pollution.  Fortunately, when conditions are favorable as it was seen in 2011, the smelt’s population could rebound and it shows that the health of the delta is recovering.

Unfortunately, the delta smelt also lives in a region with a high amount of agricultural activity and it’s protection has caused a lot of controversy.  I have been to California many times and I have seen many signs saying “Stop the Congress Made Dustbowl.”   Because one of the reasons the delta smelt is endangered is because of the lack of freshwater flow and the delta getting more salty, and to help the smelt waterflow for the smelt was increased, which reduced the freshwater that could be used in agriculture.  Many people think that the increased waterflow for the smelt is a waste of fresh water and it is solely for the smelt.  The increase in freshwater flowing will also be beneficial to the delta as a whole because the flow of freshwater also reduces the salinity in the delta.

Although the delta smelt is commonly blamed for the lack of water that can be used in agriculture, the loss of the delta smelt is due to a larger environmental issue.  The loss of freshwater flow in the delta will likely cause a decline in other species that live in the delta such as the longfin smelt and the chinook salmon.

(Picture Renee Reyes all rights reserved)

https://wildlife.ca.gov/Conservation/Fishes/Delta-Smelt

Farmers vs. Fish: The Story of Delta Smelt

The devil’s hole pupfish is possibly one of the rarest fish in the world with 65 individuals being counted as of 2013.  The devil’s hole pupfish also lives in extreme circumstances for fish by living in caverns that reach 93 degrees in The Mojave Desert.  The temperatures and oxygen levels are lethal for most fish species but the devil’s hole pupfish has been found to thrive in the conditions in the past.  The devil’s hole pupfish have one of the smallest range of any vertebrate, living in an area that is smaller than most people’s office.

Unfortunately, the devil’s hole pupfish has been declining from 550 individuals being counted when the counts started to numbers as low as 35 individuals.  Previous attempts to establish a captive population have failed until recently.  When a captive population was being attempted to be made, there was a species of diving beetle that was previously found in the caves of the pupfish and wasn’t thought to be a big deal they were in the tank with the captive population.  It was later found out that the diving beetle was eating the pupfish eggs and larva and causing the previous attempts to establish a refuge population to fail.  A successful refuge population has now been established and there are now 50 individuals in the refuge population and in 2018, devil’s hole had a population of 187 devil’s hole pupfish.

Photo by Brett Seymour

https://www.fws.gov/nevada/protected_species/fish/species/dhp/dhp.html

https://www.nationalgeographic.com/animals/article/endangered-devils-hole-pupfish-breeding-breakthrough?loggedin=true

Michigan, is an absolutely gorgeous state and as an Ohio State football fan I would never give that state a compliment unless it were true. Michigan is surrounded by four out of the five Great Lakes: Huron, Michigan, Superior, and Erie. Water health is an ongoing issue in this state, with the Flint crisis being the most famous. However, with updated EPA regulations and more rigorous testing for lead in drinking water more and more cities in Michigan as well as in Ohio could be looking at dangerous lead levels that previously went unnoticed. 

Now most of us know how dangerous high lead levels are for humans. But for those of us that don’t the CDC states that common ailments that occur with high lead exposure include anemia, weakness, and both kidney and brain damage. But what does lead exposure mean for fish that spend 100% of their life swimming in high levels of lead?

Greater concentrations of lead in water and bottom substrate can be dangerous for fish. Water with higher concentrations of lead can lead to acute lead toxicity. Acute lead toxicity damages the gill epithelium which is the thin tissue on the outside of gills that allow fish to breather underwater. Once the gill epithelium is affected this causes death by suffocation. Additionally, high lead levels in water changes the chemical makeup of their blood. This then leads to damage to the kidneys, adrenal glands, liver, spleen, and pancreas. Furthermore, a fish’s nervous system can be seriously damaged with too much lead exposure. 

Excess amounts of lead in water is not only a humanitarian crisis but an environmental crisis as well. More attention needs to be focused on the lead crisis that is currently happening. 

https://www.fao.org/3/t1623e/T1623E03.htm

https://www.cdc.gov/niosh/topics/lead/health.html

https://www.worldatlas.com/maps/united-states/michigan

Trophy fish are giant fish of different species well sought after by anglers for their size. These fish tend to either  hang on someone’s wall after being caught or posted to their dating profile.  

However, trophy fish are about to take on a whole new definition thanks to a new fad called micro-fishing. Microfishing is fishing for small fish that are not normally pursued by anglers. Some popular microfishing fish include minnows, dace, darters, and sculpin. Here in Ohio we have all four of the  popular genera in our rivers, lakes, and streams!

In order to get into microfishing you’ll need to purchase a tiny hook, light line,  a crappie rod, and your bait (worms work great)! Additionally, in order to Microfish you need some pretty good eyesight since this sport involves sight fishing. This website goes into more detail for all your microfishing needs https://microfishing.com/tackle/ or Tenkara Bum for gear. 

Microfishing originated in Japan with the fishing for Tanago (Bitterling). The purpose of tang fishing is to catch as small of a fish as possible. Many Microfisher anglers in the U.S. are pursuing different species not just for their size but also rareness. 

Microfishing has the potential to inspire awareness for fish species that are often overlooked. Microfishing can also show citizens in Ohio the many amazing fish species in our streams, rivers, and lakes and bring about further protection for our fragile waterways.

https://fishbio.com/field-notes/fish-biology-behavoir/microfishing-smoller-better

Lake Erie, shallow as can be,

Fish abundance, far as the eye can see,

Memories created, in the fondest of ways,

Illuminating sunrises reflected on crashing waves.

A grim foe, threatens tranquility,

Algae blooms, green as itchy grass,

Toxic poisons, suffocating grasp,

Great water health, of the past.

Farm fields hosting banquets,

Handed on a silver platter by Summer rains,

Sponge like wetlands saving the day,

Helping organisms carry on their way.

Over the years, Lake Erie has struggled with toxic algal blooms affecting the environment and even the local economy.  I wanted to create a short poem for this important topic to spread awareness of how truly destructive these harmful algae blooms are on surrounding ecosystems. These blooms are known to suffocate many different species of fish and other organisms in Lake Erie by depleting oxygen in the water (1). The major reason for these algal blooms is agriculture runoff from surrounding landscapes that eventually dumps potent concentrations of Phosphorus and Nitrogen into Lake Erie (2). These nutrients act as a food source for algae and causes them to exponentially grow into the blooms we see across the lake.

In the poem, I quickly mention the idea of wetlands because it’s believed they are a possible remedy for nutrient overload dumping into Lake Erie (3). Wetlands are fantastic at adsorbing nutrients, similar to a sponge, in any water that flows through them because of roots from surrounding dense vegetation. A large resource for algal blooms can then be greatly reduced by restoring wetlands in areas with high nutrient runoff before they reach Lake Erie.

References:

1) National Weather Service. Lake Erie Harmful Algal Bloom: About. National Oceanic and Atmospheric Administration. Retrieved from: https://www.weather.gov/cle/HABabout

2) Kozacek, C. (2014) Cause of Lake Erie’s Harmful Algal Blooms Gains More Certainty. Circle of blue. Retrieved from: https://www.circleofblue.org/2014/world/cause-lake-eries-harmful-algal-blooms-gains-certainty/

3) Mitsch, W. (2017) Solving Lake Erie’s harmful algal blooms by restoring the Great Black Swamp in Ohio. Ecological Engineering. (108): 406-413

Like to catch Walleye, but are concerned about overfishing?

Fear no more! Aquaculture is here to save the day.

Aquaculture is the world’s fastest growing food production industry. Many species are of aquaculture interest, including Walleye (Sander vitreus), Yellow Perch (Perca flavescens), Rainbow Trout (Oncorhynchus mykiss) and many more. Aquaculture is defined as the raising of aquatic organisms for food. The industry of aquaculture often rears sport fishes—such as the Walleye—for the purposes of stocking them. Once they are stocked, anglers catch them and eat them. Walleyes are now one of the most sought-after sport fishes, and they are found in 32 percent of freshwater ecosystems in North America. The North Central Aquaculture Center previously identified Walleye as one of the most promising aquaculture species.

Great Lakes populations of Walleye have been overfished in the past, resulting in population declines in areas of the Great Lakes. States have implemented strategies to prevent population decline, such as habitat protection as well as walleye rearing and stocking. Rearing and stocking Walleye can help keep the population at a healthy level and keep Walleye in the Great Lakes for many years to come. Walleye can be stocked as juveniles; from there they will continue to grow in the wild until they are of catching size. The U.S Fish and Wildlife service has stated that climate change has begun to affect Walleye habitat distribution. The displacement of Walleye by warm water species may change their range and population. The culturing of Walleye for stocking purposes may help to mitigate this issue.

So how is it done?

Walleye are often bred in aquaculture facilities and kept there until they are of stocking size. They are often fed commercially available foods. Typically, they are kept in large tanks with colder water, in order to best mimic their natural habitat. Tank size will vary based on the aquaculture facility or lab. In Dr. Dabrowski’s lab on the OSU campus, we keep our juvenile Walleye in 400L tanks. Here is a photo showing where they are kept!

References:

https://www.fws.gov/fisheries/freshwater-fish-of-america/walleye.html#:~:text=Great%20Lakes%20walleye%20populations%20have,the%20Great%20Lakes%20drainage%20basin.&text=Recent%20climate%20changes%20may%20be,sunfish%2C%20largemouth%20and%20smallmouth%20bass.

https://lib.dr.iastate.edu/cgi/viewcontent.cgi?article=1008&context=ncrac_whitepapers

https://www.ncrac.org/files/page/files/Chapter9.pdf

Zebrafish are a small tropical species in the Cyprinidae family, and they are native to regions in South Africa.

Have you ever wondered why Zebrafish are often used in medical research?

It turns out that Zebrafish are a model organism, and share a lot of similarities to humans! We actually share 70% of our genes with Zebrafish. They have a lot of the same physical characteristics as us, such as a heart, spinal cord, eyes, kidneys…the list goes on. Zebrafish have also been useful for studying human diseases. Since Zebrafish share a lot of the same characteristics, changes in human organs as a result of disease will also appear in Zebrafish organs as well. They have also been used for toxicology studies, such as how certain substances or drugs affect their physiology.

Zebrafish are useful for understanding areas of ecology as well. Lots of genetic experiments have been performed with Zebrafish. Since they are a model species, methodology used in genetic experiments can also be applied to other species. A lot of people may wonder about the other benefits of Zebrafish, aside from them being a model species. First, they are quite small. This makes them efficient to keep in research labs, especially where space is often limited. They are quite easy to handle, hardy, and are easy to provide proper husbandry for. Also, females are quite fecund and will produce many eggs per spawning event. This is useful for when many eggs or embryos may be needed to run an experiments. Unlike some fish, Zebrafish in captivity do not have a spawning season. Spawning can be induced anytime, which is very useful for experimentation and research purposes. Lastly, in vitro fertilization (fertilization outside the body) can be done with Zebrafish, making it very easy to control fertilization and study development.

Here’s a photo of a Zebrafish:

Here’s a photo of a Zebrafish embryo developing under the microscope (this is at the 8 cell stage!)

References:

https://irp.nih.gov/blog/post/2016/08/why-use-zebrafish-to-study-human-diseases

https://academic.oup.com/mbe/article/32/3/635/976822?login=true

The lake trout (Salvelinus namaycush) was once a thriving, native species to Lake Erie. However, after numerous effects caused its decline and ultimate demise, it has been a difficult process of attempting to restore the species back to what it once was.

Lake Erie lake trout

Photo credit: The Buffalo News, courtesy of Bill Hilts Jr.

Lake trout was a prevalent species in the fish community of Lake Erie. This changed after commercial fishing moved into Lake Erie in the 1700s. The impacts of fishing only worsened in the 1800s when commercial fishing intensified. The intensification was caused by the increase in waters that were fished, including deeper waters. Additionally, gill nets came to be used as well as larger fishing vessels, all of which led to higher catch counts, therefore harming the lake trout population to a point of decline. The impact was so great, that the average annual harvest of lake trout in the late 1800s-1900 was more than 22,000 pounds.

Once managers started noticing what was happening in Lake Erie with the lake trout population, there was an attempt for management strategies to be implemented. One of these strategies was the regulation of the fisheries, which in the beginning was not very successful. Another strategy was to stock the lake with lake trout, which began back in 1879.

As time went on, even more negative factors were affecting the lake trout species. The first of these negative factors was the alteration of Lake Erie due to pollution and eutrophication. These negative effects altered the lake water, and therefore the lake trout’s habitat, which caused multiple issues, including declines in reproductive success. A second negative factor that began influencing the lake trout population was an invasive species, the sea lamprey (Petromyzon marinus), which was considered to be a parasite to the lake trout.

A sea lamprey attached to a lake trout

Photo Credit: International Joint Commission, credit: Marc Gaden, GLFC

It is believed that the complete depletion of the lake trout occurred sometime soon after 1965. Since then, various agencies have worked together to attempt the recovery process of the species in Lake Erie, including the New York Department of Environmental Conservation and the Pennsylvania Fish and Boat Commission. Management strategies to recover the species have included control on sport fishing mortalities, prohibition on the commercial fishing of lake trout in Lake Erie, and continued treatment for reducing the sea lamprey population.

Management strategies have shown some positive outcomes on the abundance of lake trout in Lake Erie thus far, as the annual survival of the lake trout has been increasing. As time goes on it is important that managers continue to keep up with maintenance stocking and that budgets remain in place for both stocking and the treatment of the sea lamprey. Things are looking up and it does look like the future for the lake trout in Lake Erie is bright.

Literature Cited

Floyd C. Cornelius, Kenneth M. Muth, Roger Kenyon, Lake Trout Rehabilitation in Lake Erie: A Case History,
Journal of Great Lakes Research, Volume 21, Supplement 1, 1995, Pages 65-82, ISSN 0380-1330,
https://doi.org/10.1016/S0380-1330(95)71084-X.

Artist Yusei Nagashima’s muse is fish. His fascination began as a child and has manifested itself into detailed watercolor paintings of a diversity of species. He claimed that he was, “captivated by the form of the fish,” when he was young and, “how it carried itself in the water, the sparkle of its eyes and scales; the lively movements of its muscles when it was caught, its intimidating, expression as its throat swelled.”(Weeks). At age eight, his first interest in fish was peaked during a visit to a tropical fish store, where he saw baby piranhas. He expressed the contrast in the way that they are typically viewed as, being vicious and brutal, compared to the way he viewed them, as “delicate and beautiful.”(Gestalten). From that point forward, he found his art focusing on fish over everything else.

Yusei’s interest in fish does not stop in his artwork. He enjoys fishing and reflects on fond memories of fishing with his father as a child. He expressed the mixture of emotions that he felt during one particular experience where he lost his favorite rod to a large fish while angling in the ocean. He recalled being disappointed and frightened in the moment but when his father caught a fish that happened to be the one attached to his rod, he realized how impressive of an experience that was, “during which I felt both great fear of and respect for the depths of the ocean.”(Gestalten).

Three years ago Yusei began posting one painting each Friday on his blog (Yusei Nagashima). On his blog you are able to view his watercolor works that encompass a wide diversity of fish. He feels that his art can be an aid in teaching people about the importance of not only fish, but the natural world as a whole. “Nature is something that we must protect…We must think about our position as humans in nature and we should live alongside nature. I think fish and fishing reveal such a relationship.”(Gestalten).

Citations
Gestalten US Shop. “Meet Yusei Nagashima of the Fly Fisher.” Gestalten US Shop, https://us.gestalten.com/blogs/journal/meet-yusei-nagashima-of-the-fly-fisher.

Weeks, David, et al. “Japanese Artist Creates Delicate Watercolor Paintings of Fish Every Week.” My Modern Met, 16 June 2016, https://mymodernmet.com/yusei-nagashima-fish-watercolor-paintings/#:~:text=Tokyo%2Dbased%20artist%20Yusei%20Nagashima,his%20beautifully%20detailed%20watercolor%20paintings.

Yusei Nagashima Uonofu.sblo.jp, http://uonofu.sblo.jp/index-6.html.

I want to fart so hard

Despite what this meme says, this puffer fish does not have to fart. What causes these fish to look like they have really bad gas? It is a defense mechanism that they perform when threatened. The goal of inflating is to multiply the size of the fish and to present their spines. This makes the puffer fish more difficult to bite which makes them less appealing to predators. It’s not a fart, its fear! (Seattle Aquarium, 2021).

“Why Do Pufferfish ‘Puff up’?” Seattle Aquarium, https://www.seattleaquarium.org/blog/why-do-pufferfish-puff#:~:text=Pufferfish%20will%20%E2%80%9Cpuff%20up%E2%80%9D%20as,very%20appetizing%20to%20a%20predator.&text=Most%20puffers%20are%20toxic%20to%20eat.

Image: https://www.monsterfishkeepers.com/forums/threads/fish-memes.712836/page-2

They gave me a friend once…

Betta fish are infamous for being solitary and territorial creatures that do not get along with others. What many people do not know is that there is a reason that betta fish are so prone to fight. In the 1800s people discovered these fish and found that some of them were very aggressive and prone to fight, so they began to be bred for their aggression, for the purpose of betta fighting (Bryan, 2018). As a result, aggression has been maintained in their genetic makeup to this day.

Bryan, et al. “Why Do Betta Fish Fight?” Bettafish.org, 8 Aug. 2018, https://bettafish.org/faq/why-do-betta-fish-fight/.

Image: https://aminoapps.com/c/betta-keepers/page/blog/betta-fish-memes/V01d_rPqU7uMzn3V45BJVXnWvNdvjEapjvn

You see right through me

The specimen pictured in this meme is the larval form of an eel, from the suborder Elopomorpha. There are many species of eels that have transparent larva, including the conger, moray eel, and the garden eel. These larvae are transported throughout the ocean by currents from their spawning grounds to intertidal areas, where they morph into their adult form (Science Direct, 2021). Once in their adult forms they do not have the same transparent physical characteristic.

“Leptocephalus Larvae.” Leptocephalus Larvae – an Overview | ScienceDirect Topics, https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/leptocephalus-larvae.

Image: http://www.quickmeme.com/transparent-fish

In 1974 a man by the name of Keith Allies, won two goldfish at a fair and named them Fred and George. Little did he know, the fish would become his companions for the next 44 years of his life. Keith was able to share many monumental milestones with his two fish friends, including his marriage, moving into his first home, and becoming a first time father. Sadly, Fred passed away in 2017, which led to the decline of health in his friend, George, who passed away two years later, in 2019 (Middleton, 2019). Throughout their lifetime, these two old fishy souls have been mascots of the community, and one can argue, for all of Britain.

The real question is, how did those fish live for so long. It is known that most animals who live in captivity live longer lives than those in the wild but 44 years is a longgg time. Scientists and pet enthusiasts have given some helpful tips on how to extend your fish friend’s life including:

• Use the largest tank possible
• Provide enrichment for the fish
• Increase oxygen diffusion into the water
• Keep tank clean
• Allow water temperature to change as seasons change
• Properly feed your fish (Robert, 2021)

RIP George and Fred

Middleton, Lucy. “George, Britain’s Oldest Goldfish, Dies Aged 44.” Metro, Metro.co.uk, 15 Apr. 2019, https://metro.co.uk/2019/04/15/george-britains-oldest-goldfish-dies-aged-44-9210539/.

Robert. “How Long Do Goldfish Live? 5 Ways to Increase Their Lifespan.” Fishkeeping World, 28 Sept. 2021, https://www.fishkeepingworld.com/how-long-do-goldfish-live/.

Is your diet making you fat? Lake Erie Smallmouth Bass Diet

To all the fishermen and women out there. Have you wondered why Lake Erie smallmouth bass (Micropterus dolomieu) are so fat? In a recent research study done by Crane and Einhouse on Lake Erie, smallmouth bass diet data was used from the past 19 years to analyze the diet composition of a smallmouth bass diet in relation to the round goby (Neogobius melanostomus). Round gobies are an invasive species in the Great Lakes that came here from Eurasia in the ballast tanks of ships.

Round Goby

Photo credit: Paul Skawinski

The study was conducted in the eastern basin in Lake Erie near Buffalo, NY. Prior to the invasion of round goby into the Great Lakes, the smallmouth bass diet was just over 50% crayfish (Crane and Einhouse). After the invasion, round goby began to make up just under 75% of the smallmouth diet. For us humans, this is like typically eating a chicken drumstick for dinner and then switching to a routine T-bone steak and a potato every night. Diet alterations like this cause smallmouth bass to grow to sizes like the one shown below.

Smallmouth Bass

Photo credit: Jim Hanleys Fishing Charters

The round goby fight back against the smallmouth bass by predating on smallmouth bass nest sites. Even with round goby predation of smallmouth bass eggs, a higher percentage of smallmouth bass were found to survive to maturity than pre-invasion. The downside to these bass growing so rapidly is that the lifespan of the fish is decreased. With decreased lifespan, the less time the fish has to reproduce. During the study, bass were reaching sexual maturity earlier. They found the greatest size increase from ages 2-4 years. Crane and Einhouse expressed concern about the fecundity of the smallmouth bass in Great Lakes and thought that further research was needed in the following years.

Researchers and Charter fishermen agree that Great Lakes smallmouth bass have increased in size since the invasion of the round goby. As friendly advice, if you haven’t caught a Great Lake smallmouth, you have to try. You will not regret it.

Cited

Study Conducted Article-

D.P Crane, D. W. Einhouse. 2016. Changes in growth and diet of smallmouth bass following

invasion of Lake Erie by the round goby. Journal of Great Lakes Research. 42: 405-412.

https://www.sciencedirect.com/science/article/pii/S0380133015002713?via%3Dihub

Round Goby image-Paul Skawinski, fwwa.org

Smallmouth Bass image- Jim Hanleys Fishing Charters, Northeastoutdoors.com

Other Articles-

https://www.newyorkupstate.com/outdoors/2016/05/why_are_the_smallmouth_bass_in_lake_erie_so_darn_big.html#targetText=In%20fact%2C%20in%20Lake%20Erie,round%20gobies%20prefer%20as%20well.

https://greatlakesecho.org/2015/02/12/good-news-smallmouth-bass-chow-down-on-invaders/

Port Clinton, Ohio is commonly referred to as the Walleye capital of the world and for the past few years, the Walleye fishing has exceeded expectations. Charter after charter brought in full multiple-person limits, often about 36 fish per boat per day. While this is beneficial for the economic industry around Lake Erie, the high numbers of walleye might be unintentionally causing an impact on another major sport fish, the Yellow Perch. Oftentimes, when Walleye are abundant the Yellow Perch populations are inversely related. For many Charter fishing captains, this year’s Yellow Perch season is by far one of the worst. The Charter captains have been discussing potential reasons for this issue, as their living is dependent upon the quality of fishing on Lake Erie. By looking at additional factors impacting the Yellow Perch in Lake Erie it can aid in the management of this irreplaceable recreational fishery.

Currently, the Ohio Division of Wildlife implemented the daily legal limit at 6 walleye per person of at least 15 inches and 30 perch per person with no size limit.¹ It is hoped that the anglers throw back the smaller Yellow Perch to promote sustainable numbers for each spawning season. Stuart Ludsin, a professor of evolution, ecology and organismal biology at The Ohio State University, mentioned that only about 10 million 2-year-old Yellow Perch showed up in population survey catches compared to the approximately 75 million caught in the mid-1980s.² Additionally, Ludsin stated in the Outdoor News interview that there are about 46 million to 106 million predators in the western basin of Lake Erie.² In just 24 hours the predators can consume between 32 million and 189 million Yellow Perch larvae.² The main predator is the White Perch as well as the Walleye and White Bass.

There has been a strong competition among White Perch and Yellow Perch with the population of the native Yellow Perch decreasing up to 79% after the introduction of the White Perch more than 50 years ago.³ The research study performed stomach content analysis and found that there were similar diets between the two species.³ There is competition of food resources among these two fish species due to their overlapping niche. Other invasive species such as the Round Goby have been negatively impacting age-0 Yellow Perch. Age-0 is a critical period for fish to have sufficient resources available to aid in their survival. During this stage Yellow Perch typically search for rock substrate to locate a main food source, benthic invertebrates.⁴ Benthic invertebrates are a type of small aquatic animal or insect larvae that includes dragonfly larvae, snails, and worms. However, after the population boom of the Round Goby, the age-0 Yellow Perch changed their habitat from rock to sand as well as their dietary preferences from benthic invertebrates to zooplankton.⁴ Additionally, this is coupled with invasive Zebra Mussels in Lake Erie consuming the zooplankton that the age-0 Yellow Perch were feeding on. All of the pressure from multiple invasive species can accumulate. Figure 3 shown below depicts a fish biomass (not true abundance) breakdown from the Lake Erie Western Basin. It is important to consider that nonnative species make up a significant portion of this chart.

The temperature of the water throughout the year significantly impacts the fish since they are ectotherms. When the summer season is longer it allows for more growing, but when examining the reproductive success after short winters, the results were not promising.⁵ After short winters the females spawning in warmer water temperatures produce smaller eggs that hatch at lower rates as well as produce smaller larvae than females do after long winters.⁵ Figure 4 shows the difference between shorter and longer winters regarding the spawning timespan. Based on the figure, during long winters there was a continuously increasing water temperature that occurred later in the year whereas the short winters had a steady higher temperature that occurs sooner. Yellow Perch thrive in cooler water temperatures. The water temperature limiting the number of successful eggs produced could impact the population in each sequential hatch year.

While there is no single, definite answer to the sub-par Yellow Perch fishing in Lake Erie this year, it has local anglers worried. It is even possible that the Yellow Perch simply aren’t in their usual location at this time of year or might not be as interested in consuming the tackle used when fishing. The Ohio Division of Wildlife uses scientific data to calculate the daily bag limit that is sustainable for the future of the Lake Erie fishing industry. Many variables play into having an ample fish population, so it will always be important to be aware of the fluctuating dynamics of this valuable ecosystem.

Citations:

1.) Ohio Division of Wildlife. (2019). Ohio Fishing Regulations. Department of Natural Resources. Retrieved from http://wildlife.ohiodnr.gov/portals/wildlife/pdfs/fishing/2019-20%20Ohio%20Fishing%20Regs_WEB.pdf

2.) Meyerson, H. (2014). Increasing white perch affecting yellows. Outdoor News. Retrieved from https://www.outdoornews.com/2014/03/13/increasing-white-perch-affecting-eries-yellows/

3.) Guzzo M., Haffner D., Legler, N., Rush S. & Fisk A. (August 2013). Fifty years later: trophic ecology and niche overlap of a native and non-indigenous fish species in the western basin of Lake Erie. Biological Invasions. 15(8): 1695-1711.

4.) Houghton, C. (May 2015). Round Goby-Induced Changes in Young-of-Year Yellow Perch Diet and Habitat Selection. Thesis and Dissertations. 879: 1-94.

5.) Farmer T., Marchall E., Dabrowski K. & Ludsin S. (2015). Short winters threaten fish populations. Nature Communications. 6(7724): 1-10.

Fisherman pack your poles and ready your bait because Lake Erie is, quite literally, swimming with walleye.

Walleye, which are also called pickerel, yellow pike, walleyed pike, or white salmon, are a large freshwater sport fish. They typically range in size from 14 to 22 inches and weigh 2 to 4 pounds, however, they can get as large as 36 inches and 16 pounds (ODNR 2012). Walleye are found throughout most of the northern United States and Canada; they prefer cold water to warm water and like to rest on the sandy or rocky bottoms of rivers, streams, and lakes. This fish gets its name from the reflective film of pigment covering its eyes that helps it see in murky waters; this pigment also makes them more sensitive to light and active at night (American Expedition 2015). Walleye are also well renowned for their flavor.

The walleye’s value as a sport fish makes it a well monitored species. Last year a record breaking number of of 188,701 walleye were fished from Lake Erie (Hilts 2019). The good news does not end there. Every August, biologists take nets and survey about 40 locations between Toledo and Huron for young walleye (Hlavaty 2019). The most recent conclusion? Fishing is bound to be pretty good. Matt Wolf, a fishery biologist for the Ohio division of Wildlife, stated that this year’s hatch of walleye is the second-highest on record for Ohio’s waters. It’s larger than the twenty-year average of walleye hatches. In fact, the total number of walleye in the lake is estimated to have gone from 41 million fish in 2018 to 45 million fish age 2 and older in 2019 (Hilts 2019). Because walleye can live up to around 20 years, this bounty is bound to have a lasting effect on future fishing (Hlavaty 2019).

So, where’s the best spot in Lake Erie to fish? According to Cleveland.com, walleye have been caught “in good numbers” in 70 to 75 feet of water off Ashtabula, 65 to 72 feet of water off Edgewater Park and Wildwood Park in the Cleveland area and in 50 to 55 feet of water off Lorain (Egan 2019). Lake Erie’s western basin, which has an depth of about 25′ is known for being a particularly good spot for catching walleye (Lake Erie Western Basin 2014).

Good luck and happy fishing.

PHOTO SOURCE

Knepp, Timothy. Walleye (Sander vitreus) from the U.S. Fish and Wildlife Service. Accessed September 20, 2019 (https://en.m.wikipedia.org/wiki/File:Walleye_painting.jpg)

REFRENCES

American Expedition (2015) Walleye Information, Photos, and Facts. Retrieved September 20, 2019, retrieved from https://forum.americanexpedition.us/walleye-facts

Egan, D’arcy (2019, September 20) Lake Erie walleye hitting; yellow perch are hit-and-miss: Fishing Report for Sept. 20. Retrieved September 20, 2019, retrieved from https://www.cleveland.com/sports/2019/09/lake-erie-walleye-hitting-yellow-perch-are-hit-and-miss-fishing-report-for-sept-20.html

Hilts, Bill. (2019, April 17) Get Ready for Another Spectacular Fishing Year on Lake Erie. The Buffalo News, The Buffalo News, 17 Apr. 2019, buffalonews.com/2019/04/17/outdoors-fishing-recreation-lake-erie-ontario-bass-steelhead-walleye-2019/.

Hlavaty, Kaylyn (2019, September 19) ODNR says Lake Erie will be the place for Walleye, perch anglers. Retrieved September 20, 2019, retrieved from https://www.news5cleveland.com/news/local-news/oh-cuyahoga/odnr-says-lake-erie-will-be-the-place-for-walleye-perch-anglers

Lake Erie Western Basin. (2014). Retrieved November 8, 2019, from http://lakeeriefisherman.com/western-basin/.
ODNR (2012) Walleye – Sander vitreus. Retrieved September 20, 2019, retrieved from http://wildlife.ohiodnr.gov/species-and-habitats/species-guide-index/fish/walleye

Lake Sturgeon populations in the Maumee River were stable and plentiful at one time, but began to drastically decrease due to overfishing, habitat degradation, and limited access to spawning grounds (Eckes, 2018). Lake Sturgeon were declared endangered by the Ohio Division of Natural Resources and conservation efforts have come to fruition (Mertz, 2012). Lake Sturgeon are the largest fish native to the Great Lakes region, commonly found up to six feet in length (Mertz, 2012). They have no scales, but bony plates line the length of their body and rough skin. They play a critical role in their environment by consuming decaying organisms and benthic organisms, including invasive zebra mussels and quagga mussels (Pignataro, 2013). Scientists evaluated fishing regulations, habitat availability, food availability, and reproductive needs before implementing their reintroduction plan (Eckes, 2018). The reintroduction of Lake Sturgeon is actually putting them back into the Maumee River where they once lived. Scientists determined that the Maumee River is suitable habitat based on the level of sedimentation and velocity of the water (Williams, 2019). Additionally, the Maumee River holds ample food resources and the spawning grounds are relatively unimpeded by dams with appropriate flow regimes (Williams, 2019). When all conditions were compatible with reintroduction into the Maumee River, they proceeded with their action plan.

As part of the Lake Sturgeon reintroduction plan, approximately 1500 Lake Sturgeon were raised in a hatchery trailer near the Toledo Zoo using water from the Maumee River and another 1500 were raised at Genoa National Fish Hatchery with hatchery-supplied water (Eckes, 2018). Lake Sturgeon return to their natal streams to reproduce when they reach maturity. Males mature at about 15 years of age, but females take about 25 years to mature (Williams, 2019). All Lake Sturgeon suitable for release into the Maumee River will be PIT tagged and monitored (Eckes, 2018). A select few individuals were tagged with acoustic monitors for advanced monitoring (Eckes, 2018). The difference in the water supply source will help scientists to determine the importance of natal imprinting on hatchery raised Lake Sturgeon when these individuals reach maturity and return to their natal spawning grounds (Eckes, 2018). Additionally, scientists will be able to monitor the growth and survival to see if there are any differences between Lake Sturgeon raised at these two different sites. The determination as to whether this reintroduction is truly successful will not be known for more than 25 years because scientists need to see if mature hatchery Lake Sturgeon will be able to naturally support their own population through reproduction.

This reintroduction of Lake Sturgeon to the Maumee River brought awareness to the public by giving them the opportunity to sponsor a Lake Sturgeon that is being released and providing resources to learn more about this amazing fish. Anyone that gives a donation to sponsor a Lake Sturgeon is given the opportunity to release it into the Maumee River and will be notified if their Lake Sturgeon is recaptured in the future (Hageman, 2018). Additionally, the Toledo Zoo and hatchery trailers will be open to the public to learn more about Lake Sturgeon reintroduction and conservation (Eckes, 2018).

References:

Eckes, O. (2018, September 27). First Stocking of Lake Sturgeon into the Maumee River Scheduled for October 2018. Retrieved from https://www.fws.gov/Midwest////////Fisheries/fishlines-2018-09-27/feature1.html.

Hageman, J. (2018, October 1). First Maumee River lake sturgeon to be released. Retrieved from http://www.sanduskyregister.com/story/201809270019.

Mertz, M. (2012). Lake Sturgeon. Retrieved from http://wildlife.ohiodnr.gov/species-and-habitats/species-guide-index/fish/lake-sturgeon.

Pignatatro, T. (2013, September 7). Sturgeon battles back to repopulate Lake Erie, lower Niagara River. Retrieved from https://buffalonews.com/2013/09/07/sturgeon-battles-back-to-repopulate-lake-erie-lower-niagara-river/.

Williams, S. (2019, January 1). The sturgeon restoration study’s outcome won’t be known for decades. Retrieved from https://www.the-scientist.com/notebook/a-project-aims-to-reestablish-an-ancient-fish-in-an-ohio-river-65234.

Morphology and Behavior

Polyodon spathula (Paddlefish) are an intriguing and strange freshwater fish. Their long nose, or rostrum, is a distinct feature. This rostrum is formed after hatching and is covered in sensory pores. Another distinct feature is a long operculum flap which may aid in protecting the gills while feeding. Their skin is smooth and isn’t scaled, resembling that of a shark. Like sharks, they have a cartilaginous skeleton that consists mostly of a spinal cord and lack bones. They have a tail that is heterocercal and small eyes placed close to the mouth. Paddlefish can reach up to 5 feet in length and weigh over 60 pounds (Jennings, 2000).

Paddlefish feed by swimming with their mouths open, usually near the surface of the water. They travel long distances in search of food and for breeding. Paddlefish are long lived, and do not reach sexual maturity until 7-10 years of age. Spawning typically occurs in late spring during the correct conditions. Paddlefish migrate upstream in search of correct conditions for water flow, temperature, length of day, and correct substrate. Without all of these conditions, Paddlefish will not spawn, sometimes going 3 years between events. When a spawn does occur, males and females broadcast sperm and eggs over a gravel bed. Fertilization occurs externally and the eggs wash downstream to deeper pools (Jennings 2000).

Conservation Concerns

Paddlefish numbers have been gradually declining due to pollution and other human factors. One major concern is in breeding. Since Paddlefish are so picky about breeding conditions, it is of the utmost importance that breeding sites be maintained. The manipulation of riverbanks, addition of dams, and other practices affecting river level can prevent breeding. Another factor that makes their reproduction slower is old age to reach sexual maturity. Their feeding behaviors can put them at risk as well. Swimming near the surface puts them in danger of being struck and killed by boats. Finally, people exploited them in the past for meat and caviar. The meat is desirable due to the lack of bones. The Roe (eggs) are popular for caviar due to the mild flavor and large number of eggs per fish (Jennings, 2000).

Commercial Market

Paddlefish are commonly farmed. The main motivation for farming is for caviar. Their caviar can be sold for as much as $35 and ounce and females can produce about 20 pounds of caviar ($11,200 per fish). Their meat is sold as a byproduct, though it is highly sought after. Paddlefish farming is appealing to many fish farmers. In addition to improving water quality, they do not require supplemental feeding. Farm ponds are often stocked and left to sit for 7 years until females reach maturity (Jennings, 2000).

Paddlefish Caviar

For more information on this intriguing fish, check out this article!

https://pubs.er.usgs.gov/publication/1017141

Works Cited

Pictures

https://www.outdoorlife.com/articles/fishing/2015/03/egg-takers-harvesting-americas-paddlefish-caviar/

Big Fish Expeditions

Information

Jennings, C. A., & Zigler, S. J. (2000). Ecology and biology of paddlefish in North America: historical perspectives, management approaches, and research priorities. Reviews in Fish Biology and Fisheries, 10(2), 15.