Month: December 2019

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.