Pre-Construction Fish Sampling

Terrain alone makes fish sampling in these environments complicated

Fish collecting in wetland environments is notoriously difficult. Gathering representative data on the species diversity and relative abundance of each type of fish present at any given time presents major challenges. Water levels vary (and are often too shallow for sampling using traditional boat-mounted methods). Obstacles are abundant (whether in the form of diverse islands of vegetation, submerged woody debris, and/or soft sediments). Generally, sampler access is rarely easy and opportunities for refuge and sampling evasion are immense.

Fyke net setup just inside the marsh at the
soon-to-be-replaced pump structure

But on the eve of equipment mobilization for our much anticipated "Water Conveyance Replacement Project" in our West Marsh (our biggest restoration activity of the 2018 field season), we had to give it "the old college try" -- quite literally. Yesterday, one day before the start of their fall semester, three graduate students from the Bowling Green State University's Aquatic Ecology & Fisheries Laboratory volunteered to join us for a long, sweaty, and -- for a self-proclaimed "fish freak" like myself -- very FUN day in the marsh.

The goal: Utilize multiple sampling techniques to gather a pre-construction "snapshot in time" as to what fish are currently utilizing the West Marsh and the bayside communities immediately adjacent to the structure that will soon be replaced.

So, it made sense to start at what will become the construction zone. The first Fyke nets were set on either side of the soon-to-be demolished concrete structure -- one on the marsh side and one on the bay side. We then spent the balance of our first hour setting three more trap nets at other strategic locations within the West "Rest Pond" and the "Main Marsh," immediately adjacent to the south.

Fyke net setup just outside the marsh and soon-to-be-replaced
structure, extending into the estuary to Sandusky Bay

Because we were trying to accomplish our sampling blitz all within one field day (and because we also wanted to reduce the probability of turtle mortality in the hoop nets), we opted to shoot to soak the stationary traps for approximately four hours each. While there is always eager anticipation built into this waiting period, we didn't have time to dwell on the waiting game. We spent any "down time" actively sampling a handful of interior locations by pulling a 3-meter seine with an oversized collection bag. This method most certainly has its limitations (we could literally see certain species like carp and largemouth bass swimming out in front of us), but it definitely produced some unique findings.

In my experience, I've found it is a lot more gratifying to frame fish sampling in terms of what you capture (and learn) rather than what you don't. Every sampling event is another learning experience. Time of year, time of day, weather conditions, sampling methods, access capabilities -- they all play major roles. Of course, we would have loved to see more yesterday. But we caught fish!

A pile of young of year sunfish -- predominantly bluegill, pumpkinseeds, orangspotted sunfish, green sunfish,
black crappies and white crappies collected in one Fyke net haul --
nearly every one of these fish was born either this year or last

We have been waiting for a day like yesterday for a long time (for me personally, since day one). So it is normal to wish you could record every last species -- heck, every last fish -- swimming in the marsh! But yesterday was just our first effort. It was the proverbial "snapshot in time." Our human resources were limited (though highly motivated); our methods were limited (we didn't even get to backpack or boat-mounted electrofishing); and, our time was finite (although we busted a lot out between 9AM and 6PM on one humid, 90-degree late summer day).

Identifying and counting sunfish
as they are removed from the net
and released

In the end, our sampling yielded 14 species, most certainly dominated by the Centrarchid Family (the "Sunfishes"):

Bluegill (Lepomis macrochirus)
Pumpkinseed (Lepomis gibbosus)*
Black Crappie (Pomoxis nigromaculatus)
White Crappie (Pomoxis annularis)
Green Sunfish (Lepomis cyanellus)*
Orangespotted Sunfish (Lepomis humilis)
Largemouth Bass (Micropterus salmoides)

Others included:

Gizzard Shad (Dorosoma cepedianum)
Brook Silverside (Labidesthes sicculus)*
Western Mosquitofish (Gambusia affinis)
Common Carp (Cyprinus carpio)
Goldfish (Carassius auratus)
Golden Shiner (Notemigonus crysoleucas)
White Bass (Morone chrysops) -- estuary only


I maintain a master list of species that we have observed since we first started work on the property. My list of fish species is now up to 26 after yesterday's efforts. Those starred above were new finds yesterday. Those that we did not see yesterday that we have seen before on the property include: Channel Catfish, Black Bullhead, Brown Bullhead, Yellow Bullhead, Bowfin, Freshwater Drum, Emerald Shiner, Yellow Perch, White Perch, Smallmouth Bass, Northern Pike, and Steelhead (Rainbow Trout).

It would have been super cool to recapture one or more of the northerns that we stocked in conjunction with TPS this past spring. Nate, one of the BGSU masters students, is actually working on his doctoral degree on how northern pike utilize coastal habitats on Lake Erie. Sounds to me like a reason to keep sampling at Standing Rush!

Here are a few more of my favorite photos from yesterday's efforts. I'll try to post some of the individual fish species that we collected soon.

Deploying, retrieving, processing, and recovering Fyke nets -- like all fish sampling -- is best accomplished as a team

This little guy stuck with us and was completely hands-on for a full twelve hours; I woke him just before 7 AM
and we got home just before 7 PM -- we might possibly have a scientist in the making; he was in hog heaven

Our dedicated crew from BGSU -- they definitely reinforced a common student mantra: "We'll work for food!"
And they did it with smiles and enthusiasm -- appreciate it, guys; hope it can be the start of a continuing collaboration