HOOK, LINE & SCIENCE
Fishing at Wind Farms, Live Imaging Sonar, and More
Research and News for Anglers
The award-winning series curated by Scott Baker and Sara Mirabilio, fisheries specialists with North Carolina Sea Grant
WHAT FISH CAN WE EXPECT TO SEE AT THE EAST COAST’S OFFSHORE WIND FARMS?
Red snapper love the Gulf ’s oil and gas platforms — but another species in particular might enjoy the wind farms coming to the East Coast.
Research Need
During my time at Louisiana State University, I took fishing trips 10-30 miles offshore in the northern Gulf of Mexico and bottom-fished next to many oil and gas platforms. With more than 3,500 oil and gas platforms in the Gulf, fishing next to one is commonplace. Anglers know that these structures hold fish — and that the types of fish present depend somewhat on the depth of the platform and distance from shore.
One fish species that is synonymous with Gulf oil and gas platforms is the bottom-dwelling red snapper.
However, the East Coast is pretty much devoid of similar offshore structures — except for a few outposts like Frying Pan Tower — but rapid construction of offshore wind farms is on the horizon. Some projections suggest that thousands of structures will be installed within 10 years’ time.
What types of fish can we expect to see around East Coast offshore wind farms, given that most of the leased area is relatively close to shore and in waters less than 200 feet deep? What can we learn by studying the East Coast’s first offshore wind farm, Rhode Island’s Block Island Wind Farm, which sits 3.5 miles offshore in 100 feet of water?
What Did They Study?
Over the course of four days in 2021, researchers acoustically mapped out the area below surface around Block Island Wind Farm and then used hook-and-line fishing to try and catch the fish responsible for signal backscatter or “marks” at the most promising spots.
The survey crew attempted to get as close as possible to the platform base (a four-legged, steel “jacket” structure, similar to those that the oil and gas industries use) without having the acoustic signal interfere with the structure.
What Did They Find?
The research team mostly caught black sea bass (22 all told, ranging from 9 to 18 inches) — and believed the species was responsible for most of the acoustic signals they had received when mapping.
In addition, the team captured four bluefish, one scup, and one little skate. There were undoubtedly more types of fish around, but time, bait types, and fishing techniques limited the number of species they could catch.
Anything Else?
The acoustic data revealed that beyond one-tenth of a mile from a turbine, there was no noticeable increase in fish abundance. However, there were times when fish abundance near structures was similar to fish abundance hundreds, if not thousands, of feet away.
Turbines could act as fish aggregators at scales up to hundreds of feet — but effects beyond that may be sporadic.
So What?
This study only looked at one small but established offshore wind farm near Rhode Island. The planned offshore wind farm off North Carolina will be substantially bigger, with more turbines over a much larger area.
What will be the impact of that effort?
By Scott Baker
A blue catfish tournament offered 16 of 32 anglers access to live-imaging sonar. Credit: NOAA.
WILL LIVE-IMAGING SONAR HELP YOU CATCH MORE FISH?
Scientists ran an artificial fishing tournament to find out.
Research Need
New technology enters the recreational fishing community at a rapid rate. Some of it fades away, but some sticks and becomes popular or even a “must-have” with the angling community.
Need some examples? Think of how many new recreational fishing boats you’ve seen lately WITHOUT fuel-efficient 4-stroke outboard motors, high-definition downwards-facing sonar with large LCD displays in the center console, and bow-mounted trolling motors with the “spot-lock” feature that uses a GPS-enabled motor to effortlessly keep the boat in a fixed geographic location.
The challenge is that when people adopt something new en masse — and it has the potential to help anglers fish more effectively or simply change how they fish — it can quickly become a problem for managers, who are responsible for crafting policy to ensure that fish are sustainably caught and harvested.
In other words, what would happen if new tech made the sport of fishing more like catching?
This story is about one of the latest advances in fishing tech — live-imaging sonar. While its common to use downward-facing sonar to see a delayed depiction of the bottom on the boat’s depthfinder or chartplotter, live-imaging sonar is viewable “live” and users can point it horizontally in the water column to locate fish (or confirm the locations of fish). Usually attached to a bow-mounted trolling motor, the sonar has a range that depends on salinity and other factors.
Does this technology create an unfair advantage? Think of a fishing tournament without rules about it, in which some anglers use it and others don’t. How does this impact anglers’ perceptions and behaviors?
What Did They Study?
Scientists organized a mock catch-and-release blue catfish angling tournament on the Milford Reservoir in Kansas, where 16 anglers had access to live-imaging sonar and 16 anglers didn’t. The anglers had varying degrees of experience with both the technology and blue catfish.
Each team used 5/0 and 7/0 circle and Kahle hooks, as well as a selection of weights and instructions for rigging the provided baits (fresh cuts of common carp and river carpsucker).
For each day of a three-day competition each week, teams fished within a set 5-hour block. Prior to each round of competition, organizers allowed teams a pre-fishing day to get familiar with the gear provided.
After all rounds of the competition, anglers answered surveys to establish their levels of experience with live-imaging sonar and their perceptions about using it for blue catfish angling.
What Did They Find?
Teams with access to live-imaging sonar didn’t catch more blue catfish than teams without access. On average, each team caught about 35 pounds of fish per 5-hour time period.
Over the course of 440 angler hours, participants landed 454 fish, 82% of which were blue catfish.
What Did Anglers Think?
Participants who used live-imaging sonar thought both their time searching for fish and their catch totals would’ve been similar if they had NOT had access to the technology.
Conversely, anglers not allowed access to the live-imaging sonar thought they would spend more time searching for fish with the technology — and that their catch totals might have been higher if they used it.
Interestingly, angler teams with access to the technology spent more time searching for fishing spots than teams without it.
So What?
Research on the potential impact of live-imaging sonar is just getting started, and we will likely see much more of it in the future given its popularity. At least for one experiment on blue catfish in Kansas, liveimaging sonar seems to have a bigger impact on anglers’ perceptions and behaviors than on how much fish they catch.
By Scott Baker
Three main things make a fisher’s day. Credit: NC State Photos.
WHAT MAKES ANGLERS HAPPY?
Three things can make a fisher’s day.
Research Need
Fishery managers strive to maintain healthy fish populations, as well as healthy recreational and commercial fishing industries.
Managing the recreational sector requires an understanding of how anglers feel about their fishing opportunities. Satisfied anglers make individual choices that benefit the fishery, such as complying with regulations.
Unfortunately, angler satisfaction is hard to measure, because most study methods are hampered by limited time, insufficient funding, and response bias. Fishery managers need a practical way to measure angler sentiment so that they can find ways to satisfy anglers more often.
What Did They Study?
A research team focused on walleye anglers in nine states in order to test out a new approach to understanding these fishers’ levels of satisfaction. They identified angling-oriented online forums with active users in Arkansas, Illinois, Michigan, Minnesota, Missouri, Nebraska, North Dakota, Ohio, and Wisconsin and searched for posts with key words related to fisheries management.
The researchers gave each post a sentiment score based on seven variables: angler density (the number of fishers within a location), proportion of jobs, license cost, season length, agency transparency, bag limit, and special regulations. The team then averaged scores across all users in each state to estimate satisfaction at the state scale.
What Did They Find?
Angler density, bag limit, and season length proved to be the greatest influences on angler satisfaction.
The positive relationship between angler density and sentiment surprised researchers. They had theorized that crowded waterways would make for unhappy anglers. The researchers explained that an area’s unique fishing culture and the perception of “better fishing” with more crowds resulted in more satisfaction.
Ultimately, a higher angler density does reflect more social opportunities, increased bag limits create greater potential for catch success, and a longer season provides more chances for fishing trips. All three factors amount to more chances for enjoyment.
Anything Else?
Anglers in Illinois had the highest overall sentiment, while those in North Dakota had the lowest. When adjusted for the overall happiness of the general population in each state, North Dakota anglers still had the lowest, but Arkansas anglers had the highest sentiment.
The team acknowledged that more often anglers post in online forums when they have extreme emotions after having either a great day or a terrible day of fishing.
So What?
Study results demonstrate how online forums can provide insight into the satisfaction of anglers. This approach provides ample opportunities to learn more about topics that can inform fisheries management.
By Ruthie Froning, a science communication intern for North Carolina Sea Grant.
lead image credit: Pavel Muravev.
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