Tracking Fish with Acoustic Telemetry—Implementation of an Exciting Technology in Lake PontchartrainMay 31, 2016 | Posted by Emily McCalla in Hunting and Fishing, Science, Wildlife
By Nic Dixon, Outreach Associate, Coalition to Restore Coastal Louisiana
The Louisiana Department of Wildlife and Fisheries (LDWF) and many other fisheries organizations and scientists worldwide have traditionally used fish tags to keep track of fish populations. You may have even applied these simple dart-tipped plastic tags to a fish yourself. Standard fish tagging efforts (in part) identify where the fish was originally captured, Point A, and then where the fish was recaptured, Point Z. But there is not a clear picture of where these fish were for points B, C, D, etc.
Now, thanks to an acoustic telemetry project, LDWF has been able to pinpoint the exact locations of 244 speckled trout, 64 redfish and 18 bull sharks in the Lake Pontchartrain area.
What exactly is acoustic telemetry you ask? It’s the ability to track animals at a distance using sound. An acoustic transmitter that emits a pinging sound is surgically implanted into the fish. When the fish swims within a half mile of one of the dozens of stationary receivers scattered around Lake Pontchartrain, it records the transmitter’s ping as time, date and fish ID number. This data is downloaded from all of the receivers every 6-8 weeks, and LDWF publishes their data in an interactive map: the LDWF fish tracker.
This information isn’t just exciting for the intrigued anglers in Lake Pontchartrain, it’s also exciting for scientists, policymakers and conservationists alike. This newly implemented technology has started to shed light on everything from fish migration patterns and habitat preferences to residency time and environmental impacts.
Seeing how fish responded to the brief opening of the Bonnet Carre’ spillway earlier this year is of particular interest. It has allowed us to study how fish might react to a large input of river water during high water events. This technology would also be useful in determining how fish respond to changes resulting from the planned Mid-Breton and Mid-Barataria sediment diversions. Additional research would be needed to understand how this technology can be used to monitor these basins. Nonetheless, an interesting observation was made by Ashley Ferguson, LDWF Biologist and fish telemetry expert, that “under the conditions at the time of the spillway opening, including the cooler water temperatures and the short 22-day opening, adult tagged spotted seatrout (speckled trout) and red drum (redfish) were not observed leaving Lake Pontchartrain.” This observation could help inform how a future sediment diversion might be operated and minimize impact on certain fish populations.
Our coalition of organizations is excited to see this technology being developed and hope its use will extend to other places such as the Breton and Barataria Basins. It could help tremendously with the state’s plan for monitoring and adaptive management of its restoration projects’ impact on fisheries.
Nic Dixon assists in CRCL community engagement efforts with workshops, interviews, data collection, and any additional communication tasks such as producing and distributing video content. Nic has had a diversity of lab and field research experiences in ecology ranging from the Yukon River Delta in Alaska to the Mississippi River Delta in Louisiana. He joined CRCL in 2014 after graduating from Louisiana State University’s School of Renewable Natural Resources.
By Richie Blink, Plaquemines Parish Community Outreach Coordinator, National Wildlife Federation
May is American Wetlands Month, and Louisiana's coastal wetlands are some of the most productive ecosystems in North America. Not only do they provide habitat for numerous fish, wildlife and birds, but they also help improve water quality, provide recreational opportunities and protection for people and infrastructure from damaging storm surges.
Wildlife habitat and nurseries
Wetlands serve as a nursery environment for juvenile fish. The countless ponds, bays and bayous found in the Mississippi River Delta provide essential habitat for most commercial and game fish found in the Gulf of Mexico. Menhaden, shrimp, oysters and blue crab area all important commercial species that depend on healthy coastal wetlands to thrive. Additionally, fur-bearers like muskrat, beaver and mink, as well as reptiles including alligators call coastal wetlands and estuaries home.
Storm surge protection
Wetlands have an incredible value for people, too. One acre of wetlands has the capacity to hold up to 1 million gallons of water during a flood! On average, damaging storm surges are reduced by one foot for every 2.7 miles of wetlands, reducing wave energy and protecting levees and other critical infrastructure from these destructive forces of nature. The value of community protection for a one-mile strip of wetlands is valued at $5.7 million.
Wetlands also help improve water quality by filtering and retaining residential, agricultural and urban wastes. Reconnection of the Mississippi River to surrounding wetlands would help filter out nutrients that are contribute to a harmful low oxygen area in the Gulf of Mexico dubbed the “dead zone.” The shallow waters of coastal wetlands are good habitat for submerged aquatic vegetation, which can utilize the extra nutrients and potentially reduce the Gulf of Mexico dead zone as well as increasing water clarity.
Restoring Louisiana’s coastal wetlands
Louisiana holds 40 percent of the coastal wetlands in the continental U.S. and is currently experiencing around 80 percent of all coastal wetland loss in the U.S. Work is currently underway to restore and rebuild wetlands in the Mississippi River Delta through projects in the state’s Coastal Master Plan, including sediment diversions and marsh creation. The reintroduction of Mississippi River water and sediment to its delta plain allows new wetlands to build and flourish, providing habitat for wildlife, clean water, places to recreate, and protection for storm surge.
Louisiana’s wetlands are a national treasure worth protecting. Learn more about why wetlands are important: https://www.epa.gov/wetlands/may-american-wetlands-month-learn-explore-take-action.
As the Plaquemines Community Outreach Coordinator for the Restore the Mississippi River Delta Coalition, Richie Blink works closely with local stakeholders to ensure widespread support of sustainable restoration of the Mississippi River Delta. Prior to joining the coalition Richie served as the Coastal Zone Program Manager with Plaquemines Parish Government to achieve a zero net loss of wetlands. He organized grassroots wetland restoration efforts that resulted in the planting of more than 15,000 cypress trees to reverse land loss and reduce storm surge near his hometown south of New Orleans. He serves as a board member of the Woodlands Conservancy, a nonprofit land trust organization focused on preservation of Louisiana’s coastal forest ecosystems. Richie served for three years on the Plaquemines Coastal Zone Advisory Committee which selects coastal restoration projects for implementation. In his free time, he guides motorboat tours into Louisiana’s coastal wetlands for Lost Lands Environmental Tours L3C. Always exploring, Richie holds a private pilot license and is a U.S. Coast Guard licensed captain.
By Matt Phillips, Outreach Coordinator, Restore the Mississippi River Delta Coalition
On Friday, April 22nd, 2016, Restore the Mississippi River Delta Coalition staff participated in an Earth Day tree planting event. Outreach team staff joined their partners at the Lake Pontchartrain Basin Foundation and several volunteers to plant 250 cypress trees graciously donated by the St. Bernard Wetlands Foundation. Our staff and volunteers were thrilled to spend a day working in the wetlands, the sunshine and gentle breeze being a pleasant change from the normal office environment.
The nutrient-rich alluvial soils on the east bank of the Mississippi River create perfect conditions for growing cypress, and scientists at LPBF boast of a 77% survival rate for their volunteer-planted cypress trees. Cypress trees provide habitat for insects and animals, and as their tangled root masses grow, the plants establish themselves in the soil, limiting erosion while filtering water in the swamp. These trees are essential for restoring degraded wetland ecosystems.
Planting cypress in a degraded swamp requires some precautions to ensure the trees survive. Volunteers must select an appropriate substrate—not too wet, but not too far from water either—so the trees can thrive. Small wetland creatures threaten the young trees as well, and in Louisiana, nutria pose a consistent threat. The young trees contain a lot of nutrients, and the large rodents find them particularly yummy. To make sure the trees’ tender roots are protected, we installed nutria guards around their trunks.
Our team planted 250 trees, and though sweaty, sunburnt and exhausted, we could not have planned a better way to spend Earth Day.
If you would like to get involved in projects like this and other volunteer opportunities, please visit our Volunteer page!
Matt Phillips is the Coordinator for the Restore the Mississippi River Delta Coalition’s Outreach Team. He works with organizers around Louisiana on improving the coalition’s community engagement. A native of New York City, Matt graduated from Oberlin College with a Bachelor’s degree in Biology and moved to Louisiana shortly after to work on and learn about the state’s coastal land loss. He lives in New Orleans.
In the past two years, nearly 200 million tons of sediment have flowed past our vanishing wetlands and off the continental shelf.
This sediment is the key to rebuilding our coast – providing wildlife and fisheries habitat and protecting our communities for generations to come.
View the sediment counter to learn more!