New Mote postdoctoral scientist to focus on Florida snook enhancement

December 11, 2015
By Marcy Shortuse

SUBMITTED BY MOTE MARINE LABORATORY & AQUARIUM – Mote Marine Laboratory is pleased to welcome Dr. Ryan Schloesser, a postdoctoral scientist who will be working with the Fisheries Ecology & Enhancement Program to help develop and test responsible stock enhancement technology to help restore depleted snook populations and advance knowledge about wild snook stocks as part of the Lab’s Fisheries Conservation & Enhancement Initiative.

Dr. Ryan Schloesser

Snook are one of the most sought-after catches in Florida’s saltwater recreational fishing industry, which draws more than $6 billion to the economy annually. However, increased fishing pressure, habitat loss and natural challenges such as freezes and red tide have contributed to a decline in snook populations. Thus, for more than 25 years, Mote and Florida Fish and Wildlife Conservation Commission (FWC) scientists have partnered on research studies designed to evaluate if stocking hatchery-reared snook can be an effective fishery management tool for replenishing snook stocks.
Mote researchers document snook that have been hatchery-reared and released into Sarasota Bay as part of small-scale pilot studies. These studies recover vital data that can be used to adjust release protocols. Past release results have revealed that changes in snook-release strategies have improved survival of stocked snook by as much as 200 percent.
As part of the Fisheries Conservation & Enhancement Initiative, Schloesser and other Mote researchers will be conducting these small-scale studies on a larger scale than before, releasing tens of thousands of hatchery-reared snook into Sarasota Bay.
Sarasota philanthropists Carol and Barney Barnett have made generous donations to help Mote implement its Fisheries Conservation & Enhancement Initiative that helps protect and restore fisheries in the Bay. The Barnett’s have challenged the community to raise $3 million more for Mote’s Oceans of Opportunity Campaign.
Schloesser received his Bachelor’s degree from Texas A&M University at Galveston in 2006, his Master’s degree from Texas A&M at Galveston in 2008 and his Ph.D from College of William & Mary’s Virginia Institute of Marine Science in 2015.
Much of Schloesser’s experience involves studying juvenile fish behavior and habitat use. Because not all habitats offer the same survival rates for fish, identifying essential habitat helps researchers best help fish populations prosper.
For his graduate research, Schloesser focused on bluefin tuna otolith chemistry. Otoliths are found in fish ears, and help the fish maintain orientation and balance in the water. It is very similar to how human ears function, but the interesting thing about otoliths is that they accrete a layer around them daily. Just like rings in a tree, these layers can help identify the age of the fish. Moreover, that layer of material reflects the chemistry of the water the fish grew up in. Schloesser used that chemistry to determine which nursery habitats produced the bluefin tuna being caught in the fisheries.
For his Ph.D, he worked with juvenile Atlantic croaker, summer flounder and striped bass – three commercially and recreationally important fishes in the mid-Atlantic. His main focus was on determining what gets more fish in the fisheries: 1,000 healthy juveniles or 5,000 unhealthy juveniles.
His research focused on whether healthier fishes are able to better survive migration or endure winter conditions than unhealthy fishes, and if so, why. He studied how the health of these juvenile fishes changes throughout the year and among different habitats. Schloesser determined how juvenile fishes prepare for the physiological challenges that they’ll face, such as cold weather, and which habitats produce healthier juveniles that are better prepared to survive those challenges and enter the fisheries.
Schloesser started working in Mote’s Fisheries Ecology and Enhancement Program on September 23 and will be conducting fish ecological research at Mote’s main campus in Sarasota and also learning some skills in marine fish aquaculture at Mote Aquaculture Park; e.g., learning how to raise snook to the juvenile stage.
“We are so excited to have Ryan as part of our dedicated, hard-working fisheries ecology and enhancement team,” said Dr. Kenneth Leber, Associate Vice President for Mote’s Directorate for Fisheries and Aquaculture. “He brings incredible experience in studying juvenile fish, and we think he will be a great addition to our new Fisheries Conservation & Enhancement Initiative in Sarasota Bay.”
Mote’s Fisheries Ecology and Enhancement Program focuses on developing optimal stocking strategies — based on factors such as fish size, release habitat, timing of releases, magnitude of releases, acclimation measures — and strategies for using conservation hatcheries to answer key questions about wild fish ecology and help with the restoration of declining fish populations.
Schloesser’s goal is to use his experience in working with juvenile fishes to help support Mote’s Fisheries Conservation & Enhancement Initiative.
“The reason I came to Mote Marine Laboratory is because I have the incredible opportunity to work with Dr. Kenneth Leber and his team on the snook stock enhancement project and research the health of hatchery-reared juvenile fishes, identify what habitats are critical for these snook to survive and examine how juveniles and adults use various different habitats,” Schloesser said. “This provides an ideal opportunity to apply all my background experience toward one common goal, the enhancement of the snook stock.”