Correia et al. 2023. Hurricane Effects on Seagrass and Associated Nekton Communities in the Northern Gulf of Mexico

Correia, Kelly M., Scott B. Alford, Benjamin A. Belgrad, Kelly M. Darnell, M. Zachary Darnell, Bradley T. Furman, Margaret O. Hall, Christian T. Hayes, Charles W. Martin, Ashley McDonald, and Delbert L. Smee. 2023. “Hurricane Effects on Seagrass and Associated Nekton Communities in the Northern Gulf of Mexico.” Estuaries and Coasts. doi: 10.1007/s12237-023-01276-w.

On 10 October 2018, Hurricane Michael made landfall along the Florida panhandle as a category 5 storm, with maximum sustained winds of 259 km h−1 and storm surge of 4.3 m. To assess impacts on seagrass meadows and nekton communities, we sampled seagrass beds in three estuaries along a gradient of storm intensity: one proximate to the hurricane track (St. George Sound, FL), one that experienced storm surge without hurricane-force winds (Cedar Key, FL), and one outside the storm path (Chandeleur Islands, LA). The nekton community and seagrass characteristics were assessed prior to and shortly after the storm and again 1 year later. In St. George Sound, we observed post-storm changes in seagrass species composition and declines in seagrass cover, shoot count, and canopy height as well as a shift in associated fauna. Seagrass cover declined from 83 ± 9 to 50 ± 8% following the storm. Shoot height and shoot count were also reduced by over 50%. Nekton species most commonly found prior to the storm were Lagodon rhomboides (pinfish), Orthopristis chrysoptera (pigfish), and Bairdiella chrysoura (silver perch). Two weeks following the storm, the most commonly collected species shifted to pinfish, penaeid shrimp, Chilomycterus schoepfi (striped burrfish), and Eucinostomus argenteus (spotfin mojarra). Widespread declines in species-specific nekton abundances were also observed, with continued reductions in some species the following year. Overall, both the seagrass and nekton communities showed signs of recovery. Cedar Key and Chandeleur Islands both exhibited minimal changes in vegetation and nekton. Despite storm intensity and substantial physical damage to upland habitats, the estuarine seagrass communities were resilient to the effects of a powerful category 5 hurricane.

Figure 2. Pre- and post-storm monitoring of seagrass metrics bracketing of Hurricane Michael in 2018. Seagrass percent cover, mean seagrass shoot count, and mean canopy height (± SE) by sampling time for a St. George Sound, FL, proximate to landfall; b Cedar Key, FL, storm surge only; and c Chandeleur Islands, LA, no storm. Early2018 and Late2018 represent the sampling performed before the passage of the storm in May to June 2018 and August to September 2018, respectively. PostHurricane represents the sampling done 2 weeks after the storm. Early2019 and Late2019 represent that early and late sampling that took place 1 year following the storm (May to June 2019 and August to September 2019)