Patterns of Species Dominance in Two Coastal Restorations: Evidence of Sustained Seagrass Success over Long Time Scales

Restoration in coastal settings by reconstructing seagrass coverage after widespread loss has generally been monitored over a short time, with few studies extending ≥5 years. We assemble monitoring data available from two seagrass restoration areas in Florida, USA, to examine community development of benthic macrophytes from 1989 to 2025 after planting of the early successional seagrass, Halodule wrightii. Using field data collected at varying intervals, we (1) examined patterns of species persistence, investigating species replacement or persistence of benthic macrophyte taxa and (2) compared temporal patterns of species dominance in restored versus nearby natural reference sites. The pattern and tempo of seagrass expansion by H. wrightii at each of the two restoration areas differed. At Lassing Park, episodes of H. wrightii dominance were intermixed with a period of multi-species composition and co-dominance. After a bloom of the macroalga, Caulerpa prolifera, displaced seagrass in 2006, H. wrightii quickly recolonized the restoration site. At Shell Key, H. wrightii was the only species recorded at the restoration site over two decades. Species dominance by H. wrightii was recorded in both restoration and natural sites. Our findings illustrate the value of long-term monitoring for evaluating the resilience of restoration efforts and adopting extended monitoring programs. Such efforts would be enhanced by the genesis of innovative ideas for data collection and new methods for following the post-planting of seagrass.