The mesh size effect: counting long thin fish in seagrass

• Concentric trawl net fractions compare mesh sizes used in seagrass ichthyofauna surveys. • Fish species and lengths are markedly affected by changes in trawl-net mesh size in seagrass. • Pipefish are globally data-deficient and of conservation concern; surveys significantly underestimated abundance when using larger net-mesh. • Consideration of mesh size is critical for accurately quantifying cryptic fish in seagrass. • Managers may use mesh...