Seagrass Restoration Calculator

Restoration ecology has to plan for mortality, not just coverage — this calculator's core number, total shoots needed, divides your target area's raw shoot requirement (area × planting density) by your expected first-year survival rate, so a 60% survival rate means you're planting nearly twice as many shoots as the final target density calls for. The code deliberately rounds that division to six decimal places before rounding up to a whole shoot, because floating-point division can land a fraction of a unit above a clean boundary (1000.0000000000001 instead of 1000), which would otherwise force an unnecessary extra shoot into the estimate. From there, labor hours and total project cost (materials plus labor) follow directly from your planting rate and cost inputs.

The carbon and ecosystem-value outputs are drawn from published marine science rather than derived from your planting inputs directly: annual CO2 sequestration uses an average rate of 83 grams of carbon per square meter per year for established seagrass meadows (Fourqurean et al. 2012), scaled by your survival rate as a proxy for how much of the target area will actually establish; ecosystem service value applies a commonly cited $19,000-per-hectare-per-year figure from Costanza et al. for the flood protection, fisheries habitat, and water filtration seagrass beds provide. Both of these are averages across species and sites — actual sequestration and value for Zostera versus Thalassia meadows, or degraded versus pristine sites, can vary substantially from the figures used here.