Table 1.

Reported CH₄ flux data for seagrass systems.

Location	Seagrass	Method	CH4 Flux (µmol m−2 hr−1)	Notes	Reference
Florida Keys, FL, USA	Thalassia testudinum	Benthic chambers and incubations	1.81–1.86		43
Bimini, Bahama Island	Syringodium sp.	Benthic chambers and incubations	0.14–0.47		43
Moreton Bay, Australia	Zostera capricorni	In vitro incubations	14.5	Est. for top 20 cm of bed	44
Red Sea	Multispecies: Thalassodendron ciliatum, Cymodocea serrulata, Halodule uninervis, etc.	Core incubations	0.004–23.6	Salinity range = 37.98–42.29	49
Ria Formosa Lagoon, Portugal	Zostera noltii	Benthic chambers	4.4	Aerial exposure at night	82
Ria Formosa Lagoon, Portugal	Zostera noltii	Benthic chambers	6.9	Aerial exposure during day	82
Ria Formosa Lagoon, Portugal	Zostera noltii	Benthic chambers	9.0–30	During tidal flooding	82
Ria Formosa Lagoon, Portugal	Zostera noltii	Benthic chambers	4.4–71(mean = 12.8)		82
Florida Bay, FL, USA	Thalassia testudinum	Benthic chambers and porewater samples	0.567	Dead seagrass areas in winter	83
Florida Bay, FL, USA	Thalassia testudinum	Benthic chambers and porewater samples	14.21	Live seagrass areas in fall	83
Cape Lookout Bight, NC, USA	Zostera marina and Halodule sp.	Core extraction, centrifuging, porewater sampling	20–2000	Seagrass not specifically studied but occurs in the general study area	84
Arcachon Bay, France	Zostera noltii	Benthic chambers	1.6–32.7	Sed-water flux with seasonal variation	85
Chilika Lagoon, India	Multispecies: Halodule spp., Halophila spp.	Open water and sediment samples	4.17, 5.6	Wet and dry season averages	86
Tomales Bay, CA, USA	(Zostera marina)	Benthic chambers	2.08	Summer eelgrass bed	87
Tomales Bay, CA, USA	(Zostera marina)	Benthic chambers	0.896	Winter eelgrass bed	87
South Bay, VA, USA	Zostera marina	Benthic chambers	13.110 ± 4.570	Seagrass spring average	This study
South Bay, VA, USA	Zostera marina	Benthic chambers	3.136 ± 1.307	Seagrass summer average	This study
South Bay, VA, USA	Zostera marina	Benthic chambers	0.845 ± 0.255	Seagrass fall average	This study
South Bay, VA, USA	Zostera marina	Benthic chambers	5.697	Seagrass 9-month average	This study
South Bay, VA, USA	Zostera marina	Benthic chambers	1.778 ± 0.930	Bare spring average	This study
South Bay, VA, USA	Zostera marina	Benthic chambers	0.050 ± 0.021	Bare summer average	This study
South Bay, VA, USA	Zostera marina	Benthic chambers	0.387 ± 0.104	Bare fall average	This study
South Bay, VA, USA	Zostera marina	Benthic chambers	0.739	Bare 9-month average	This study