Krumhansl Kira A, Lee Katherine C, Ma Yongxing, Wu Yongsheng, Baker Thomas H A, Wong Melisa C, Azetsu-Scott Kumiko, Gentleman Wendy C
Bedford Institute of Oceanography, Fisheries and Oceans Canada, Dartmouth, Nova Scotia, Canada.
Department of Engineering Mathematics and Internetworking, Department of Oceanography, Dalhousie University, Halifax, Nova Scotia, Canada.
Sci Adv. 2025 Jun 27;11(26):eadw1952. doi: 10.1126/sciadv.adw1952.
Coastal vegetated ecosystems are recognized for their role in cycling and storing carbon in the world's oceans (i.e., blue carbon); however, high uncertainty in carbon sequestration rates is partly due to an absence of studies estimating carbon export to the deep sea. We modeled export from nearshore kelp forests and seagrass beds, showing variability by orders of magnitude across spatial scales (3 to hundreds of kilometers), kelp and seagrass species, seasons, and carbon forms, raising caution in using generalized export rates in blue carbon accounting. Our results also show rapid (20 to 30 days) and extensive export of neutrally buoyant dissolved organic carbon particles to the shelf break (up to 44% within 90 days), contrasting sinking particulate organic carbon particles that largely remained within 100-meter water depth in the nearshore. These results improve estimates of carbon sequestration by blue carbon ecosystems and reveal contrasting patterns of export relative to other regions of the globe.
沿海植被生态系统因其在全球海洋中碳循环和储存（即蓝碳）方面的作用而受到认可；然而，碳固存率的高度不确定性部分归因于缺乏对向深海碳输出的研究。我们对近岸海带森林和海草床的碳输出进行了建模，结果表明，在空间尺度（3公里至数百公里）、海带和海草物种、季节以及碳形态方面，碳输出存在数量级差异，这使得在蓝碳核算中使用通用的输出率时需谨慎。我们的研究结果还表明，中性浮力溶解有机碳颗粒能快速（20至30天）且大量地输出至陆架坡折（90天内可达44%），这与下沉的颗粒有机碳颗粒形成对比，后者大多停留在近岸100米水深范围内。这些结果改进了对蓝碳生态系统碳固存的估计，并揭示了与全球其他地区相比截然不同的输出模式。
