Benthic ecology from space: optics and net primary production in seagrass and benthic algae across the Great Bahama Bank

Marine Ecology Progress Series

Lisa A. Drake¹  David Burdige¹  Richard C. Zimmerman¹  Heidi M. Dierssen¹ 

关键词: Primary productivity;    Remote sensing;    Ocean color;    Inherent optical properties;    Benthic reflectance;    Bahamas;    Grapestone sediment;   

DOI  :  10.3354/meps08665

学科分类：海洋学与技术

来源: Inter-Research

【 摘 要 】

ABSTRACT: Development of repeatable and quantitative tools are necessary for determining the abundance and distribution of different types of benthic habitats, detecting changes to these ecosystems, and determining their role in the global carbon cycle. Here we used ocean color remote sensing techniques to map different major groups of primary producers and estimate net primary productivity (NPP) across Great Bahama Bank (GBB). Field investigations on the northern portion of the GBB in 2004 revealed 3 dominant types of benthic primary producers: seagrass, benthic macroalgae, and microalgae attached to sediment. Laboratory measurements of NPP ranged from barely net autotrophic for grapestone sediment with thin microalgal biofilm to highly productive for dense accumulations of brown macroalgae. A logarithmic relationship between NPP and green seafloor reflectance described the general trend in NPP across various benthic constituents. Using a radiative transfer-based approach, satellite-derived estimates of NPP for the region totaled ~2 × 10¹³ gC yr^–1 across the GBB. The prevailing benthic habitat was mapped as sediment with little to no microalgal biofilm. Moderate to dense seagrass meadows of Thalassia testudinum were the dominant primary producers and contributed over 80% of NPP in the region. If the vast majority of seagrass leaves decompose in the primarily carbonate sediments, carbonate dissolution processes associated with this decomposition may result in sequestration of seagrass above- and below-ground carbon into the bicarbonate pool (2.4 × 10¹³ gC yr^–1), where it has a residence time on the order of tens of thousands of years.

【 授权许可】

Unknown