Seagrass Ecosystem Services and Their Variability across Genera and Geographical Regions

Abstract

Threats to and loss of seagrass ecosystems globally, impact not only natural resources but also the lives of people who directly or indirectly depend on these systems. Seagrass ecosystems play a multi-functional role in human well-being, e.g. food through fisheries, control of erosion and protection against floods. Quantifying these services reveals their contributions to human well-being and helps justify seagrass conservation. There has been no comprehensive assessment as to whether seagrass ecosystem services are perceived to vary over the globe or amongst genera. Our study compiles the most complete list of ecosystem services provided by seagrasses so far, including bioregional- and genus-specific information from expert opinion and published studies. Several seagrass ecosystem services vary considerably in their (known) provision across genera and over the globe. Seagrasses genera are clearly not all equal with regard to the ecosystem services they provide. As seagrass genera are not evenly distributed over all bioregions, the presence of an ecosystem service sometimes depends on the genera present. Larger sized seagrass genera (e.g. Posidonia, Enhalus) are perceived to provide more substantial and a wider variety of ecosystem services than smaller species (e.g. Halophila, Lepilaena). Nevertheless, smaller species provide important services. Our findings point out data gaps, provide new insight for more efficient management and recommend caution in economic valuation of seagrass services worldwide.

Anthropogenic disturbance homogenizes seagrass fish communities

“…We use seagrass meadows across the Pacific coast of Canada-a globally important nearshore habitat (Nordlund, Koch, Barbier, & Creed, 2016)-as a model foundation species that can be highly responsive to perturbation and degradation (Duarte, 2002;Short & Wyllie-Echeverria, 1996;Unsworth, Collier, Waycott, Mckenzie, & Cullen-Unsworth, 2015). We predicted that coastal activities would have reduced specialist species with traits poorly adapted to anthropogenic disturbance, and increased species with more generalist, opportunistic traits within nearshore ecosystems, resulting in spatial biotic homogenization.…”

A Synthesis of Blue Carbon Stocks, Sources, and Accumulation Rates in Eelgrass (Zostera marina) Meadows in the Northeast Pacific

“…Seagrasses are globally distributed marine angiosperms that form underwater meadows along boreal, temperate, and tropical shorelines, providing some of the most biodiverse and productive habitats in coastal regions (Cullen‐Unsworth & Unsworth, ; Green & Short, ; Mtwana Nordlund et al, ; Orth et al, ). Seagrass meadows can exhibit high rates of primary productivity and the tissues of many seagrass species are recalcitrant and subject to low rates of herbivory, creating excess biomass available for long‐term storage (Duarte et al, ; Duarte & Cebrián, ).…”

Rocking the Boat: Damage to Eelgrass by Swinging Boat Moorings

“…However, very slow long-term recovery from disturbances such as dredging have also been reported (Hilary et al, 2005). Z. marina has a circumglobal distribution throughout the northern hemisphere where it plays a critical role in supporting, amongst others things, fisheries production, carbon storage and sediment stabilization (Jackson et al, 2001; Bertelli and Unsworth, 2014; Mtwana Nordlund et al, 2016). Unfortunately there is extensive and growing evidence of the large scale loss and degradation of Z. marina meadows across its range (Waycott et al, 2009; Jones and Unsworth, 2016; Lefcheck et al, 2017).…”