Spatial variation in the abundance of eelgrass (Zostera marina) at eight sites in western Newfoundland, Canada

Eelgrass 2014-2015

The abundance of eelgrass (Zostera marina) was quantified at eight sites along the west coast of Newfoundland (NL), Canada. Two video procedures were employed to generate preliminary data on the percent cover of eelgrass. A GoPro high definition camera was mounted on a two meter 1.3cm diameter PVC pipe and attached 30 cm above a 19 x 19 cm quadrat. Still images were generated of quadrats or of the benthos during free swims. A 3 x 3 grid was added to the center of each image and the mean percent cover was calculated from these grids. The percent cover of eelgrass ranged between 5.89 and 69.27 %. Eelgrass abundance increased between June/July and September at sites 2, 4, and 7, before decreasing again in October at site 7. Overall, the percent cover of eelgrass peaked at 81.18% in September at site 4. Globally, sea grasses are declining in response to multiple stressors, including eutrophication, shoreline development, climate change, and aquatic invasive species. Eelgrass provides critical ecosystem services to coastal environments by stabilizing shorelines, contributing organic biomass to coastal food webs, and by increasing habitat heterogeneity along shallow subtidal shores. The degradation and loss of this highly productive habitat can have dire consequences for the stability and integrity of coastal environments in Atlantic Canada. Efforts to conserve this habitat will have long term benefits for populations of commercially, recreationally, and culturally important coastal species.


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