Canada’s Oceans Now: Atlantic Ecosystems, 2022 - Nitrate: Key nutrient offshore, potential threat inshore

Nitrate: Key nutrient offshore, potential threat inshore

In this infographic there are three sections illustrating the difference in phytoplankton growth between offshore and inshore under different conditions of nitrate concentration.

Offshore

• Phytoplankton growth depends on nitrate. With lower nitrate, there are fewer phytoplankton leading to less energy for marine food webs.

Below average nitrate

There is a green phytoplankton bloom on the surface of the water with the black text saying small phytoplankton bloom. In the water column there is a large blue arrow pointing upwards with the white text saying upwelling/mixing and four light blue bubbles below with blue text with NO₃- inside each. Three text boxes underneath indicate time periods when these conditions were observed in bioregions. Left to right:

• Red box: GSL 2017–2018
• Teal box: NLS 2017–2018
• Orange box: SS 2017–2020

Above average nitrate

There is a larger phytoplankton bloom with the black text saying large phytoplankton bloom. In the water column is a large blue arrow pointing upwards with white text saying upwelling/mixing. There are a larger number of light blue bubbles with blue text with NO₃- inside each. Two text boxes underneath indicate time periods when these conditions were observed in bioregions. Left to right:

• Red box: GSL 2019–2020
• Teal box: NLS 2019–2020

Inshore

• Excess nitrate from agricultural runoff can threaten coastal ecosystems.

Excess nitrate levels

At the top there is orange plume representing runoff from land to the ocean, and a green bloom as well as floating green plants with white text indicating it is a phytoplankton and macroalgae bloom. Below in the water column in white text:

• Shading of light
• Hypoxia (with an icon of illustrated bubbles with the text O₂ inside and a downward arrow)

There are four fish swimming along the bottom with patches of light green sea lettuce on the right and dark green Eelgrass on the left. Text in a red box under the section indicates where these conditions have been observed:

• Southern GSL Estuaries