Habitat Mapping

Bull Kelp (Nereocystis luetkeana)

Resources

• Biodiversity Galiano iNaturalist Observations

Galiano Island Status: 57 observations around Galiano Island

Description

Bull Kelp (Nereocystis luetkeana) is a common variety of Phaeophyceae (brown algae). It can be easily identified by its bulbous floating structure known as a ‘pneumatocyst’, which contains gasses that aid in keeping it afloat at the surface. Attached to the pneumatocyst are a number of ‘fronds’, which are comparable to leaves on a tree. At the surface, these fronds photosynthesize, contributing to the algae’s astonishing growth rate of up to half a metre in a day. Under the surface, the kelp’s pneumatocyst connects to a ‘stipe’, which, like the stem of a plant, can be traced downwards to its base. Instead of roots, however, bull kelp is secured to rocky areas of the seafloor with what’s known as a ‘holdfast’. 

Habitat

Anchors to rocky substrates typically in areas with moderate wave action. Prefers cold nutrient-rich waters.

Range

The Aleutian Islands to central California.

Threats

Anthropogenic threats include boating, overfishing, pollution and climate change. Urchins are highly efficient kelp grazers and can decimate kelp forests when left unchecked.

Photo Credit

kathawk, Sherry Kirkvold

Eelgrass (Zostera marina)

Resources

• BC Species and Ecosystems Explorer Entry
• Biodiversity Galiano iNaturalist Observations

Status

• BC: Yellow (Secure)
• COSEWIC: Not Ranked
• SARA: Not Ranked
• Global: G5 (Secure)
• Galiano Island Status: 44 observations around Galiano Island

Description

Eelgrass (Zostera marina) is a marine perennial flowering plant, one of 60 seagrass species globally. Eelgrass can be identified by often vibrant green 3-foot long, ¼ inch wide blades, anchored to silty, sandy, and gravelly substrate on the sea floor by rhizomes (roots). It looks like tall grass growing under water; yet, despite its name, eelgrass is not a grass, nor is it a seaweed, as many that encounter it assume. 

Habitat

Found in brackish (semi-salty) and saltwater coastal areas, from the lower intertidal down to a 6m depth. 

Range

Global distribution

Threats

Humans increase local sediment levels through construction or coastal development causing eelgrass to struggle to photosynthesize through the murkier waters. Additionally, development in coastal regions may in some cases result in the displacement of eelgrass habitat, or cause harm through dredging and vessel-driven turbidity increases. Eelgrass is also particularly susceptible to damage through trampling and dragging of boat anchors, as well as pollution.

Photo Credit

hunterefs, Brian Starzomski