Restoration Project

Norwegian Institute of Water Resources (NIVA) - Hammerfest - Finnmark

Restoration Objective:

The objective of restoration was to establish a new substrate/habitat on a sandy bottom outside a sea urchin barren for kelp establishment, and supporting associated macrofauna and juvening fish.

Site Selection Criteria:

A site was selected with a sandy bottom, 10m depth and away from rocky substrate with high urchin densities.

Cause Of Decline:

The kelp species Saccharina latissima and Laminaria hyperborea form highly productive dense forests in the sublittoral zone along the Norwegian coast, providing habitat, food, nutrients, and shelter to numerous species. The total kelp forest area along the Norwegian coast line was estimated to be about 7900 km2 in 2011, but this is estimated to be less than 50% of the original coverage, with an estimated 9800km2 of kelp forest lost. The causes of kelp forest loss include climate change, increased runoff of particles, increased nutrients and growth of filamentous algae. However the major cause is overgrazing caused by high densities of sea urchins.

Key Reasons For Decline:

Overgrazing

Scientific Paper

Runde reef in Hammerfest 2006-2010. NIVA Report,

H. Christie, , p.5.

Organisation:

Norwegian Institute of Water Resources (NIVA)

Site Observations:

Observation Date

Action Summary:

An artificial reef was installed on a sandy bottom away from sea urchins.

Lessons Learned:

Kelp recovery was successful, but sea urchins will eventually colonise kelp patches if not controlled.

Project Outcomes:

Saccharina kelps recruited in dense beds in the first season after planting. Rapid kelp recovery to the new substrate was observed, lasting for 4 years before urchins grazed kelps.

Nature of Disturbance:

After 4 years, urchins appeared in the reefs and grazed kelps.

Key Reasons For Decline:

Overgrazing

Area of Restoration (In Square Metres)

3,000

Indicator Data:

Indicator:

Ending Value:

Starting Value:

Relative Abundance

10
Costings:
Cost Currency:NOK
Capital Cost:5