Restoration Project

University of Tasmania - Emerald Bay

Restoration Objective:

The aim of this study was to determine whether the introduced seaweed Undaria pinnatifida is preventing re-establishment of String Kelp (Macrocystis pyrifera) in the Mercury Passage.

Site Selection Criteria:

Sites were selected in urchin barrens that anecdotally had Macrocystis beds twenty or more years ago but now support healthy stands of Undaria.

Cause Of Decline:

Concern has been raised over the state of Macrocystis pyrifera forests in Tasmania due to the perceived loss of the alga around the Tasmanian coastline. The alga is thought to be highly productive and provides food and shelter for a wide range of animals and plants. Possible reasons for the decline include overharvesting, overfishing of lobsters (leading to increases in urchins), increased boat traffic, sediment disturbance, invasive species, warming waters and El Niño.

Key Reasons For Decline:

Overgrazing

Scientific Paper

Restoration of string kelp (Macrocystis pyrifera) habitats on Tasmania's east and south coasts. Final Report to Natural Heritage Trust for Seacare. Technical Report. Tasmania, Australia.

C. Sanderson, , Tasmania, Australia.https://eprints.utas.edu.au/12306/

Organisation:

University of Tasmania

Site Observations:

Observation Date

1st Jul 2000 – 26th Nov 2002

Action Summary:

Sites were given one of three treatments; 1) Undaria removed, Macrocystis added; 2) Urchins removed, Macrocystis added; 3) Undaria and urchins removed, Macrocystis added; 4) Control, Macrocystis added; 5) Control.

Lessons Learned:

Plants were stunted on almost all occasions, which may reflect low nutrient conditions at sites.

Project Outcomes:

No recruitment was evident at any of the sites in the Mercury Passage. Most of the plants that survived the transplant operation were stunted. Only once, at Emerald Bay did plants reach their full height.

Key Reasons For Decline:

Overgrazing

Indicator Data:

Indicator:

Ending Value:

Starting Value:

Adult Kelp Count

050
Costings:
Cost Currency:USD