University of Tasmania - Blackjack Rocks

Restoration Project

University of Tasmania - Blackjack Rocks

Restoration Objective:

The objective of this project was to restore Macrocystis pyrifera in Tasmania, as it is thought to be declining and provides habitat and food for a wide range of species.

Site Selection Criteria:

Transplant sites in the Derwent were chosen that had a reef substrate and were exposed to a moderate amount of wave action. Sites were chosen at progressive distances up the river in case there was some factor that moderated downstream such as pollution.

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:

Ocean warming

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/

Site Observations:

Observation Date

16th May 1998 – 16th Mar 2002

Action Summary:

Four restoration methods were trialled in each site: 1) transplanting juveniles from healthy donor sites; 2) Transplanting fertile sporophylls to recipient sites; 3) culturing spores in the laboratory until they were 0.5 cm long, then transplanting to field; 4) transferring rope inoculated with Macrocystis from beds with Macrocystis to other areas. One hundred Macrocystis juveniles were planted at these sites from 1998 - 2000.

Lessons Learned:

This study employed multiple transplant methods.

Project Outcomes:

The greatest survival and recruitment success was achieved at Black Jack Reef, where there is now a small thriving population. There has also been limited success at White Rock, Tranmere and Glenvar Bay. These sites are all closest to the mouth of the estuary.

Key Reasons For Decline:

Ocean warming

Area of Restoration (Ha)

0

Indicator Data:

Indicator:

Ending Value:

Starting Value:

Adult Kelp Count

10.000090.0000