sites where Macrocystis has seriously declined or disappeared,
it may be possible to re-establish Macrocystis forests by transplanting
juvenile plants from healthy donor sites. This has been successfully done
in California in the wake of sea urchin plagues. This could be an continuing
program in Tasmania if this action was seen as justifiable from a biological,
intrinsic and commercial point of view. Growing from spores is also an
option but normally requires laboratory facilities and is thus more expensive.
For the trials so far (April 2002), there are six sites in the Derwent
Estuary region, one site at Binalong Bay and four in the Mercury Passage.
In 2002, SeaCare will be planting at three extra sites in more wave exposed
areas near the Mercury Passage. These are sites that have historically
had large beds of Macrocystis but now have none. These sites are
Point Home, Hellfire Bluff, and Cape Paul Lemanon. (click
here to see maps of Macrocystis Sites)
Transplant and donor sites are surveyed by suitably qualified marine
biologists before transplants occur, and at regular intervals thereafter.
These surveys will examine the possible effects on donor populations of
taking plants as well as monitoring for any possible enhancement effects
on surrounding biota at transplant sites. Transects are filmed on video
when they are surveyed.
The total number of Macrocystis plants taken from a donor area
is than 10% of the total population in that area. Volunteer divers collect
the Macrocystis plants from an area prescribed by the researchers
and replant a designated sites. Transplantation of plants should take
place between autumn and spring (latest early
December). Plants will consist of juveniles at least 10 cm in length up
to mature plants with up to one-five fronds. Once gently wedged off the
rocks, transplants are taken to the surface and kept moist and cool. Ideally
they are re-planted the same day or the following day at the latest.
Plants are carefully returned to the water at recipient sites. Plants
can be secured using elastic bands to bricks or rocks. The bricks or rocks
are then placed on, or adjacent to the reefs and wedged into cracks and
Culture of Macrocystis is an option. Young plants can be seeded
on to small rocks or other suitable substrate and then dispersed from
the surface into the sea or attached to the bottom. This method is currently
being trialled using the Marine Studies Centre facilities at Woodbridge
in the D'Entrecasteaux Channel and involving students with an interest