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Abstract

Analysis of the results of the long-term monitoring was restricted to notable changes
occurring within the largest Tasmanian coastal MPA at Maria Island. After nine years
of protection at the Maria Island MPA, mean size of lobsters was significantly greater
than in the surrounding fished waters and still increasing. The total abundance of
lobsters now appeared to be relatively stable following a threefold increase during the
first five years of protection. The mean size of abalone continued to slowly increase,
while the abundance of abalone appeared to have declined by 50% over the nine years..
This decline may be due to several causes, including an increase in predator density (eg.
lobsters and large fishes) and increased competition resulting in delayed emergence or
higher mortality. Urchin abundance has declined by up to 40% and may also be related
to increased levels of predation. The monitoring has revealed shifts in species
distributions that may be related to long-term oceanic cycles, and patterns in the
invasability of an introduced macroalgae Undaria pinnatifida.
Monitoring by community based volunteers demonstrated that with a limited level of
training on species identification and quantitative techniques, volunteer groups could
provide data that were sufficiently reliable to characterise a “place” at a particular point
in time with respect to the assemblage present. While the results of individual divers
were highly variable, pooling results of volunteers at each location produced a result
similar to that obtained by skilled observers.
At an individual species level, or for estimation of the mean size of individual species,
the volunteer data was less reliable than that provided by skilled researchers, however,
with sufficient training volunteer data may show significant improvement. An essential
component of community involvement is to ensure adequate training and feedback for
all divers, that events are well coordinated, and adequate post dive support is on hand to
ensure species are identified and recorded accurately and legibly.
With good training and professional facilitation of volunteers, community based
monitoring may provide data with sufficient reliability to detect substantial shifts in reef
ecosystems. However, unless this is organised on a large scale by volunteer
organisations, logistical constraints mean data obtained by this method are likely to be
substantially less cost effective or reliable than that obtained by research organisations
with adequately trained staff.

Item Type:	Report (Technical Report)
Authors/Creators:	Barrett, NS and Edgar, GJ and Morton, AJ
Publisher:	University of Tasmania
Additional Information:	Copyright © The Tasmanian Aquaculture and Fisheries Institute, University of Tasmania
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