Download the data used in the graph (XLXS, 9K)
See research and monitoring for information about how this data was collected. The dotted lines in the graph show how the numbers of butterfish (greenbone, mararī) may have changed in the large time intervals between surveys.
Natural levels of butterfish in the marine reserve are unknown so their status cannot be assessed at this time.
Surveys in 1992, 1999 and 2000 showed more butterfish inside the marine reserve than outside. The 2013 survey results indicate similar numbers of butterfish inside and outside the marine reserve, due to an increase in butterfish outside the marine reserve.
Other research in 2008, 2009 and 2010 found more butterfish inside the marine reserve than outside. This data could not be included in the graph above because the research methods used were not comparable.
There is not enough data to report any changes in the last 5 years so the trend is undetermined.
There is no regular monitoring of butterfish in the marine reserve. Occasional studies are carried out or supported by DOC, staff and students at Waikato and Victoria Universities and other researchers.