Monitoring in Kapiti Marine Reserve

There have been a number of monitoring studies undertaken in the Kapiti Marine Reserve. These are:

1. Victoria University study of KMR, 1998-2000

Diver doing study in the Kapiti Island
Marine Reserve

Monitoring of Kapiti Marine Reserve to establish what differences existed in size and abundance of 34 key species (including algae, fish and invertebrates) between the reserve and control sites. Data was compared to that collected by NIWA study in 1992 prior to the establishment of the marine reserve to determine what changes had occurred over time.

Results:

• Sites inside the marine reserve supported a greater species abundance, and in some cases, larger size classes. There was some evidence for a general shift in the community structure particularly in algal plants.
• Evidence of greater species diversity at the northern end of the Island with decreasing diversity towards the south.
• Banded wrasse, scarlet wrasse, blue cod, paddleweed (Ecklonia radiata), and kina were significantly different in abundance among the four sites in the KMR. Banded wrasse and blue cod were significantly different in abundance between reserve and control sites. Butterfish were significantly different in size between reserve and control sites.
• No changes in abundance or size of species measured were found between this study and the 1992 NIWA study, although specific data analysis indicated a reserve effect.
• The one off survey conducted in 1992 was inadequate to use as a baseline against which to detect changes, as it did not have provisions for temporal replication and very little spatial replication.

Not all species have shown an effect in response to marine protection, but this is probably due to the fact that response times vary from species to species.

2. NIWA survey of Kaimoana, 1999-2000

In 1999-2000 a NIWA survey investigating effects of three different management regimes was undertaken. Taiapure (Palliser Bay), open fishing (Wellington South Coast), and marine reserves (Kapiti Marine Reserve) were compared. Around Kapiti they undertook surveys in the following sites: west control (fished), west reserve, north control (fished), east control (fished) and east reserve; and compared abundance and size of rock lobster, butterfish, kina and paua between these sites.

Results:

• Significant increase in rock lobster abundance in the west reserve compared to control (fished) areas since the establishment of the marine reserve. There was no significant difference between these areas prior to the marine reserve being gazetted.
• No significant difference in rock lobster size between areas since marine reserve was established. The proportion of lobsters over the legal size was 55% compared to 44% legal size in the control (fished) areas.
• Significant increase in abundance of butterfish in the west reserve compared to all control (fished) areas since the marine reserve was established. There was no significant difference between these areas prior to the marine reserve being established.
• Significantly larger butterfish (on average by 30%) in reserve than in the control (fished) areas since marine reserve was established. No difference in size between areas prior to the marine reserve. Presently nearly 80% of the butterfish observed in the west and east reserve areas are of legal size, and in the control (fished) areas the proportion is about 50% legal.
• No significant difference in blue cod abundance between areas since the marine reserve was established. However, blue cod are slightly more abundant in the reserve areas. No significant difference in abundance between areas prior to the marine reserve.
• Significantly larger blue cod (on average by 25%) in reserve than in the control (fished) areas since the marine reserve was established. Nearly 70% of blue cod in marine reserve were of legal size compared with only 10% legal in adjacent control (fished) areas. No evidence of increased abundance or size of kina in the marine reserve area compared to other control areas. Overall, kina are more common and larger on the western side of Kapiti Island possible due to more suitable habitat.
• There were more paua in the east reserve than other areas. Note that habitats in the western reserve were not suitable for paua.
• No evidence of increased size of paua in the marine reserve area. However, largest paua were in the east and north control (fished) areas compared to control (fished) areas. More common on the eastern side.
• Red and blue moki are naturally in low abundance and it was not possible to determine any trend over time or among areas. Wrasse species were not included in the survey, but appeared to be in great abundance, with many large individuals in the reserve areas.

There have been some responses in abundance and mean size by some populations of previously exploited species to the change in management regime inside the marine reserve boundaries. The response has not been uniform across species or areas, indicating that other factors such as species specific rates of recruitment, movement and habitat specific growth or mortality play an important role in determining the local population characteristics. "Species" response to marine reserve status is also a function of the reserve size and length of time since protection.

3. Victoria University blue cod study, 2003-2004

The aim of this study was to determine the most appropriate technique for monitoring blue cod at Kapiti Marine Reserve. The study compares three different survey techniques in an attempt to determine the most effective method in assessing the mean size, spatial distribution and relative abundance of blue cod at Kapiti Marine Reserve. Sites with Kapiti Marine Reserve and comparable sites outside the reserve were surveyed. Methods included Underwater Visual Census (UVC), Baited Underwater Video (BUV) and Experimental Angling. Blue cod were also tagged to examine the degree of individual movement that is exhibited among sites within and outside the marine reserve.

Results:

• Blue cod are larger and more abundant in the marine reserve.
• Mark-recapture was not successful in determining the abundance of blue cod because of the low recapture rate, which indicates the fish are in good abundance.

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