Dead stingrays in the Ōrākei Basin.

I asked that staff address the following points as to multiple community concerns when dead stingrays were seen in the Orakei Basin. I requested in writing;

·         Further information on the sluice gates and their ongoing maintenance and why they haven’t been operating.

·         Confirmation of the process moving forward if an incident like this occurs again.

·         Clear outline of who is responsible for what area/action (including MPI and DOC).

·         Staff consider reaching out to Kelly Tarlton’s to include them in any future process.

·         Any information on the cause of death of the stingrays and how we might prevent this from happening again.

Staff have developed the following written responses.

Context: Ōrākei Basin sluice gates

·         The Ōrākei Basin sluice gates are managed by the council’s Community Facilities department on behalf of Auckland Council.

·         The resource consent conditions for the sluice gates specify the Ōrākei Basin be flushed fortnightly (approximately 27 times a year), opening the sluice gates during high tides. This regime results in useable water levels for 78% of daylight hours during the year.

·         Community Facilities have an agreement with the Auckland Water Ski Club (the ski club) whereby the ski club manually operate the sluice gates to allow the flushing of the basin and to maintain adequate water levels. The ski club have resource consent for the basin to remain filled for a certain number of days per year to allow for water sports. The ski club and waka ama groups use this facility.

·         Up until 11 May 2020, the sluice gates have been managed as required by the ski club with regular monitoring of water levels and operation of the sluice gates. On 14 May 2020 the ski club reported to Community Facilities a malfunction with the electrical system which prevented the sluice gates from opening.

·         Community Facilities initiated repairs to the electrical system and upgrade of the system control panel. Repairs were completed on 6 August 2020.

·         The sluice gates were operated on 7 – 9 August to flush the basin. The sluice gates were opened again on 17 – 21 August 2020.

·         Three of the four sluice gates remain open this week (17 – 21 August 2020) as the first cylinder is removed and the overhaul of the hydraulic cylinders begins. This is due to be completed by 31 October 2020. Community Facilities will continue to monitor water levels within the basin during this time.

·         Automation of the sluice gates is due to be completed by 31 June 2021.

Accountability: Auckland Council responsibilities and processes moving forward

·         Generally, for freshwater bodies on Auckland Council land, Community Facilities contractors are responsible for removing dead animals from the land and Healthy Waters contractors are responsible for removing dead animals from the freshwater.

·         Healthy Waters contractors would not normally be responsible for removing dead animals from marine environments such as the ocean or beaches. However, because the Ōrākei Basin is controlled by council managed tidal gates, Healthy Waters are managing the removal of the dead stingrays in the water.

·         The Ōrākei Basin is one of several bodies of water where it is ambiguous whether it is a marine or freshwater body – it is intermediate in nature. As part of the learnings of this incident the council’s i-Know procedures for the call centre and response staff will be amended so it is clear that Ōrākei Basin, and some other similar bodies of water should be treated as freshwater bodies from a procedural perspective.

·         In this instance, Community Facilities contractors removed six stingrays that could be reached from the shore and Healthy Waters contractors removed six stingrays from the water.

·         If a similar incident (dead animals floating in Ōrākei Basin) happens again, the council’s call centre staff should direct the request to the Healthy Waters contractor. Healthy Waters will in turn liaise with Community Facilities.

·         The council’s procedures require that the Department of Conservation is informed in the case of any dead native animal. The Department of Conservation’s interest is around establishing whether the dead animal is a protected species. If it is not (as is the case with these stingrays) then they have no responsibility.

·         The Ministry for Primary Industries are interested in establishing whether the deaths were the result of some sort of exotic disease. In this case they consider that the stingray carcases are too decayed to establish this.

Preventing reoccurrence

·         Presently, there is uncertainty about why or exactly when the stingrays died in Ōrākei Basin. Water quality testing carried out over 13 – 14 August 2020 indicates salinity levels to be in the normal range for the Ōrākei Basin and no obvious evidence of wastewater contamination.

·         Marine experts from the Ministry for Primary Industries and the Department of Conservation consider that the degree of decomposition of the carcasses makes it difficult to establish cause of death. It is difficult to speculate on how long the rays had been dead before washing up. It is possible that at some point in time water quality conditions in the basin may have contributed. Stingray carcasses have been frozen in case they can provide some information.

·         Scientists from the council, the Ministry for Primary Industries and the Department of Conservation are intending to meet as a group to discuss this within the next week. Marine biologists from Kelly Tarltons will be invited to participate in this.

·         The Healthy Waters Safeswim team monitors the public health risk in Ōrākei Basin on a periodic basis. The frequency of testing will be increased, and other water quality parameters will be added to the monitoring programme to help determine whether toxic or harmful water quality is occurring within the basin, and what this means for the flushing regime.

·         Automation of the sluice gates will provide opportunities for increased integration with water quality monitoring.

·         In terms of next steps, you will be informed of any outcomes of the expert meeting and in due course of water quality investigations.

I will update further on this as more information comes to hand