https://nzlakes.org/blog daily 0.75 2022-08-30 https://nzlakes.org/blog/whats-in-that-lake monthly 0.5 2020-12-29 https://nzlakes.org/blog/blog-post-title-four-c6wke monthly 0.5 2020-07-26 https://nzlakes.org/blog/blog-post-title-three-x9w2r monthly 0.5 2020-08-02 https://nzlakes.org/blog/blog-post-title-two-wa229 monthly 0.5 2020-09-13 https://nzlakes.org/Home daily 1.0 2022-09-17 https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/1603351445008-WXX2WB01WZAV4AWVOVJ7/ACondor1.jpg Home https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/1603351421663-L8BPVR6QQQWT8TOZZQ25/PB_logo_compass_FINAL_20200514.png Home https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/f09f48b6-7a34-4da5-a90c-3eefad639fdb/submerged+logo.PNG Home https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/1603430660924-KGT2LM3VVXLFEK51F3WK/untitled-design-4.png Home https://images.squarespace-cdn.com/content/v1/5ec321c2af33de48734cc929/1618497259178-6XJGK9GR6YAVBQL5L519/20140301_Trade-151_012-2.jpg Home https://images.squarespace-cdn.com/content/v1/5ec321c2af33de48734cc929/1607694583486-2PQT0LQ193RL7MCB6DX4/20140228_Trade+151_0046.jpg Home https://images.squarespace-cdn.com/content/v1/5ec321c2af33de48734cc929/1607694644871-IC85FNH781UNZSZEGHDR/Aro+Ha_0428.jpg Home https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/3dd76452-d148-40cd-8c60-c415597ec339/Lake+rotonuiaha.jpg Home https://nzlakes.org/trainingcontact daily 0.75 2020-04-14 https://nzlakes.org/gallery daily 0.75 2025-09-22 https://nzlakes.org/team-2 daily 0.75 2025-09-22 https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/9028ab85-56f0-42a7-b145-90d572308cf4/Lou+picture.PNG The Team https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/1601779263499-BYOEN2EYL79PHOLAQP2D/image-asset.png The Team https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/1601779353057-TM5GG4YI9MMEO458R9HO/Me.PNG The Team https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/1601780329817-BN47ULX9OGV3SF05BD1F/Russ+%26+Lou.PNG The Team https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/1601780004366-CJVHOQVWU9OC4H0G6MXU/Wednesday.PNG The Team https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/1601780037641-SNM4PYFP3QQORCF8W219/Josh+and+Annika.PNG The Team https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/1603348909217-TUVQGCQYC8MQLVITA25B/nunu.PNG The Team https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/1603348302925-MB4O024FLUP76NATG269/mark.PNG The Team https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/1603348473502-AEKE4C637G9L4847BZAD/holly.PNG The Team https://nzlakes.org/contact-us-1 daily 0.75 2020-10-22 https://nzlakes.org/reports daily 0.75 2022-09-17 https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/1656205153230-RE80O1RZX1ATQSDWB3XR/Tikitatapu.PNG Reports https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/1656206822524-E87IPM2CF4GKIP29YNWJ/Rotoroa+image.PNG Reports https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/1656207387309-4ZKCAC97AMW9PNSH3Z3X/GOPR8360.JPG Reports https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/1659056237226-XG5PFNF6WF29UYAYGX28/Kakahi_rotonuiaha.PNG Reports https://nzlakes.org/education-resources-2 daily 0.75 2022-06-26 https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/e369ee61-6337-41ef-b50e-baafb9bc783f/kakahi03-flat.jpg Resources - Kākahi Threats Kākahi (freshwater mussel) also known as Torewai and Kaaeo are NZ’s only freshwater filter. They are a keystone, taonga and indicator species that deserve recognition. https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/49540b50-2c30-46e6-87a4-673345436e2b/Pupuke%404x.jpg Resources - Lake Pupuke Pupuke moana also known as Roto Pupuke or Lake Pupuke is a deep volcanic lake in the heart of Takapuna, Auckland. https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/d87fd57f-4e42-4a17-8375-7e785f221db0/Rototoa+Case.PNG Resources - Lake Rototoa Lake Rototoa is considered the “gem of Auckland”. It is a deep sand dune lake in South Head. Despite having its water quality monitored for some time by the regional council and it all looking fine, beneath the surface paints a different story. Read about it below. https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/82e782c6-2f33-4ed7-9a3a-31e2164ebb7a/Lake+Dynamics+%282%29.png Resources - Lake Dynamics (TLI) Lakes health is often described with terms called TLI (Trophic Level Index) although there are limitations in its use as a indicator for lake health (it only uses water quality rather than ecology) it is important to understand the different states a lakes water quality can have and what some implications are. https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/4c4e8c8a-5b3a-463e-9eb9-66db99f64651/Stratification.PNG Resources - Lake Stratification Lake Stratification is the formation of distinct thermal layers. This concept is important to understand as it helps you understand your lakes health. https://nzlakes.org/portfolio-2 daily 0.75 2020-08-30 https://nzlakes.org/portfolio-2/project-two-a23nl monthly 0.5 2020-10-31 https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/1599962824225-XU9IS4VOBU5AE1P2P6MT/_D3B8248.jpg Our Projects - Lake Pupuke - How it started We have been diving in Lake Pupuke since 2013 and quickly came to realize that this lake was under threat. The water clarity had decreased and according to the local dive schools this deterioration had been noticed for many years prior. In the summer of 2014, a thick algal bloom developed and turned the entire lake chocolate, this had not been recorded previously. Samples taken by the team and Auckland Council identified the bloom as Ceratium hirundinella which is a nontoxic species. It was quite puzzling that even though Ceratium has always been present in the lake it had never formed large scale blooms until 2014. This bloom was thought to be a once off event until it occurred the following year and every summer since. To understand what had caused this change we began looking at the available monitoring data but could not find anything that pointed to the exact cause of these reoccurring blooms. We also noticed that almost no subsurface observations existed and many of our ad hoc findings have never been documented before. This is when we started the Lake Pupuke project in 2017 with a focus to collaboratively work with volunteers, research organizations and the Auckland Council to collect data that would complement current projects and address the subsurface knowledge gaps. https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/1599964543833-TWPLO8ZGWIBRWUBPHUJS/GOPR7999.JPG Our Projects - Lake Pupuke - In the beginning We initially started collecting very basic data like subsurface visibility, temperature, general meteorological information and algal bloom formation but this quickly ramped up into water quality and sediment sampling as well as installing continuous water quality sensors at various depths to get a better understanding of the seasonal fluctuations. Understanding the seasonal dynamics of the lake is critical but the more we learnt the more questions we had. There was no way we could solve this puzzle without understanding all of the pieces so we set up a series of targeted studies, each with its own objectives, that together will help us understand what is going on in the lake and what can we do to help this precious resource. https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/1601777687363-V1TT0KNSFHXZGW7WWKUI/170806_1.6m.JPG Our Projects - Lake Pupuke Visual clarity monitoring station https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/1601777209545-M0YRHQSVMFQNJBPHOSPF/1551505835252-1771472610.jpg Our Projects - Lake Pupuke Water quality monitoring station at 5m https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/1601777479274-5JEVO4PMN8TY7HGBK8SI/GOPR1915.JPG Our Projects - Lake Pupuke Surface algal bloom https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/1601774242555-XNJRUFO6JIOD4NLYJELR/GOPR5690.JPG Our Projects - Lake Pupuke Mid-water hydrogen sulphide layer at 11 m https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/1601775202132-374P4I9E7CKMY6OYNAIY/GOPR4655.JPG Our Projects - Lake Pupuke Dissolved oxygen sensor in macrophyte bed https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/1601774589006-1ABE0K3JOMOOV4J8GJUU/GOPR5461.JPG Our Projects - Lake Pupuke Sediment sampling https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/1601774405646-QXG28W3QR1V9RTQ6PY8K/GOPR7999.JPG Our Projects - Lake Pupuke Permanent macrophyte transect https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/1601776399797-AMVB1WJP8P2FJMWG5UN8/GOPR6911.JPG Our Projects - Lake Pupuke Historic mussel bed at 24 m https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/1604123051479-4V52C6HHVU6J8OKONQNO/GOPR8469.JPG Our Projects - Lake Pupuke Invasive perch https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/1599964069315-6H7XO39PB6AVYRY2RGTA/33579884_1812767635412174_6885979735482957824_o.jpg Our Projects - Lake Pupuke https://nzlakes.org/portfolio-2/lake-tomarata monthly 0.5 2020-10-22 https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/1601779949631-VKLFB9UIU5EWAOWPONRD/20200919_125605.jpeg Our Projects - Lake Tomarata - How it started Lake Tomarata has always been an an interest of ours and as a result of our findings at Lake Rototoa and Pupuke we wanted to see if this lake is experiencing similar issues. We know the lake is now completely devoid of submerged vegetation and that pest fish are an ever increasing issue. The impacts of these factors and the regular use of motorized craft has not been comprehensively assessed so we set out to establish a baseline ecological assessment. Through our initial exploratory dives we began to see familiar signs of environmental deterioration. The Auckland Council has a project that is focusing on the ecological effects of pest fish at Lake Tomarata which presented the perfect opportunity to design a collaborative project that would encompass wider ecosystem health. The over arching goal of this project will be to create a well informed biodiversity restoration plan. https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/1601779308530-WH2AWM7CQCEAALY16K0S/GOPR8255.JPG Our Projects - Lake Tomarata - Project overview This project encompasses several aspects of lake health and is made up of a series of targeted studies, each with their own set of outcomes. The investigations are centered around the following specific aspects of lake ecosystem health: Water quality Freshwater mussel surveys Impacts of pest fish & management Macrophyte establishment/restoration potential Wetland habitat & extent monitoring Overall ecosystem health & restoration The outcomes from all these targeted investigations will be used to draft a collaborative lake restoration plan focused on restoring native biodiversity values back to this precious lake. https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/1601779202617-HA9SCJ04SCK4QKB5SSLM/GOPR8280.JPG Our Projects - Lake Tomarata Dissolved oxygen, temperature & pH sensors https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/1601777953340-0CBRDHN6UK9VWTWWL4RE/GOPR8147.JPG Our Projects - Lake Tomarata Mature freshwater mussel https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/1601778355063-SAMPMC21L5K12SIMX5N5/GOPR8264.jpg Our Projects - Lake Tomarata Common bully under threat from pest fish https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/1601778901035-O1G21PPI5PKWM7CHJAVZ/GOPR8294.JPG Our Projects - Lake Tomarata Mussel & habitat survey https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/1601778583136-JQW8FHL97TBVWKJNZSSS/GOPR8114.JPG Our Projects - Lake Tomarata Lake bed devoid of macrophytes https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/1601781519617-NHKLN69UGPB3MVAPYDSN/IMG_5777D.jpeg Our Projects - Lake Tomarata Drone used for wetland mapping https://nzlakes.org/portfolio-2/project-one-669y4 monthly 0.5 2020-10-21 https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/1596331385856-BCW76BH7EQRM874KJLQT/GOPR6494.jpg Our Projects - Lake Rototoa - How it started We began diving this lake in 2014 and became accustom to seeing extensive mussel beds. Over time we noticed a general decline in lake condition and wanted to know how the mussel populations are being effected. The Aotearoa Lakes Dive Team mapped almost 1 km of mussel bed during our initial scoping dives and quickly realized that the situation was far worse than we imagined. Majority of the mussels were dead and there were clear signs of a mass die off. https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/1599965997676-8UVVNK3M1QH336Z8NBKJ/IMG-20200913-WA0001.jpg Our Projects - Lake Rototoa - Working together We approached the Auckland Council to see what they had planed for the lake and to notify them of our rather scary observations. The Council had just started a long term project aimed at managing and restoring native biodiversity in Lake Rototoa. They were already investigating plant and fish populations as well as invasive species management but, did not consider freshwater mussels. We began developing a collaborative monitoring programme that aims to assess the current population dynamics, potential limiting factors and habitat preferences of these mussels. The project consists of four phases: method development, survey testing, lake wide surveys and repeat surveys. Through these four phases we will be able to monitor mussel population responses to pest management and restoration techniques as well as building the most comprehensive freshwater mussel data set in the region. https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/1596339133403-58BBXLSQ52HC1X4GE8C7/s3.jpg Our Projects - Lake Rototoa - Phase 1 Phase 1 involved developing a standardised survey methodology that would allow us to capture the data we need to achieve the project objectives. There was no existing survey methods that would satisfy all of our needs so we designed one from scratch. The survey method involved teams of 3 - 4 divers that would run a 50 m transect parallel to shore along the upper extent of a mussel bed. They then run perpendicular transects every 10 m along the parallel transect, these transects extend to the maximum depth extent for that specific mussel bed. Quadrats are placed every 2 m along the perpendicular transects and all the mussels in each quadrat are counted and measured. The divers also collect a variety of metadata across the mussel bed as well as photos and videos. https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/1596337467911-BD84JZ78KYW1FFDNPMZH/Bed+Overview.png Our Projects - Lake Rototoa - Phase 2 Once the survey methods and data collection protocols were developed we tested them on a variety of mussel bed types and locations to ensure that they equally applicable in all situations. We tested the methods on three different mussel beds that represent the varying bed formations seen in Lake Rototoa as well as other lakes. Bed 1 was deep and had a relatively steep gradient, this bed was also representative of open water beds. Bed 2 had a narrow band of mussels between the reed edge and the macrophyte beds and was very shallow with a gentle slope. Bed 3 had characteristics that were between beds 1 and 2 with a moderate depth and slope. The method performed well across all three beds and with some fine tuning and minor tweaking we began Phase 3. https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/1596338525300-ENQO5EO82VG9Z6PABHTE/GOPR6654.JPG Our Projects - Lake Rototoa - Phase 3 Our initial survey were done on the three test beds and the results thus far are frightening. These initial surveys covered 2120 m2 of lake bed. A total of 1604 Kākahi (Echyridella menziesii) were counted with an average count of 10.35 mussels per quadrat. The combined mussel density across all three sites was 41.39 mussels per m2. Out of the 1604 mussels found, 1320 (82.29%) were dead and only 284 (17.71%) were still alive. No juveniles were seen during any of these surveys and all the mussels were larger than 51 mm. The surveyed population is composed entirely of mature adults (approximately 20 - 30 years old), 64.08% of live mussels were larger than 70 mm in length, 30.63% were between 61 to 70 mm and the remaining 5.28% was in the 51 – 60 mm size class. This ageing population and lack of younger individuals is a sign that limited to no viable recruitment had occurred in the surveyed area for more than a decade. Considering that the majority of the live mussels were at the upper end of their life expectancy and no recent recruitment was evident, the long-term viability of the surveyed population is low. It is clear that a mass extinction event is occurring in Lake Rototoa and if nothing is done we risk losing these key stone species for good. https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/1599965786919-V45RLKH0L8QMLLK6C6XA/GOPR6478.JPG Our Projects - Lake Rototoa https://nzlakes.org/portfolio-2/project-three-gw536 monthly 0.5 2022-06-26 https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/96637f54-430c-44e3-a909-40d080edc6af/Lake+rotonuiaha.jpg https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/08d6da6c-ed1e-4726-9693-f14d0550b3db/Kakahi_rotonuiaha.PNG https://images.squarespace-cdn.com/content/v1/5e9502812b85ce7fcd6ad30e/99916845-862b-4b0f-b772-fdf464341f34/Rotoroa+image.jpg