Monitoring Changes in Biological Communities
Climate and Environment Monitoring
Citizen Science Habitat Mapping Project
Ecology of Black Coral in Fiordland and the Impacts of Stressors
Impacts of Climate Change on the Ecology of Sponges
How will climate change impact broadnose sevengill sharks in Fiordland?
Monitoring Changes in Biological Communities
To understand any impacts of climate change it is important to have a good understanding of the natural changes that occur in populations and communities. The SFI have established four sentinel sites where we will not only be monitoring changes in temperature through time, but we are also monitoring the biological communities. This work is primarily focusing on the sea floor communities. We are taking photographs and videos from the surface down to 80m utilising the VUW Boxfish Remotely Operated Vehicle (ROV). The ROV is used to collect the pictures from deep water, while scuba divers collect the data down to 30 m. We will also be monitoring fish communities at these sites using simple video surveys and baited remote underwater video (BRUV) deployments. We know very little about how the benthic communities in the fiords change over time, and this component of our project will address this knowledge gap. This biological information will be critical to see if any of the changes we might see in our environmental data are impacting the animals and plants that live in the fiords.
Climate and Environment Monitoring
A key aim of the SFI is to understand how the climate in the southern fiords is changing. Currently, there is no long-term environmental monitoring in Dusky or Breaksea sounds, which clearly limits our ability to see if the climate is changing. The SFI has taken several approaches to address this major gap in our ability to detect change. We have installed temperature logger chains in several locations in the fiords from 0 to 20 m, and at the 4 sites where we are monitoring the biological communities, we also have temperature loggers in both shallow and deeper water (> 70m). Finally, VUW has provided the SFI team with a CTD, which is a device that can measure salinity, depth, and temperature. As the MV Pembroke travels throughout the fiords the CTD will be deployed to the seafloor, collecting data as they go. This will build up an important picture of how the environmental conditions vary across the fiords and will help us better understand any future changes. The next step in this part of the programme is to work with the Department of Conservation to install above water environmental monitoring stations. We hope these will be installed at some of the DOC huts throughout the fiords and will provide valuable data to complement that from our in-water sensors.
Citizen Led Habitat Mapping
Understanding the distribution of major biological communities is critical for effective management and measuring large-scale change over time. If we don’t know where important or unique communities are located then they can’t be protected. The SFI has developed a citizen science-led habitat mapping project, where we aim over the next decade to describe the distribution of different communities throughout the southern fiords. Recent seafloor surveys in the fiords have mapped all the physical rocky habitats and we aim to collect biological data to overlay on this existing information. By creating habitat maps, we will be able to observe any larger scale changes over time within the fiords. Guests boarding the MV Pembroke will have the opportunity to contribute to the programme as citizen scientists. They will be given initial training on the types of data we want to collect, which includes information on some of the dominant organisms (such as black corals and sharks), the physical environment (e.g. sediment present and rock angle), and will conduct standardised video transects that will be later analysed by researchers at Victoria University of Wellington to complete the maps. This is a long-term project as it will take many dives to collect the level of information required to create detailed habitat maps.
ECOLOGY OF BLACK CORAL IN FIORDLAND AND THE IMPACTS OF STRESSORS
The SFI has a key focus on some of the ecologically important protected species in the fiords. Antipathella fiordensis is a nationally important and iconic endemic black coral species that is endemic to New Zealand. It is classified as an ‘at risk’ species due to its restricted range being found only in the Fordland region. This species is unique amongst other black coral species in New Zealand as it can be found in very shallow water (< 5m) and large colonies can be over 300 years old, making them one of the oldest shallow water organisms in New Zealand. The long-life span, restricted range and shallow distributions makes A. fiordensis particularly susceptible to anthropogenic impacts.
The aim of this project is to increase our understanding of the ecology of the poorly studied black coral Antipathella fiordensis in Fiordland and determine how this species will respond to environmental impacts including fishing, climate change and changes in land use. It is anticipated that this information will support the future management, protection, and conservation of this iconic New Zealand species.
This project will focus on five areas to increase our understanding of A. fiordensis.
1) Distribution patterns
We will conduct diver and ROV surveys at multiple locations across Doubtful, Dusky and Breaksea Sounds to estimate black coral size and abundance patterns. These will be correlated with potential environmental drivers (e.g., temperature, salinity, PAR, nutrients, and food) to assess not only the upper depth limits of corals, but also spatial distribution patterns across fiords. Using this data, we will generate, and ground-truth species distribution models for these three fiords based on existing environmental data layers.
2) Population dynamics
We will establish long term monitoring plots (likely belt transects) and map the location of specific black corals using an x,y coordinate approach so that they can be tracked through time to assess population dynamics and measure patterns of recruitment and mortality.
3) Connectivity patterns
We will use markers to assess the levels of connectivity and gene flow between different fiords and with depth. This data will help us to understand how localised mortality or impacts might be offset from larvae coming from different places.
4) Climate change and other stressor impacts
We have very limited information on the impacts of other stressors on black coral generally, and no controlled experiment stressor work has yet been conducted on black corals in New Zealand, so we have no idea of thresholds. We will carry out experimental manipulations where we will collect coral fragments set up treatment tanks based at Victoria University of Wellington to assess tolerance thresholds and responses of black corals to a range of stressors.
5) Fishery impacts
Given their large 3-dimensional structure and longevity, interactions between humans and the sea floor, have the potential to impact black corals. Potential activities include potting, trawling, line fishing and SCUBA diving. At present we have very limited information on how these activities in Fiordland have impacted black corals in the past or how they are currently impacting A. fiordensis. While there is limited commercial potting activity in the inner fiords, potting for crayfish and blue cod occurs towards the entrances of the fiords where back coral still occurs. Recreational line fishing occurs throughout the Fiordland Marine Area. We aim to create a better understanding of how these activities might be impacting black corals in several ways.
IMPACTS OF CLIMATE CHANGE ON THE ECOLOGY OF SPONGES
Sponges are very important components of the seafloor communities across Fiordland, and likely play key roles in nutrient recycling and habitat provision, making a major contribution to coastal productivity. Sponges pump water very effectively, and Prof Bell’s group has estimated that all the sponges in the fiords can process the total volume of water in the fiords every few weeks. As sponges pump water, they filter the small food particles and plankton, and the product of this process is the movement of food to the sea floor where other organisms make use of it. Sponges form a critical link between the water column, the sea floor, and then organisms further up the food chain. Any loss of sponges in Fiordland is likely to have wide impacts on food chains in the fiords. In May 2022, Professor Bell’s research group reported the first case of so-called ‘sponge bleaching’ of Cymbastela lamellata in Fiordland. This was the first report of widespread sponge bleaching in NZ, and one of only a few reports world-wide of this phenomenon. The bleaching was reported throughout Dusky, Breaksea and Doubtful Sounds, and likely the entire FMA, from 5 to 40+ meters. Prof Bell estimated that millions of sponges were bleached as this is one of the most abundant sponge species in Fiordland. On examination of the satellite data for the region, Prof Bell’s group found evidence of an extreme temperature event (around 5°C warmer than normal), which was subsequently confirmed by oceanographers at the University of Otago. Bell’s group believes this temperature spike may be the cause of the bleaching. Given the significance of this event the story was covered by national and global media, and the public are very concerned about this issue. The aim of this programme of research is to understand more about the ecological roles of sponges in Fiordland, and how they might be impacted by climate change. In addition, this project has a specific focus on the recent sponge bleaching event.
HOW WILL CLIMATE CHANGE IMPACT BROADNOSE SEVENGILL SHARKS IN FIORDLAND?
The Broadnose Sevengill shark, Notorynchus cepedianus is an iconic apex predator
throughout New Zealand (NZ) coastal waters. They are numerous in Southern Fiordland,
especially during the summer when they are regularly encountered by divers and fishers.
Surprisingly, we know relatively little about this species; where they reproduce, what
ecosystems are important for them, and importantly, how they might be affected by climate
change. The SFI will target research on the Broadnose Sevengill shark, and through the first
tagging study of this species in New Zealand, we hope to discover how water temperature
(across all depths), and weather influence the distribution, habitat use, and behaviour of
Sevengills. With the help of data obtained from our monitoring of benthic habitats and fish
communities, we will also determine how important Southern Fiordland is for the
persistence and resilience of Sevengills, and other coastal shark species.
The main aim of this project is to understand how climate change and extreme weather
events will influence the distribution, habitat use and behavior of Broadnose Sevengill
sharks in Southern Fiordland, but specifically, we will ask:
1. How does ontogeny (stage of life) and seasonal changes in water temperature influence
the horizontal and vertical movements of Sevengill sharks?
2. Do Sevengills utilise deep water to avoid thermal stress, and how does their behaviour
change in the short term during extreme weather events?
3. How does the abundance, and availability of Sevengill prey change throughout the
seasons and during extreme weather events?
4. Is Southern Fiordland a Sevengill shark nursery?