There are the FOUR case studies of management strategies in different locations.

The themes explored are RESTORATION, PROTECTION and SUSTAINABILITY.

• Case study 1: Operation Crayweed (New South Wales)

• Case study 2: Giant Kelp (Tasmania)

• Case study 3: Green Gravel Project (Western Australia)

• Case study 4: Marine Protected Areas ( Victoria and South Australia)

CASE STUDY 1

Location and spatial patterns

Crayweed (Phyllospora Comosa) is a species of brown macroalgae growing up to 2.5 metres in length in dense underwater forests to depths of 5 -18 metres.

Crayweed forest ecosystems are located on the temperate rocky reefs from Port Macquarie to Tasmania and are a part of Australia’s Great Southern Reef.

The Sydney crayweed forests are a subsection of that ecosystem.

Unique characteristics

Crayweed ecosystems support high levels of biodiversity including fish and invertebrates such as abalone and crayfish. As well as providing food and habitat, crayweed provides detritus (decaying plant matter) to adjacent ecosystems and soft sediment habitats such as seagrasses. Crayweed supports unique biodiversity not found in places dominated by other seaweed species including 7 – 10 times more abalone than other species in the region.

Forest loss

The once abundant crayweed on Sydney’s rocky reefs began disappearing in the 1980s but went unnoticed and unreported until 2008 by which time the loss, attributed to sewage pollution, extended for 70 km along the Sydney coastline.

‘The local disappearance of crayweed from the most urbanised stretch of coastline on the Australian continent was linked to the high volumes of poorly treated sewage that used to flow onto Sydney’s shores before the construction of deep ocean outfalls in the 1990s. These outfalls and improvements in wastewater treatment practises have vastly increased water quality around Sydney since the 1980s, but despite this, crayweed has failed to recover’.

http://www.operationcrayweed.com

The AIMS of Operation Crayweed are RESTORATION and SUSTAINABILITY.

This means restoring crayweed to bare rocky reefs where healthy forests once grew to a level when reproduction and ongoing colonisation are self-sustaining.

Restoration began in 2011 as the signature project of the Sydney Institute of Marine Science (SIMS).

The METHOD developed by scientists involves transplanting healthy, fertile adults from places north and south of Sydney where populations are plentiful, by attaching them to rocks on biodegradable mesh frames. Volunteers play an important role in Operation Crayweed restoration projects at many sites and, in 2021, the Gamay Indigenous Rangers worked with scientists at Kurnell.

The DESIRED OUTCOME - to produce ‘craybies’ in the transplanted patches that would then attach themselves to the rocky reef surfaces to form new, self-sustaining populations that would expand to cover the bare rocky reef over time. Once the Crayweed habitat is re-established biodiversity would return.

LOCATIONS

Transplanting has taken place at nine locations along 70 km of the Sydney coastline including Cabbage Tree Bay, Freshwater, Kurnell, Long Bay and Little Bay, North and South Bondi, Coogee and Newport.

FUNDING - was provided by government and non-government organisations, businesses, and individuals. These include the NSW Department of Primary Industries, the Australian Research Council, the John T Reid Foundation, the Evolution & Ecology Research Centre of UNSW Sydney and the Sim-Lutton and Breen Initiatives. Restoration at Newport in March 2021 for example, was funded by Patagonia and the site at Freshwater, originally planted in 2016 was extended in 2020 with the support of local government through the Warringah Communities Environment grant. A full list of supporters here.

EVALUATION

The success of Operation Crayweed has been evaluated using visual observations, scientific monitoring, and a criteria-based tool created by the Society for Ecological Restoration. Video productions, websites and academic articles refer to the success of Operation Crayweed in kelp forest restoration at all sites on the Sydney coastline. The transplanted crayweed in the first trials (2011) and subsequent plantings have had survival rates of around 70%, much the same as those in natural populations and surprisingly, higher reproduction and birth rates.

The ‘babies’ of transplanted, fertile adults had firmly attached to rock up to hundreds of metres from originally restored patches and had become reproductive.

In Kelp Forest Restoration in Australia, Operation Crayweed was judged the most successful marine restoration project in Australia to date, however the conclusion was also drawn that more time was needed to see if species are restored in all food pyramid levels.

Educating the public about the value of kelp forests has become an important component of Operation Crayweed. While volunteerism has played an important role in crayweed restoration, increasing public awareness and emotional engagement was considered important in getting people to care.

Successful initiatives to engage the public emotionally in Operation Crayweed included:

1. Operation Crayweed Artwork Installation, Bondi 2016

2. Primary School restoration site visits

3. Manly Seaweed Forests Festival 2021

1. Workload and cost - initially, about 5 days is required at each site for site marking and preparation, securing mesh mats for crayweed attachment, collection of crayweed and transplanting. Estimated costs include:

- $US 6,850 per site for a 4-person team, boat and tow-vehicle, SCUBA tank fills, equipment and consumables.

- $US18,500 p.a. for project management and monitoring at multiple sites

Source: Kelp Restoration in Australia https://www.frontiersin.org/articles/10.3389/fmars.2020.00074/full

2. Project scale - restoration projects have been completed at a small to medium local scale with high levels of success. Scalability of kelp forest restoration to the seascape-scale at which crayweed losses have occurred remains a challenge.

Operation Crayweed, Sydney Institute of Marine Science

http://www.operationcrayweed.com

Kelp Forest Restoration in Australia Cayne Layton, Melinda A. Coleman, Ezequiel M. Marzinelli, Peter D. Steinberg, Stephen E. Swearer, Adriana Vergés, Thomas Wernberg and Craig R. Johnson. Sourced July 20, 2021, from Frontiers in Marine Science at https://www.frontiersin.org/articles/10.3389/fmars.2020.00074/full

Adriana Vergés

https://www.youtube.com/watch?v=VnpepI2X8Uw&t=83s

Bringing back our underwater forests: Q&A with Adriana Vergés

https://www.secondnature.org.au/bringing_back_our_underwater_forests_q_a_with_adriana_verg_s

Project under way to bring rock lobsters and abalone back to Kurnell waters

https://www.theleader.com.au/story/6853567/ocean-habitat-returns/?fbclid=IwAR1LusUFXHB5ivPTy_QVNwjQi3vaoibMukJNzXaZCyBu4l1ALby1pzCCusg

Manly Seaweed Forests Festival

https://www.seaweedforestsfestival.com

Seaweed Forest Festival podcasts

https://www.seaweedforestsfestival.com/podcasts/

Operation Crayweed Facebook page

https://www.facebook.com/OperationCrayweed

Turpin Crawford Studio Operation Crayweed Art-Work Site

https://turpincrawfordstudio.com.au/work/operation-crayweed-art-work-site