1 Restored oyster reef, Chesapeake Bay 1 Putting the reef back into “Ridge to Reef” Catchment Management for Pumicestone Passage. Ben Diggles DigsFish Services Pty Ltd

2 We need catchment management…

3 We need a Catchment Action Plan…

4 4 PP Catchment Action Plan Oysters are mentioned in “Actions for future consideration”: Oysters are mentioned in “Actions for future consideration”: FC23 (pge 40). Investigate potential health risks associated with eating wild oysters harvested from Pumicestone Passage and its tributaries. FC23 (pge 40). Investigate potential health risks associated with eating wild oysters harvested from Pumicestone Passage and its tributaries. A commendable goal, but suggests “oysters only for eating” - nothing could be further from the truth. A commendable goal, but suggests “oysters only for eating” - nothing could be further from the truth. We already know the answer, “dodgy if it rains” We already know the answer, “dodgy if it rains”

5 5 Is this good enough ? No. There is no mention of restoration of oysters or other bivalves….. No. There is no mention of restoration of oysters or other bivalves….. This is despite their undoubted ecosystem benefits to water quality, habitat and biodiversity, and overall sustainability. This is despite their undoubted ecosystem benefits to water quality, habitat and biodiversity, and overall sustainability. Bivalves are also culturally significant, especially to traditional owners, as well as socially and economically important. Bivalves are also culturally significant, especially to traditional owners, as well as socially and economically important. In essence they tick all the boxes – they cannot be ignored. In essence they tick all the boxes – they cannot be ignored.

6 6 Oysters = Ecosystem engineers Bivalves, being filter feeders, are the “lungs of the estuary”. Oysters in particular provide the following “ecosystem engineering” services: Bivalves, being filter feeders, are the “lungs of the estuary”. Oysters in particular provide the following “ecosystem engineering” services: Food and reef habitat for fish and crustaceans. Food and reef habitat for fish and crustaceans. Filtration of water (decreased turbidity). Filtration of water (decreased turbidity). Carbon sequestration (into shells). Carbon sequestration (into shells). Nutrient cycling (e.g. dendrification of N). Nutrient cycling (e.g. dendrification of N). Bentho-pelagic coupling (consuming nutrients from water and energy from sun (via phytoplankton) and converting these into animal material useful to other animals in the system). Bentho-pelagic coupling (consuming nutrients from water and energy from sun (via phytoplankton) and converting these into animal material useful to other animals in the system). i.e. They are the foundation of a healthy estuary. i.e. They are the foundation of a healthy estuary.

7 7 Oysters = Ecosystem engineers

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Declining bivalves – global trends But…. Despite being a vital link in the estuarine food chain, natural oyster reefs are at risk in many parts of the world. But…. Despite being a vital link in the estuarine food chain, natural oyster reefs are at risk in many parts of the world.

1111 Case study- rock oysters in Pumicestone Passage Historically, Sydney rock oysters were massively abundant in Pumicestone Passage. Historically, Sydney rock oysters were massively abundant in Pumicestone Passage. Ninghy = Aboriginal word for “plenty of oysters”. Early settlers in the mid 1800’s described subtidal oyster reefs down to 4+ meters and intertidal reefs 300 yards long. Ninghy = Aboriginal word for “plenty of oysters”. Early settlers in the mid 1800’s described subtidal oyster reefs down to 4+ meters and intertidal reefs 300 yards long. But today subtidal oyster reefs are extinct and around 96% of oyster zonation has been lost. But today subtidal oyster reefs are extinct and around 96% of oyster zonation has been lost. Underlying cause is due to recruitment failure from poor water quality and habitat change. Disease is the symptom, NOT the cause. Underlying cause is due to recruitment failure from poor water quality and habitat change. Disease is the symptom, NOT the cause.

1212 Case study- rock oysters in Pumicestone Passage

Estuaries without bivalves – what do you get ? Reduced food and biogenic reef habitat for fishes and crustaceans = unhealthy fisheries. Reduced food and biogenic reef habitat for fishes and crustaceans = unhealthy fisheries. Reduced bentho-pelagic coupling = poor utilisation of available nutrients which favours the algal-microbial loop = Undesirable algal growth and/or algal blooms, microbial problems in shellfish. Reduced bentho-pelagic coupling = poor utilisation of available nutrients which favours the algal-microbial loop = Undesirable algal growth and/or algal blooms, microbial problems in shellfish. Increased turbidity, which reduces seagrass growth and survival. Increased turbidity, which reduces seagrass growth and survival. In other words, exactly what we see in Pumicestone Passage today. In other words, exactly what we see in Pumicestone Passage today. Dead zones (low or no O 2 ) to come next ? Dead zones (low or no O 2 ) to come next ?

14 Obviously catchment management that reduces sediment and nutrient inputs is vitally important. Obviously catchment management that reduces sediment and nutrient inputs is vitally important. Riparian buffer zones / artificial wetlands to recover nutrients and clean runoff/stormwater. Riparian buffer zones / artificial wetlands to recover nutrients and clean runoff/stormwater. Restoration of oyster reefs – precedents from the Chesapeake Bay Program are worth examining. Restoration of oyster reefs – precedents from the Chesapeake Bay Program are worth examining. Dead zones in Cheasapeake Bay made things very difficult for them – don’t let it happen here. Dead zones in Cheasapeake Bay made things very difficult for them – don’t let it happen here. What can be done about it ?

15 They are doing it !

16 Three pronged catchment management effort to restore their waterways. Three pronged catchment management effort to restore their waterways. 1. Reduce Pollution 1. Reduce Pollution 2. Restore Habitats 2. Restore Habitats Restoring oyster reefs Restoring oyster reefs Replanting seagrasses Replanting seagrasses Restoring wetlands Restoring wetlands Restoring fish passage Restoring fish passage 3. Manage Fisheries 3. Manage Fisherieshttp:// Chesapeake Bay Program At top of the list because restored oyster reefs help with both 1. and 3. as well as restoration of seagrasses (through improved water clarity) and wetlands (through bank stabilisation)

17 Australia’s first oyster reef restoration program recently announced in Port Phillip Bay, Victoria. Australia’s first oyster reef restoration program recently announced in Port Phillip Bay, Victoria. Partnership between a local fishing club, Victoria Fisheries and The Nature Conservancy (TNC, an eNGO). Partnership between a local fishing club, Victoria Fisheries and The Nature Conservancy (TNC, an eNGO). TNC is world authority on oyster reef restoration. TNC is world authority on oyster reef restoration. I am corresponding with them re: the Port Philip Bay project and suggesting to them that Pumicestone Passage should be next. I am corresponding with them re: the Port Philip Bay project and suggesting to them that Pumicestone Passage should be next. Oyster Reef Restoration in Australia

18 Oyster Reef Restoration in Australia

19 Significant community support to do something tangible for Pumicestone Passage by conducting our own pilot oyster reef restoration project. Significant community support to do something tangible for Pumicestone Passage by conducting our own pilot oyster reef restoration project. Seed funding up to $55,000 available from Toorbul Fish Stocking Association. Seed funding up to $55,000 available from Toorbul Fish Stocking Association. Support from traditional owners (Ngunda- Joondoburri, Gubbi Gubbi), Sunfish, BIEPA, SEQ Catchments, QLD Fisheries, and TNC. Support from traditional owners (Ngunda- Joondoburri, Gubbi Gubbi), Sunfish, BIEPA, SEQ Catchments, QLD Fisheries, and TNC. Aquaculture facilities (at Woorim) if needed. Aquaculture facilities (at Woorim) if needed. Restoring oyster reefs is a key to restoring and maintaining a healthy Pumicestone Passage in the face of ongoing urban development. Restoring oyster reefs is a key to restoring and maintaining a healthy Pumicestone Passage in the face of ongoing urban development. Community support

20 Get oyster reef restoration onto the Catchment Action Plan. Oysters to be placed in subtidal reefs for environmental remediation only (not to eat). Get oyster reef restoration onto the Catchment Action Plan. Oysters to be placed in subtidal reefs for environmental remediation only (not to eat). Aim to top up seed funding from local community with FRDC/TNC and other sources (offsets ?) to conduct initial data collection to enable site selection, baseline mapping and analysis. Aim to top up seed funding from local community with FRDC/TNC and other sources (offsets ?) to conduct initial data collection to enable site selection, baseline mapping and analysis. Community, scientific and stakeholder review. Community, scientific and stakeholder review. Blueprint – budgeting, permitting, sourcing funds and raw materials, setting restoration goals. Blueprint – budgeting, permitting, sourcing funds and raw materials, setting restoration goals. Implementation, monitoring and evaluation. Implementation, monitoring and evaluation. Our Plan (courtesy Harris Creek oyster restoration, MD)

21 Thank you.