Putting the reef back into Ridge Ridge Putting the reef back into - - PowerPoint PPT Presentation

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Restored oyster reef, Chesapeake Bay

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Putting the reef back into Putting the reef back into “ “Ridge Ridge to Reef to Reef” ” Catchment Management Catchment Management for for Pumicestone Pumicestone Passage. Passage.

Dr Ben Diggles Dr Ben Diggles

DigsFish Services Pty Ltd DigsFish Services Pty Ltd

www.digsfish.com www.digsfish.com

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Future development for Future development for Pumicestone Pumicestone Catchment Catchment…… ……

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We We need need effective catchment effective catchment management management… …

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Is the status quo good enough ? Is the status quo good enough ?

• When scale of future development is considered,

When scale of future development is considered, frankly, No. frankly, No.

• The

The Pumicestone Pumicestone Catchment Management Plan Catchment Management Plan is a good start, but in it there is a good start, but in it there’ ’s no mention of s no mention of restoration of shellfish reefs restoration of shellfish reefs… ….. ..

• This is despite their ecosystem benefits to water

This is despite their ecosystem benefits to water quality, biodiversity, and overall sustainability. quality, biodiversity, and overall sustainability.

• Shellfish (oysters, mussels etc.) are culturally

Shellfish (oysters, mussels etc.) are culturally significant, especially to traditional owners, as significant, especially to traditional owners, as well as socially and economically important. well as socially and economically important.

• In essence they tick all the boxes

In essence they tick all the boxes – – as a tool in as a tool in the management shed, they cannot be ignored. the management shed, they cannot be ignored.

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Shellfish = Ecosystem engineers Shellfish = Ecosystem engineers

• Bivalves, being filter feeders, are the

Bivalves, being filter feeders, are the “ “lungs of lungs of the estuary the estuary” ”. Shellfish reefs provide the . Shellfish reefs provide the following following “ “ecosystem engineering ecosystem engineering” ” services services: :

• Food and habitat for fish and crustaceans.

Food and habitat for fish and crustaceans.

• Filtration of water (decreased turbidity).

Filtration of water (decreased turbidity).

• Carbon sequestration (into shells).

Carbon sequestration (into shells).

• Nutrient uptake (e.g. Nitrogen).

Nutrient uptake (e.g. Nitrogen).

• Bentho

Bentho-

• pelagic coupling (consuming nutrients

pelagic coupling (consuming nutrients from water and energy from the sun (via from water and energy from the sun (via phytoplankton) and converting these into phytoplankton) and converting these into material useful to other animals in the system material useful to other animals in the system (food for fish, nutrients for (food for fish, nutrients for seagrass seagrass). ).

• i.e. They are the foundation of a healthy

i.e. They are the foundation of a healthy estuary. estuary.

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Shellfish = Ecosystem engineers Shellfish = Ecosystem engineers

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Shellfish = Ecosystem engineers Shellfish = Ecosystem engineers

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Shellfish Reefs Shellfish Reefs – – research highlights research highlights

• Assimilate

283% more nitrogen than mud or sand banks

• Generate

1300% to 10,000% more fish and crabs than mud banks

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Declining bivalves Declining bivalves – – global trends global trends

• But

But… … despite being recognised as a vital link in despite being recognised as a vital link in the estuarine food chain, natural shellfish reefs the estuarine food chain, natural shellfish reefs are at risk in many parts of the world. are at risk in many parts of the world.

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Case study Case study-

• rock oysters in

rock oysters in Pumicestone Passage Pumicestone Passage

• Historically, Sydney rock oysters were massively

Historically, Sydney rock oysters were massively abundant in abundant in Pumicestone Pumicestone Passage. Passage.

• Ninghy

Ninghy = Aboriginal word for = Aboriginal word for “ “plenty of oysters plenty of oysters” ”. . Early settlers in the mid 1800 Early settlers in the mid 1800’ ’s described s described subtidal subtidal oyster reefs down to 4+ meters and

• yster reefs down to 4+ meters and

intertidal reefs 300 yards long. intertidal reefs 300 yards long.

• But today

But today subtidal subtidal oyster reefs are extinct and

• yster reefs are extinct and

around 96% of oyster zonation has been lost. around 96% of oyster zonation has been lost.

• Underlying cause is due to recruitment failure

Underlying cause is due to recruitment failure from poor water quality and habitat change. from poor water quality and habitat change. Disease is the symptom, NOT the cause. Disease is the symptom, NOT the cause.

www.digsfish.com www.digsfish.com

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Estuaries without bivalves Estuaries without bivalves – – what what do you get ? do you get ?

• Reduced food and reef habitat for fishes and

Reduced food and reef habitat for fishes and crustaceans = unhealthy fisheries. crustaceans = unhealthy fisheries.

• Reduced

Reduced bentho bentho-

• pelagic coupling = poor

pelagic coupling = poor utilisation utilisation of available nutrients which

• f available nutrients which favours

favours the the algal algal-

• microbial loop = Undesirable algal growth

microbial loop = Undesirable algal growth and/or algal /jellyfish blooms, microbial problems and/or algal /jellyfish blooms, microbial problems in shellfish (and swimmers/ other water users). in shellfish (and swimmers/ other water users).

• Increased turbidity, which reduces

Increased turbidity, which reduces seagrass seagrass growth and survival. growth and survival.

• In other words, exactly what we see in

In other words, exactly what we see in Pumicestone Pumicestone Passage today. Passage today.

• It can get worse: Dead zones (low or no O

It can get worse: Dead zones (low or no O2

2) to

) to come next ? come next ?

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• Obviously responsible town planning is vitally

Obviously responsible town planning is vitally important important – – need catchment management that need catchment management that reduces sediment and nutrient inputs. reduces sediment and nutrient inputs.

• Riparian buffer zones / artificial wetlands to

Riparian buffer zones / artificial wetlands to recover nutrients and clean runoff/ recover nutrients and clean runoff/stormwater stormwater. .

• Restoration of shellfish reefs

Restoration of shellfish reefs – – precedents from precedents from the Chesapeake Bay Program in the US are the Chesapeake Bay Program in the US are worth examining. worth examining.

• Dead zones in

Dead zones in Cheasapeake Cheasapeake Bay made things Bay made things very difficult for them very difficult for them – – don don’ ’t let it happen here. t let it happen here.

What can be done about it ? What can be done about it ?

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• Three pronged catchment management effort to

Three pronged catchment management effort to restore their waterways. restore their waterways.

• 1. Reduce Pollution
• 1. Reduce Pollution
• 2. Restore Habitats
• 2. Restore Habitats
• Restoring shellfish reefs

Restoring shellfish reefs

• Replanting

Replanting seagrasses seagrasses

• Restoring wetlands

Restoring wetlands

• Restoring fish passage

Restoring fish passage

• 3. Manage Fisheries
• 3. Manage Fisheries

http:// http://www.chesapeakebay.net www.chesapeakebay.net/track/restoration /track/restoration

Chesapeake Bay Program, USA Chesapeake Bay Program, USA

At top of the list At top of the list because restored because restored shellfish reefs help shellfish reefs help with both 1. and 3. with both 1. and 3. as well as as well as restoration of restoration of seagrasses seagrasses (through improved (through improved water clarity) and water clarity) and wetlands (through wetlands (through bank bank stabilisation stabilisation) )

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They are doing it ! They are doing it !

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• Australia

Australia’ ’s first shellfish reef restoration program s first shellfish reef restoration program has just started in Port Phillip Bay, Victoria. has just started in Port Phillip Bay, Victoria.

• Partnership between a local fishing club, Victoria

Partnership between a local fishing club, Victoria Fisheries and The Nature Conservancy (TNC, an Fisheries and The Nature Conservancy (TNC, an eNGO eNGO). ).

• TNC is world authority on shellfish reef restoration.

TNC is world authority on shellfish reef restoration.

• They sponsored a National workshop in Melbourne

They sponsored a National workshop in Melbourne (February 2015) leading to development of a (February 2015) leading to development of a National Shellfish Restoration Strategy Document. National Shellfish Restoration Strategy Document.

Shellfish Reef Restoration in Australia Shellfish Reef Restoration in Australia

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• Significant community support to do something

Significant community support to do something tangible for tangible for Pumicestone Pumicestone Passage by conducting Passage by conducting

• ur own pilot shellfish reef restoration project.
• ur own pilot shellfish reef restoration project.
• Seed funding over $50,000 available from

Seed funding over $50,000 available from Toorbul Toorbul Fish Stocking Association Inc. Fish Stocking Association Inc.

• Support from traditional owners (

Support from traditional owners (Ngunda Ngunda-

• Joondoburri

Joondoburri, , Gubbi Gubbi Gubbi Gubbi), Sunfish, SEQ ), Sunfish, SEQ Catchments, QLD Fisheries, environment groups. Catchments, QLD Fisheries, environment groups.

• Aquaculture facilities (at

Aquaculture facilities (at Woorim Woorim) if needed. ) if needed.

• Restoring shellfish reefs is a key to maintaining a

Restoring shellfish reefs is a key to maintaining a healthy healthy Pumicestone Pumicestone Passage in the face of Passage in the face of

• ngoing urban development.
• ngoing urban development.

Local community support Local community support

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• Mini trials conducted in

Mini trials conducted in late 2014 with local oyster late 2014 with local oyster farmers set spat collectors farmers set spat collectors (clean oyster shell) to (clean oyster shell) to monitor shellfish monitor shellfish recruitment. recruitment.

• Results found oyster spat

Results found oyster spat settlement increased with settlement increased with water depth showing water depth showing shellfish reef restoration is shellfish reef restoration is a feasible option for a feasible option for Pumicestone Pumicestone Passage Passage

We can do it too ! We can do it too !

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Intertidal (0 m) Subtidal A (-2.1 m) Subtidal B (-3.5 m)

Spatfall per kg shell

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We can do it too ! We can do it too !

• Most exciting was evidence

Most exciting was evidence

• f large numbers of fish
• f large numbers of fish

eggs (top) and small crabs eggs (top) and small crabs (bottom) recruiting to (bottom) recruiting to subtidal subtidal (but not (but not intertidal intertidal) ) shellfish reef material placed shellfish reef material placed in in Pumicestone Pumicestone Passage. Passage.

• Suggests increases in fish

Suggests increases in fish and invertebrate biomass and invertebrate biomass upwards of 500 upwards of 500-

• 1000% (or

1000% (or more) could be expected if more) could be expected if subtidal subtidal shellfish reefs could shellfish reefs could be restored in be restored in Pumicestone Pumicestone Passage on a large scale. Passage on a large scale.

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• Phase 1. Baseline mapping to enable site

Phase 1. Baseline mapping to enable site selection, Permit applications, community selection, Permit applications, community consultation, oyster spat surveys consultation, oyster spat surveys– – est. $50 k

• est. $50 k

funding needed. funding needed.

• Phase 2. R&D field project

Phase 2. R&D field project – – reef restoration reef restoration materials to be placed in materials to be placed in subtidal subtidal reefs reefs only

• nly and

and their effects scientifically monitored and their effects scientifically monitored and

• evaluated. Est. $360 K funding needed of which
• evaluated. Est. $360 K funding needed of which

$50 K already pledged ( $50 K already pledged (Toorbul Toorbul FSA) FSA)

• Phase 3. Develop environmental offset models to

Phase 3. Develop environmental offset models to help generate funds to conduct shellfish reef help generate funds to conduct shellfish reef restoration on ecologically significant scales. restoration on ecologically significant scales.

Our Plan Our Plan (courtesy Harris Creek oyster restoration, MD)

(courtesy Harris Creek oyster restoration, MD)

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• Preliminary meetings with

Preliminary meetings with State authorities identified State authorities identified a potential research area a potential research area near near Ningi Ningi Ck. Ck.

• Looking for funding to kick

Looking for funding to kick start Phase 1. (Mapping, start Phase 1. (Mapping, permit applications). permit applications).

• Simon from SEQ

Simon from SEQ Catchments will give you Catchments will give you more details about how more details about how Council can help get this Council can help get this

• ff the ground.
• ff the ground.

We need Council support ! We need Council support !

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Questions? Questions?