Habitat Restoration

Question 1

Oyster habitats

Answer 1

Engineered by oyster or mussel species
Important fisheries resource
Excellent filters, important for quality

Question 2

Oyster habitat loss

Answer 2

85% of oyster reefs were lost globally, >99% loss in 37% estuaries
Losses due to overfishing, eutrophication, coastal dev, sewage inputs, sedimentaiton, habitat disturbance
Bad for communities that rely on harvest for employment and food
Reduced water quality

Question 3

Habitat restoration benefits

Answer 3

Boost local fish and crustacean fisheries, more fishing
Improve water quality
Protect shorelines
Improve estuary condition
Particles drawn from water and deposited to benthos, decreases turbidity and enriches sediments
Oyster reeds support higher biodiversity and abundance

Question 4

Solent Oyster Restoration Project

Answer 4

In 1978, 450 vessels were involved in oyster fishing and 15 million oysters were removed.
In 2013, fishery collapsed, oyster fishing was banned as molluscs were failing to reproduce.
Native oysters classified as a priority species

Question 5

Oyster hatchery

Answer 5

Use local oysters at correct temp and diet
In close confinement will breed
Allow larvae to settle on old oyster shells.
Placed mature brood stock oysters at high densities in cages hung in water beneath pontoons.
Cages refuge for other marine life

Question 6

Solent Project

Answer 6

Oyster beds filter the water column, removing N, sequestering C and providing habitats for 100s of species
Oysters feed on algae and phyto and gills act as a sieve to help remove contaminants
Restoration of this key habitat by relaying millions of oysters into the solent
12 sites

Question 7

Solent restoration numbers

Answer 7

Over 1 billion larvae released in 2017
105,000 oysters restored into nurseries or seabed
130 species identified in nurseries
Intertidal oyster ranching pilot sites established
One oyster reef in Langstone Harbour, 361m3 of cultch across 2000m2

Question 8

Chesapeake Bay

Answer 8

Overfishing and pollution caused decline.
2004 42 ha oyster reef by placing dredged oyster shells 180 mil oysters.
More recently 2012-2016, 142ha in harris creek, cost $28mil, no commercial fishing allowed

Question 9

Chesapeake Results

Answer 9

Reefs are monitored 3 years after restoration, reefs seeded in 2012 and 2013 (78 ha) have been monitored. All but 1.2 ha exceeded the threshold oyster biomass
47 ha exceeded the higher target biomass and density
Stone base reefs averaged 4 times the higher oyster densities than shell-base reefs and shell base reefs showed higher density than seed only

Question 10

Success of bivalve restoration

Answer 10

Mgmt action that results in multiple S, econ and eco benefits to estuaries and community
Advertise S&E benefits to get support from a wider audience of stakeholders
Expanding into new geographies

Question 11

Solent Sea scape project

Answer 11

Actively restore 8 Ha of saltmarsh, 7 Ha and 10 breeding seabird nesting sites.
Increase habitat extent and catalyse recovery across the wider seascape

Question 12

Chichester salt marsh

Answer 12

Salt marsh restoration in chichester:
- Uses sediment dredged from the harbour to rebuild the degraded shoreline where salt marshes have been lost
- 58% of saltmarshes since 1946 has been lost
- Raising the height of the area should enable pioneer species to recolonise the sediment and stabilise it, allowing other species to follow suit.