Ecosystems at Risk Case Study - Wetlands

Question 1

What is the spatial patterns and dimensions of Wetlands

Answer 1

• estuarine environment
• water temperature greater than 24 degrees
• along tropical and subtropical coastlines (25N - 25S)
• Nigeria, Indonesia, Brazil, Australia 43% of all wetlands
  Altitude - they exist within the limits of the coastal range (low altitudes)
  Size/ shape continuity - the area covered by intertidal wetlands is determined by the limits of the tidal range and increasingly by human obstruction and imposed land restriction

Question 2

Spatial distribution of Ash Island

Answer 2

33S, 151 E
780 ha
160km North from Sydney
14.2km NW from Newcastle

Question 3

biophysical processes (6)

Answer 3

• soil formation - weathering and deposition
  = anaerobic (low in oxygen)
  = high in biodiversity from lead litter –> 1 million microbes in 1 teaspoon of soil
• succession (mangroves –> mudflats –> salt marsh –> forest)
• tidal changes = 2 times daily (high and low tide)
• hydraulic action (stops erosion and weathering of coastal line)
• modifications (pneumatophores, waxy leaves, suicide leaves)
• transport and deposition - brings in nutrients and fish from up stream

Question 4

Natural stresses and rate (3)

Answer 4

• constant changing tides + low oxygen levels in soil
• in flux of high salt water from natural run off –> mangroves are constantly inundated with salt water then flooded with fresh water resulting in sudden alternation of salinity levels
• Sediment accumulating at a rate of 1.5 - 2 cm per year

every slow rate of change, enabling adaptions of occur

Question 5

Modification to changing tides/low oxygen levels

Answer 5

Development of pneumatophores
Root system which grows upwards from the main root. They absorb oxygen from the air when submerged in water

The root system also provides support to the mangrove in unstable sediment.

Question 6

Modification of wetlands to tolerate high levels of salinity (4)

Answer 6

• Ability to secrete salt, which occurs through special glands which are found on the leaves where tiny white flecks of salt are visible
• Ability to exclude salts, achieved by the root based cells that prevent the larger salt ions from entering and take in the smaller water water molecules (excludes 90% of salt)
• suicide leafs, where mangroves store/ concentrate salt into older leaves which falls off taking the excess salt with them
• Minimize water loss by their thick, waxy leaves or dense hairs that reduce transpiration

Question 7

Modification of wetlands for sediment accumulation

Answer 7

• specialized form of reproduction
  In contrast to reproducing by producing flowers and relying on pollination
  Once pollinated the mangrove seed remains on the parent plant where it germinates and grows stems and roots before being dislodged. Once in the water they travel and get lodged in the mud where they quickly produce roots and begin to grow.
  Other species release their seed inside a capsule which floats until it is deposited in a suitable location.

Question 8

Why protect wetlands - Heritage

Answer 8

• provides an insight into ways people lived in the past
• they represent a legacy to be passed on to future generations
• Protecting the history of the traditional Worimi, Awabakal peoples land where they hunted, gathered and cared for the ecosystem of Ash Island
• Protect historic history as Ash Island was where the Awabakal and Worimi people made first contact with Europeans

Question 9

Why protect wetlands - utility value

Answer 9

• The production of wood for construction and heating purposes
• harvesting of marine life
• once these resources have been used the land is often reclaimed for agricultural industrial and residential purpose
• Historically Ash Island was a large source of red cedar and ash
• Also areas used for breeding shrimp as they use mangroves as a nursery and refuge for the shrimp and they help purify the water

Question 10

Why protect wetlands - maintaining genetic diversity

Answer 10

• many organisms of intertial wetlands are yet to be identified and recorded hence these ecosystem should be preserved to enable further research
• animals that use the wetlands are inextricably linked to many other ecosystems
• Over 200 species of birds live/visit the hunter river esturary
• 34 species are migratory where they travel over 11, 000km trip from northern Asia and Alaska to breed - sometimes flying non-stop for 7 days. Hence need to maintain ecosystem to support these animals
• Contains endangered green and golden bell frog

Question 11

Why protect wetlands - intrinsic value

Answer 11

• the decrease in fish stocks and increase in harmful algal blooms have forced the appreciation of the unique characteristics of wetlands
• there’s a growing recognition that ecosystems have the right to exist irrespective of any utility value
• Activities e.g. bird watching, educational tours and reaction

Question 12

Why protect wetlands - need to allow processes of selection, evolution and change

Answer 12

• the area protected must be large enough to allow evolutionary processes to operate as they would in nature
• the inhibition to enable evolution will result in the vulnerability of ecosystems and especially biodiversity

Question 13

What are the historic Human impacts

Answer 13

Removal of all vegetation during European settlement
- 1791 timbre removal e.g. red cedar and ash were removed and sent down stream to Newcastle
- Farming era = created cattle grazing, 17 dairies, fractured the land for 55 families = produced high quality beef from Hereford herd
- Industrial area = accommodate residential and industrial land use, transport facilities and waste disposal sites
Degradation and loss of fisheries and other wildlife habitat in the estuary due to over 200 years of draining, filling, dredging and clearing
-Loss of over 1700Ha of mudflat/saltmarsh land

Question 14

What are the current Human Impacts

Answer 14

Contemporary
- used for urban development and lose of construction
- close proximity to Pacific Hwy
- close of Hexham MacDonalds = limits extent of ecosystem, decreasing resilience

Shrimp farming
- Thailand lost 56% wetlands in5 years to shrimp farming

Question 15

Traditional management strategies

Answer 15

Totem
- Awabakal (traditional custodian of the land) Eagle totem = goof for protecting biodiversity of this animal but may decrease population of other species to compensate
- seasonal calenders/ seasonal hunting - dictates when important natural occurrences (hunting season, when certain foods can be harvested) - enabled areas to regenerate
- nomadic lifestyle

Question 16

Contemporary management strategies

Answer 16

Restoring vegetation (Kooragang wetland rehabilitation project)
Boardwalk
Mesh wired fence with curved top and extend below the ground
- stops domestic animals
- stops foxes

-Breeding - capture and rescues
- golden bell frog and freckled ducks
- ‘adopt a duck’

RAMSAR Convention
- 172 countries
- ‘wise use’ of wetlands

Question 17

What’s the aim of the Kooragang Wetland Rehabilitation Project

Answer 17

Aim - to address the loss fisheries, shorebirds, threatened species and other wildlife habitat in the Hunter Estuary due to clearing, draining and filling over the past 200 years

Question 18

What were actions of the Kooragang Wetland Rehabilitation Project

Answer 18

• since 1996 32, 000 native plants have been replanted after European settlement
• 2000 Melalevca trees
• contracted ponds providing ‘stepping stones’ and established special features to improve habitat for endangered bell frogs
• improve habitat by protecting riverbanks
• managing water flows
  conserving saltmarsh
  managing weeds and feral animals
  revegetating areas of the floodplains using local native plants

Question 19

What were the educational actions of the Kooragang Wetland Rehabilitation Project

Answer 19

• the hunter Bird Observers Club which educated visitors on the 200 species of birds providing a birding route guide for Ash Island
• provides a library of all of the species in the area are other fact sheets
• signage
• visitor facilities

Question 20

How does the Kooragang Wetland rehabilitation Project protect intragenerational equity

Answer 20

• Developed Kooragang City farm to showcase farming in harmony with wetlands, utilising sustainable agriculture e.g. rotational grazing, off-stream watering and shade to take grazing pressure off the riverbank.
• This enabled the land and cattle being in better condition during drought
• walkway, boardwalks and cycleways to allow access without damaging the environment

Question 21

What did the ecosystem look like before the Kooragang Wetland Rehabilitation Project

Answer 21

In the 1800s the area was cleared of floodplain forest and drained for agriculture - Phoenix Flats. As a result salt tolerant exotic herbaceous vegetation became dominate due to the low elevation, proximity to saltmarsh and increased tidal flows in the adjacent tidal creel. Given these local conditions and sea level rise, the site was assessed to be more suitable for establishment of intertidal habitats rather than forest restoration.

Question 22

What did the Kooragang Wetland Rehabilitation Project do to fix the Phoenix Flats

Answer 22

Saltmarsh was formed by contouring the former paddock and connecting it to tidal flows from a tidal creek.
A monitoring program was established to track development of the created saltmarsh relative to control and reference sites.

Question 23

What was the outcome for the Kooragang Wetland rehabilitation fixing the Phoenix Flats

Answer 23

The Phoenix Flats is now a highly functional mosaic of open, water, saltmarsh and mudflat with peripheral rainwater fed swales now supporting a range of wildlife. this includes migratory shorebirds (Pacific Golden Plover and Easter Curlew).
It is part of a range of activities taken place in the Hunter estuary aimed at helping readdress the considerable loss (over 1700hs) of saltmarsh in the estuary since 1954 as well as planning for climate change retreat corridors

Question 24

what are the contemporary management strategies - exclusion

Answer 24

• raised path way to enable tourism while protecting the natural state
• also reduced entrance to a specific area
• Wire fence around the perimetre which extendes underground to prevent the enterence of predators
• however lack of funding ($7 per ha) mean inability to properly maintain

Question 25

what are the contemporary management strategies - education

Answer 25

Initially wetlands were regarded as smelly, mosquito ridden wastelands. Education campaigns have helped to change public perceptions and engender public support for the protection of these highly productive yet threatened ecosystems.
Education provides an opportunity to inform people about an ecosystem’s unique characteristics, its needs and problems, and the ways people can minimise their impacts.

Ash Island
Has signage which educates the public on the different vegetation , the history of the site, different vegetation zones

Question 26

what are the contemporary management strategies - legislation

Answer 26

RAMSAR Convention on Wetlands
Convention which encourages the designation of sites containing representative rare or unique wetlands or wetlands that are important for conserving biological diversity. Its aims are to halt the worldwide loss of wetlands and to conserve through wise use and management. This requires international cooperation, policy making capacity building and technology transfer.
- 1971
- 2,208 wetlands protected
- 168 countries have signed this agreement
-Must designate at least one site that meets the Ramsar criteria
- include wetland conservation within their national land use planning
- establish nature reserves on wetlands and promote wetland training

RAMSAR allows of wise use of wetlands which is the ecologically sustainable development aspect of this agreement. wise use = sustainable utilisation of wetlands for the benefit of mankind in a way compatible with eh maintenance of the natural properties of the ecosystem