2.0 One Mile Beach: Seagrass Investigation
One Mile Beach is located south of Myora National Park on the northwestern coast of the island. Seagrass beds cover the muddy sand flats of One Mile Beach. Seagrasses are marine flowering plants with the same basic structure of terrestrial plants. They commonly have long leaves like cooch grass or oval shaped leaves. Seagrass beds form meadows in estuaries and shallow coastal waters with sandy or muddy floors (EPA). Seagrass is commonly thought as seaweed, a type of algae. However they are much different. Seagrasses produce flowers, fruit and seeds, have roots, leaves and rhizomes and are vascular plants (EPA). These are all different to algae’s characteristics with seagrass being closely related to lilies. Seagrasses rely on nutrients usually obtained from mangroves and sunlight. The water must be clear otherwise floating sediments or other plants could block its sunlight that would cause the seagrass to die (EPA). They cannot grow well in areas where they will dry out at low tide and grow better if protected by a sand bar that protects it from wave action and turbulent muddy water. Despite normally growing in shallow water, seagrass has been found in clear water 68m deep (EPA). Seagrasses have developed adaptations to their marine environment. Different species have different salinity tolerance, depending on where they are located. The rhizomes anchor the plants into the shore and collect water and nutrients like the leaves (EPA). Seagrass has high ecological importance, forming the basis of a complex ecosystem. They stabilise the sand and mud banks, which keeps the water clear, and reuse nutrients that are dissolved in the water. Seagrasses are the basis of many food chains, suppling food to dugongs, green turtles, sea urchins and some small fish (EPA). The leaves also support tiny seaweeds that attach themselves to the leaves and tiny filter-feeding animals like bryozoans, sponges, molluscs and hydroids. These provide food for small fish which feed the larger fish. Bacterial decomposition of dead seagrass plants provides food for worms, sea cucumbers, crabs, anemones and ascidians (EPA). Plankton, both plant and animal, is a food source for prawns, fish and filter feeders. Seagrass beds have high economic importance as well as ecological importance. They act as nurseries and breeding grounds for commercially caught fish and prawns. They are also homes to bait used by fishers and fish species apart of the food chain of commercially fished species.
Abiotic
- Erosion
- Exposed at low tide
Table 1: Biotic Data of Seagrass Investigation
Discussion of which organisms live where and why
Seagrass form the basis of One Mile beach. Two types of seagrass were found to be at One Mile, Zostera capricorni and Halophila ovalis. Seagrass grows well in this area as it is protected from high-energy waves and wind as it faces Moreton Bay not the Pacific Ocean and sand bars are adjacent to the beach. Seagrasses are low-lying short grasses that are food for a variety of organisms. Dugongs, turtles and birds, which live in the area, directly consume the seagrass. Seagrass also provides habitats for many tiny fish, plankton and epiphytic, microbial and parasitic organisms. Snails and crabs also live in the seagrass area as their predators rarely visit seagrass beds and they are protected from strong wind and waves. Mangroves are present on the inland fringe of the beach. During high tide many tiny fish and other animals shelter here from prey and search for food. The mangroves benefit from this location as they experience periodic flooding by the ocean.
Classification
Kingdom: Animalia
Phylum: Annelida
Class: Polychaeta
Order: Aciculata
Family: Phyllodocidae
(Wikipedia)
Green paddle Worm Phyllodoce novaehollandiae
Green Paddle Worms have long thin green bodies with pairs of unusually large leaf-like appendages on each segment. They have small heads with four small antennae and the first segment of the body has a group of tentacles. Green Paddle Worms secrete a profuse amount of mucous and reaches 5 to 10 cm long. They are found Australia-wide, wriggling on muddy sands of intertidal flats, usually in seagrasses or rocks. They feed on small polychaetes and crustaceans. They build tubes to live in, which are strengthened with mucous and are firmly anchored in the sand. This is so that they are not washed away by the tides. http://bellnetweb.brc.tamus.edu/adaptati.htm
Food Web
Table 2: Seagrass Transect Results
Figure 1: Transect of Seagrass
3.0 Myora Springs: Mangrove Investigation
Myora Springs and Myora Conservation Park are located along East Coast Road, north of Dunwich. Myora Springs is a freshwater stream that is part of the underground water table. This is the only place apart from 18 Mile Swamp that the water table can be seen above ground. Myora Springs is located further North of Myora Conservation Park and is approximately four kilometres from Dunwich (Google Maps). Mangroves are usually trees but can also be shrub or palm and are found in the littoral zone (EPA). They live on the coastlines that are inundated with tides periodically. Approximately 75% of commercially caught fish spend some time in mangroves or depend on food chains that begin with mangroves. The species that make up the other 25% probably also rely on nutrients exported from the mangroves. Mangroves protect the coast by absorbing energy from storm driven waves and wind (EPA). They also prevent silting of the adjacent marine habitats by trapping sediments with their roots. Silting could cause coral and seagrass to die from underexposure of sunlight. Mangroves additionally absorb pollution (EPA). Mangroves are useful in medicines, fishing and their wood is used for different purposes. However with vast areas of mangroves being destroyed worldwide, the way humans use mangroves should be stopped. Mangroves have developed adaptations against the salty environment of the littoral zone. Mangrove roots, like those of the Red Mangrove, have developed filters to keep out salt, which can keep out as much as ninety percent of salt. Mangrove leaves have salt glands that excrete salt out quickly after entering the system (EPA). Another method is to concentrate salt in old bark or leaves, which will take the salt with them once they fall off. To prevent water loss the leaves have a waxy cuticle or dense hairs to reduce transpiration. Stomata are the location of most water loss so they are located below the leaf surface where they are protected from winds (EPA). The leaves are usually succulent so the store water in their fleshy internal tissue. Mangroves grown on the western side of NSI instead of the eastern side as the island acts as a barrier from high energy waves which may erode the shore and prevent seedlings from growing. Mangroves are periodically covered with salty water, while at low tide can be covered by fresh water, especially after rain. They have to cope with the changing salinity and water temperature (EPA). Mangrove distribution is affected by these factors along with wave energy, soil oxygen levels, drainage and differing nutrient levels. Different mangrove species prefer different conditions, which lead to zones of mangroves where particular species are quite dominant (EPA). Mangrove roots support the plant and obtain essential nutrients and oxygen. The roots grow down two metres beneath the ground, probably no further due to limited oxygen.
Abiotic
Substratum Colour – greyish brown sand with green algae
Temperature – 26.9°C
Oxygen levels – 4.06 mg/L
pH level – 7.53
Salinity – 2.94%
Smell – Sulphur
Turbidity – 1.04 NTU
- High evaporation
- Changing tides
- Strong storms
- Desiccation
Table 3: Biotic Data of Mangrove Investigation
Discussion of which organisms live where and why
Myora Springs is essentially a mangrove ecosystem. Three species of mangrove were located at Myora: Red, Grey and Orange mangroves. Mangroves develop well at this site as they experience high and low tides, with flooding by salt water at high tide from the ocean, and by fresh water from the underground water table at low tide. The mangroves protest the island from high-energy waves and wind, stopping the dunes from degrading. Mangroves, especially the red mangrove due to its prop roots, provide shelter for many kinds of organisms, like small fish, from predators. They also act as nurseries for young organisms as the area around mangroves when underwater is relatively calm. It is also an excellent feeding ground for larger organisms to feast on smaller organisms. Oysters attach themselves to mangrove roots, usually red mangroves, and benefit from the periodic flooding as well.
Classification
Kingdom: Plantae
Phylum: Magnoliphyta
Class: Magnoliopsida
Order: Malpighiales
Family: Rhizophoraceae
Red Mangrove Rizophora Stylosa
The Red Mangrove can either be a shrub or small tree that grows to 6m in subtropical regions (Queensland Museum). They have arching prop roots that spread the weight of the tree. Their leaves grow about 10 cm long and grow in clumps at the end of branches. Small, white flowers grow about 1.2cm long and are pollinated by wind or insects. Seedlings develop to 20-40 cm long and tapered at one end. These roots drop to the ground and hopefully dig into the ground so the plant can re-establish. Red Mangroves occur in the intertidal zone, where its roots are submerged during high tides (AIMS). They are found in Australia in the northern parts of the coastline. They prefer well-drained soft muds and grow well with the grey mangrove especially around edges or shallow protected inlets (Queensland Museum). Red Mangroves are salt excluders, by eliminating salt at their roots as water is taken up. Excess salt in the plant is stored in the leaves and then lost from the plant when the leaves die and fall from the tree (DPI).
Food Web
4.0 Main Beach: Sand Dune Investigation
Main Beach is part of the western coast of North Stradbroke Island is almost and endless expanse of sand. At Main Beach, large vegetated sand dunes that cover the island can be seen fantastically, but also some human impacts. Various types of dune plants are found at this site and have all developed adaptations to the harsh abiotic factors. Also, an array of animals can be observed, inhabiting this ecosystem and have also developed adaptations to various factors. Vegetated sand ridges, or dunes, are formed behind beaches by dry sand blown up from the beach. As more sand gathers, the sand dunes became taller and larger. Plants help to stabilise the sand from wind, trapping the sand particles. Sand dunes act as a buffer for the coastline, protecting it from wave damage during storms and from salt water. Dunes also act as a reservoir of sand, to fix and maintain the beach from erosion. Vegetation is vital for sand dunes otherwise the dunes will be diminished or go through a process of succession, taking over land behind and. Plants found on the frontal dunes are limited and have adapted to salt spray, sand blast, strong winds, and flooding from the ocean. They usually have waxy or hair covered leaves and stems that grow low to the ground and have extensive root systems. The dunes further back from the beach begin to have larger plants that are protected from windy and salty conditions. As plants grow, humus accumulates and enriches the sand and soil, which now holds more water. This enables other types of vegetations to grow.
Discussion of which organisms live where and why
Main Beach has developed from wind blowing sand up from the beach forming dunes. The dunes have been vegetated, with more tolerant plants at the frontal dunes and less tolerant and larger plants at the rear dunes. Low creeping plants, like Spinifex and Goat’s Foot inhabit the frontal dunes. This is because they are the only plants that can survive the extreme conditions of strong winds, salt spray etc. Gradually, plants like the Coastal Wattle and Banksia are found as they are short trees or shrubs and are protected in the swales of dunes. At the back of the dunes are Coastal Teatree and Casuarina’s, which can tolerate the conditions this far back from the beach. They protect the island from strong winds. Wallabies and kangaroos, particularly grey kangaroos, visit the dunes for food. Other animals present include many insects and birds. These animals all visit for food, usually flowers and fruit but sometimes to feed one each other. Other animals cannot survive the conditions or are not found on the island.
Abiotic
- Low nutrient levels
- Unstable soil and sand
- Easily damaged by wind and waves
- Salt blows
- High salinity
- Direct sunlight/heat
- Lack of Moisture
- No reliable water supply beyond high tide mark
Classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Passeriformes
Family: Meliphagidae
Brown Honeyeater Lichmera Indisitincta
Brown Honeyeaters are a small to medium sized birds found in Western and Northern Australia. They have olive brown upper parts with greenish yellow edges on their tails and feathers. They live in inland open forests, mangroves and usually in bayside areas or along watercourses. Brown Honeyeaters feed on insects and nectar and are found Australia-wide (Queensland Museum).
Food Web
Table 4: Biotic Data of Sand Dune Investigation
Table 5: Vegetation Data of Sand Dune Investigation
Table 6: Animal Data of Sand Dune Investigation
Table 7: Sand Dune Transect Results
Figure 2: Sand dune Transect
Table 8: Vegetation Information for Sand Dune Investigation
Sources: http://www.epa.qld.gov.au/environmental_management/coast_and_oceans/beaches_and_dunes/beach_conservation/ and Vegetation Identification Cards
5.0 18 Mile Swamp Investigation
18 Mile Swamp is the largest swamp of its type in Queensland (HWS). This is a United Nations listed Ramsar wetland and is extremely unique, due to its size and importance. Ramsar is The Convention on Wetlands of International Importance is an intergovernmental treaty that aims to conserve and show wise use of wetlands. NSI is ecologically important as it is home to many species of plants and animals. Moreton Bay became a Ramsar listed site in 1993 and is 113,314 ha (Peck, D). It supports an extremely high species diversity with over 50,000 migratory waterbirds migrating here for winter (Peck, D). Canal estates have access to the bay, in turn destroying mangroves, and support important fishery. Morton Bay is popular for recreational activities and tourism. Annually, up to one million tonnes of sub-fossil coral and 150,000m3 of sand are extracted. Behind dune systems are sometimes freshwater swamps like 18 Mile Swamp. Paperbark trees usually dominate the swamp vegetation.
Abiotic
Colour – clear dark brown/black
Turbidity – 5 NTU
Oxygen levels – 3.44 mg/L
pH level – 5.5
Salinity – 0
Nitrites NO2 – 0
Nitrates NO3 – 0
Temperature – 21.5°C
Discussion of which organisms live where and why
18 Mile Swamp is host to a large variety of organisms that benefit from living in this environment. Coastal Teatree, Coastal Wattle and Broad-Leaved Paperbarks are the most dominant trees at 18 Mile Swamp and are attracted by the wet soils. Aquatic vegetation includes reeds, water lilies, selaginella and rush and they provide habitats for aquatic organisms, like freshwater shrimps and whirligig beetles. Mammals visit usually only for drinking purposes and there is limited aquatic bird life as the water surface is almost covered in vegetation. Brown Honeyeaters and Reed Warblers are among the terrestrial birds that visit the site. Unfortunately, mosquito fish have invaded the swamp, like they have in many places throughout Australia. They were introduced to control mosquito numbers but have disrupted the food chain and have caused a decline in other fish numbers of similar size (Native Fish Australia).
Classification
Grey Rush Lepironia articulata
The grey rush is clumps of blue-green grass stems that grow up to 2m tall. The stems are stiff with sharp tips that produce small brown flowers growing sideways out of the stem. It grows on the edge of water bodies, such as creeks and lagoons, and is found mainly in Qld, especially Moreton Bay, NT and NSW. The grey rush proves the soil is wet and full of nutrients; otherwise the grass would not grow (Queensland Museum).
Food Web
Table 9: Biotic Data of 18 Mile Swamp Investigation
Table 10: Animal Survey on 18 Mile Swamp
6.0 Brown Lake Investigation
Brown Lake is a located on NSI inland east of Dunwich. Tourists and locals frequently visit Brown Lake for swimming and recreational activities. Until recently, motorized equipment was allowed to on the lake. It is a perched lake, which is where water is collected like in a bowl. Perched lakes are usually surrounded by higher land and are found at elevations of 100m or more above sea level. They exist due to the layering effects of coarse sand over much finer sand called Teewah Sands. The water cannot reach the fresh water lens that is between the layers of bedrock and sand because of the Teewah sand. It is directly reliant on rainfall for their water source and can rise and fall by several metres within a year depending on the amount rainfall.
Abiotic
Colour – clear brown
Turbidity – 3 NTU
Oxygen levels – 4.48 mg/L
pH level – 4.99
Salinity – 0
Nitrites NO2 – 0
Nitrates NO3 – 0
Temperature – 23.3°C
Discussion of which organisms live where and why
Brown Lake attracts many visitors for recreational purposes. This creates distraction and disturbances to wildlife. Similar plants like the Coastal Teatree and Broad-Leaved Paperbarks are common at Brow Lake like at 18 Mile Swamp. Aquatic Vegetation is limited but includes reeds and rushes, providing habitats for aquatic organisms, like the water strider and water measurer. Kookaburras, Fryer Birds Wood Ducks and Crows visit the Brown Lake for nesting and feeding, especially the crows which are attracted by the humans. There is too much human activity for aquatic birds to inhabit the lake. Unfortunately like 18 Mile Swamp, mosquito fish have invaded the lake and are also causing a decline in other fish numbers of similar size (Native Fish Australia).
Classification
Kingdom: Plantae
Phylum: Magnoliophyta
Class: Magnoliopsida
Order: Myrtales
Family: Myrtaceae
Broad-leaved Paperbark Melaleuca quinquenervia
The broad-leaved paperbark is usually up to 12m tall but can grow as tall as 25m (Queensland Museum). It is famous for its white paper-like bark that forms multiple layers and can peel off. The leaves are stiff, leathery and are a bluish green colour (ASGAP). During September to May each year, it produces cream bottlebrush flowers (Queensland Museum). It is commonly found along streams, swamps, coastal plains, dry slopes of waterways, and is located from Cape York, Queensland to Central New South Wales (ASGAP). This tree brings many animals for food, including the scarlet honeyeater and lorikeets for their flowers, squirrel gliders for their flowers and bark and koalas for their leaves. This tree is well suited to poorly drained sites (ASGAP), which means that the soil is wet and it helps to stop erosion, as it roots stabilise the soil, like many other trees (Queensland Museum).
Food Web
Table 11: Biotic Data on Brown Lake Investigation
Table 12: Animal Survey on Brown Lake
7.0 Protection and Conservation of North Stradbroke Island
In 1993, the Queensland Government declared Moreton Bay a marine park, called the Moreton Bay Marine Park (MBMP) that is managed by the Queensland Parks and Wildlife Service. The MBMP, extended in 1997, is approximately 3400 sq. km and the eastern boundary reaches three nautical miles off the east coast of Bribie, Moreton, North Stradbroke and South Stradbroke Islands (EPA). The highest astronomical tide is the boundary line along the coast from Caloundra to the Gold Coast Seaway. The MBMP was formed in response to community pressure as Moreton Bay incorporates environmental, economic, social, cultural and historical uses (EPA). Ideally for the wellbeing of Moreton Bay, it should be closed off to all recreational activities, fishing, tourism, shipping and other ecologically damaging activities. However governments, councils, companies, developers and residents would not support this idea as uneconomical, undesirable and limiting. So to understand the needs of Moreton Bay environmentally and by humans, the MBMP was produced. A marine park is different to national park, as it allows people to do most things while still protecting the natural environment. Moreton Bay is one of South East Queensland's most significant natural, recreational, cultural and economic resources (EPA). Economically the bay is utilizes by shipping, fishing, recreation and tourism industries that provides jobs and income for some of the two million residents living in the Moreton region. However, the Bay remains mostly in its natural state, an internationally significant wetland providing habitats crucial for migratory shorebirds, turtles and dugong (EPA). A unique zoning plan was developed to provide a balance between human and environmental needs. Each zone has activities that are allowed or not and those that require special permits. The zones are general use, habitat, conservation, buffer and protection. There are also designated, turtle and dugong and commercial bloodworm gathering areas (EPA). In the marine park there are also many rules and regulations to limit human impact on the bay. Table 13 shows impacts on the mangrove ecosystem and strategies that could be implemented to protect it even further than what the current management plan does. The mangrove ecosystem is being focussed on as it has extreme value to Moreton Bay as other mangrove systems have been destroyed due to canals and housing.
Table 13: Impacts on the Mangrove Ecosystem and Strategies
8.0 Conclusion
North Stradbroke Island is the largest island in Moreton Bay and it is imperative that its habitats are maintained properly and adequately. The recommendations for the management of Moreton Bay and surrounding habitats detailed in this report will provide a strategic management plan for the future. The location of the bay and islands in relation to Brisbane has had an impact on what can and has been done to protect its existence. Its importance to people both locals and indigenous as well as a diverse range of organisms was recognised to help form a plan that will suit all needs. Five different habitats on the North Stradbroke Island, most importantly Myora Conservation Park, were investigated to observe the different organisms found in the area. The Management Plan that was developed from the investigation will provide for the ongoing change in the Moreton Bay Marine Park management.
9.0 Bibliography
Association of Societies for Growing Australian Plants (ASGAP). Melaleuca quinquenervia. [Online] Available 11/11/06
Department of Primary Industries and Fisheries. Know your mangroves 2. [Online] Available 13/11/06
Flesser, K. Boondall Wetlands. [Online] Available 13/11/06
Gerlach, A-M. 2006, Vegetation Identification Cards.
Native Fish Australia. Exotic Fish in Australia. [Online] Available 11/11/06
Peck, D. The Annotated Ramsar List: Australia. [Online] Available 4/11/06
Queensland Museum, 1998, Wild Guide to Moreton Bay, Queensland Museum, South Brisbane.
Queensland Museum, 1995, Wildlife of Greater Brisbane, Queensland Museum, South Brisbane.
Queensland Museum, 2003, Wild Plants of Greater Brisbane, Queensland Museum, South Brisbane.
Ray White North Stradbroke Island. Welcome. [Online] Available 29/10/06
Redland Shire Council. North Stradbroke Island. [Online] Available 8/09/06
Redlands Tourism 2006, North Stradbroke Island [Brochure], Redlands Tourism, Cleveland.
Stradbroke Getaways. North Stradbroke Island - A Near Perfect Climate. [Online] Available 15/10/06
The State of Queensland (Department of Natural Resources and Water). Hydrology of North Stradbroke Island. [Online] Available
21/10/06
The State of Queensland (Environmental Protection Agency). Beach Conservation. [Online] Available 29/05/06
The State of Queensland (Environmental Protection Agency). Coastal Dunes. [Online] Available 20/10/06
The State of Queensland (Environmental Protection Agency). Mangroves. [Online] Available 9/10/06
The State of Queensland (Environmental Protection Agency). Seagrass. [Online] Available 3/11/06
The State of Queensland (Environmental Protection Agency). Wetlands – More Than Just Wet Land. [Online] Available 12/11/06
Appendix
Appendix A – Annotated Bibliography
Queensland Museum
Three Queensland Museum publications were widely used for information on plants, animals and habitats. These publications were Wild Guide to Moreton Bay, Wildlife of Greater Brisbane and Wild Plants of Greater Brisbane. These books proved highly valuable as they relate to South East Queensland and Moreton Bay where this report was undertaken. The plants, animals and habitats were those that were observed during the field trip. The Queensland Museum has researched plants, animals and habitats in Queensland for many years, keeping information on them as it is discovered. This information is continually updated when new information is discovered.
The State of Queensland (Environmental Protection Agency).
The Queensland Government websites were used for information regarding habitats and plants. These websites were useful as they relate to plants and habitats found in Queensland, as they are Queensland Government websites. These plants and habitats discussed are those that were observed on the field trip. The Queensland Government has up to date information from most of the research conducted in Queensland, which can easily be obtained by them.
Redland Shire Council/Redlands Tourism
The Redland Shire Council website and the Redlands Tourism Brochure, which is owned by the Council, provided information on the Redlands district. This information relates to North Stradbroke Island as it is apart of the Redland Shire and provides data on it. The Redland Shire Council has archives that have been kept which document information or events that occur in the Shire.