North Stradbroke Island Research Paper
North Stradbroke Island is an island that is located within Moreton Bay in the Australian state of Queensland. The island is approximately thirty seven kilometres long and eleven kilometres wide. The island spans 27,520 hectares and of that only 445 hectares had been declared National Park. The highest peak is Mt Hargrave sand dune around 229 meters and the average rainfall is about 1803 mm per year. The rain does percolate through the sand into the islands water table. Underground water supplies are extensive; so much so that large amounts of water flow have literally formed the swamps on the island.
North Stradbroke Island has been formed by large quantities of sand which have their origin in the rocks of the Great Dividing Range which became …show more content…
eroded by streams flowing into the sea. Before 1896 the island was part of the Stradbroke Island. In that year a storm separated it from South Stradbroke Island, forming a channel. North Stradbroke Island consists almost entirely of sand, with rocky outcrops at Point Lookout and small outcrops of sandstone at Dunwich. Some of the rock formations at Point Lookout are volcanic rocks formed during the Mesozoic era. The sands which make up the dunes originated in the highlands of eastern New South Wales and southern Queensland. There seems to be three major dune forming periods. Hence the dunes are classified as ancient, old and recent.
Although it consists almost entirely of sand, North Stradbroke Island exhibits a wide range of habitats, each supporting a diversity of plants and animals. The most important habitats along the eastern, or ocean, side of the Island consist of open beaches, frontal dunes and the 18 Mile Swamp, together with a small area of rocky headland at Point Lookout. The western, or Moreton Bay, side of the Island is characterized by mangroves and tidal swamps. The bulk of the Island consists of sand dunes - some low and others up to 100m in height, with steep sides. A series of lakes and lagoons occurs between the dunes, the most notable being Blue and Brown Lakes. These waters are generally acidic and support little animal life. The sand dunes are mostly covered with mixed forests, usually dominated by eucalypts. Extensive areas dominated by smaller banksias and acacias, ranging down to low heathlands, also occur. Inland swamps are usually dominated by paper-barks. A small patch of dry rainforest or vine scrub occurs at Myora. Large areas of sand and muddy sand flats occur on the Moreton Bay side of the Island and these support communities of seagrass. North Stradbroke Island has a great range of biodiversity. These ecosystems are home to many different animals, because of the islands isolation many rare and endangered land and sea creatures inhabit the island. There is even a remnant rainforest at Myora Springs near Dunwich. There are 18 species of land mammals including wallabies, kangaroos, echidnas, koalas and bandicoots. Marine mammals include whales, dolphins and dugong. Reptiles include turtles, tortoise and lizards. There are several frog species and hundreds of bird species.
The island has been the site for sand mining for more than sixty years. Many of the animals on the island demonstrate examples of succession and adaptation their specific biomes and environments. Two mining companies currently operate on the Island; Consolidated Rutile mines the high dunes, while Associated Minerals chiefly mines the frontal dunes. Mining began in the 1950s on the beachfront and this caused minimal disruption to the environment. A similar mining moved further inland on the island in the late 1960s with greatly increased, size and scale. The impact on Stradbroke's ecosystem increased with Consolidated Rutile Limited (CRL) starting dredge-mining on Stradbroke's high dunes. Dredge mining involves levelling the high dunes and stripping vegetation to create the dredge pond and this dramatically changed the landscape of Stradbroke.
MANGROVES – Myora Springs
Mangroves are a unique range of trees, shrubs or ground ferns that differ in terms of genus and species; however they share common adaptions that enable them to live in unbalanced and challenging environments. Mangrove forests typically grow in tropical and subtropical latitudes near the equator. Densely populated mangrove forests can be recognized by their dense tangle of prop roots that make the trees appear to be standing on stilts above the water typically exceeding one half metre in height, mangroves usually grow above sea level in the intertidal zone of marine coastal environments. Being propped up allows the trees leafs to stay out of the water and prevents the trees from drowning in the water. All of these trees grow in areas with low oxygen soil, where slow-moving waters allow fine sediments to accumulate. These sediments will build up the muddy ground and stabilise the surrounding coastline. By stabilising the surrounding coastline mangroves can reduce erosion, currents and tides. The extensive root systems provide great cover for organism, creating a biome for smaller organisms. Explicitly looking at the mangrove ecosystem at Myora springs, a variety of organisms have been identified, each having its own distinctive characteristics and adaptions that have allowed it to survive in the rough conditions. These organisms include the Mud Crab, the Grey and Red Mangrove.
Mud Crab – Scylla Serrata
The Mud Crab is commonly found in the estuaries and mangroves near the high tide line. In their most common form, the shell colour varies from a deep, mottled green to very dark brown. This adaptation helps the Mud Crab blend into its environment and remain hidden from predators. Similar to the mangroves, both share similar colour. The Mud Crab can to stay out of the water for months, and have gills for breathing in the water; however they have a primitive lung which allows them to live on the land. This specific adaptations allow the Mud Carb to survive out of the water for long durations at a time. These crabs have a high tolerance to both nitrate and ammonia. Their high ammonia-N tolerance may be attributed to various unique physiological responses which may have arisen due to their habitat preferences. A vital role played by the Mud crab in salt-marsh ecology is assisting in keeping marshes clean, which enables them to grow. This mutualism with its environment benefits both parties positively, by keeping the floor clean and allowing the mud crab to grow to large sizes. This is supported by their feeding and burrowing.
Grey Mangroves – Avicennia Marina
Grey mangroves are the most common and widespread mangrove along the mainland coast of Australia. Much like the Red mangrove, Grey mangroves occur in intertidal zones on a range of soft muds to sandy soils. The average soil PH level at Myora Springs was eight which is consistent with the ideal conditions for the Grey Mangroves. Flowering occurs in mid to later summer, with pale green flattened fruits. The flattened fruits and leafs allow the tree to soak up sunlight. The flatness of the fruits (seeds) allows it to float much faster on the water and lodge its self into soil, mud or sand much easier than a round seed. This adaptation allows the mangroves to spread all along the coastline and populate it heavily. This adaptation can be directly linked to the mangroves stabilising the surrounding coast lines. The grey mangrove has a high salt tolerance much like the Red Mangrove; however it is very tolerant to extreme saline conditions whereas the red mangrove is not. This is important because the mangrove always populates coastlines, which a most likely to be salient. This could be an adaptation formed over time. It resists the salient water by actively restricting the uptake of salt at the roots. This specific adaption to the environment assists the organism to survive in its environment.
Red Mangroves –Rhizophora mangle
Red mangroves are a common species of the Rhizophoracea family.
They can be found stretched across costal northern Australia. The average soil PH level at Myora Springs was eight which is consistent with the ideal conditions for the Red Mangroves. These type of mangroves form extensive, often pure stands around the shores of shallow bays. Preferring soft, well drained muddy soils. In North Queensland, Red mangroves are able to grow up to ten metres high, however it is most common to see five metre high trees; most likely because of the lower and sparser human population and density towards the coastlines. A main feature of this species is their stout, a large arching prop of roots that contain numerous lenticels (air pores) that support the main trunk and enable to tree to live. Red mangroves have adapted to their salient ecosystem by tolerating salt. They eliminate salt from their roots as water is occupied. Excess salt is then stored in the leaves and the tree sheds these leaves later on. Although the Grey mangrove can withstand much higher salt concentrations, both species lived side by side at Myora Springs. This is because the average soil PH level was eight, which is not high enough to stop the red mangrove from
growing.
SAND DUNES – 18 Mile Swamp
18 Mile Swamp is located on the eastern side of the island. The dunes provide much needed habitat for highly specialized plants and animals, including rare and endangered species. The sand dunes at 18 Mile swamp are important because they help protect beaches from erosion and recruit sand to eroded beaches. Not all of 18 mile swamp is protected. Certain patches have been extensively mined. A variety of organisms have been identified, each having its own distinctive characteristics and adaptions that have allowed it to survive in the rough conditions. These organisms include the Ghost Crab, spinifex and the Goat’s foot.
Ghost Crab – Ocypode
The Ghost Crabs is relatively small in comparison to other species, with flecks of pink and yellow on its almost translucent exoskeleton. This adaptation to its environment allows the crab to camouflage against the sand to hide from predators and it also allows the crab to camouflage when hunting. Its eyes appear to be the end of long stalks, which may assist is seeing birds of prey. The ghost crab is found Australia wide and usually inhabit the intertidal beach areas. The Ghost Crab will stay in the cool protection of its burrowed habitat during the day and will make its way towards the water during the night to hunt for food. Its burrow is built high up on the shore, to prevent flooding from the ocean. Their burrows can be dug around one metre deep, which keeps them protected from predators; if anything did try to dig one metre is too deep and the intruder would give up. Although Ghost crabs live away from the water they are semi-terrestrial and breathe oxygen from the air through moistened gills, meaning they must periodically wet their gills with seawater. Usually by taking water from moist sand or by running into the surf and letting the waves wash over them. Running from their burrow to the surf and back can be dangerous however their colour adaptation will assist their necessity for water to live. Ghost crabs also have the ability to change colors to match their surroundings by adjusting the concentration and dispersal of pigments within their chromatophores. They can even match the specific colours of the grains of sand in their habitats, although ghost crabs are capable of morphological colour change, it occurs over a longer span of time. This adaptation allows the crab to adapt to its changing environment, depending on the colour of the sand. Similarly to the mud crab the ghost crab is a scavenger and it has a mutualistic relationship with its environment by keeping it clean.
North Stradbroke Island has been formed by large quantities of sand which have their origin in the rocks of the Great Dividing Range which became …show more content…
eroded by streams flowing into the sea. Before 1896 the island was part of the Stradbroke Island. In that year a storm separated it from South Stradbroke Island, forming a channel. North Stradbroke Island consists almost entirely of sand, with rocky outcrops at Point Lookout and small outcrops of sandstone at Dunwich. Some of the rock formations at Point Lookout are volcanic rocks formed during the Mesozoic era. The sands which make up the dunes originated in the highlands of eastern New South Wales and southern Queensland. There seems to be three major dune forming periods. Hence the dunes are classified as ancient, old and recent.
Although it consists almost entirely of sand, North Stradbroke Island exhibits a wide range of habitats, each supporting a diversity of plants and animals. The most important habitats along the eastern, or ocean, side of the Island consist of open beaches, frontal dunes and the 18 Mile Swamp, together with a small area of rocky headland at Point Lookout. The western, or Moreton Bay, side of the Island is characterized by mangroves and tidal swamps. The bulk of the Island consists of sand dunes - some low and others up to 100m in height, with steep sides. A series of lakes and lagoons occurs between the dunes, the most notable being Blue and Brown Lakes. These waters are generally acidic and support little animal life. The sand dunes are mostly covered with mixed forests, usually dominated by eucalypts. Extensive areas dominated by smaller banksias and acacias, ranging down to low heathlands, also occur. Inland swamps are usually dominated by paper-barks. A small patch of dry rainforest or vine scrub occurs at Myora. Large areas of sand and muddy sand flats occur on the Moreton Bay side of the Island and these support communities of seagrass. North Stradbroke Island has a great range of biodiversity. These ecosystems are home to many different animals, because of the islands isolation many rare and endangered land and sea creatures inhabit the island. There is even a remnant rainforest at Myora Springs near Dunwich. There are 18 species of land mammals including wallabies, kangaroos, echidnas, koalas and bandicoots. Marine mammals include whales, dolphins and dugong. Reptiles include turtles, tortoise and lizards. There are several frog species and hundreds of bird species.
The island has been the site for sand mining for more than sixty years. Many of the animals on the island demonstrate examples of succession and adaptation their specific biomes and environments. Two mining companies currently operate on the Island; Consolidated Rutile mines the high dunes, while Associated Minerals chiefly mines the frontal dunes. Mining began in the 1950s on the beachfront and this caused minimal disruption to the environment. A similar mining moved further inland on the island in the late 1960s with greatly increased, size and scale. The impact on Stradbroke's ecosystem increased with Consolidated Rutile Limited (CRL) starting dredge-mining on Stradbroke's high dunes. Dredge mining involves levelling the high dunes and stripping vegetation to create the dredge pond and this dramatically changed the landscape of Stradbroke.
MANGROVES – Myora Springs
Mangroves are a unique range of trees, shrubs or ground ferns that differ in terms of genus and species; however they share common adaptions that enable them to live in unbalanced and challenging environments. Mangrove forests typically grow in tropical and subtropical latitudes near the equator. Densely populated mangrove forests can be recognized by their dense tangle of prop roots that make the trees appear to be standing on stilts above the water typically exceeding one half metre in height, mangroves usually grow above sea level in the intertidal zone of marine coastal environments. Being propped up allows the trees leafs to stay out of the water and prevents the trees from drowning in the water. All of these trees grow in areas with low oxygen soil, where slow-moving waters allow fine sediments to accumulate. These sediments will build up the muddy ground and stabilise the surrounding coastline. By stabilising the surrounding coastline mangroves can reduce erosion, currents and tides. The extensive root systems provide great cover for organism, creating a biome for smaller organisms. Explicitly looking at the mangrove ecosystem at Myora springs, a variety of organisms have been identified, each having its own distinctive characteristics and adaptions that have allowed it to survive in the rough conditions. These organisms include the Mud Crab, the Grey and Red Mangrove.
Mud Crab – Scylla Serrata
The Mud Crab is commonly found in the estuaries and mangroves near the high tide line. In their most common form, the shell colour varies from a deep, mottled green to very dark brown. This adaptation helps the Mud Crab blend into its environment and remain hidden from predators. Similar to the mangroves, both share similar colour. The Mud Crab can to stay out of the water for months, and have gills for breathing in the water; however they have a primitive lung which allows them to live on the land. This specific adaptations allow the Mud Carb to survive out of the water for long durations at a time. These crabs have a high tolerance to both nitrate and ammonia. Their high ammonia-N tolerance may be attributed to various unique physiological responses which may have arisen due to their habitat preferences. A vital role played by the Mud crab in salt-marsh ecology is assisting in keeping marshes clean, which enables them to grow. This mutualism with its environment benefits both parties positively, by keeping the floor clean and allowing the mud crab to grow to large sizes. This is supported by their feeding and burrowing.
Grey Mangroves – Avicennia Marina
Grey mangroves are the most common and widespread mangrove along the mainland coast of Australia. Much like the Red mangrove, Grey mangroves occur in intertidal zones on a range of soft muds to sandy soils. The average soil PH level at Myora Springs was eight which is consistent with the ideal conditions for the Grey Mangroves. Flowering occurs in mid to later summer, with pale green flattened fruits. The flattened fruits and leafs allow the tree to soak up sunlight. The flatness of the fruits (seeds) allows it to float much faster on the water and lodge its self into soil, mud or sand much easier than a round seed. This adaptation allows the mangroves to spread all along the coastline and populate it heavily. This adaptation can be directly linked to the mangroves stabilising the surrounding coast lines. The grey mangrove has a high salt tolerance much like the Red Mangrove; however it is very tolerant to extreme saline conditions whereas the red mangrove is not. This is important because the mangrove always populates coastlines, which a most likely to be salient. This could be an adaptation formed over time. It resists the salient water by actively restricting the uptake of salt at the roots. This specific adaption to the environment assists the organism to survive in its environment.
Red Mangroves –Rhizophora mangle
Red mangroves are a common species of the Rhizophoracea family.
They can be found stretched across costal northern Australia. The average soil PH level at Myora Springs was eight which is consistent with the ideal conditions for the Red Mangroves. These type of mangroves form extensive, often pure stands around the shores of shallow bays. Preferring soft, well drained muddy soils. In North Queensland, Red mangroves are able to grow up to ten metres high, however it is most common to see five metre high trees; most likely because of the lower and sparser human population and density towards the coastlines. A main feature of this species is their stout, a large arching prop of roots that contain numerous lenticels (air pores) that support the main trunk and enable to tree to live. Red mangroves have adapted to their salient ecosystem by tolerating salt. They eliminate salt from their roots as water is occupied. Excess salt is then stored in the leaves and the tree sheds these leaves later on. Although the Grey mangrove can withstand much higher salt concentrations, both species lived side by side at Myora Springs. This is because the average soil PH level was eight, which is not high enough to stop the red mangrove from
growing.
SAND DUNES – 18 Mile Swamp
18 Mile Swamp is located on the eastern side of the island. The dunes provide much needed habitat for highly specialized plants and animals, including rare and endangered species. The sand dunes at 18 Mile swamp are important because they help protect beaches from erosion and recruit sand to eroded beaches. Not all of 18 mile swamp is protected. Certain patches have been extensively mined. A variety of organisms have been identified, each having its own distinctive characteristics and adaptions that have allowed it to survive in the rough conditions. These organisms include the Ghost Crab, spinifex and the Goat’s foot.
Ghost Crab – Ocypode
The Ghost Crabs is relatively small in comparison to other species, with flecks of pink and yellow on its almost translucent exoskeleton. This adaptation to its environment allows the crab to camouflage against the sand to hide from predators and it also allows the crab to camouflage when hunting. Its eyes appear to be the end of long stalks, which may assist is seeing birds of prey. The ghost crab is found Australia wide and usually inhabit the intertidal beach areas. The Ghost Crab will stay in the cool protection of its burrowed habitat during the day and will make its way towards the water during the night to hunt for food. Its burrow is built high up on the shore, to prevent flooding from the ocean. Their burrows can be dug around one metre deep, which keeps them protected from predators; if anything did try to dig one metre is too deep and the intruder would give up. Although Ghost crabs live away from the water they are semi-terrestrial and breathe oxygen from the air through moistened gills, meaning they must periodically wet their gills with seawater. Usually by taking water from moist sand or by running into the surf and letting the waves wash over them. Running from their burrow to the surf and back can be dangerous however their colour adaptation will assist their necessity for water to live. Ghost crabs also have the ability to change colors to match their surroundings by adjusting the concentration and dispersal of pigments within their chromatophores. They can even match the specific colours of the grains of sand in their habitats, although ghost crabs are capable of morphological colour change, it occurs over a longer span of time. This adaptation allows the crab to adapt to its changing environment, depending on the colour of the sand. Similarly to the mud crab the ghost crab is a scavenger and it has a mutualistic relationship with its environment by keeping it clean.