Hey, Hey It’s

Broome!

Western Australian coastal features

• WA has got the biggest shoreline in Australia consisting of 2000+ beaches and 20 estuaries along with mangrove swamps and a staggering 22000km of shoreline.

• Across the south, there is an extensive amount of sea grass meadows system.

• Across the north are some of the biggest undisturbed mangrove forests and extensive amounts of coral reefs.

Broome coastal features

• The shoreline consist of sand cliffs and bays facing Indian ocean.

• It stretches from north of the Timor sea and across gorges , river valleys and cave systems.

• Gamtheaume point is a place on cable beach which consist dinosaur footprints from cretaceous age.

• Roebuck bay receives million of show bird and migratory birds from east Asia as visitors and migratory birds

Cable Beach

Roebuck Bay

WeatherClimate

AnimalsPlants

QUESTIONS

Cable Beach

Rock Type Wave

WindHuman Impact

Caring for the Environment

Roebuck Bay

WaveRock Type

WindHuman Impact

Caring for the Environment

Animal in FocusTURTLES

• Green turtles Chelomia midas most commonly sighted

• Flatback, Hawksbill, Logger Head and Olive Ridely turtles inhabit Bay but in smaller numbers

• Number of turtles visiting bay varies between seasons- affected by El Niño*

• Turtles found in Australian Waters are protected species

• Roebuck Bay and Cable Beach considered as nesting habitats

*El Niño- drought

Turtle nesting on shores of Roebuck Bay

Plant in FocusSEAGRASS• Marine flowering plant, vital

component of healthy marine ecosystem

• Staple food of many mammals such as turtles

• Turtles eat 2kg of sea grass each day • Provides habitats critical for

biodiversity• Predominately found in Roebuck Bay• Cable Beach famous for long stretch

of sandy beaches- no mention of sea grass

• Cable Beach is mainly rock and sand

Roebuck Bay aerial

Cable Beach aerial

Roebuck Bay- Environmental Conservation Program

• Sea grass monitoring PROBLEM: • Bloom of blue green algae (Lyngbya majuscula)CAUSE:• Entry of human waste into bay ecosystem• Leeching of nitrogen and phosphorus containing fertilizers and pesticidesCONSEQUENCES:• Depletes sea grass population• Linked to decrease in population of endangered animals e.g. Snubfin

Dolphin• Decrease in population of migrating animals such as turtles, dugongs and

dolphinsDRIVING FORCE BEHIND CONSERVATION PROGRAM:• Conservation of biodiversity

Cable Beach- Environmental Conservation Program

FOCUS:• Sanitation• State’s cleanest BeachACTION:• Voluntary monitoring of sea turtle population and

identification of nesting grounds• Separation of vehicle no-go zones• Dog free areasDRIVING FORCE BEHIND CONSERVATION PROGRAM: • Tourism

Cable Beach and Roebuck BayWeather between 11th April to the 14th AprilMonday 11th- 24C°- 34C° sunnyTuesday 12th 23C° - 34C° sunnyWednesday 13th 22C°- 34C° cloudyThursday 14th 22C° - 34C°

The weather from Roebuck Bay and Cable Beach is quite similar. The forecast shown shows hot weather with rainfall and strong winds. The average weather for Cable Beach and Roebuck Bay for the end of dry season but the average rainfall for the month is quite low this could be from climate change and human impact.

Climate for Cable Beach and Roebuck Bay

In Broome there are not the normal seasons. There are two seasons the dry and wet seasons. The dry season lasts from April/May until September/October and that weather in Broome will be perfect. Warm weather, balmy nights, clear blue skies everyday. Notice how there dry weather is when our wintery months are. The wet season starts around October/November with stinking hot days, isolated thunderstorms and the occasional torrential downpours. between January and March you will see monsoonal activity, possible cyclones, lots and lots of rain and possible flooding.

FAIL

CORRECT!!

Caring for Coastal environments

With a lot of pressure being placed on coastal environments each year, people need to think about the way they care for them.

Some coastal areas are designed as reserves to ensure protection of plant and animal habitats and historical and cultural relics. Such small things such as walking on the tracks and putting your rubbish in the bin can help minimize the impact on coastal areas.

Ways to Look After Coastal EnvironmentSand Dunes - By walking on tracks down towards the beach it will avoid any

damage to sand dunes. - Plants grow on sand dunes to hold it together and can be easily

damaged and blown away.

The coast also acts as homes for plants and animals, and the conservation of the habitats assist survival of them.

Rock pools - act as habitats and you should return any rocks to their original position if moved

Pollution - rubbish make coastal areas dangerous, unhealthy as well as being unattractive

Rock Types

Cable beach

• The reef is constructed of large granite rocks.• Has marine sand which helps in making sand dunes.• Has cliffs made up by erosion.• The rocks used are transported from the process of

erosion using the natural agents and mainly rocks are received from inland.

Rock Types

Roebuck bay

• Changes in sea levels since dinosaur days resulted in the deposition of sediments that now cover much of the region.

• They include the poorly cemented sedimentary rocks that form well exposed and attractively weathered outcrops behind the narrow beaches of northern Roebuck Bay.

• Soft rocks is clay and silt on roebuck bay.• Harder rocks are made up of granite.

Human Impact On Cable Beach

There are concerns that Cable Beach, which is of outstanding natural beauty and a major tourist attraction for Broome and the Kimberley region of northwest Australia, is suffering damage from recreational use, particularly that caused by off-road vehicles

Burrows of both the ghost crabs Ocypode spp, and the sand bubbler, Scopimera inflata, were less numerous in areas of high vehicle use than those of low use. Both species may be valuable in monitoring human impacts on Cable Beach.

Human Impact On Roebuck Bay

• Toxic Blue-green AlgaeDEC in collaboration with the RBWG, are investigating toxic blue-green algae Lyngbya (Lyngbya majuscule) in Roebuck Bay.

• Lyngbya occurs naturally in areas across most of the tropical zone, however can bloom in response to elevated nutrient inputs. The seasonally high level of Lyngbya is of great concern for the natural ecosystem, recreational activity and fishing, as this particular species can be severely toxic at stages in its growth leading to impacts on wildlife and symptoms in humans who come in contact with the blooms.

• Lyngbya competes with sea grass leading to a reduction in density and adversely impacts on fish, dugong and turtles.

Caring for Roebuck Bay

• We can care for roebuck bay by limiting vehicle access to beaches along the northern shore of the Bay.

• The Department of Environment and Conservation (DEC), in association with Keep Australia Beautiful, coordinates clean up days for volunteers to remove rubbish from the beaches near Crab Creek.

Caring for Cable Beach

• Cable Beach is an area focused on the natural environment, with many community groups, including Council involvement, participating in wildlife rehabilitation and protection.

• This includes caring for migratory birds, sea turtles, sea grass monitoring, crabs, and even working in with DSE to protect and monitor visiting crocodiles.

• Along with the protection of turtles through the demarcation of vehicle no go zones, there is also a number of dog free areas, along with great educative materials available throughout the area.

Wave Impact on Cable Beach • Beaches are wave deposited accumulation of sediment including small amount

of cobalt and boulders.• The wave impact on cable beach causes movement of sand or other loose

particles and they are held in suspension by the action of waves. • The waves also move the sand by saltation(bouncing movement of particles). • The materials or particles from the erosion of offshore rocks (mainly roebuck

bay) that are deposited on cable beach giving it coarser coastal sand comparing it to other beaches.

• It usually depends on the action of wave which determines the steepness and length of beach.

• Cable beach is a dominant destructive wave beach with small amounts of constructive waves

• Cyclones driven waves have caused extensive beach erosion • Cyclone surf can last from a few days to a few weeks, depending on the speed

and direction at which the cyclone is moving

Wave Impact on Roebuck Bay • Bays are formed because of erosion process from agents like

wind and wave.• There are calmer waters around bay as less wind action due to

surroundings blocking most waves and reducing winds.• Bays are usually formed with beaches and roebuck bay is an

example of this. • Wave refraction disposes away most of energy on coastline

eroding away the softer rocks causing the harder rocks to be chipped and made of irregular coastline.

• There is less wave action compared to cable beach because of adjacent position of roebuck with cable beach.

• The harder rocks are still present adding to the effect of less wave action because of harder rocks taking away the majority of energy from waves.

Wind Action on Cable Beach • The wind impacts does play important role as most of the winds

are coming from the side of equator. • The winds are only able to pick selective and finer particles like

clay and silt and are raised into air. • This transportation helps in making of sand dune as they are

made from erosion process taking place from inland rocks. • The amount of vegetation around the coast is less as presence of

too many coastal dunes. • The process of abrasion usually occurs as well because of wind

from equator coming towards south chipping away surfaces of materials.

• Cyclones have impacted on coastal areas. Winds have been up to 170km/h

Wind Action on Roebuck Bay

• There are eroded orange cliffs because of wind pressure with particles from cable beach formed to get narrowed sandy beaches forming on the northern shorelines.

• Usually ,the faster the air, the more of the erosion process but with adjacent position , erosion occurs even faster as wind mainly comes from one direction.

• 2 process taking place- • surface creep- particles and materials rolling. saltation – material and particles bouncing.

Questions!!1. True or False? What are the differences between the dry and wet

seasons?a) In the dry seasons the weather is humid and with no rain

FALSETRUE

b) In the wet season Broome experiences torrential rain and hurricanes

c) In the wet season the weather is perfect with balmy weather and clear blue skies.

TRUE FALSE

FALSETRUE

Questions!!1. El Niño affects the number of turtles visiting the coast

2. Seaweed is unimportant for biodiversity

3. Lyngbya majuscula depletes sea grass

4. Cable Beach is one of the most polluted coastlines

TRUE

TRUE

TRUE

TRUE

FALSE

FALSE

FALSE

FALSE

Questions!!1. In Roebuck Bay, what are harder rocks made out of?

2. What is Cable Beach Reef constructed of?

3. What is one of the ways we can help care for Roebuck Bay?

4. In Cable Beach, decrease in burrows of ghost crabs and sand bubblers are caused by off-road vehicles

5. Nutrients inputs in Roebuck Bay to cause Lyngbya to bloom

b) Granite b) Limestone

a) Large Granite Rocks

b) Small Granite Rocks

a) By limiting vehicle access to beaches along the northern of the Bay

b) By not allowing any visitors in Roebuck Bay

TRUE

FALSETRUE

FALSE

Questions!!1. What kind of waves shape up the Cable Beach and its steepness?

2. What kind of soft rock is present in Roebuck Bay?

3. What is the main reason that Roebuck Bay gets more of of wind action than wave action

4. Why does process of abrasion play a major role in the process of erosion?

5. What kind of coastal environments are present in north and south of WA.

a) Destructive Waves

b)Constructive Waves

a) Silt and Clay b) Granite and Limestone

a) it’s adjacent position with cable beach

b) it’s rocks shelter them from hard impact of waves

a) The winds coming from equator are strong which

chips away material faster and as it happens, the creation of

sand dunes are faster

b) because the process of deposition is not

an option.

a) Towards the north- undisturbed

mangrove forest and coral reefs

b) vegetation consist of sea grass vegetation.

Thanks For Watching!