To investigate the Biodiversity of Wonga Point Rock Platform, through the following: -Examining adaptations of the plants and animals for life of the rock platform -Measuring abiotic characteristics of the rock platform
-Examining and comparing the richness of species in sub habitats on the rock platform -Measuring the abundance and distribution of some molluscs and algae on the rock platform
During the investigation we undertook four fieldwork activities such as: -Investigation of adaptations to life on a rock platform
-Abiotic Factors on and around the rock platform
-Species richness of Sub-habitats on the rock platform
-Distribution and Abundance of Selected Animals and Plants
It was found that the adaptations to life on a rock platform varied through the size, feeding habits and habitats of these plants and animals through the certain needs of the plants and animals.
I concluded that adaptations are a result of the animals and plants needs, to meet with the abiotic features of the environment and the environment itself, this also contributes to the abundance of species.
Introduction:
Rock platforms are rich in biodiversity, mostly distributed as a result of the interactions of abiotic and biotic factors. They are wave eroded and generally flat, inter-tidal areas are usually at the base of rocky headlands. The rock platform hosts a range of microenvironments such as crevices, boulders, rock pools and cobbles to suit different ranges of species.
Some interesting features of the Bateau Bay rock platform were that the different microenvironments hosted an array of different species that may not be in one microenvironment but are in another, such as crabs who were found in crevices and not rock pools. Another interesting feature of the rock platform was that all of the species had a role on the rock platform.
The importance of studying Bateau Bay rock platform was that we were able to physically see adaptations and the environments first hand, as well as being able to understand how the abiotic and biotic features worked through hands on fieldwork. It was also important studying the Bateau Bay rock platform to understand and observe the human impact from the sewage outfall of secondary treated sewage, as well as the impact from the caravan park situated south of the beach.
Materials and Methods:
Thermometer
Infered thermometer
PH Strips
Refractometer
Hoops
Tape measure
Compass
All materials varied depending on experiment and procedure
Procedure for measurement of temperature, ocean salinity and pH: 1. Take thermometer to measure the Ocean and Rock pool, record results. 2. Use the infra-red thermometer to measure the temperature of the air, bare rock and the crevice. 3. Use the refractometer to measure the salinity of the Ocean and Rock pool, take sample from each and place it on the slide and insert it into the refractometer then read results and record. 4. Use the pH strips to indicate the pH of the ocean and rock pool by dipping the strip in the ocean and pulling it out immediately and compare the results to the pH indicator chart, repeat for the rock pool an record results.
Procedure for measurement of plant and animal distribution using quadrats:
Record the number of different species that can be found in a 3-minute search of each sub-habitat. 1. Keep the number of observers constant and select sub-habitats in close proximity to each other (to reduce variation between tide zones) 2. Only record living organisms
3. Use field guides to assist identification. Assume different coloured encrusting algae are different species. 4. Search carefully under ledges, under cobbles and along the sides of crevices and pools. Be careful to replace cobbles as they are. 5. Record Results
Procedure for measurement of plant and animal abundance using transect: 1. Set tape measure transect across the rock platform (on a compass baring of 110 degrees towards the ocean) 2. Beginning at the landward end place a 0.25m quadrat against the transect at 0m. Adopt this positioning as a role for all the quadrats (eg at each 5m interval place quadrat on right hand side of the tape) 3. Count and record the number of individuals of each of the target animals. 4. Estimate and record the percent cover of each target algae in the quadrat. 5. Note other observations eg other animals, elevated, crevice or rock pool etc. 6. Move quadrat to the next position on the transect and repeat steps 3-6. 7. Record results.
Procedure for recording observations of human impact:
1. Observe the rock pool and the surrounds for litter, oyster shells, footprints, fishing wire, as well as other forms of human interaction. 2. Record results
Results:
Abiotic Data:
Recent Weather: Warm, Breezy and sunny.
Tide: Low Tide 10:37am
Ocean
Air
Bare Rock
Rock Pool
Crevice
Under Cobble
Temp
Infra-red thermometer
20
15
17
21
9
N/A
Salinity %
Refractometer
3.9%
3.5%
pH
Indicator paper
8.5
7.5
Abiotic Data Graphs:
Quadrat data and population estimates:
Transect Diagram:
Flora and Fauna Summary of the ecosystem:
Limpet- found
Black Periwinkle- found
Blue Periwinkle- found
Oyster Borer- found
Barnacle- found
Cunjevoi- found
Swift-footed Crab- not found
Sea Anemone- found
Bembicium- found
Neptune’s Necklace- found
Coraline Algae- not found
Noduled Periwinkle- not found
Chiton- not found
Oyster- not found
Sea hare- not found
Crabs- found
Waratah Anemone- not found
Star cushion- not found
Brittle star- not found
Galeolaria worm- not found
Sargassum- not found
Mulberry Whelk- found
Black Nerite- found
Observations of Human Impact data presented in a suitable format:
Amount
Type of Human impact
N/A
Small
Medium
Large
Litter
Oyster Shells
Fishing wire
Foot steps
Evidence of disturbance to environment
Evidence of disturbance to Flora and Fauna
Discussion
Summary and Explanation of Results:
Abiotic Data:
Ocean temperature is average, considering the time and the weather. Results varied for the Bare Rock, where it was in the sun or in the shade. Rock pools were usually 1 degree above the ocean temperature this may be because there is not as much water cover; they are generally shallow and are placed in the sun. The air temperature was average considering the time of day and time of year.
This data shows that the salinity a relatively average, as the world’s seawater salinity is generally 3.5%.
The pH levels of the ocean and rock pool are average, and have not a large gap between the measurement of the rock pool and ocean.
Species Richness of Sub-habitats:
The majority of species were found on flat rock areas were mostly browsers, producers, filter feeders and predators. The strength in each varied, and was not consistent. The total of animals found on/in each habitat was usually 3-5 species.
Transect Diagram:
The results of this investigation would have varied greatly to other groups’ measurements and observations, as we all investigated different areas.
Encrusting algae covering percentage varied from great amounts (75%) to (3%),
however there was no cover when water was present.
Limpets were seen to be the largest species distributed throughout the transect. Black Nerite was seen to be in mostly water-covered areas. Mulberry Whelk was the less distributed species throughout the transect.
Observations of Human Impact:
Large amounts of footsteps were seen. Evidence of disturbance to the environment, flora and fauna was at large. Oyster shells were found at a medium amount, hence indicating human disturbance to flora and fauna.
Trophic Interactions:
Identification of two plant species:
Coraline Algae:
Coraline Algae is found in the low tide zone. It’s loose and is not holding, although is partially binder onto rocks etc. which means there is no risk of washing away. It neither seeks protection nor shuts down. Coraline Algae is flexible in shape and pink in colour, which assists in producing food. Coraline algae are a producer.
Neptune’s Necklace:
Neptune’s necklace is found in the low to mid tide zone, there is no evidence of the plant protection seeking or holding on. It does not shut down and is flexible in shape, which means it can be easily washed away. The colour of Neptune’s Necklace is yellow-brown; it’s also a producer.
Identification of two animal species:
Swift-footed Crab:
The Swift-footed crab is a scavenger, which resides in the low to high tide zone, there is no evidence of the crab holding on, and however it does seek protection, it can also shelter, as well as move away if needed. The crab is flexible in shape and varies in colour; there is no evidence of the crab
shutting down.
Oyster Borer:
The Oyster Borer is found in the mid to high tide zone, it is slightly holding on and is not protection seeking. The Oyster Borer is bulky in shape and is black and white. This animal shuts down which helps keep the moisture at low tide and is a predator.
Distribution and Abundance of two named molluscs across the sampling area:
Black Periwinkle:
The Black Periwinkle was found in masses across the rock platform. It was found in Crevices and on Boulders, as well as on flat rock.
Limpet:
The Limpet was seen in masses of up to 50 together in a quadrat. It was found on flat rock and in rock pools.
Describes and Analyses human impact of the ecosystem:
There was clear evidence of human impact in the ecosystem, with a large amount of footprints and a medium amount of oyster shells. It was obvious that there was disturbance to the environment with rock being moved to further the investigations of the rock platform. There was a large amount of disturbance to the flora and fauna, with shells being moved and the fauna protection seeking is crevices eg. Crabs.
Evaluates the variability and reliability of measurements recorded for the ecosystem: The results of all investigations would have varied depending on different groups investigating different areas.
My group’s investigation of the 3-minute search of the distribution and abundance of sub habitats would be unreliable as the time and areas could have different varying the current results.
If we set up several transects, our results would have varied dramatically
for the investigation of plant and animal abundance using a transect. We could have changed the positioning of intervals that the quadrats were placed etc.
Measurements of abiotic data could have been varied if we did several measurements and different times of the day. The measurements of human impact may not have varied greatly, although if the investigation area was widened it may have varied greatly.
Therefore, our measurements recorded for the ecosystem was unreliable and the variability could have been greater.
Conclusion:
The results for the abiotic data were all relatively normal, in consideration of the time of day and year.
As shown throughout the flora and fauna summary, the transect results and species richness of sub-habitats results there was no evidence of an overly large variety of species, although most species that were found had large abundance. The species richness may have varied if the disturbance of the environment was at a low.
If the investigations of all experiments were taken at numerous times of the day there may have been improvements to the results, before and after high tide may also have contributed to changes to the results. Changes to the times and lengths of some investigations such as the transect investigation and the sub-habitat investigation would have also improved the results.
The significance of findings to the health of the ecosystem decides whether the ecosystem needs to be protected, have human interaction reduced and be monitored more or completely shut off for leisure activities. These findings in relation to the sewage outfall may be threatened or perfectly intact. Findings of species may indicate that animals and plants are being reduced from collection by humans interacting with the rock platform, what may seem
harmless at the time can impact greatly to the environment and biodiversity of the rock platform.
Our investigation could have benefited greatly to the environment if it had been more reliable, although it gives us an indication of what the biodiversity of a rock platform entails.
