Depth Study Biology PDF

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Depth study fo biology year 11
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Depth Study Biology Activity 1- Rock platforms in Australia Definition of a rock platform or rocky shore A rocky shore is an intertidal area that consists of solid rocks it is often a biologically rich environment and can include many different habitat types like steep rocky cliffs, platforms, rock pools and boulder fields. The rocky reefs are exposed to air at low tide and covered by water at high tide. They provide habitat for a huge variety of plants and animals that are uniquely adapted to a harsh physical environment that includes strong wave action, fluctuating weather conditions and changes in the tide. Rock platform or rocky shores are flat (planar) platforms are formed when waves, wind and rain carved into rock. Often, the back of the rock (the bit which has not been eroded yet), forms a cliff, while the ocean edge of the platform steps down into the water. They provide habitat for a huge variety of plants and animals that are uniquely adapted to a harsh physical environment that includes strong wave action, fluctuating weather conditions and changes in the tide. Some of the rock platforms are heavily dissected and contain abundant rock pools, or channels and crevices between the rock slabs. There are many micro-habitats on and in intertidal reefs, such as under ledges / overhangs, in rock pools, in crevices, and underneath rock slab. Description of rock platforms on the Eastern coast of Australia Rocky shores are found where the sea meets the land, they support a diverse mix of plants and animals which have adapted to survive this habitat's unique conditions. Some Eastern coast rock platforms include, Shelly Beach on the Central Coast, Shelly beach at Cronulla, and Batemans Marine Park. Rock platforms not only include the rocky shores but also organisms that live in that environment. At a rock platform there is high tide, low tide and intertidal zone when effect the organism that live in the rock platform. At high tide, this environment may be battered by waves while prey-seeking predators roam at all shore levels. At low tide, algae and animals are baked by the sun and sometimes drenched by salt-free rainwater. Intertidal zone is where various rock types are exposed to air at low tide and covered by water at high tide. Because high-tide levels vary from day to day and during the month, some fixed creatures high on the shore may not be wetted for days, or even weeks at a time. Animals and plants in these habitats survive being flooded in high tide and drying out at low tide and have several adaptations to survive. Animals and plants that live on rock platform are, Neptune necklace, kelp, sea star, black periwinkle etc. Rock platform vary from, human impact, competition, and predation. Human actions affect the way the organisms are living on rock platforms by affecting the home of the organisms, such as pollution and rubbish. Rubbish is left behind from visitors which will harm the organisms such as plastic or tiny rubbish get caught in the animals. There is competition of space between animals such as, Neptune Necklace compete for sunlight to photosynthesize. Furthermore, predation is where there is preying of one animal on others an example of this on rock platforms is Mulberry whelks’ prey on sea snails and barnacles. These are some factors which impact the organisms that live on the rocky shores. As it is important to acknowledge the organisms that live on the platform as they provide many homes for many animals and are a productive food source and understand the relationship between the organisms. Predications of abiotic features Abiotic factors on the rock platform vary from, temperature, humidity, salinity, pH, sunlight, wave action and tidal exposure. The most important abiotic factors are wave action and tidal exposure. Wave action refers to a conservable measure of the wave part of a motion which result in high or low tides when the wind is blowing across the surface of the water. Tidal exposure refers to the areas of the rock platform where low or high tides occur. When high tides occur, the region is covered with water, and you can find organisms like barnacles, crabs, or snails. When low tide occurs, the region is usually covered with water, organism is not well adapted to long periods of dryness of extreme temperature such as sea lettuce, sea urchins, shrimps or tube worms. The organism will need the adaptations as they may not have the ability to survive as tides rise and fall. Temperature is moderate due to the sea breeze that occurs throughout the day. Rock pools have a very wide range of

temperatures because it is isolated from the rest of the sea and is quickly heated up by the warm rocks, air, and the sun. The water temperature of rock pools at night is chilled as it loses heat to the rocks and air. In summers, humidity will rise in the morning and afternoon, however at night the temperature falls due the sea breeze. They are pounded waves, exposed to extremes of temperature and salinity, and flooded by sea water and exposed to drying air twice every 24 hours. Sunlight is another also affects the organisms. When there is too much sunlight, organisms can dry out (desiccation) or overheat. Light can also damage certain body parts (like sunburn). However, plants need sunlight to carry out photosynthesis. while plants need sunlight to carry out photosynthesis, they also need water. Too much sunlight can increase water loss by evaporation causing the organism to dry out (desiccation).

Activity 3 – Adaptations Life in Rock Pools Species on the rock pool require different adaptation to live on the platform such as intertidal zone, temperature drops and salinity changes. Food and a place to live is an important key for animals to survive on the rock platform. Limpets control the algae by scraping it from the rocks, when a limpet wonders off to feed it leaves behind a trial of mucus, so it can find its way back to its home. Finding a home for rock platform animals is very important, competition for space, and finding for their home could be between life and death. Limpets are attached to rocks or other ground. They attach themselves mucus and a muscular foot, which seals them against the rock and protects them from desiccation during low tide, and from high-energy waves action. The high and low tides in intertidal zones faces some of the most extreme conditions and animals consistently adapt. Different creatures have different ways in dealing with the return of the tides. Mollusks developed evolutionary marble a protected thermo regulated home. Sea slugs’ major adaptations is that they absorb toxins and make themselves an unpleasant snack but the complex defenses of the world that cannot stand against these creatures. Sea stars have evolved sophisticated tube feet to feed on mollusks. Rocky Shore Zonation and Kelp Holdfast A holdfast is a root-like structure at the base of an alga (seaweed) that fastens the alga to a hard substrate like a stone. Holdfast vary in shape and from depending on both the species and the substrate type. Seaweeds, including kelp, do not have roots. The gnarled structures attaching this giant seaweed to the rock is the kelp's holdfast. Kelp grow on rocky bottoms, not sandy shores. Their holdfasts are tangled to cling tightly to the rocky substrate. Young kelp must compete for space to settle and grow, as the rocky bottom is carpeted with smaller algae and invertebrates like anemones and sponges. The stipe is like a plant’s stem. It is strong, yet flexible, allowing kelp to sway in the currents of the ocean. Many fish use this middle area of the kelp forest as hunting grounds. The blades contain a special gas, which act like a float, keeping the kelp blades close to the surface of the water where they absorb energy from the sun.

Turban Snail with Operculum Operculum refers to the structure attached to the animal’s muscular foot and serves as a type of door, trapping moisture in and keeping enemies out. Snails have an operculum that acts as a ‘trap door’ over their opening, allowing them to close when external threats exist. In intertidal marine snails during low tide, operculum enables freshwater to survive through drought and dry weather as it helps the snail to survive from drying up and avoid predators entering the shell. Neptune Necklace in the waves The Neptune necklace have a major adaptation such as their structural features. Neptune necklaces has vesicles full air which helps to keep the plant in the upright position, giving them more access to sunlight and nutrients in the water. Neptune necklaces have strong attachments to ensure that its wont sweep apart by strong waves as they have flexible structure. Animal with adaptations and how the adaptations increase the organism’s ability to survive Blue periwinkle are tiny snails which tend to cluster in the splash zone, and high intertidal zone but can survive in lower zones aswel. Periwinkles actively seek out crevices in rocks to lodge themselves in to reduce the drying effect of wind exposed periods. Periwinkles can orient their shell towards the sun to reduce the surface area exposed to the light. The thick shell reduces water loss, and radiation effects. This is because due to the lower density of air compared to water, abiotic factors such as light, and so heat and radiation etc., is much more potent as the snails are exposed. They also have an operculum that seals the moisture inside their shells, which prevents desiccation. Blue Periwinkles especially adapt to the harsh conditions of the dry upper littoral zone. They can trap water inside their shell to prevent moisture escaping, and cling to the rock face while the tide is out. When the tide is high, they move around “grazing” on tiny plants growing on the rock surface. Periwinkles can also attach themselves to rocks with a mucous thread from the aperture, so that they are not in direct contact with the hot rock therefore it will not overheat as easily. They also have an ability to lower their metabolic rates during exposed periods to minimize oxygen consumption, which is physiological adaptation, because living in the higher intertidal zones it means these species will only be submerged by very high tides, which occur sparingly.

Shell Shell door Operculum

Plant with adaptations and how the adaptations increase the ability of the organism to survive Kelp are large brown algae seaweeds, that have many adaptations to survive in the rock platform. At the bottom of the kelp are the “roots” of the kelp or what is known as the holdfast. This root-like structure enables the kelp to attach itself to a rock. Where each “leaf” or blade comes off the stipe, in some species there is also an air bladder attached. Since kelp does not have a strong structure like a tree, the air bladders are like balloons that lift the kelp towards the surface to help it reach the sunlight. These adaptations help kelp to survive as the air bladders allow kelp to reach sunlight, so the plant does not die therefore there is a long period of the plant surviving. Kelp depends on moving water to provide a steady supply of nutrients for photosynthesis. As water flows by the blades, their serrated edges help to increase water mixing. This drives more nutrients past the kelp plants. These nutrients are then absorbed by all parts of the kelp, which helps kelp to survive.

Activity 4 – Selection pressures effect organisms 1. For the plant or animal chosen in Activity 3: - describe one selection pressure that effects the organism in the rock platform environment A selection pressure that effects Blue periwinkles on the rock platform is dehydration as it occurs due to evaporative water loss. Periwinkles need water for many of their living processes and are constantly using it. As their movement requires mucus-containing water to allow them to slide along surfaces to collect food. Dehydration occurs for blue periwinkles, when there are low tides, this is where no water reaches to the blue periwinkles and they are not able to stay hydrated. Blue periwinkles are generally found in the intertidal zone, and here dehydration can highly affect the blue periwinkles when there is low wave action which can affect the amount of water reaching the blue periwinkles. However, to deal with the selection pressure or dehydration, blue periwinkles have many adaptations such as the outer shell, operculum also known as the trap door. - describe the selective advantage the organism possesses to survive the selection pressure The selective advantage of blue periwinkles to survive the dehydration, is that they protect themselves by withdrawing into their shells and closing the aperture with the operculum. So, to prevent dehydration from occurring Periwinkles actively seek out crevices in rocks to lodge themselves in to reduce the drying effect. Periwinkles can orient their shell towards the sun to reduce the surface area exposed to the light as the thick shell reduces water loss by this the periwinkles are able to maintain the moisture in their shell.

Activity 5 – Abiotic factors

Abiotic factor

Equipment

Measurements

Relative humidity Air temperature Sun light intensity Wind direction Wind speed Water temperature Water pH Water salinity

hygrometer

Trial 1 Trial 2 51 52

Trial 3 Trial 4 53 52

Trial 5 Average 54 52.4

Unit %

Thermometer

22

21

21

°c

Light meter

34300 51000

50800 44300

46900 45460

compass

N

N

N

N

N

N

Anemometer Thermometer

6.8 23

7.9 23.5

9.3 23.5

9 23

7.5 23.5

8.1 23.3

Kph °c

8 40

8 40

8.5 40

8 40

8.2 40

Ppt

pH paper 8.5 Refractometer 40

21

21.5

21.3

Lux -

-

Activity 6 – Niches Define “niche” In ecology a niche refers to the way in which an organism fits into an ecological community or ecosystem, by the set of conditions, resources, and interactions it needs (or can make use of). It subsumes all the interactions between a species and the biotic and abiotic environment, and thus represents a very basic and fundamental ecological concept. A niche is a role of the organisms that plays in the ecosystem as it includes more than what the organism eats or where it lives, it also describes how the species interacts with other species in a habitat. Kelp -

-

Provide an extensive ecosystem for many organisms Helps organisms to search for food, such as crabs holding onto the stipe to find food Many organisms feed on the kelp and then in turn feed other animals. Kelp provides shelter for many forms of sea life. Kelp also protect coastlines from damaging wave action

Blue Periwinkle -

-

Herbivore Periwinkles have a major role in the ecosystem, through the food chain. Blue periwinkle is a food source for animals such as sea aeneous and octopus. However, there is minimal effect on the octopus if they do not eat the periwinkles. Octopus can eat shrimps, small fish, or whelk. Also, if there is no periwinkles in the food chain, there could be overpopulation of the weed mats however there are other animals such as sea hare Chiton or limpet who also eat weed mats, therefore again there is minimal effect if the periwinkles are removed. They feed on small invertebrates such as barnacles’ larvae Breaking down dead plant material

Activity 7 – Measuring populations of organisms using sampling techniques

Species Black Periwinkle Neptune Necklace

Q1 1

Q2 13

Q3 12

Q4 10

25%

75%

80%

10%

Note: Usually for plants such as Neptune necklace, we could estimate abundance as percentage cover

Activity 8 – Estimating ecosystem area Assume ecosystem area is 1000m²

Activity 9 – Estimating population size Number between cells 93 to 97 = 81 Assumed sample area= 81/1000m sq Population density of Black periwinkles is 0.081 periwinkles/m sq Activity 10 – Distribution

L L L L N

N N

N

L

N

LN

N N

L L

N

Looking at the distribution of black periwinkles and Neptune necklaces. The black periwinkles are in the mid region of the intertidal zone between 4 to 22 meters. Neptune necklace again are between the mid region, mainly in the low tide region as that is where Neptune necklaces are mainly found.

Activity 11 – Impact of biotic factors Predation- one organism obtains nutrition from another. Example- Mulberry whelks prey on sea snails and barnacles. They drill holes in the shells of their prey with their rough radula (tongue-like appendage with tiny teeth). Then they chop up the soft mollusc body with their radula and suck it up through the hole to eat. Competition- rivalry between organisms or species for the same limited resource Example- Neptunes Necklace also competes for sunlight in order to photosynthesize. Furthermore conniwink and blue periwinkles have competition, as with their tongue called a radula they scrape tiny algae for food from the rocks. Therefore there is competition of food, for limited algae. Symbiosis: Mutualism - a loose association between two organisms, from which both gain benefit Example- Lichen is an algae and a fungus growing together where both benefit. Fungus benefits from the algae’s photosynthesis; the fungus shelters and traps moisture for the algae. Symbiosis: Commensalism - A close association between two organisms where one benefits and the other is neither harmed nor helped Example-Commensalism is a very common relationship on the rock platform. As organisms compete for space many 'piggy back' on other species. View the photos for specific examples. Symbiosis: Amensalism - One species is inhibited or destroyed while another species remains unaffected Example- Trampling by humans (fisherman, surfers, students) can damage or kill periwinkles and other species. There is no nutritional gain to humans, but the snails are negatively affected.

Activity 12 – Feeding interdependencies Filter feeder- An animal that obtains its food by filtering organic matter or minute organisms from a current of water that passes through some parts of the system. An example of this is, Barnacles use some form of feeding apparatus to catch food particles (plankton and detritus) in the water. As barnacles have tiny feet that they kick out to trap and filter plankton. Producer: These range from microscopic algae on the rock surface, to small to be seen without a microscope, to the larger green, brown and red algae that grow in different parts of the rock platform and below the surface. Examples include, Neptune necklace, sea lettuce

Herbivore- A Herbivore is any animal that eats only plants. An example is blue periwinkles. Carnivore- A carnivore is an animal whose food and energy requirements derive solely from animals’ tissues or meat, whether through hunting or scavenging. An example of a carnivore on rocky shores is anemones, using stinging tentacles, they eat most small animals, such as blennies, prawns, crabs and sand hoppers. Detritivore- an animal which feeds on dead organic material, especially plant detritus. An example is fiddler crab Food Chain – 1) 2) 3) 4) 5) 6)

Kelp Sea Hare Black Bream Weed Mats Periwinkle (herbivore) Octopus (Carnivore) Microscopic algae Chiton Ribbon Worms Debris Crab Ribbon Worms Phytoplankton Calceolaria Oyster Borer weed mats periwinkle (herbivore) Sea Anemones (Carnivores)

Activity 14 Human Activity Surfing, snorkeling

Fishing, spearfishing

Rubbish

Impact Trampling animals and plants when entering and exiting water. For example, blue periwinkles ar...