Preparing for Marine Ecology

1. Preparing for Marine Ecology Rocky Shore Investigations

2. Session outline: • What is ecology? • What determines the population size of a community? • What determines the population structure of a community? • Is ecology really that important? • How to collect your own ecological data, draw conclusions from it, and write up a scientific investigation

3. What is ecology? Ecology is the study of how living things interact with one another and their environment Ecologists often write about the distribution of organisms in an ecosystem, trying to link why organisms are found where they are to biological pressures and environmental factors How do they do it?

4. How is ecology carried out? Ecologists cannot count EVERY animal or plant on the rocky shore because of large numbers and/or difficulty in finding every single one Instead, they study a small area or “slice” of the rocky shore for example in great detail and assume that the “slice” tells us something about the ecosystem as a whole The “slice” is called a transect

5. Example: experimental design for the rocky shore. Variable – Shore Height Quadrats High shore Transect Low shore

6. Population size is determined by… - How many predators the species has and how well it can avoid them - How well adapted the species is to its environment - The better adapted, the more likely it is to survive and pass its genes onto the next generation Population Size 1. Predation 3. Adaptation 2. Competition - How much competition there is from other organisms for resources in short supply e.g. food, shelter - Stronger competitors will survive and pass their genes to the next generation

7. Population structure Clumped Evenly spread Randomly spread Question – Which structure(s) do you think are most likely to be present on the rocky shore for example?

8. Why is Ecology important? Helps us monitor changes in habitats that may have a huge impact on the wider-ecosystem and mans use of the marine environment Some examples include: • Climate change • Overfishing • Pollution Collecting data on the relative abundance of plants and animals on the rocky shore over time could tell us whether native organisms are moving further north due to increasing sea surface temperatures We can search for non-native species to tell us whether warming seas is causing species not naturally found on the shore to settle We can monitor levels of pollution and determine safe limits of disposal

9. A little more data collection is sometimes needed • Sometimes ecologists also need to collect information about the environmental factors in a habitat as well as the organisms that live there • Examples include: • Light intensity • Temperature • Salinity • pH • Oxygen concentration • Often though, noting down the environmental conditions in each habitat you study will likely be enough information to draw conclusions from your data

10. Your turn to become Marine Ecologists! Limpet shell shape Limpet shell shape varies on the upper and lower shore because of several environmental factors. Limpets on the upper shore tend to have taller, pointy shells, whereas limpets on the lower shore tend to have flatter, more streamlined shells Why do you think this is? Think about the environmental factors acting on the upper and lower shore What would be your prediction? How would you test this statement was true? How would you collect your data?

11. The five golden rules of rocky shore investigations 1 - Try to disturb the ecosystem as little as possible 2 - Only remove small samples if absolutely necessary and always put them back after you have finished with them 3 - Always turn rocks back over when looking for organisms 4 – Don’t run around on the rocky shore, it is a slippery and therefore dangerous environment 5 – Don’t go into the sea!

12. Graphing your data Think about the type of data you collected. Is it continuous data (i.e. is it a list of numbers) or discrete data (i.e. in categories). What type of graph would show your trends best, if there are any? Line graph? Scatter graph? Bar Chart? Histogram?

13. Writing up your investigation Key sections to include: An Introduction Write a few sentences about limpets, what environmental factors might affect their population size on the lower vs. the upper shore, and how limpets might be adapted to live on the rocky shore in each habitat you study A Prediction (hypothesis) State the question you are investigating (hypothesis) and predict what you think the results might be A Method Explain what you did and how you did it A Results section Produce a suitable graph of results and explain briefly what the graph shows A Conclusion Conclude as to what you found and state whether or not your prediction was correct. If it wasn’t correct, briefly explain why