top of page

Fieldwork Activities

Activity Five: Ecological Studies
 
Certain questions could be posed at the start of the fieldwork which will get students to actively observe the way different species interact with abiotic and biotic factors in their habitat. In this way students could be guided to :
  • find species which interact together in some way
  • find species which show adaptations to hot, dry weather
  • find species which show adaptations to living in a coastal area
  • see how species change form the coastline upwards and determine the factors which are responsible for this change
 
The topic of Ecology could thus be integrated into practically all of the activities carried out. 
Activity Two: Quadrat Sampling 
 
Students can be divided into groups and each group is responsible for sampling a particular area of the rocky beach. Ecological data such as species richness, species cover, species frequency, species density and diversity index could be collected through quadrat sampling.  
 
Quadrat sampling can be of two types:

 

 

Random Sampling : "If analysis of species and or environmental data using inferential statistics is anticipated, the quadrats should ideally be located at random" (Gilbertson, Kent, Pyatt, 1989)
 
A grid of co-ordinates can be set up over the area and grid squares to be studied chosen by randomly selecting pairs of numbers, or else quadrats are thrown at random. 
 
Such sampling is used in homogeneous areas; so it is not very suitable for rocky beaches were an enviornmental gradient occurs.

 

 Activity One: Classification 

 

 

 

Rocky beaches are home to many species of flora and fauna. While carrying out the fieldwork, a member of each group could be entrusted with taking photos of each different type of species found. During or after the fieldwork, the website species catalogue could be used in order to identify each species. Alternatively, the key could be used. This would necessitate listing of characteristics for each species, which will help students develop the useful skill of observation.
 
It is also possible for each group of students to be given a list of species beforehand, which they will then have to locate and photograph. In addition they could answer questions about them, such as the habitat where they were found, how many there were and any additional interesting observations. 
Systematic Sampling : "If the vegetation is sampled at fixed intervals, usually along a line, this is knows as systematic sampling. Such a systematic approach is often combined with the transect approach where a sampling line is set up across areas where there are known to be clear environmental gradients." (Gilbertson, Kent, Pyatt, 1989)
 
Two types of systematic sampling which can be used on a rocky beach are Line Transects and Belt Transects. This is because the area from a rocky shore upwards represents an environmental gradient to which different species exhibit different tolerance. Therefore a zonation in the presence and number of different species is likely to be found in such an area, which can be investigated using these two types of transects.
Line Transect 
  1. Identify the direction of the zonation and set up a piece of string or tape to mark a line across the zonation.
  2. Start sampling; this can be done along the whole line, at regular intervals or at random points. Different groups can use different methods.
  3. The presence/absence and number of different species is recorded.
  4. Data can be recorded in table form and later used to form a graph.
Belt Transect
This is quite similar to the line transect but a wide belt is used for sampling instead of a line.
  1. Two strings or pieces of tape are used to mark a belt of approximately 0.5 to 1 metres and then quadrats are used for sampling.
  2. As for line transects, sampling can be done throughout the whole belt, at regular intervals or at random points.
  3. Data can be recorded in table form and later used to form a graph.
Quadrat Surveys :  
 
The following are types of data which can be worked out during quadrat sampling.
 
Plant Cover : This is the area which is covered by a particular species when viewed from above and can be calculated as a percentage.

 

Frequency : This refers to the probability of finding a particular species in a sample area or quadrat. This can be calculated by expressing the number of quadrats in which a species was found as a percentage of the total number of quadrats used.Alternatively a quadrat can be divided into 10x10 subunits and percentage frquency expressed according to the presence/absence of the species in each sub-unit.

 

Density : This refers to the number of individuals of a particular species in a quadrat. To improve accuracy sub-divided quadrats should be used to calculate density.
 
Species Richness : This refers to the number of different species covering an area. A note can be taken of each different species found in every quadrat and at the end data is grouped and the total number of differnt species in the area is found.
 
Species Evenness : This is a measure of the relative abundance of each different species making up the species richness of an area. For a community to have more evenness, the total number of individuals of each different species should be evenly distributed. 
 
Diversity Index : This is a numerical representation of the diversity of species in a community and depends on the number of different species and the abundance of each type of species. There are different types of diversity indices used.
 
One of them is Simpson's Index. Simpson's Index takes into account both species richness and species evenness. Simpson's Index is calculated using the following equation: D= [∑n(n-1)] / [N(N-1)]
(where "n" is the number of individuals of a particular species and "N" is the total number of individuals of all species)
Activity Three: Abiotic Factors
 
Abiotic factors such as wind force, soil pH and temperature can be meausured in order to determine the effect of different abiotic factors on the type and number of species present. Thus these values can be measured in each quadrat. An ammeter is used to measure wind force, a pH metre to measure soil pH and a thermometre to measure soil and air temperature.

Activity Four: Rockpool Study

 

 

On rocky beaches one usually observes the presence of several rockpools which are host to quite a number of species of flora and fauna. Rockpools are interesting to study and ideal for fieldwork as groups of students can be assigned to investigate different rockpools. The data collected could then be compared. Surveys of species present could be carried out along with a study of abiotic factors in a rockpool.

All the material found in this website is under copyright of the authors of this site- Daphne Agius, Sephora Debono /www.maltarockybeaches.com /Malta. (2012-2014)

bottom of page