Ecology Fieldtrip

          Groovy Mangroves!  Aww YEA!

 

          Mangrove is a very specific ecosystem where the salt water meets the fresh water.  Isn’t that groovy?  Although one may think that mango can be collected in mangrove but they are wrong.  Plants and life in mangroves have special adaptations to the special condition of the brackish water found only at mangroves.  The mangroves have special adaptation because their roots are higher than the ground to supply air and that the salt is perspired through the leaves.  The techniques used to study the abiotic and biotic factors affecting mangroves are quadrats and transect.  We use quadrat for site A and transect for site B.

          The two sites that we investigated the abiotic and the biotic factors is one that is close to the river and one that is further away.   For the abiotic factors, the temperature of the air and the water is 31°C and 28°C for both site and the dissolved oxygen are both 6.6mg/L and the pH are both about 7.  Other factors like conductivity, turbidity, nitrate level, ammonia level, and phosphate level are about the same.  However the water depth for site B is a little bit deeper than site A.  The main difference between the two sites is the light intensity.  Site A is more crowded with taller mangroves so the there is little light compared to site B where the mangroves are not as crowded and not as tall.

Abiotic Factors	Site A	Site B
Air Temperature (°C)	31	32
Water Temperature (°C)	28.5	28
Dissolved Oxygen (mg/L)	6.6	6.6
pH (probe reading)	7.38	7.21
Conductivity (uS/cm)	25414	25000
Turbidity	25	25
Nitrate (mg/L)	10	10
Ammonia (mg/L)	0	0
Phosphate (mg/L)	1	1
Water Depth (cm)	7	8.68
Light Intensity	Cloudy, Covered by lots of trees	Partially Clouded
Substrate	Damp, Sticky (5.8 cm), darker, more fertilized	Damp, sticky (depth 9.34 cm)

 
         

 

          For the biotic factors, the data collected is not very accurate.  We don’t have enough time to observe and count all of the organisms in the mangrove so we counted those that we found inside the quadrats.  This is where there are sources of errors.  The quadrats that we chose is not random, we choose the quadrats that are convenient to us such as the one next to the bridge pathway and the one in the line of our designated area.  The organisms may not live in these quadrats because it is close to the bridge.  The bridge will cause disruption to the organisms and that is maybe why they live further away where we cannot get to.  Also the animals may hide from us causing the data to not be accurate and some of the animals are too small or we cannot just spot them in the quadrat.  In transect for site B, there are lots of ants and we cannot count all of them so we just write down the observation that there are many ants.  With so many errors, a clear comparison cannot be made between site A and site B for the biotic factors.

Biotic Factors	Number of Organisms in Site A	Number of Organisms in Site B
Spider	1	0
Red mangrove	5	4
Mud Crab	0	2
Scallop	0	0
Lichen green	0	0
Flies	0	0
Lichen yellow	0	0
Fish (leopard)	0	0
Snail #1 (ground snail)	0	0
periwinkle	0	1
snail #2	0	0
Water strider	0	5
Seeds	0	0
Hermit Crab	1	0
Merder’s Mangrove crabs	4	0
Zipper like Worm	0	0
Mosquito	0	0

 
HOOOO!!!! Who’s living under the sea?

Where does Spongebob Squarepants live in?  Where does Captain Jack Sparrow fight with the Kraken?  Where does Poseidon rule?  Where does life starts?  The answer to all these questions is the sea.  In Earth, there is about 70% water and so many things live in it.  The sea has been influencing living things since the origin of life to the Ancient Greeks, to the New World, and to Bikini Bottom.  Millions of living things are still under the sea and that is why we went there.

During the visit, we collected data regarding the abiotic and the biotic factors affecting the rocky shore.  This rocky shore is artificial and it is created in order to decrease shore erosion.  This means that the rocky shore is not natural and therefore not very old.  Abiotic factors are nonliving factors such as precipitation, sunlight, wind, temperature etc.  Biotic factors are the living factors like the crustaceans and the mollusks.  The abiotic factors identified to influence rocky shore are temperature, wave frequency, wind direction, and light intensity.  The water temperature is 31°C.  The wave frequency is 48 waves per minute and the wind direction is in the north east direction.  The light intensity is very sunny.  This can be seen in the table below.

Temperature	Wave Frequency	Wind Direction	Light Intensity
31°c	48 waves/min	North East	Sunny

Limpets

 

           To collect data on the biotic factor affecting the rocky shore, we will have to use the transect method.  This is because we don’t want to randomly collect data about the number of organisms in the rocky shore but we want to see the changes in distribution of organisms along the rocky shore.  The belt transect is perfect for this data because we can see the distribution of organisms into the sea.  The transect starts in the water just further from the rocky shore and extend upwards into the shore.  Five 50cm x 50cm quadrats are measured along this transect line so transect extends for 250 meters from the sea into the shore.  The further it is from the shore, the deeper the water gets.  In the first quadrat the depth of the water is about 1 meter and this decrease to no water at all in the fifth quadrat.  In each quadrat, the number of organisms per species is counted.  The species found include periwinkle, knob periwinkles, barnacles, and limpets.  However not all species are found in every quadrats.  This is shown in the data table and in the bar chart below.

Periwinkles

 

		Periwinkle	Knob Periwinkle	Small Barnacles	Big Barnacles	Limpets
Quadrats	1	0	0	0	0	0
	2	4	0	100	50	2
	3	3	0	0	0	0
	4	7	6	0	0	0
	5	2	0	11	0	0

         

 

          The biotic factors collected show that the second quadrat has the most organisms.This means that most organisms live in 51 to 100 centimeters from just further from the rocky shore.This shows that the best condition for organisms living in a rocky shore ecosystem is where there are alternating later level and depth.At about quadrat 2 and 3, this is where the depth of water and the water level changes as a result of the high and low tide.Most organisms live here so that means that the organisms also need some period of time to be above the surface of water.