I hope everyone had a great
week and found some sort of water source to take a sample from! On February
10th, our lab was lucky to have the Marine Science Center's, Special Projects
Coordinator, Chad Macfie. Chad went over what our lab on February 17th will
basically cover and the procedures of completing it. He showed us what a seine
net is, what are its purposes, and how to use one. He also taught us how to use
a dichotomous key for fish identification. The way it works is it asks you a
question with two choices and depending on your previous answers, the key will
narrow down the fish until you find the one you’re looking for. Luckily for me I
had the opportunity to use both seine nets and dichotomous keys at Seacamp over
the summer for experiments so I have some basic knowledge of the expectations
to come Friday morning. Along with showing us fish seining methods, we were
given some important terminology that is often used in marine biology such as fish
stock, population, recruitment, maximum sustainable yield, optimal yield, catch
per unit effort, and catch per unit area. All the terms having an important
meaning that help scientists monitor the fish populations and allow them to
regulate species numbers for fisherman. With
the terminology came the numbers that must be recorded along with the research
we’re collecting. Much of the data we are recording is math based and will take
some time to analyze and calculate.
Our assignment this week was to create a graph from the data that recent
labs collected doing the same exact experiment in the same locations. For mine
I chose to see if there was a correlation between the CPUE and CPUA. As you can
see in my graph, there is a positive relationship between the two with a R2 value
of 0.88967. This graph shows that as
more fish are caught per minute, there are more fish in one squared meter.
There are two outliers. One is 524 CPUE with a CPUA of 2.4. The other is 273
CPUE and 2.1 CPUA.
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| Relationship between CPUE and CPUA from recent lab experiments in Ponce Inlet |
Christian--not sure that this relationship is really useful. They actually should be related by the simple fact that they are both associated with 'catch'. It would be more telling to see what other variable this 'catch' is related to. For example, is catch greater when water temperatures are higher/lower? or maybe salinity is greater/less? When creating a graph, keep in mind--does it make sense? Does it provide useful information? What 'story' does it tell?
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