Dear well-esteemed academicians,

I am looking at the diversity composition of fishery landings of selected species of fish in a state and compare the composition of the state to the (larger) country of the state. I wish to conduct Bray Curtis similarity matrix on my composition data.

I have two possible ways to ordinate the composition and both have their pros and cons, I wish to get your opinions on this:

1) Using the actual landing number (matric tonne). This is the best set. However, if we to compare between the larger set (country) and the subset (state), means that there is a bias towards the larger set when we ordinate it, right?

2) Using percentage abundance composition (%). This will even the weight between the country and the state. However, how do I calculate the percentage abundance of the composition? using the total mass of the selected species? or the total lading mass of all fish?

I hope my questions are clear. Thank you for your attention.

Cheers,

Boo