General observations: wonderful sharpness and color (I'm not big on sunsets). Perhaps some, particularly the flowers, suffer from being too centered - if you read this forum often you will see rule of thirds posted at least several times a day.
What set-up did you use for the aquarium shots? I was at the Georgia Aquarium this summer and the rules were no flash, no tripod resulting in minimal keepers (I don't have hi-end gear and forgot to reset the ISO anyway so I got what I deserved - try again later this year).
Thanks for responding, the aquarium photos were taken in melbourne last year and i actually lucky that i was just getting used to change iso settings. I used iso400, but the tanks all had lighting which luckily helped me. I put my lens write upto the tank and put a piece of cloth round the lens to stop it from shadowing back came out really well. What sort of photography are you into?
Generally, I would limit the posted pictures to about 3, indicate shooting parameters like tripod, shutter, ISO, aperature, flash, and ask a specific question to get the best feedback but here goes on a few.
Silouhette Sunset - has too much trees and not enough sunset for me. I would try with only one tree on the side. It feels a bit tilted.
Spanish Trip Barcelona 2002 - has awkward framing at bottom where you cut through people, cars and fence. And it is titled.
Spaninsh Trip is nicely framed with nice mood. I am not sure black and white is the best choice because it flattens a not overly featureful picture. For me black and white is better in a busy picture than a simple picture.
Jellyfish seem soft with lots of halo. Nice idea though.
P1000787 has nice features foreground to background which is good but I think would be better with more leading out to sea. The horizon is at the right 1/3 down level.
P1000786 has nice colors and lighting but has an unatural tilt feeling. I would try to untillt and if I had a longer lens back up so it the perspective is not so extreme for this picture.
I really likeed P1000606 - nice colors, and has a 3d look to it. It is a bit 2 centred and is a bit tight on the left on the fin and the frame. it is best to leave a bit of space on right where he is pointing and no so centred but It is nice
Welcome to the forum. I have run out of steam on this last one.