“Because of the increased concentration of fish [Pygmy Suckerfish], you have an increased chance to catch a shark from fishing pools.”

This pool skill change is more interesting:

“Don’t forget, in patch 3.3.0 you never catch trash from fishing pools, regardless of skill.”

Never catch junk from a pool, even at skill 1. Kalu’ak Fishing Derby rewards below.

Dread Pirate Ring
Binds on Account
Unique-Equipped
Finger
+34 Stamina
Requires level 1 to 80 (80)
Equip: Improves critical strike rating by 53.
Equip: Improves hit rating by 29.
Equip: Experience gained from killing monsters and completing quests increased by 5%.

Boots of the Bay
Binds When Picked Up
Feet
Requires Fishing (200)
Equip: Increased Fishing +15.
Use: Whisks you away to the finest drinking establishment in Booty Bay. (1 Day Cooldown)

For more information, read the Kalu’ak Fishing Derby page, or discuss on the forums.

“The all-new Kalu’ak Fishing Derby, a test of fishing skill with a healthy dash of luck, has come to Northrend! Every Wednesday beginning at 8 PM players can try to catch the elusive Blacktip Shark. Elder Clearwater sits in Dalaran for one hour awaiting the return of the quickest, most experienced fisher to bring him this shark. This champion fisher will be rewarded in-kind for returning with the first catch. Those who aren’t able to return with the first catch will still receive just reward for getting the Blacktip Shark to Elder Clearwater before he takes his leave. It is said that these sharks’ favorite meal are the bite-sized Pygmy Suckerfish. Perhaps a hook in their waters will do the trick.”

Via Twitter (thanks DarkMime64):

“Up for grabs – a new heirloom ring!”

Read on for further quest information.

Based on the MMO-Champion database (which is based on raw, often incomplete data): The Blacktip Shark (Binds when picked up, unique, 1 hour duration) is an objective of 2 quests:

• Soul of the Kalu’ak – Rewards either a finger or a cloth foot item. Plus 175 Kalu’ak reputation. Both items are new and unknown. Speculation that the finger item is the heirloom ring.
• Better Luck Next Time – Rewards a normal Bag of Fishing Treasures and 125 Kalu’ak reputation.

Both quests are flagged “daily”, although that may simply be a method of limiting repeat attempts to win. Speculation is that the first quest is for the winner, and the second quest if for everyone else that turns in the fish during the Derby. Please keep discussing it on the forums.