I have a couple of articles that could work, though some of them are similar to ones alerady suggested. A lot of them could be connected with events. Things in ( ) are variables, and things in [ ] are my own explinations.
A massive storm is approaching the sea from the (direction). The islands of (Islands in the way of the storm) will experience massive rain falls and waves over the coming days.
[These islands, if they are an inhabited town, may have higher prices on food/supplies, but higher buying prices for food/supplies as well. This could also lead to the “Castaways at sea” newsletter after the city is hit, since these cities will be hit hard and people may get lost.]
A massive group of (small/giant/golden) fish have been spotted (at/around, depending on lakes) (island name). Fisherman are clamoring to catch as much as they can at (island)!
[This would lead to NPC fishing boats being around this island, or NPC fisherman spawning in at the lakes/ponds around the island. This could lead to some nice robbery activities for criminals, and some nice catching activities for people trying to grind the fish encyclopedia.]
A gang of pirate ships have been spotted around (island). Local authorities suspect this group of pirates to be using swarm tactics to overpower merchant ships and strip them of supplies. The Grand Navy has set a bounty on this gang, dubbed (generic NPC name).
[This would be a world event that you could participate in. A group of 3-6 pirate ships would all be working together looting other ships. Defeat all of them, and you get the booty. In the future updates when the giant ships are added (the faction ones that you can build), this could also spawn in, though this may be saved for higher level areas, like other seas.]
A mysterious explosion was seen at sea between (two islands). Local authorities refused to give an opinion on the matter, but local rumors suspect that a (star/meteor/comet, no real difference, up to choice/random chance) may have crashed down into the sea!
[These meteors would be a place for you to find rare gems and materials. They could also touch down on islands, but that may interfere too much with day-to-day gameplay. Bigger meteor=more gems to find.]
A massive ship battle has taken place in the sea near (island). Local authorities report (minimal/decent/substantial) losses on (both/one) side, and advise that anybody passing through the area to be on the lookout for castaways and lost cargo.
[A world event of a big battle between two factions (like Pirates vs Assassins, AG vs Pirates, ect.). This would allow you to look around the area for castaways, while a massive graveyard of ships full of cargo and chests would sit in groups/divided clumps].
Supplies at (island) are (dwindling/overflowing). Local citizens are begging for merchants to (buy cargo from them/sell cargo to them) in this time of need, or else many people may starve.
[Too much supplies = lower buy prices for cargo at that area and cheaper ship repairs, too little supplies = higher sell prices at that area, higher ship repair costs.]
These last ones are less ‘big news’ and more ‘small/local news’. Basically filler articles you’d see IRL.
(NPC name), a resident of (island) recently caught an abnormally giant (fish name). This fish is the largest documented fish of this type in recorded history!
Today, as soon as the sun sets below the horizon, a rare meteor shower will be visible for the first time in over 10 years! Make sure to say your wishes, as this wont be happening for another 10 years!
[Would spawn in a nice animation of a meteor shower, just so the Agora wouldnt lie to us].
A local dispute over ship parking rights has lead to two disgruntled merchants being arrested by the AG after a short - yet explosive - fight at (island). Visitors to (island) are advised to park politely in the future.
[Sorry if some of these are bad/the comment is a wall of text, but I quite like this suggestion and would love to have a bit more spice in the Agora. One last suggestion though: Maybe the Agora could even have specific, dedicated sections for these things, (like politics, fights, stocks/supplies, ect.) to sort them out. Other than that, thanks for your time and/or reading!]