I noticed some errors with the fishing lists for HG/SS. No, this isn't connected to the lack of Seaking in that area of Mt. Silver that I mentioned some time ago; this has to do with the reported percentages. I'll mention a couple other errors as well.
http://www.serebii.net/pokearth/kanto/route6.shtml#4th
http://www.serebii.net/pokearth/kanto/route22.shtml#4th
http://www.serebii.net/pokearth/kanto/route28.shtml#4th
http://www.serebii.net/pokearth/kanto/viridiancity.shtml#4th
http://www.serebii.net/pokearth/johto/route30.shtml#4th
http://www.serebii.net/pokearth/johto/route31.shtml#4th
http://www.serebii.net/pokearth/johto/route35.shtml#4th
http://www.serebii.net/pokearth/johto/route43.shtml#4th
http://www.serebii.net/pokearth/johto/route45.shtml#4th
http://www.serebii.net/pokearth/johto/blackthorncity.shtml#4th
http://www.serebii.net/pokearth/johto/ecruteakcity.shtml#4th
http://www.serebii.net/pokearth/johto/ilexforest.shtml#4th
http://www.serebii.net/pokearth/johto/mt.silver.shtml#hgss-outside
http://www.serebii.net/pokearth/johto/ruinsofalph.shtml#hgss-outside
http://www.serebii.net/pokearth/johto/violetcity.shtml#4th
With the Super Rod in these areas, Poliwag's encounter rate is 94% and Magikarp's encounter rate is 6%, but they were reported as 93% and 7%, respectively.
http://www.serebii.net/pokearth/kanto/route20.shtml#4th
http://www.serebii.net/pokearth/kanto/route21.shtml#4th
http://www.serebii.net/pokearth/kanto/route26.shtml#4th
http://www.serebii.net/pokearth/kanto/route27.shtml#4th
http://www.serebii.net/pokearth/kanto/cinnabarisland.shtml#4th
http://www.serebii.net/pokearth/kanto/pallettown.shtml#4th
http://www.serebii.net/pokearth/kanto/vermillioncity.shtml#4th
http://www.serebii.net/pokearth/johto/route41.shtml#4th
http://www.serebii.net/pokearth/johto/route47.shtml#4th
http://www.serebii.net/pokearth/johto/newbarktown.shtml#4th
With the Good Rod in this area, Chinchou's encounter rate is 6% and Shellder's encounter rate is 4%, but they were reported as 7% and 3%, respectively. Also, with the Super Rod in this area, Tentacruel's encounter rate is 6% and Lanturn's encounter rate is 4%, but they were reported as 7% and 3%, respectively. Also, Vermilion City is misspelled - there's only supposed to be one L.
http://www.serebii.net/pokearth/kanto/route19.shtml#4th
http://www.serebii.net/pokearth/johto/route34.shtml#4th
http://www.serebii.net/pokearth/johto/route40.shtml#4th
http://www.serebii.net/pokearth/johto/cherrygrovecity.shtml#4th
http://www.serebii.net/pokearth/johto/cianwoodcity.shtml#4th
http://www.serebii.net/pokearth/johto/olivinecity.shtml#4th
http://www.serebii.net/pokearth/johto/unioncave.shtml#hgss-b2f
With the Good Rod in these areas, Krabby's encounter rate is 36%, Corsola's daytime encounter rate is 4%, and Staryu's nighttime encounter rate is 4%, but they were reported as 37%, 3%, and 3%, respectively. Also, with the Super Rod in these areas, Krabby's encounter rate is 66% and Kingler's encounter rate is 4%, but they were reported as 67% and 3%, respectively.
http://www.serebii.net/pokearth/kanto/route12.shtml#4th
http://www.serebii.net/pokearth/kanto/route13.shtml#4th
http://www.serebii.net/pokearth/johto/route32.shtml#4th
With the Good Rod in Route 32, Tentacool's encounter rate is 39% and Qwilfish's encounter rate is 1%, but they were reported as 38% and 2%, respectively. Also, with the Super Rod in all of these areas, Magikarp's encounter rate is 6% and Qwilfish's encounter rate is 4%, but they were reported as 7% and 3%, respectively.
http://www.serebii.net/pokearth/kanto/route9.shtml#4th
http://www.serebii.net/pokearth/kanto/route10.shtml#4th
http://www.serebii.net/pokearth/kanto/route24.shtml#4th
http://www.serebii.net/pokearth/kanto/route25.shtml#4th
http://www.serebii.net/pokearth/kanto/ceruleancity.shtml#4th
http://www.serebii.net/pokearth/kanto/tohjofalls.shtml#4th
http://www.serebii.net/pokearth/johto/route42.shtml#4th
http://www.serebii.net/pokearth/johto/darkcave.shtml#hgss-route31
http://www.serebii.net/pokearth/johto/darkcave.shtml#hgss-route45
http://www.serebii.net/pokearth/johto/mt.mortar.shtml#hgss-1f
http://www.serebii.net/pokearth/johto/mt.mortar.shtml#hgss-1f-3
http://www.serebii.net/pokearth/johto/mt.mortar.shtml#hgss-b1f
http://www.serebii.net/pokearth/johto/slowpokewell.shtml#hgss-1f
http://www.serebii.net/pokearth/johto/slowpokewell.shtml#hgss-b1f
http://www.serebii.net/pokearth/johto/unioncave.shtml#hgss-1f
http://www.serebii.net/pokearth/johto/unioncave.shtml#hgss-b1f
With the Super Rod in these areas, Magikarp's encounter rate is 6% and Seaking's encounter rate is 4%, but they were reported as 7% and 3%, respectively. Also, the Dunsparce swarm only occurs on the Route 31 side of Dark Cave, and even though it's possible to find Pineco by using Headbutt in Route 25, I don't see it listed.
http://www.serebii.net/pokearth/johto/whirlislands.shtml#hgss-1f
http://www.serebii.net/pokearth/johto/whirlislands.shtml#hgss-b2f
With the Good Rod in these areas, Krabby's encounter rate is 36% and Horsea's encounter rate is 4%, but they were reported as 37% and 3%, respectively. Also, with the Super Rod in these areas, Kingler's encounter rate is 6% and Seadra's encounter rate is 4%, but they were reported as 7% and 3%, respectively.
http://www.serebii.net/pokearth/johto/lakeofrage.shtml#4th
With the Good Rod in these areas, Magikarp's encounter rate is 96% and Gyarados's encounter rate is 4%, but they were reported as 97% and 3%, respectively. Also, with the Super Rod in these areas, Magikarp's encounter rate is 70% and Gyarados's encounter rate is 30%, but they were reported as 90% and 10%, respectively.
http://www.serebii.net/pokearth/kanto/route4.shtml#4th
Guess what? You can find Pokemon in Route 4 by surfing and fishing. The Pokemon found in Route 4 by surfing and fishing are the same as those in Cerulean City.