Certainly you would expect to be able to catch Bass, either from the beaches or inshore. And species like Bluefish and Little Tunny would occasionally show up. Slightly further north I've also seen anglers catching eels in the estuaries.
Offshore is more intriguing. Certainly there would be opportunities to fish for Bigeye Tuna, Albacore and occasional White Marlin plus, and these are a bit like 'hens teeth' but I recall one was hooked last year, Blue Marlin. That was lost on the light tackle they were using for Whites but appeared to be in the 400lb range. But to stress it's probably only one or two Blues a year they hook up.
I picked up details of that from Roddy Hays web site - www.legendlures.com - which unfortunately doesn't have a forum per se. From memory the posting was from a private boat owner - an occasional poster. So it might be worth just keeping an eye on postings to that site.
I'd certainly be interested in any information you manage to glean once you're down there.
Chairman - Sportfishing Club of the British Isles www.scbi.org.uk
I found this post again after a long delay, so I'm sorry I didn't report back!
I only managed to get fishing 4 times in as many months. Blanked the first 2 times, but went out to "Cap De L'Homy" finally hooked up. Got to the beach early to avoid the throngs of tourists and surfers. About 7am a big rowing boat turned up with about 30 guys on the beach and proceded to trawl the beach with a huge net. They leave one end of the net on the beach, row out and back in a big arch and the pull the net in by hand! I went over to see what thay had caught - 50 FEET FROM ME!! Only a few mullet, 1 Dorade, 2 schoolie bass and one sole. I carried on fishing regardless and about 2 hours later had the first bite. Turned out to be a Greater Weever about 14 inches long!! This was then followed a double and 3 more on different casts. All took mackerel. These things grow to 3lb and have really poisonous spines on their back.
Fished again the following weekend - from 5:30am to 12 and didn't even have a bite!!! All baits came back as they went in! 5 other guys fishing with me - 3 plugging and 2 with baits. Only one of them had any success with 2 bass - 1 36cm and the other about 12cm. He caught those with a collar type rig with the lead attached to the main line and a line off it to a small rubber eel. Tried it myself for a while and on the last cast got swamped by a wave that came over the top of my waders!! Nearly swept me off my feet!! The waves would dry the beach for about 100 feet out and then come back in again. You had to walk to the edge, cast out and then run back to where it was relatively safe - I think I wasn't safe enough!!!
Now I'm stuck in the middle of Poland, miles away from the sea so spend my weekends distance casting - still not catching any fish!!
I've just returned from Arcachon which is north of you near Bordeaux. I was investigating charter fishing there and had a good mooch about the fish market. I saw some very nice Bass which are apparently much more numerous in November and March so they could be migratory? Lots of Blondes and Turbot, Tope, Blue shark and some sort of Tuna to 25lb. Also huge amounts of squid and bait fish. The coast there was basically an atlantic storm beach 1000 miles long! It looks very fishy indeed but not many beachcasters around at all. I counted 15 small fash fishers in Arcachon basin which is about the size of Poole Harbour - and then found out that was unusually high as it was an open Bass (Bar) comp that day! They were all using rapala type plugs very close in along the channels at low tide. Dunno if that helps any???