Travel blog: Swimming with the fishes in Rio do Plata

Rhian Nicholson has swapped the bright lights of London for a three month journey across South America from the Pacific to the Atlantic coast. Here is her 15th blog entry:

Take the mafia connotations out of swimming with the fishes and the whole experience can be rather pleasant. Well, until you come eyeball to bulging eyeball with a shimmering shoal of your newfound scaly friends with lips like Leslie Ash, Dracula-style fangs and an unhealthy fascination with your toes. To be fair, that was only one variety of fish inhabiting the Rio do Plata in Bonito but the other 34 were no more attractive...

Kitted out with snorkels and wetsuits, you find yourself trampling as quietly as possible along a tranquil woodland trail keeping a beady eye out for any of the seemingly mystical creatures featuring on the signposts en route. They all must have had a heavy night before because save for the odd butterfly all was very quiet on the animal front. Still, 30 minutes later, once the humidity had sent your sweat glands into overdrive, you find yourself at the start of your fish-tank experience, a natural swimming pool framed by overhanging branches and inhabited by swimming things, floating things and sinking things. Luckily with your wetsuit tightly zipped up to the point of suffocation, you´re one of the floating things.

So with the warning not to touch the riverbed in any shape or form firmly lodged in your brain, the day took a distinctly fishy turn. Swept along by the current through cold clear waters with your snorkel exhibiting a magnetic tendency to collect water you find yourself surrounded by the inquisitive scaly critters wondering if you in fact a giant piece of bait. Fish fanatics may disagree but one fish looks pretty much like another and bobbing alongside them doesn't quite have the same therapeutic benefits as swimming with dolphins. So after ten minutes of this natural flotation tank experience you find yourself getting pretty bored - and wishing that one of the camouflaged caimans lazing on the river bank would suddenly develop an insatiable appetite for a fish lunch.

No such luck. Fish certainly wasn't the dish of the day, not even at the all you can at lunch buffet us humans got to devour. Shame, those metallic blue ones looked like they could have gone well along some rice and refried beans....

Piranhas on the other hand are one type of fish you certainly wouldn't want to share a giant bath tub with. Indeed, what they lack in size they make up for with their hearty love of raw meat - especially when the bait in question is one of their own. It actually makes fishing quite an entertaining way to while away the hours in the Pantanal (the world's largest wetland area) - the piranhas always bite but actually hooking one of the carnivorous little fish beasts is a tricky task. Still, 93-odd attempts and one close encounter between a fish hook and your nose later, your efforts finally pay off - only for the guide to unhook the measly thing with a derisory snort and throw it back in to meet its fate at the snapping jaws of its companions.

Luckily there were much bigger fish to be fried that day - and at dinner the chef duly served up a rather tasty piranha soup with whole fried piranha for those who could be bothered to extract the tiny amount of fish-meat from the large mass of bones.

Twice as vicious as the piranhas, however, were the mosquitoes on a mission to make their mark on any available patch of skin regardless of how much repellant you put on. For some reason they feel the same draw to my blood as I feel towards a bottle of decent Rioja. Still, something would be wrong if the Pantanal, a wetlands area the size of France which is home to 20 million caiman, an army of loquacious howler monkeys and the odd anaconda wasn't bug central. And when you´re standing on a rickety bridge gawping down into the open jaws and staring beady eyes of a caiman, mozzies seem like positively friendly creatures. Indeed, even the vulture pulling the brains of a dead caiman out through its eye socket seemed a preferable companion.

Wading through the grassy heart of the wetlands, however, you could be back on London´s Hampstead Heath, save for occasional monkey and the watery ruts that those not terrified by the prospect of leeches can traipse through barefoot. In wet season, the water rises to your waist, turning a simple walk in a park into an aqua aerobics session.

This is where horse riding really comes into its own, getting them on to do the hard work while you bounce about in the saddle and keep a beady eye out for any low hanging branches and wildlife with sharp snappy jaws. A couple of hours later though when your horse is truly sick of trudging through the sludgy waters, they exact their revenge, breaking into a gallop that leaves you hanging on for dear life and certain in the knowledge that you´re no going to be able to sit down comfortably for a good few days. Ah the joys of the great outdoors....

Rhian Nicholson