Jellyfish

The bay of Sao Francisco do Sul in Santa Catarina, southern Brazil, is a calm and tranquil place, but when we visited on Sunday there were one or two dangers to be aware of. About 30 jellyfish had washed up on the beach.

A study in 1999-2002 found that 76% of jellyfish stings in Santa Catarina* occured at times of high southerly winds, when they are driven inshore from the deep sea. Jellyfish are known locally as "agua vivas" or "living water" and you can see why, these extraordinary creatures are virtually transparent and don't resemble any other creature.


But scattered around the beach these foot wide disks were also rather reminescent of land mines, and that too has some sense, they pack a powerful punch. Stinging cells known as nematocysts inject powerful toxins and they can cause intense pain, as anyone who has been stung can testify. This is how they kill their prey. Several jellyfish on the beach had dead crabs attached, but whether they had been caught out at sea, or killed trying to feed on the beach, it was hard to say.
If you are stung you should wash the wound, but not with fresh water, this will burst any nematocysts still in the wound. Vinegar works, but yes, the urban myth of using urine will also work too at a punch. Better is go to a hospital and get an injection of dexamethosome.

Which species these are I cannot say, but the commonest on the beaches of Santa Catarina is reported to be Olindias sambaquiensis* - hopefully so as it only causes relatively mild, local, symptoms. Unless you are a crab.

*The occurrence of jellyfish stings on the Santa Catarina coast, southern Brazil
Resgalla et al 2005. Brazilian Journal of Oceanography, 53, 183-186.

Strawberries from the hills

When you think of Brazilian fruit you maybe think of oranges (they are the world's largest producers) or pineapples. But there are also more European fruits, especially in the south or up in the hills. When immigrants came from Germany, Pomerania or north Italy they bought their tastes, and their farming skills, with them, so there are apples, grapes, and strawberries. So much so that the town of Domingo Martins actually has a Strawberry Festival each August.


It has to be said though that Brazil is not a major player in the world of strawberries ("morangos"), producing 40,000 tonnes in 2005, which sounds a lot until you consider that Spain produced 320,000 in the same year, and the US 1,050,000. Still, theres a big domestic market, and strawberries are regarded as a high value crop.

Strawberries are not annual plants and will flower for several years, but yield goes down each year so thats not what is usually done. Runners, little plants on the end of stalks, are cut off and replanted each year. You can grow strawberries from seeds, but again it's not very commercial.

There are lots of varieties of strawberries, bred for flavour, or different conditions. The main difference though is if they are destined to be eaten fresh, or used as food flavouring. In Brazil, half of all strawberries are destined to be eaten directly, half to be used industrially. Here's a breakdown of some of the commonest varieties.

To be eaten fresh


Campinas – named after a city in Sao Paulo state and a major growing area. Good size and flavour and tolerant of angular leaf spot, but vulnerable to antracnose and verticillium wilt

Vila nova – early maturing and very productive with an intense flavour, that allows them to be used industrially as well. Resistant to many things but vulnerable to grey mould (Botrytis cineria).

Tangi – vigorous and resistant to spider mites, but late maturing and only averagely productive. The fruit are more pink than red and with a slightly acid flavour

Oso grande – highly adaptive vigorous plants with large leaves. Large fruit, at least at the start of the flowering season.

Selva – not the best, irregular fruit and it's susceptible to many common Brazilian diseases

For flavouring food

Santa Clara – very vigorous with a good flavour, but the fruit are of uneven size and shape. Quite disease tolerant.

Burkley – vigorous, matures early and very productive, but the fruit have a sour taste if eaten fresh and susceptible to mildew.

Mangrove mayhem

For much of the weekend the Brazilian town of Vila velha will be without water. The culprit is a burst pipe which has to be replaced, necessitating the closure of much of the town's water supply.


Now, the pipe runs through an old mangrove swamp. Mangrove mud is stuffed full of bacteria. Mangrove trees produce about a kilo of litter per metre per year, which has to be broken down, not to mention debris from fish, crabs and shrimp which make a rich organic soup. In fact, there are so many bacteria that the available oxygen is used up and anaerobic bacteria (which can survive without oxygen) flourish, including those called “sulphate reducing bacteria” - these are the ones that produce hydrogen sulphide, the “rotten egg” smell. Unfortunately, the smell is not the only problem.

The action of anaerobic bacteria causes corrosion on the surface of metal objects. Additionally, the waterlogged soil of a mangrove swamp is high in iron pyrites, and when exposed to oxygen this forms sulphuric acid. As the water level in coastal mangrove swamps goes up and down with the tide and through the seasons, sometimes aerobic, sometimes anaerobic, metal there gets attacked from both sides.


The pipe in this case was made of 1 cm thick cast iron, and laid about 30 years ago. Gradual corrosion and water pressure inside the pipe eventually caused it to burst so it had to be replaced, but as it was now 6m below ground (due to a landfill project) that was easier said than done. Hence the chaos!

Rubber

It has just been announced that the small Brazilian state of Espirito Santo, part of the Mata Atlantica region, is the 4th largest rubber producing state in Brazil, with 14,000 hectares of “seringueiras”, or rubber trees. Most of the rubber latex produced is bought up by two cooperatives and sent to Michelin, who process it and turn it into tyres. There is a state plan to expand to 75,000 hectares by 2025.

What does this mean for the countryside? Well the rubber tree, Hevea brasiliensis, is native, sort of. Actually it comes from the Amazon rain forest, but grows well further south, as long as it is below 800m and with less than 1,000 mm of rain per year. It is very vulnerable to frost so needs north facing slopes (this is the southern hemisphere remember) and tends to be susceptible to fungi, though there are resistant varieties.

It is a tall tree, up to 144ft if given it's head, but normally kept to 80ft to encourage latex production. This means that it doesn't start producing rubber until about 5-6 years old – only 8,000 hectares of the 14,000 in Espirito santo are actually producing. Because of this young plantations are usually combined with cash crops such as pineapple or papaya, or animals such as goats. Even perennial crops such as coffee or pepper.

When the tree has reached the end of it's useful life you can of course use the wood. But, frankly, it's main advantage is that it is very cheap. It warps easily, and is very liable to rot, so cannot be used out doors. If you see something made from “parawood” or “Malaysian oak”, beware!