Acid hurts prawns

fast-ed.com.au

WE ARE blessed in Australia by both the volume and variety of prawns found in our coastal waters.

Unlike so many parts of the world where prawns exist in monoculture, we enjoy 13 species of prawns that are commercially harvested as well as several other locally specific subspecies targeted by recreational fishers.

Yet a revolution is coming, made necessary by the impending change to our climate and the way in which it is modifying the temperature of seawater, as well as its acidity. Warmer water should present advantages to prawns, after all that’s where the worms and microorganisms that make up the bulk of their diet are found in abundance.

However, the principal reason for the warming oceans is carbon dioxide emission. It’s a gas that is absorbed by water and that has an inverse effect on its pH level. As the carbon dioxide content of the sea rises, its pH falls towards more acidic.

Even subtle changes in acidity can have profound effects on the life cycle of prawns for two key reasons.

Primarily, it makes their shells unstable and can even cause corrosion of the carapace (the shell surrounding the head) which will eventually cause mass prawn die-off.

Secondly, increased acidity makes it harder for prawns to reproduce.

Thankfully, here in Australia we have a well-established and worldleading industry of on-land prawn farms.

While the ideal result would be that stakeholders around the world find the potential loss of their favourite food as motivation to make the necessary changes to energy policy, there is no guarantee of that. In the meantime, we have a back-up plan.

PRAWN CACCIUCCO

SERVES: 4

Ingredients

1 red onion, sliced

12 cloves garlic, sliced

2 long red chillies, seeded and diced

2 bay leaves

1 tsp fennel seeds, cracked 4 anchovy fillets

2 tbsp extra virgin olive oil

2 x 400g can cherry tomatoes 2 tsp red wine vinegar

2 tsp brown sugar

Sea salt flakes and freshly ground black pepper

20 large green king prawns, peeled and deveined

Pesto and cornbread, to serve

Method

1. Saute the onion, garlic, chillies, bay leaves, fennel seeds and anchovies in olive oil for 3 minutes, until aromatic. Mix in the tomatoes, vinegar and sugar, then simmer for 5 minutes.

2. Add the prawns, then cook gently. Season with salt and pepper. Serve with pesto and cornbread.