SEWAGE PLANTS ON THE LAKE CLEAN THE WATER OF IMPURITIES SUCH AS PHOSPHATE. WHAT SOUNDS LIKE A GOOD THING RIDS THE WATER OF NUTRIENTS, THAT ARE NECESSARY FOR FISH TO FEED ON AND SURVIVE. IF KARL MAKES A CATCH, HE DELIVERS THE FRESH FISH TO RESTAURANTS AND ALSO SELLS THE FISH IN HIS SHOP. BUT IN ORDER TO SURVIVE FISHERMEN ARE FORCED TO BUY FISH FROM COUNTRIES SUCH AS NORWAY OR ICELAND.