Pit bull terriers, German shepherds, and Rottweilers were the offending breeds implicated in our study, and have accounted for the majority of dog bites according to other investigators.hese actions range from outright bans on the possession of pit bull-type dogs, to restrictions and conditions on pit bull ownership. They often establish a legal presumption that a pit bull-type dog is prima facie a legally dangerous or vicious dog.
Common causes of oxygen depletion include cloudy weath-. er, sudden death of algae or plants in the pond, and wind. mixing the pond water. Just two to three days of overcast. weather can cause oxygen production to diminish. When. the oxygen demand remains the same or increases, oxygen. levels begin to decrease.
Plankton die-offs cause rapid oxygen depletions for two reasons: 1) the remaining dissolved oxygen is consumed by aerobic bacteria and fungi in the process of decaying the dead algae and 2) few live phytoplankton remain to produce more oxygen. Secchi disks can be used to monitor bloom densities.xygen dissolves in water at very low concentrations. Our atmosphere is 20% oxygen or 200,000 ppm but seldom will a pond have more than 10 ppm oxygen dissolved in itsâ water. Dissolved oxygen concentrations below 3 ppm stress most warmwater species of fish and concentrations below 2 ppm will kill some species.