January, February and March 2011 saw high fish mortalities in the waters surrounding Ascension, leading to thousands of dead fish being washed up on to the beaches. Records indicate that a similar occurrence happened also in 2008, at which time samples of fish were sent for testing. It was suggested that the fish may have become ill with an opportunistic bacterial infection, whereby the fish become more susceptible to bacteria due to stressful events such as spawning. Other hypotheses are that the fish mortalities are caused by either toxic algae or waters with a low level of oxygen. Following the 2011 incident, samples of seawater and fish were sent to the Centre for Environment, Fisheries and Aquaculture Science (CEFAS) in the UK. While CEFAS reported that no toxins of potential harm were found in the samples, elevated levels of phospholipids were found in some liver samples, consistent with algal blooms, although none of the evidence was conclusive. Research is subsequently on-going.