article_snippet.sent: Dr Pickerell remains optimistic, adding: 'It's a question of glass half full or half empty.
article_snippet.sent: But these rules were never systematically enforced and did not bring much relief.
article_snippet.sent: Numbers fell to below 70,000 tonnes for the first time in 1999 and reached its lowest level of 28,900 tonnes in 2006.
article_snippet.sent: Researchers warned a lower life expectancy meant a lower birth rate and a faster decline.
article_snippet.sent: We would have been in the dark without this research.'