There were other "inter-related challenges'', including climate change.
Social challenges included "the underinvestment in health'' by the previous government, as well as "increasing homelessness and the critical lack of affordable homes''.
"We are seeing environmental limits and other pressure points being reached at alarming rates.
"The country's homelessness rate of nearly 1% of the population is higher than any other OECD country.''
Pressure on our freshwater through intensified land use had led to poor water quality, which, in turn, "threatens recreational use'' and the "country's image''.
"Alarmingly, 72% of native freshwater fish are threatened by or at risk of extinction,'' he said.
Otago had 11 species of threatened native freshwater fish- the most of any region in the country, he said.
In another talk, Central Otago poet Brian Turner took issue with what he termed an overemphasis on "progress and development'' and said there had been environmental "degradation'' in many parts of Otago.
He had spent 10 years of his early life growing up in a family house at Harbour Tce, North Dunedin, and had extensively explored the nearby Water of Leith, which was once home to abundant populations of several fish species.
He was critical of some of the subsequent changes to this waterway.
He said tussock had once been much more extensive in Central Otago, and he fondly recalled early experiences of fishing in Lake Mahinerangi.
He also reflected on the important role that rivers had played in his poetry over the years.
North Canterbury artist Sam Mahon at a Dunedin water symposium. Photo / Gregor Richardson
North Canterbury artist Sam Mahon also discussed his use of visual art to highlight environmental threats, including to the Hurunui River.
Otago Regional Council deputy chairwoman Gretchen Robertson outlined the aims of the council's draft biodiversity strategy.
Biodiversity in Otago was "big and buzzing'', with 13 ecological regions, 39 ecological districts - 17 unique to Otago - and at least 65 active organisations.
She also asked if there were ways "we could be more effective'' over maintaining biodiversity and if the council could do anything to help.
