By Mike Joy and Sylvie Mclean
Biodiversity is a term that means different things to different people. Its use has exploded with people’s increased appreciation of the magnitude of the decline and the importance of diverse biotas to the human future. Popularly biodiversity is understood as the number of species in a given country or ecosystem. To scientists it is a deeper concept that includes genetic and ecosystem diversity and has crucial components like endemicity (species found nowhere else), native diversity (the proportion of native species) and keystone species (species that are crucial to ecosystem function).
There are three main components of biodiversity: the number of species, the number of different ecosystems and genetic variability. Globally they are all undergoing unprecedented declines. It is estimated that we are now losing species at 1,000 to 10,000 times the background or natural rate. This is resulting in a process of global biological homogenisation, where the biotas of all countries become more and more similar and a small number of species that thrive in human-dominated habitats are flourishing across the world.
Sadly, nowhere is the loss of biodiversity more pronounced than here in Aotearoa New Zealand: with around one-third of our species listed as threatened we have the highest proportion of threatened indigenous species in the world. And roughly an additional one-third of named species are listed as ‘data deficient’ so its likely many more should be on the threatened list had they been assessed. And then there are the species that have not been named that we have absolutely no idea about. Threat classification, globally and in Aotearoa New Zealand, is complex because there are multiple levels ranging from nationally critical to at-risk. Therefore, it is simpler when describing levels of biodiversity decline to look at the proportion of species listed as ‘not-threatened’. Currently only around 18% of beetles, 26% of freshwater fish, 38% of marine mammals, 12% lizards 5% of snails and 50% of plants are listed as ‘not threatened’ or not ‘at-risk’. A rather dire situation to behold especially given the 100%-pure slogan used to market Aotearoa New Zealand overseas. Another important facet of Aotearoa New Zealand’s biodiversity decline is that we have extraordinarily high levels of endemicity, with around 40% of plants, 90% of fungi, 70% of animals and 80% of freshwater species fish found nowhere else. Meaning that if they are lost here they are lost entirely.
Embarrassingly (and perhaps conveniently) for Aotearoa New Zealand, our Department of Conservation in their recent sixth report to the United Nations Convention on Biological Diversity could not say for sure whether our biodiversity was declining or not. This is because one-quarter of the nearly 4000 species currently classified as threatened or at-risk have only been assessed once, so there is no way to know whether their conservation status has changed. Of the remaining roughly 3000 threatened or at-risk species, 10% had worsened to a more threatened ranking, while only 3% had improved their threat ranking.
The legislation intended to protect biodiversity in Aotearoa New Zealand is largely ineffectual. While the Wildlife Act (1953) purportedly gives absolute protection to all wildlife, it is not enforced in any meaningful way, and therefore has had no impact on biodiversity conservation. The Native Plants Protection Act (1934) stipulates that native plants have protection on conservation land but makes no mention of protection outside conservation land and in any case is not enforced. Crucially for our native fish they are not covered by the Wildlife Act so have virtually no protection either.
Apart from ineffective species protection there are many other reasons for our high proportion of threatened species including the multiple impacts of human alteration of land-cover. The impacts occurred initially with Polynesian arrival, and then again more severely after European colonisation, with massive forest clearance and water draining, and more recently land-use intensification mainly dairying leading to significant loss of biodiversity has occurred in the last handful of decades. Freshwater fish species are a good example, where the increase in the proportion of threatened species has gone from around one quarter in the early 1990s to three quarters now, with an average increase in threatened or at-risk species of around 2% per year. This recent loss reveals the failure of successive governments to protect biota, their habitats and ecosystems, and particularly the lowland coastal forests and wetlands, which continue to be degraded by human activity.
To give an indication of just how drastically land-cover has been changed, indigenous terrestrial vegetation cover is less than 30% down from approximately 90% in pre-human times. And 23% of our land area now has less than 10% of its natural indigenous cover, and 33% of the country is now exotic grasslands.
When it comes to protecting ecosystems, having one third of the country putatively protected by being within Conservation Estate in Aotearoa New Zealand sounds impressive. However, this value obscures the true state of the “protected” areas. The ecosystem types in the estate are far from a representative selection; it mostly contains the areas too steep to farm and too inhospitable to live in. The areas in the estate also receive a wide range of levels of protection.
The decline of biodiversity through the failure to protect habitats is revealed by the reductions in ecosystem diversity: 62% of the ecosystems classified as rare are now listed as threatened, and more than 90% of wetlands have been destroyed. This is loss is not confined to past actions, estimates are that 214 wetlands (1250 ha) were lost between 2001–2016 and a further 746 wetlands declined in size.
Protection levels of marine habitats are even worse than for terrestrial ones. The marine area of Aotearoa New Zealand is 15 times larger than the land area and contains an estimated 80% of the indigenous species. But this marine biodiversity is very poorly regulated and only 0.4 per cent is covered by ‘no-take’ marine reserves.
Aotearoa New Zealand is a signatory of the United Nations Sustainable Development Goals (SDGs) and thus we are obligated to reduce biodiversity loss. We have committed to achieving SDG 14 (Life under water) and SDG 15 (life on land). The former stipulates that we “conserve and sustainably use the oceans, seas and marine resources for sustainable development”, and the latter that we “protect, restore and promote sustainable use of terrestrial ecosystems, sustainably manage forests, combat desertification, and halt and reverse land degradation and halt biodiversity loss”. If we are to achieve these goals, then marine and terrestrial biodiversity loss be halted, and improvements be made.
There is no sign of any real achievement in these areas, and while the requirement to develop a specific biodiversity strategy was achieved with a National Biodiversity Strategy and Action Plan 2000, it has been largely ineffective at improving the state of biodiversity in Aotearoa New Zealand – because, as the OECD has noted, the strategy and plan lack clarity and clear implementation pathways. It would not require a cynical outlook to conclude that our strategy exists in order to make us look compliant, rather than to address our actual biodiversity issues.
We have tried writing plans with no teeth, and they have been incredibly ineffectual with biodiversity decline accelerating. Therefore, now is the time for action and this needs to come from all levels of society. Individual action must be taken to protect and enhance local biodiversity. Cities and regions need to work to ensure parks and protected areas are adequately managed and areas outside them receive appropriate action. At the level of government work must occur to update our ineffective legislation and then genuine commitment to enforcing the law must be undertaken. For any of this to happen we all need to speak up and a national discussion must be had about biodiversity so that it all perspectives are heard, and people feel engaged in the issue. Putting pressure on government from many sectors of society and holding them accountable will force change to occur. And change must occur if reducing biodiversity loss in Aotearoa New Zealand is to happen.