Greenhouse gas emissions threaten the ecosystems in marine protected areas, according to a new research study published on Sunday in the journal Nature Climate Change. The paper points out that 42% of areas with fishing bans will be exposed to warming waters and decreasing oxygen levels that exceed natural variability by 2050. Researchers at a number universities in the UK and in the US, led by John Bruno, investigated 8,263 marine protected areas across the globe, including 309 areas where fishing is banned. To reach their findings, the researchers modelled sea surface temperatures and oxygen concentrations, at both moderate and high emissions scenarios, to predict the impact on protected ecosystems. The research highlights how the emergence of ecosystem factors differ between regions, saying that shifts in protected areas due to one factor may result in exposure to another. Depending on the outcomes of the model and field studies, the team calculated a community thermal safety margin (CTSM) for each ecosystem. For all species, the CTSM presents the average of the margin between each species' temperature tolerance and the local maximum temperature. Exceeding the CTSM could lead to substantial loss of biodiversity. The findings of the study showed that marine protected areas are predicted to warm at a similar rate to unprotected areas, with the exception of the polar regions. The tropics will be the first to exceed the CTSM by about 2050, with temperate latitudes following by around 2150.
