Anthropocene Sea

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The Anthropocene era can be defined as the current geological era, where the climate change plays a key role by increasing pressures to ecosystems. The main changing forces are phenomena like sea temperature rise and ocean acidification. or human activities like blast or cianide fishing.

Coral reefs

Bleached corals

Healthy corals

Coral reefs are among the biggest households for life in the sea, nursing close to a quarter of all known marine fish in 1995, providing invaluable services like food provisioning, turism and shoreline protection. Coral reefs are evaluated at nearly US$800 billion, with potential to stream around US$30 billion/year. similar to big companies such as Apple.

Even though global efforts are being made to maintain temperature below 2 °C above pre-industrial levels it may not be enough even with rapid transitions to zero carbon emissions. To protect at least half of the coral reefs, temperature should be kept below 1.2 °C above pre-industrial levels, particularly because there is no evidence that corals can evolve and adapt fast enough to overcome this increasing thermal stress.

Ocean acidification is another emerging problem that interferes with the calcification process on corals, reducing skeletal growth and possibly changing global coral distribution. Despite that, recent findings show that this problematic would be less aggravated throughout tropics and sub-tropics. Most experiments are exaggerated and do not represent CO₂ range that reefs are likely to experience for the next century. Even though ocean acidification is undoubtedly having an impact on reefs, it seems not to be the biggest challenge. Despite these uncertainties, the window of opportunity to save large fractions of coral reefs seems small and rapidly closing, and the majority of thermal studies is limited and do not represent an accurate scenario of global warming

Although the climate change impact on corals is problematic, there needs to be a recalibration on future experiments to understand how they cope in more realistic, but less extreme environments.

From 1997 to 2017 occurred three intense coral bleaching episodes, mainly caused by global warming.But some species of corals are already thriving in a changing climate, because they can respond to a broader temperature spectrum. Some can respond with more heat-tolerant symbionts after bleaching events, others can adapt DNA to better respond heat stress events. Habitats that come across periodic temperature extremes can promote heat-resistant corals that can be crucial for coral reef tenacity through Anthropocene.

As alarming as this may be, coral reefs are not expected to disappear, but instead to change to completely different configurations from what we know today. The focus should be to control coral reef adaptations throughout this warming period instead of maintaining the status quo.

Human-nature interactions

In this era, were humanity is more dependent on ecosystems, society is becoming aware of human dependence on nature, not only for food, water or other resources, but also every service ecosystems contribute to human wellbeing. Until recently, science has ignored distal drivers of change, like human behavior, sometimes oversimplifying a bigger problem. Addressing this problematic with a social-ecological approach is emerging. Models that derive from this approach can be much richer and help understand how ecosystems cope with human pressure. An analysis of multiple interaction needs to emerge in marine studies, as it as been central to sustainable management in terrestrial ecosystems. When several drivers are modeled simultaneously, their combined effects are evident, becoming easier to understand the "safe operating space".

Phase shifting

New assemblages of species are arising from human interactions. Coral reefs are not expected to disappear, but instead to change to completely different configurations from what we know today Management and governance should not focus on restoring or maintaining past configurations, but instead adapt to the continuous change for the upcoming times.

Relationship between biodiversity and ecosystem functions is not fully understood, particularly how ecosystem functions will respond to changes in species resulting from anthropogenic drivers. Although corals have high biodiversity, they are vulnerable because key ecological functions are commonly performed by as little as one species, suggesting that biodiversity may be not as important as functional composition.

Solutions

Reducing drivers of change – Marine reserves, limiting fishery or minimizing anthropogenic interaction need to address distal drivers, like poverty and market demand, even before the impacts are detected by ecological indicators. For example, by reducing poverty or encouraging shifts in fishery norms can impact positively coral reefs as well society that depends on that ecosystem.

Manipulate thresholds – This solution seeks ways to manipulate ecological thresholds so that drivers have less impact. For example, innovation in fishing gear or processes that help buffering the harmful effects of social drivers.

Feedback alteration – This approach involves weakening positive feedbacks that result from a degraded ecosystem. For example, incentives to fisheries to exit a declining stock.

References

This article "Anthropocene Sea" is from Wikipedia. The list of its authors can be seen in its historical and/or the page Edithistory:Anthropocene Sea. Articles copied from Draft Namespace on Wikipedia could be seen on the Draft Namespace of Wikipedia and not main one.

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