Are there any threats to the great barrier reef

It shows the total number of threats has increased from 41 in to 45 now. Of the 45 threats, 42 threaten its remarkable ecosystem. The new threats include the loss of cultural knowledge, especially by the Indigenous traditional owners, and the potential negative impacts of genetic modification which are not well understood but could occur when modified organisms are released into the wild. The table below shows the most alarming 21 risks to the Great Barrier Reef ecosystem.

It is becoming clear that many of the risks are serious, and the situation is getting worse. Click here for a version of the above table including additional data. They include:.

Vegetation clearing damages important ecosystem services for many marine species. This will increase the incentive for such activity on the Great Barrier Reef, with major consequences for some species and habitats. These weather events are natural processes in tropical regions, but when severe can prolong recovery times of coral ecosystems by up to 20 years. An increase in speed and the southern extent of the East Australian Current has already been observed.

Such changes could irreversibly affect how eggs, larvae and juvenile organisms are naturally distributed. Coral bleaching events are a reaction by coral to environmental stress.

A bleaching event is a visible SOS by coral, indicating that something is going very wrong. Bleaching doesn't directly kill coral, but it weakens them severely, often later leading to death as they become more vulnerable to disease. Coral, as you may remember from science class, are animals that live in a symbiotic relationship with certain photosynthetic algae, called zooxanthellae. The coral provide the algae with a safe environment and compounds needed for photosynthesis, while the algae reciprocate with food, oxygen and waste removal along with their vibrant colors.

This relationship can break down, however, due to environmental stress — namely high seawater temperatures, the risk of which are rising due to human-induced climate change. This thermal stress can force the coral to eject their zooxanthellae, which is initially helpful since heat can cause the algae to produce corrosive substances. If the water remains too hot for too long, however, corals can gradually starve as they turn white due to a lack of zooxanthellae hence the name "bleaching". On top of this danger to corals themselves, whose fates tend to foreshadow broader trends, here are some of the greatest threats to the reef ecosystem overall:.

Climate change is the largest threat to the reef, because it affects the following:. Ocean acidification: Since the s, about 30 percent of the extra carbon dioxide that humans have pumped into the atmosphere has been absorbed by the oceans. This has changed the oceans' chemistry, making them more acidic — a process known as ocean acidification — which makes it harder for corals and many other marine animals to build their calcium-based skeletal structures.

Cyclones: Climate change also favors the development of more powerful tropical cyclones, which can cause significant damage to shallow coral reefs. In addition, during cyclones or other strong storm events, more freshwater and sediments which essentially smother corals can make their way into the reef. Rising sea levels and sea temperatures: The fast-moving changes caused by climate change mean that shoreline plants and animals don't have time to adapt to changes in sea level or temperature.

While sea level has risen and fallen over thousands of years, climate change means it happens much faster, so life isn't able to adjust quickly enough. Migration: Warming ocean temperatures are causing the Great Barrier Reef to move south away from the equator, according to research. Climate change is not directly addressed in the Reef plan, which some experts on the Reef advisory committee have called out as a huge problem.

Considering the severity of the reef's health, some of those experts are calling for a plan to simply maintain the ecological function of the reef, saying it's already too late to restore its former glory. There are things affecting the reef health that are easier for the Australian and Queensland governments to do something about, since they are issues that can be addressed regionally. None of these is as impactful as climate change, but they can help corals on the margins stay alive versus dying out.

When more fish are caught than an ecosystem can sustain over time, that's overfishing. On the Great Barrier Reef, that happens due to sport and commercial fishing of certain kinds of large, predator fish like coral trout and snapper. When you overfish at the top of the food chain, it causes significant changes all the way down.

A less diverse reef is a less resilient reef, and that affects coral health. In her paper, Boaden looked at areas where fishing was allowed versus areas where fishing was banned green zones and found a significant difference.

In areas that allowed commercial and sport fishing, the number of predator fish was lower, as was diversity. Illegal fishing in those "no-fishing" zones is on the rise. There can be two or more times higher [fish numbers] as a minimum in protected, closed zones and therefore it becomes an attractive proposition. The good news is that managing fishing is one of the easier ways to protect the reef ecosystem, and patrols and fines for people fishing in green zones have been stepped up.

A new fisheries management plan is still being worked through, with many in the commercial fishing industry opposing it. Tons of plastic waste end up in our ocean every year; smothering coral and killing wildlife. But it's not the only form of waste devastating our reef. This makes our reef more vulnerable to local stresses, like the crown-of-thorns starfish.

While the dangers are real and immediate, there is hope. But it is critical that more of us start taking action now. Together, we can ease the pressures that the reef faces - but we need your support to do it.