flemingo
14.05.2021 22:37:14
Major threats to coral reefs and their habitats include: more
See full version: Coral Reef Threats and Salvation
Major threats to coral reefs and their habitats include: more
Roughly one-quarter of coral reefs worldwide are already considered damaged beyond repair, with another two-thirds under serious threat.
This image depicts all of the areas that the Millenium Coral Reef Landsat Archive covers. Red dots indicate coral reef data at the website: http://seawifs.gsfc.nasa.gov/cgi/landsat.pl (Photo credit: Wikipedia) more
10 Easy Steps to Help Protect Coral Reefs
The Crown of Thorns starfish is a coral reef predator that preys on coral polyps. Large outbreaks of these starfish can devastate reefs. They account for most damage to reefs. here
On top of that diseases in corals and pest outbreaks of crown-of-thorns starfish and cyanobacteria seem to be happening more often and with greater impact. more
Climate change won’t just affect the coral on our Reef – some fish’s preferred temperature range lead them to seek new areas to live, thus causing chick mortality in seabirds that prey on the fish. Climate change will also affect the population and available habitat of marine mammals including the sea turtles and dugong.
Scientists have discovered that outbreaks in Crown of Thorns Starfish numbers on the Great Barrier Reef are closely related to runoff from polluted rivers. This pollution comes from chemicals used to fertilise crops that is washed into rivers after big rains. The pollution helps plankton grow in large numbers and this plankton is the perfect food for young Crown of Thorns Starfish. here
The Great Barrier Reef Outlook Report for 2009 lists a range of actions that are of significant risk to the conservation Reef ecosystems: removing top predators by fishing (e.g. sharks), catch fish of conservation concern while fishing, illegal fishing or collecting, death of discarded species during fishing or collecting, fishing in unprotected fish spawning areas, and poaching (illegal hunting) of species of conservation concern.
Each year, the ocean absorbs about one-quarter of the carbon dioxide emitted from the burning of fossil fuels (oil, coal, and natural gas). Since the Industrial Revolution, ocean acidity has increased by about 30%, a rate that is more than 10 times what has previously occurred for millions of years. Further, ocean acidity levels are expected to increase by an additional 40% above present levels by the end of this century.
Coral reefs are in decline in the U.S. and around the world. Many scientists now believe the very existence of coral reefs may be in jeopardy unless we intensify our efforts to protect them (Frieler et al. 2013). Threats to coral reefs come from both local and global sources.
Coral reefs face many threats from local sources, including:
Ocean acidification refers to a change in ocean chemistry in response to the uptake of carbon dioxide from the atmosphere. The amount of carbon dioxide in the atmosphere is in equilibrium with that in seawater, so when atmospheric concentrations increase so do oceanic concentrations. Carbon dioxide entering seawater reacts to form carbonic acid, causing an increase in acidity.
Most coral reefs occur in shallow water near shore. As a result, they are particularly vulnerable to the effects of human activities, both through direct exploitation of reef resources, and through indirect impacts from adjacent human activities on land and in the coastal zone. Many of the human activities that degrade coral reefs are inextricably woven into the social, cultural, and economic fabric of regional coastal communities.
The aggregate effects of these stressors can decrease resilience of the reef overall and increase susceptibility to disease and invasive species. Invasive species can create an imbalance in the biological checks and balances of a reef ecosystem.
How to help coral reefs
Last week over spring break I had the amazing opportunity to go diving off the shores of Turks and Caicos and it was truly one of the most breathtaking sights I have ever experienced. I also have the pleasure of taking the SCUBA kinesiology class here at Penn State and have learned a little bit about the different environments divers encounter. Specifically, diving in the caribbean and warmer water is more popular, and these areas are homes to millions of species, including coral reefs. [links]
Why are coral reefs being threatened? more
How are coral reefs affected by climate change? more
The number of healthy coral reefs is diminishing at an alarming rate and it is something that could change the way thousands of underwater species live.
The majority of reef loss or damage is not deliberate. Coral reefs are being degraded by an accumulation of stresses arising from human activities. In simple terms, stresses can be grouped by the actions of people extracting material from, and placing materials upon, coral reefs. Overfishing, pollution and coastal development top the list of chronic stressors. In many situations chronic stresses are overwhelming the resilience, (or the capacity for self-repair), of reef communities. Some coral reefs are covered with sand, rock and concrete to make cheap land and stimulate economic development. Others are dredged or blasted for their limestone or to improve navigational access and safety. In addition to this, long-term changes in the oceans and atmosphere (rising sea temperatures and levels of CO2), and acute stresses from highly variable seasons, severe storms, earthquakes and volcanic eruptions also affect coral reefs.
Climate change is a direct cause of coral bleaching. Image credit: buttchi 3 Sha Life/Shutterstock
Coral reefs worldwide face the impacts of climate change since human-caused global warming has led to the heating of the earth’s atmosphere and the elevated surface temperature of ocean waters. The microscopic algae living in coral polyps and contributing to the health of coral, called zooxanthellae, are sensitive to higher temperatures. Therefore, a slight increase in the ocean temperature results in the expulsion of the zooxanthellae by the corals, exposing their limestone skeleton and leading to the whitening or bleaching of the coral tissues. When these bleached corals are exposed to warmer ocean waters for several days at a stretch, the corals will eventually die and the reef will turn into a barren habitat. It has been estimated that the optimal water temperature facilitating coral growth is around 20-28°C. However, if the water temperature becomes lower than 18°C or increases above 30°C, most of the corals will be bleached. With global warming continuing to heat the planet unabatedly, coral bleaching is expected to become more severe.
The brilliant and vibrant hues of coral reef ecosystems attract tourists in great numbers. Fishing, diving, snorkeling, and boating are some popular recreational activities that tourists enjoy near the coral reefs. Touching the reefs, stirring up the sand and sediments in the seabed, and collecting corals are some of the activities that damage the reefs and disturb the species that inhabit such reefs.