Saturday, October 29, 2016
The Great Barrier Reef
We may ‘muddle through’ and adapt to climate change, but the latest disturbing news from Australia shows that it may be too late to save some of its ancient wonders, like Tasmania’s prehistoric forest and Queensland’s Great Barrier Reef.
- Amy Spurling, Engineering & Technology (E&I), Oct 13, 2016
1. Scleractinian corals
2. 500-milligram calcium supplements made from calcium carbonate
4. More coral
6. Sea anemone
8. Fourth Grader
9. Massive coral
10. Branching coral
11. Great Barrier Reef (GBR)
13. GBR seen from space
14. Another view from space
15. Humpback whale
17. Red-throat emperor
18. Sea snake
19. Olive Ridley
20. Saltwater crocodiles
22. Giant clam
23. Cone snail
26. White-bellied sea eagle
27. Sea grass
31. More coral
33. Albino sperm whale
34. Tourists looking for whale
36. Destructive fishing
38. Coastal development
40. Thermal stress
41. Ocean acidification
42. Crown-of-thorns starfish
Scleractinia, which are also called stony or hard corals, are marine animals in the phylum (a principal taxonomic category that ranks above class and below kingdom) Cnidaria that usually live on the bottom of the sea in shallow water, and which build themselves hard skeletons out of calcium carbonate (CaCO3, strong evidence suggests the presence of calcium carbonate on Mars, although probably not coral based. It would be really cool if it was though). The individual animals inside that stony exoskeleton are known as polyps and have a cylindrical body crowned by an oral disc with a mouth surrounded by tentacles. Although some species are solitary, most live in colonies. The polyp that starts everything, or the founder, settles on the seabed and starts to secrete all of that calcium carbonate to protect its soft mushy body. Solitary corals can be as much as 10 inches across but in colonial species the polyps are usually only a few millimeters in diameter. Some polyps reproduce by budding but remain attached to each other, forming a multi-polyp colony with a common skeleton, which may be up to several feet in diameter or height according to species.
The shape, size, and appearance of each coral colony depends not only on the species, but also on its location, depth, the amount of water movement, and other factors. Many shallow-water corals contain symbiont (an organism living in symbiosis, or the relationship between two different kinds of living things that live together and depend on each other, like Donald Trump and Sean Hannity) unicellular organisms known as zooxanthellae (a yellowish-brown symbiotic dinoflagellate (a large group of flagellate (a cell or organism with one or more whip-like organelles called flagella) protists (the members of an informal grouping of diverse eukaryotic (any organism whose cells contain a nucleus and other organelles enclosed within membranes) organisms that are not animals, plants or fungi) that constitute the phylum Dinoflagellata) present in large numbers in the cytoplasm of many marine invertebrates) within their tissues.
These symbionts give their color to the coral which thus may vary in hue depending on what species of zooxanthellae it contains.
The coral provides the zooxanthellae algae with a protected environment and compounds they need for photosynthesis. In return, the algae produce oxygen and help the coral to remove wastes. Most importantly, zooxanthellae supply the coral with glucose, glycerol, and amino acids, which are the products of photosynthesis. The coral uses these products to make proteins, fats, and carbohydrates, and produce calcium carbonate.
The relationship between the algae and coral polyp allows a tight recycling of nutrients in nutrient-poor tropical waters. In fact, as much as 90 percent of the organic material photosynthetically produced by the zooxanthellae algae is transferred to the host coral. This is the driving force behind the growth and productivity of coral reefs.
Stony coral polyps are closely related to sea anemones and jellyfish (I had a bad experience with jellyfish when I was in the navy and hate them with a red hot passion... I suppose there are some good jellyfish, but I’ve never met one), and like them are armed with stinging cells known as cnidocytes.
Corals reproduce both sexually and asexually. Most species release gametes into the sea where fertilisation takes place, and the resulting larvae drift around until they settle down, or are eaten, but a few species brood their eggs. As we’ve discussed, asexual reproduction is mostly by fragmentation or budding, when part of a colony becomes detached and reattaches elsewhere.
Stony corals occur in all the world's oceans. Hard corals that are colonial can and do form part of reef structures; and which most utilize zooxanthellate and are found in the shallow waters into which sunlight penetrates. Other corals do not form reefs, some of which occur in deep water where no light reaches.
Hard corals first appeared in the Middle Triassic (a geologic period and system which spans 50.9 million years from the end of the Permian Period 252.17 million years ago (MYA), to the beginning of the Jurassic Period 201.3 MYA. The Triassic of course is the first period of the Mesozoic Era), but their relationship to the tabulate and rugose corals of the Paleozoic (the longest of the Phanerozoic eras, and is subdivided into six geologic periods (from oldest to youngest): the Cambrian, Ordovician, Silurian, Devonian, Carboniferous, and Permian. As every fourth grader knows the Paleozoic comes after the Neoproterozoic Era of the Proterozoic Eon, and is followed by the Mesozoic Era) is currently unresolved, a situation which quite frankly keeps me up at night.
Coral reefs begin to form along the edges of islands or continents. As the corals grow and expand, reefs take on one of three major characteristic structures —fringing, barrier or atoll.
Fringing reefs, which are the most common, project seaward directly from the shore, forming borders along the shoreline and surrounding islands. Barrier reefs border shorelines as well, but at a greater distance outward. They are separated from their adjacent land mass by a lagoon of open, often deep water. If a fringing reef forms around a volcanic island that sinks completely below sea level (the world’s volcanic ocean islands are sinking. As the young volcanic rock cools and is carried away from the volcanic “hot spot” by the movement of tectonic plates, the island sinks down as rapidly as a few millimeters per year) while the coral continues to grow upward, you’ve got yourself an atoll. Atolls are usually circular or elliptical, with a central lagoon. Parts of the reef platform may emerge as one or more islands, with gaps in the reef providing access to the central lagoon
In addition to being some of the most beautiful and biologically diverse habitats in the ocean, barrier reefs and atolls also are some of the oldest. With growth rates of 0.3 to 2 centimeters (2 centimeters equals 0.78742 inches) per year for massive corals (Massive corals are characteristically ball- or boulder-shaped and relatively slow-growing), and up to 10 centimeters (3.93701inches) per year for branching corals (branching corals are characterized by having numerous branches, usually with secondary branches).
It can take up to 10,000 years for a coral reef to form from a group of larvae. Depending on their size, barrier reefs and atolls can take from 100,000 to 30,000,000 years to fully form.
Off the coast of Queensland, Australia, lies the Great Barrier Reef (GBR), the world's largest coral reef system. It is composed of over 2,900 individual reefs and 900 islands stretching over 1,400 miles over an area of approximately 133,000 sq miles.
The GBR is the only living organism that can be seen from outer space. Take a look at the pictures above if you don’t believe me. I assure you, they weren’t photoshoped.
Thirty species of whales, dolphins, and porpoises have been recorded in the Great Barrier Reef, including the dwarf minke whale, Indo-Pacific humpback dolphin, and the humpback whale. Large populations of dugongs live there. More than 1,500 fish species live on the reef, including the clownfish, red bass, red-throat emperor, and several species of snapper and coral trout. Forty-nine species mass spawn, while eighty-four other species spawn elsewhere in their range. Seventeen species of sea snake live on the Great Barrier Reef.
Six species of sea turtles come to the reef to breed: the green sea turtle, leatherback sea turtle, hawksbill turtle, loggerhead sea turtle, flatback turtle, and the Olive Ridley. The green sea turtles on the Great Barrier Reef have two genetically distinct populations, one in the northern part of the reef and the other in the southern part. Fifteen species of seagrass in beds attract the dugongs and turtles, and provide fish habitat.
The largest predator in the world barring certain sharks and whales, the saltwater crocodile, live in mangrove and salt marshes on the coast near the reef. Around 125 species of shark, stingray, skates or chimaera live on the reef. Close to 5,000 species of mollusc have been recorded on the reef, including the giant clam and various nudibranchs and cone snails. Forty-nine species of pipefish and nine species of seahorse have been recorded. At least seven species of frog inhabit the reef islands.
215 species of birds come to the reef for vacations, or nest or roost on the islands, including the white-bellied sea eagle and roseate tern. Most nesting sites are on islands in the northern and southern regions of the Great Barrier Reef, with 1.4 to 1.7 million birds using the sites to breed (it’s not known who counted them).The islands of the Great Barrier Reef also support 2,195 known plant species; three of which are endemic.
There are 15 species of sea grasses on the Great Barrier Reef. See grasses grow in shallow water where sunlight reaches them as they require sunlight for photosynthesis. They are true plants (unlike seaweed and algae, which are fake plants) with roots, flowers and seeds.
There are at least 330 species of ascidians on the reef system with the diameter of 0.4–4 in. Not only that, there are between 300 and 500 species of bryozoans that live on the reef as well!
Four hundred coral species, both hard and soft inhabit the reef. Five hundred species of marine algae or seaweed live there, including thirteen species of genus Halimeda, which deposit calcareous mounds up to 110 yds wide, creating mini-ecosystems on their surface which have been compared to rainforest cover.
The GBR is the home of between17 and 23 species of merewif (Donec piscis dominae), or mermaids. Fishing for, or the removal of these creatures to be recruited as sex slaves in the Netherlands, is strictly prohibited.
A rare albino sperm whale visits the reef on a regular basis at least twice a year (April and October predominantly), and is a huge attraction for tourists, who have named him after an American DJ, singer, songwriter, musician, photographer and animal rights activist and the 37th President of the United States. No one knows why.
The reef was born during the Miocene epoch, 23.03 to 5.3 million years ago. As the sea level rose and fell throughout the passage of time the reef built itself into a vast system of shallow-water reefs and atolls extending 140 miles off the Australian coast and ending in an outer wall that plunged half a mile to the sea bed.
The first humans arrived in Australia from Asia about 60,000 years ago, when the sea level was low. Of course they didn’t call it Australia back then. They called it Macaroon for some reason. I don’t know why.
Aboriginal people hunted and fished the reef’s waters and cays for thousands of years, and continue to do so.
Captain James Cook became the first European to navigate the GBR in 1770.
“The sea in all parts conceals shoals that suddenly project from the shore, and rocks that rise abruptly like a pyramid from the bottom,” he wrote in his journal. Cook’s ship foundered on one of those shoals and was nearly sunk, but after several months Cook escaped the mighty grasp of the hungry reef.
Once the reef was discovered by Europeans and other non-indigenous people it became very popular. All kinds of people, explorers, scientists, artists... janitors, and tourists flocked to the reef to fondle it.
Yet, the evil government in Queensland attempted to lease nearly the whole thing to oil and mining companies in the 1960s.
Anything to make a buck, right?
That particular course of action was not popular, and spawned Australia’s first conservation movement and a decade-long “Save the Reef” campaign that culminated in the 1975 creation of Great Barrier Reef Marine Park (the Great Barrier Reef Marine Park protects a large part of the GBR from damaging activities. It is a great big, some might call vast, multiple-use Marine Park which supports a wide range of uses, which include commercial marine tourism, fishing, various ports and shipping, recreation (including synchronized swimming), scientific research and a means of support for the indigenous people of Australia.
Again, fishing and the removal of artefacts or wildlife (fish, coral, merewif, sea shells, etc.) is strictly regulated, and commercial shipping traffic must stick to certain specific defined shipping routes that avoid the most sensitive areas of the park.
Currently 75% of the world's corals are threatened due to:
1. Overfishing. Overfishing is a form of overexploitation wherein fish are fished until there are so few fish that the fish have a hard time finding other fish in order to mate and have little baby fish. This can happen anywhere! In ponds, rivers, lakes, home aquariums, oceans... anywhere! Overfishing can result in resource depletion (the consumption of a resource faster than it can be replenished), reduced biological growth rates (growth rates refer to the percentage change of a specific variable within a specific time period, given a certain context) and low biomass levels (the mass of living biological organisms in a given area or ecosystem at a given time).
2. Destructive fishing. As fish stocks decrease around the world, methods of harvesting them have become increasingly extreme. Destructive fishing techniques refers to any type of fishing system that destroys the fish habitat and devastates the marine environment, including bottom trawling (bottom trawling is trawling (towing a trawl, which is a fishing net) along the sea floor. Some people, certainly not me, refer to it as "dragging". Scientists divide bottom trawling into benthic trawling (the benthic zone is the ecological region at the lowest level of a body of water such as an ocean or a lake, including the sediment surface and some sub-surface layers) and demersal trawling (the demersal zone is the part of the sea or ocean (or other deep body of water) comprising the water that is near to (and is significantly affected by) the seabed and the benthos. The demersal zone is just above the benthic zone and forms a layer of the larger profundal zone (the area of water wherein sunlight does not penetrate)), bycatch (the unwanted fish and other marine plants and animals caught during commercial fishing for a different species, such as sharks, dolphins, and aquatic Blue Jays), the use of poison and explosives (using poison and explosives to catch fish, like Kangaroo Dundee and Uncle Joe), and ghost fishing (any discarded, lost, or abandoned, fishing gear such as nets or traps and pots, in the marine environment that continues to fish and trap animals, entangle and kill marine life, disseminate habitat, and act as a hazard to navigation. This gear is sometimes called “ghost gear,” in honor of the Swedish heavy metal band. I cannot overstate the amount of impact this gear has on today’s marine environment.
3. Coastal development. Coastlines around the world and other places are steadily turning into new housing, holiday homes, and tourist developments. This intense human presence does not bode well for marine ecosystems and species. 60% of the earth’s population (as of a couple of seconds ago the world’s population stood at 7, 460,497,384. There’s a lot more people on the planet now (even accounting for deaths). 60% of 7, 460,497,384 is 4,476,298,430.4) live within 37 miles of the coast. Unfortunately, rising sea levels (which are still illegal in North Carolina) directly related to global warming will have huge adverse effects on this large percentage of the nation’s, and the world’s population. Accordingly, thousands of local YMCA’s in these affected areas have begun free swimming seminars in the hopes of mitigating this pressing situation. 80% of all tourism takes place in coastal areas, with beaches and coral reefs among the most popular places for people to wander off to. Similar to habitat loss, which is more than likely the greatest threat to the variety of life on this planet today (and is why we are seeing so many bears and alligators on our city streets), and identified as a main threat to 85% of all species described in the International Union for Conservation of Nature’s list of species officially classified as "Threatened" and "Endangered,” coastal development and tourism are major irritants to the marine environment.
4. Pollution. Pollution (the introduction of contaminants into the natural environment that cause adverse change. Pollution can take the form of chemical substances or energy, such as noise, heat or light. Pollutants, the components of pollution, can be either foreign substances/energies or naturally occurring contaminants (such as microorganisms, radionuclides (radioactive elements that can be found in rock and ground water), radon, nitrates and nitrites, heavy metals (metals that weigh more than 20 pounds), and fluoride). Pollution, mostly of the man made variety has obvious disadvantageous effects on not only the animals comprising and inhabiting the world’s reefs, but the entire marine environment.
5. Thermal stress. F A = - E a d T. Having said that, corals thrive in locations that also happen to be near their physiological limits of endurance (just as most plants and animals live within a small window of environmental parameters that allow life to flourish... if the temperature is too extreme, hot or cold, life cannot exist. If there is not enough oxygen in the atmosphere most forms of life cannot exist. If the air pressure varies too much life cannot exist, etc.), making them sensitive to stresses caused by sea temperature anomalies (which are correlated to a warming overall planetary climate) resulting in the phenomenon known as coral bleaching.
6. Ocean acidification. A more acidic ocean interferes with the formation of calcium carbonate to form shells or calcified skeletons which may significantly change the physiology of calcifying marine organisms like coral. Calls to add massive amounts of sodium carbonate (soda ash) or sodium bicarbonate (baking soda) to the world’s oceans in an effort to lower ocean acidity have been largely panned as being highly impracticable.
7. Crown-of-thorns starfish. The crown-of-thorns starfish (Acanthaster planci) is native to coral reefs in the Indo-Pacific region. On healthy coral reefs, the coral-eating starfish plays an important role, as it tends to feed on the fastest growing corals such as staghorns and plate corals, allowing slower growing coral species to form colonies. These animals are particularly common on the GBR, but they tend not to be picky and will eat coral wherever they come across it. Contrary to popular belief coral eating starfish are not advantageous to the life and health of coral itself, and reefs in particular.
8. Introduced invasive species. Most introduced marine invasive species have been brought to Australian waters unintentionally through shipping activities and mariculture (a specialized branch of aquaculture involving the cultivation of marine organisms for food and other products in the open ocean, an enclosed section of the ocean, or in tanks, ponds or race ways (an artificial channel used in aquaculture to culture aquatic organisms) which are filled with seawater). Australia, for example, has a large volume of shipping trade with South-east Asia and the similarity of their marine environments increases the risk of introducing foreign marine species. Yachts and smaller vessels can also unintentionally provide a mechanism for transporting marine invaders either as fouling (refers to the undesirable growth of marine organisms on immersed artificial structures such as ship hulls, jetty pilings, navigational instruments, aquaculture net cages, marathon swimmers, and seawater intake pipes. If you’ve ever seen a pier piling covered with barnacles then you’ve seen marine fouling) or in ballast water. Heavily fouled vessels can carry up to 11pounds of gross, living, yucky stuff per square meter of exposed surface. Under the right circumstances, foreign species can hitch a ride and be released or spawn in Australia’s marine environment. It is estimated that about 7000 different marine species, including viruses, bacteria and small marine invertebrates are transported around the world in ballast water every day. More than 150 million tons of ballast water is discharged into Australia’s major ports each year. Toxic dinoflagellate algae for example can survive in ballast water for weeks. Dinoflagellates can accumulate in mussels, oysters and scallops and when eaten cause paralytic shellfish poisoning in people.
Larger organisms can be pesky as well. For instance the introduction of European rabbits (Oryctolagus hoppididness), that were first introduced to Australia by the First Fleet (The First Fleet is the name given to the 11 ships that left England on May 13th, 1787, to found the penal colony that became the first European settlement in Australia) in 1788 (and are suspected of being the most significant known factor in species loss in Australia), is analogous to the Indo-Pacific lionfish (Pterois volitans), which was introduced to Florida waters in the early 1990s (experts speculate that people have been dumping unwanted lionfish from their home aquariums into the Atlantic Ocean for up to 25 years), and is currently spreading rapidly throughout the west Atlantic, Caribbean and Mediterranean Seas. This carnivore may cause harmful changes in coral-reef ecosystems via predation on native fishes and invertebrates, as well as competing with native predators.
A mass bleaching event, fueled by warming water, has affected corals around the world, but has proved most visibly destructive on the GBR. Almost a quarter of the reef’s coral has died off, with the previously healthy areas of the ecosystem’s north, the worse off.
Coral bleaching occurs when prolonged high temperatures cause coral to expel their zooxanthellae, their symbiotic algae, turning the coral into snow-white skeletons.
Corals can recover from this but some just die. Divers on the GBR have spotted large areas of degraded coral, with some reporting the smell of rotting, decaying coral when they emerge from the ocean’s waters.
Almost all parts of the GBR have suffered bleaching, but not all of it has died. Scientists hope that large parts of the reef, and the animals that depend on the reef, will recover, although the long-term warming and acidifying of the oceans pose a grave threat to reefs around the entire world.
Some scientists have suggested the only way to repopulate the GBR and other reefs around the globe is the employment of genetic engineering.
I suggest that the sickness of the reefs are indicative of a much larger problem. We as a world populace have to face the difficult problems that dealing with global warming and climate change, over fishing, invasive species, and pollution present, not only to the reefs and the ecosystem that depend on them, but for our species, the human species, for if we hide our heads in the sand and continue to ignore these pervasive problems then the human community will be the ones who next will undoubtedly face a different world, a more difficult world (for our children and grandchildren), possibly a world in which men and women cannot exist.
The GBR is a harbinger of are own fate. Will we take these issues seriously?
I don’t believe there was one question regarding global warming, or environmental issues during the three presidential debates we’ve recently suffered through, and Hillary Clinton mentioned them only in passing.
Climate change is without a doubt the gravest problem, the greatest danger, that our species has ever faced. We need to treat this issue with the seriousness that it deserves.
Or is it already too late?
Some think so. This is an example of what some believe.
And this describes our possible future if we continue on our current path.
I don’t know if it is too late or not to avoid the catastrophic consequences of our inaction, and our devotion to corporate profit rather than species.
I do know that if we continue to do nothing then the future for our progeny will certainly be bleak.
Hopefully the is still time for hope. I certainly hope so.
As for the coral, it’s health is synonymous with ours, and they face the same threat that we do, and some feel there is hope for it still.
Kim Cobb, a coral reef expert at Georgia Tech states, “I have studied corals off Christmas Island in the Pacific where 85% of them have died, it was a graveyard. But even there, I was shocked to see remarkable resilience. Amid the graveyards of the reefs there were areas that looked like nothing had happened.
There is a lot we can do to minimize climate change and we need to get going on that. To say reefs are finished and we can’t do anything about it isn’t the message we need going forward.”