AP Biology class blog for discussing current research in Biology

Tag: Great Barrier Reef

Sea Cucumbers Soon to be Vegetables?

A recent article has established that our sea cucumber population is in great danger. The main cause of the newly endangered species is the high demand for sea cucumbers in East and Southeast Asia. The Great Barrier Reef is home to thousands of unique species, tropical sea cucumbers being one of the many. Sea cucumbers are often believed to just “exist” and not have any purpose, but they are in fact vital to the underwater ecosystem.

Coral Outcrop Flynn Reef

Well, what is their purpose? Sea cucumbers are classified as deposit feeders which means they play a vital role in nutrient cycling in the ocean. They enhance and benefit the habitat of many underwater animals that live near the ocean floor. They redistribute surface sediment and secrete inorganic nitrogen and phosphorus. These processes prevent the ocean from becoming overly acidic which keeps the coral reefs healthy. In recent years coral reefs have been rapidly dying, and without help from sea cucumbers, our earth’s coral reefs may be in even greater danger. For more information on the benefit of sea cucumbers, click here.

Dr. Kenny Wolfe from The University of Queensland led a research team to collect data from Australia’s primary sea cucumber fishing ground and they concluded that the area was in desperate need of change. Out of the 16 species of endangered species of sea cucumbers in the world, 10 of them live in Australia’s Great Barrier Reef. Since sea cucumbers are viewed as a delicacy, they are being overharvested, not allowing them to fulfill their duties of keeping the seafloor clean. Particularly, the white and black teatfish are in the most danger, due to their high market value and low reproduction rate. Though this has been established, they are still being harvested and exported. Luckily in December of 2021, it was ruled that the harvest of black teatfish would no longer be permitted. Though this is progress, what will happen to the other 9 endangered species of sea cucumbers in the Great Barrier Reef?


Since the Great Barrier Reef’s sea cucumber fishery has been running under a non-regulatory performance regulatory system, regular assessments of sea cucumber stock were supposed to take place, but they did not. This left the industry operating without any indicator of how their harvest is actually impacting stock sustainability.

In AP Biology this year, we learned about how living organisms create energy in the form of ATP through cellular respiration.  In underwater animals in general, it may be hard to imagine how they can obtain oxygen to begin this process. Sea animals get their oxygen from the water around them (H2O). Sea cucumbers are actually very unique in the way that they ingest oxygen. Most underwater animals take in oxygen through their gills, but sea cucumbers actually inhale oxygen through their anus!

Holothuria cf arguinensis

Sea cucumbers undergo cellular respiration by taking O2 from H2O and glucose and converting it to ATP energy with waste products of CO2 and H2O. They get glucose through the food they eat at the seafloor, such as algae and waste particles. The sea cucumber initially takes water in through the anus and cloaca, then the water is pushed to the respiratory trees where gas exchange is completed. This process repeats over and over to keep the sea cucumber alive.

This summer I went scuba diving in Hawaii and got to see and touch a living sea cucumber first hand.  I was amazed at the complexity of his animal that appeared to be so simple on the outside. Something that you would normally expect to act as a plain cucumber (the vegetable) on the seafloor, actually has a great impact on the environment surrounding it. We have to make sure that we do everything in our power to protect this beautiful and adorable species!

Are Politics Playing a Role in the Fate of the Great Barrier Reef?

The Great Barrier Reef is one of the Seven Wonders of the World, but that does not mean that it is invincible. In fact, it has been in grave danger for some time now. A new study, written about in ScienceMag, explains how the Australian government is stepping up to initiate protocols to protect the Great Barrier Reef. They focus a lot on short-term goals. This seems to be because, in the public’s eye, the Australian government is supposed to be doing something to fix this problem, so they are, but not enough to truly guarantee the safety of the reef. One main reason that the Australian government is getting involved at all is to insure that tourism doesn’t get negatively affected.


But would if really be a bad thing if tourism to the Great Barrier Reef were negatively affected?


The answer isn’t so clear-cut. It really depends on one’s perspective. From the point of view of someone truly interested in keeping the Great Barrier Reef alive, a decline in tourism at the reef would be much preferred. This is because the unprecedented number of people entering the reef disrupts the reef’s ecosystem. The foot traffic, fuel pollution, and anchor damage inflicted by tourism on the reef is a big reason for the steady decline in the reef’s life.


Tourism isn’t all to blame, though. A huge factor in the death of the Great Barrier Reef is global warming. Now this is where the Australian government stays silent in regards to the reef. Global Warming is responsible for the long-term death of the Great Barrier Reef. The increase in water temperature, even if it is just by a degree or two, is not good for the survival of the coral. If water temperatures don’t return to their lower temperature, there may be nothing that can be done to save the Great Barrier Reef.


But for now, people are just happy that something is being done to save the reef, even if it is counterproductive in the long run.

The Great Barrier Reef Not So Great?


Image By Paul Holloway, Flickr

The first adjective I use when thinking about the Great Barrier Reef is great. But, according to a new study published by the Australian Institute of Marine Science (AIMS) in Townsville, Australia, it is rapidly shrinking. The shrinking is due in part to the recent storms, an increase in the number of crown of thorns starfish in the reef and coral bleaching.

The Great Barrier Reef has lost half its coral in just over 27 years. John Gunn, the CEO of AIMS, said that we must “… adapt to the challenges of rising sea temperatures and ocean acidification.” He goes on to say, “We can’t stop the storms but, perhaps we can stop the starfish.”

Another concern for the Great Barrier Reef is that if this trend of shrinking continues at the rate it is going, then by 2022 the coral could shrink in half again.

But, there is some good news for the reef. It is able to regenerate itself. It will take about 10-20 years for the reef to fully recover, that is if it does not shrink in size anymore than it has already. This is quite near impossible though because there is no way to stop storms or ocean warming, which causes coral bleaching. The ocean warming stems from Global Warming, which is an epidemic in itself. The only thing that we can help to prevent is the crown of thorns starfish from destroying the reef. Scientists can continue to study them to find out how to reduce their numbers in the reef. Without the crown of thorns the reef with increase by 0.89% per year, a small recovery for the Great Barrier Reef. The whole process will take time, but if successful we can save the Great Barrier Reef from becoming a thing of the past.


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