Category: Great Barrier Reef

Reef HQ and GBRMPA: Managing for the Future

By:  Lin Cao, Ben Lasley and Peggy Mullin

Budgeting for Sustainability by Lin Cao

Reef HQ Aquarium has long been dedicated to sustainability, and “Earth” is included as part of their triple bottom line. It is one of only 15 organizations in Australia to have achieved triple tier ecotourism certification, and over the years it has made large strides towards environmentally friendly practices. In 2006 and 2007, Reef HQ used nearly 2,438 megawatt hours of coal-fired power, enough to power 305 homes for a year. This cost the aquarium about $550,000 a year. At this time, the aquarium had no formal strategies for sustainable use of business resources. However, in 2006 they set a goal of 50% reduction in energy expenditure costs (from 2,438 megawatt hours to 1,200 megawatt hours).

They began by first assessing their current energy expenditure costs, and it was found that the vast majority of their costs came from chilling and pumps. They decided to first tackle issues that could be quickly fixed, and in their first year they performed air-conditioning system maintenance, raised the temperature set point from 23℃ to 24.5℃, tinted windows, removed hot skylights, and installed air curtains. Finally, they tried to improve staff behavior, emphasizing turning off lights whenever possible and closing doors to prevent loss of cooler air. These steps reduced their carbon footprint and brought their power use down by 13%.

At this point a 5-year strategic plan was developed and was the product of energy audits, technical audits, feasibility assessments, and strategic infrastructure planning. After the development of the plan, the Reef HQ team started by focusing on lighting. Though lighting represented only 6% ($18,000) of their total energy expenditure, lighting is easily fixed and has quick payback time, making it a valuable investment. Energy efficient lighting such as dichroic lighting, compact fluorescent lights, and LED lights were used to replace older lights. Reef HQ also imported the first plasma light into Australia. These lights have very low heat output, contain no mercury, produce better quality light, and require significantly lower maintenance. Overall the plasma light produced 50% more light for less than half the power, and while the light was initially expensive, the payback time was only about 2.5 years.

Next, Reef HQ addressed their pump problems. Cheap pumps were costing around $21,300 more per year than the highest quality pumps, so improved pumping systems were installed. Motors were also replaced to increase operating efficiency. In their most extreme example, it cost Reef HQ $1500 to change a pump motor that eventually saved them over $10,000 a year in energy. With one of their major energy drains addressed, Reef HQ then began to examine ways to improve their heating and chilling needs. They put in glass solar tinting and also used reflective roof paint to prevent heat from entering. They also did a comprehensive assessment of heat inefficiency sites. It was found that doors were regularly left open, causing hot spots, and the heat exchangers on aquarium tanks were inefficient. Pipe design also allowed a lot of heat to leak, and an inefficient chiller system stopped and started nearly 20 times a day. To deal with this, a new chilling system was installed with multiple pumps for low load periods. The chiller also had thermal storage to minimize starts and stops in low load periods. Heat exchangers in the aquariums were also replaced with more efficient ones, and a smart building management system was put in place to manage the entire system. This allowed the building to regulate heat use based on activity and time of day, shutting off any systems that were not needed. Though many of these replacements were expensive, the upgrades are expected to save Reef HQ up to $4.8 million in the next 25 years. The final initiative taken by the Reef HQ group was the installation of solar panels. Reef HQ is the only aquarium in the world registered as a power station, and in 2015 the solar power station offset energy consumption by 20 to 30%.

What Reef HQ has accomplished with their energy minimization plan is truly amazing. They met their reduction goals and expanded their business at the same time. As of 2017, the payback for the total of $1.7 million on all of Reef HQ’s sustainability measures from 2007 to 2014 will have been reached.

 

A Multifaceted Approach to Management of the Great Barrier Reef by Ben Lasley

Reef HQ has indeed accomplished much in the management of their inner mechanisms. However, their outward goal is just as important: the whole and effective management of the Great Barrier Reef. The Great Barrier Reef is one of the most biologically diverse areas on the planet, comprising 344,400 square kilometers, stretching 1400 miles from north of Cape York to Bundaberg in the south. As a reaction to to potential oil drilling in the reef, it was declared a marine park in 1975 and a world heritage site in 1981. In addition to establishing the Marine Park, a federal agency was created in order to oversee and manage the reef. The Great Barrier Reef Marine Park Authority, with offices in Canberra and Townsville, helps manage commercial fishing, tourism, shipping, traditional activities, and recreation.

The logo of the GBRMPA (Picture courtesy: GBRMPA)

In 2003, a decade long study was completed that analyzed the GBR, finding seventy-six bioregions, and new zoning procedures were established as an insurance policy to protect at least twenty percent of each bioregion. There are seven levels of zoning, from the most lax to extremely stringent. They are general use zones, habitat protection zones, conservation park zones, buffer zones, scientific research zones, marine national park zones, and preservation zones. As the zones increase in significance the limitations on fishing, trawling, trolling, research, boating, tourism increase to the final level of no disturbance other than research. In the roughly fifteen years since the introduction of the zoning laws, there has been an increase in previously reduced species, aided by the protection zones. The no-take and no-entry zones are centers of growth and competition that force the growing populations to spread further out, eventually migrating out of the protected area and in to new areas, increasing the marine park’s distribution of the species. As well, the Great Barrier Reef Marine Park Authority has released their long term management plans until 2050, targeting the main pollution offenders and their plan of action.

However, there continues to be threats to the Great Barrier Reef. Commercial shipping has increased since 2003, and there are calls for increasing shipping channels to the major ports. The expansion not only impacts the immediate health of the reef through expansion efforts, but also long term. The increase in shipping and shipping channels increases the risks for groundings that could spill coal and oil into the ecosystem. Australia is one of the larger exporters of coal in the world, and the proposed Adani Mine in Western Queensland would increase the exportation of coal to different countries, such as India. Both major political parties have pledged their support, because of the increase in supposed jobs and current political climate, but they have forgotten the economic importance of the Great Barrier Reef for ecotourism and fishing. The support for the Adani coal mine comes at the expense of the Great Barrier Reef, and while one flourishes the other will suffer. As well, climate change will continue to negatively impact the Great Barrier Reef for an extended amount of time. While some may want to curl up and call it quits, this is yet another reason why we should fight for the Great Barrier Reef. Yes, this is an uphill climb, but we cannot give up. We must not give up; we must fight the good fight.

 

Under Pressure: The Threat of Crown-of-Thorns Sea Stars by Peggy Mullin

The Great Barrier Reef is not dead, but it is stressed. The reasons for large-scale coral bleaching and mortality are vastly varied and complex, surrounding mounting anthropogenic pressures in the area including fishing and shipping ports, as well as large-scale ecological pressures including temperature rise, climate change and global ‘weirding’ of weather. At a more local level, however, one of the most devastating threats to coral reef health are outbreaks of Crown-of-Thorns sea stars.

Crown-of-Thorns sea stars (Acanthaster planci) are large, multi-armed organisms that are native to the Indo-Pacific region. These sea stars feed on a diet of coral polyps from rocky or hard corals, an appetite which is directly incongruous with the simple narrative of coral restoration. Crown-of-Thorns sea stars, or COTS, actually hold a key ecological role in that when they inhabit an area in the right proportions, they prevent overgrowth of rocky or hard corals. However, when they explode in large numbers, known as COTS outbreaks, they can sweep an area and completely devastate a reef’s population of live coral.

This image shows a Crown-of-Thorns sea star engulfing a coral boulder (Picture courtesy: NOAA)

COTS are extremely efficient and have been recorded to move across a reef at speeds of up to 10 kmh according to a display at Reef HQ. The organism accomplishes this using its many arms and tube feet. Like other sea stars, they digest their prey by pushing their stomach outside of their body, engulfing a population of corals and processing them with enzymes from the lining of the stomach. COTS, in particular, possesses venomous spines all along their body, which can cause intense burning and swelling in humans, as well as a lasting effect of nausea.

There is not yet a definitive cause for COTS outbreaks on the Great Barrier Reef. Some theorize that it could be linked to a decline in water quality, while others seem to think it may be linked to predator removal. Whatever the cause, outbreaks tend to be cyclical and have increased to unprecedented levels of frequency in the past 10 years, according to data from the Australian Institute of Marine Science.

This graph exhibits the trend of COTS outbreaks in the past 20 years. (Picture courtesy: GBRMPA)

Managing COTS on the Great Barrier Reef is one of the most pressing issues facing Great Barrier Reef ecologists to date. One of the most effective methods of control is the manual injection of bile salts (from the stomachs of oxen) or sodium bisulfate into the body of the sea star. This results in COTS mortality within a week of injection, yet causes no toxicity to the surrounding marine environment.

Injection has proven to be an effective short-term solution, but the greater focus is on long-term goals for the reef ecosystem. According to Reef HQ, these reef-oriented goals include improving water quality, increasing knowledge about reef structure and function, and improving ecosystem resilience in anticipation of future changes to the reef environment. Along with their financial and energy-related goals, Reef HQ is actively working to make steady progress towards education of the en

Along with their financial and energy-related goals, Reef HQ is actively working to make steady progress towards the education of both tourists and locals. The hope is that Reef HQ will act as a key intermediary between scientists and the public to work towards a more clear understanding of the active pressures affecting the Great Barrier Reef area.

Our Eye on the Reef!

  by CJ Miles and Sophia Wilhelm-Demekas

  At Reef HQ, the education center for the Great Barrier Reef Marine Park Authority (GBRMPA), we learned about the Eye on the Reef Program. This program encourages monitoring of the Great Barrier Reef and allows anyone who visits the reef to have the opportunity to participate in the assessment of the reefs health as well as its protection. This program includes an Eye on the Reef App that allows you to report observations, upload photos and videos, and provide up-to-date information about the reef’s condition, and it’s easy to use regardless of your experience level. The app is completely free and also includes an educational aspect that allows you to learn more about the Great Barrier Reef and the species that inhabit it. Another component of the program is the Rapid Monitoring Survey. This survey allows people with a little more time and experience (who can snorkel or dive) to record certain things that they see on the reef using an underwater monitoring slate and relay this information to the GBRMPA. This data includes the presence of protected or iconic species, benthos cover, coral impacts, and the presence of rubbish and pollution. Once participants complete a survey, they can upload it through an online webpage for submission to GBRMPA. Further, an online multimedia training program is also available to help people learn more about how to complete these surveys correctly and upload the information to the webpage. For professionals such as marine scientists, marine tourism operators, and marine rangers, there are even more reef health and impact surveys as well as tourism monitoring surveys that require a little more dedication and time.

     All of the information collected through the Eye on the Reef Program is compiled into a single reporting system that includes an interactive activity map that allows you to see how many surveys of reef health, tourism activity, and rapid monitoring have been taken for each site along the entire GBR in the past two years. This data is available to all registered users and ultimately helps provide . One of the greatest aspects of this program is that it really encourages all kinds of people – professional or tourist, local or international – to get personally involved with the protection of the Great Barrier Reef, creating vested interest in its health and increasing community action and awareness.

 

This short video provides more information about The Eye on the Reef Program, it’s creation and purpose, and how people can get involved, as well as actual footage of the surveying process.

“Eye on the Reef is a large-scale monitoring program that enables anyone who cares about the Great Barrier Reef to help keep an eye on its health. The program has two community-based tools and two professional tools so, no matter who you are, there’s somewhere you can plug in and give something back to the Great Barrier Reef Marine Park.”

As study abroad students studying the Great Barrier Reef, we were given the opportunityto participate in the Eye of the Reef program. As a group, we spent 3 full days on a live-aboard boat doing between two and three scuba dives and/or up to five snorkels per day. We stayed in the middle section of the Great Barrier Reef, near Townsville in Northern Queensland. In our time there, we were able to visit three specific sites: Lodestone Reef, Keeper Reef, and Wheeler Reef. On the boat with us was a group of graduate students studying marine biology at James Cooke University who were collecting data and conducting surveys to monitor the health of the Reef. Before each dive or snorkel, we were given a briefing about the specific reef and what species we should expect to see in that area. Then, we were each handed one of three surveys and tasked with completing them during our 40-60-minute swim. The three surveys were called: Reef Search, Coral Watch, and Rapid Monitoring.

 

Coral Watch was a survey focused solely on monitoring the type and color of the coral colonies on site. As we swam, we were supposed to choose 20 of the coral colonies we passed and note the type of coral (table, branched, boulder, or soft) and its coloring. Because many coral colonies were multi-colored, we were meant to record both the lightest and darkest shade present. This was significant because many of the corals had undergone bleaching (loss of color due to release of zooxanthellae) in only some polyps and not the entire colony.

 

The Rapid Monitoring survey was slightly different because, rather than focusing solely on the coloring of coral colonies, it concentrated on the overall benthic cover by comparing percentages of live and dead coral. The method of surveying was also more complex and thought-out than the other two surveys. The survey process was as follows:

First, the surveyor (scuba diving or snorkeling) had to designate a survey area by selecting a central point and extending the area five meters around this central point in all directions, creating a circle of ten diameters as their area to monitor.

Then, as visible in the picture to the right, the percentage of differing benthos covering had to be estimated and recorded. Several images were provided in order to visually aid participants in making estimations on such a large scale. The different benthos covers to be recorded were: macroalgae, live coral, recently dead coral (white), live coral rock, coral rubble, and sand. Additionally, specific questions were asked about whether obvious bleaching was present and whether coral predators were seen in the survey site (Crown-of-thorns starfish and Drupella snails). Finally, more specific questions were asked regarding the presence and type of rubbish within the site.

While the Coral Watch survey provided information about the health of 20 randomly selected coral colonies purely based on their coloring, this Rapid Monitoring survey provided data about how much damaged coral there was compared to live coral as well as about the presence of potential threats to the coral colonies within the area.

However, as it was only focused on a circular area of ten-meter diameter, many of these surveys would need to be completed at once in order to provide any reliable, significant data.

Taking part in surveys like these made us focus much more as students on what it was we were seeing and what the consequences of coral bleaching actually looked like. After each survey session, we would all come back onto the boat, compile our data, and evaluate whether any meaningful conclusions could be made from our analysis. Although the surveys aren’t perfect and can only provide limited information about the state of the Great Barrier Reef, the fact that Eye on the Reef provides them to the larger public and encourages individuals to take action is important for spreading awareness and inspiring action to protect it.

 

 

 

Climate Change and Resilience Management on the Great Barrier Reef

by Danny Oh and Sophia Wilhelm-Demekas

Although 97% of climate change scientists agree on climate change, there still seems to be some debate in the general public. According to ABC News, a survey of over 2,000 Australians shows that 77% believe climate change is occurring. The United States is still behind on this matter with the general public agreeing at 70%, according to Yale Program. Even though there is skepticism, climate change is evident: global temperatures have risen by 0.85°C since 1880, the strongest El Niño on record occurred in 2015, and the hottest recorded temperatures occurred in the last three years. In addition to rising ocean temperatures and increased deglaciations, atmospheric CO2 has been on a constant rise since the beginning of the Industrial Era. For 650,000 years, CO2 has never been above 300 ppm, but it is currently around 400 ppm. But what does this all mean in the context of Australia and the Great Barrier Reef?

In October 2007, 86 experts released Climate Change and the Great Barrier Reef: A Vulnerability Assessment, which assessed the potential impacts of global warming on the Great Barrier Reef. It listed the following effects that would have the greatest impact on islands, coral and wildlife: higher air temperature, sea level rise, higher ocean temperatures, changes to rainfall and clouds, increased storm severity, increased atmospheric CO2 concentration, and increasing acidity of the ocean. Some of these impacts are more of a long-term concern, but some of them have already led to extinction of unique species found in Australia.

Rising global temperature leads to increased disease threat: immune systems of plants and animals are weakened, and the environmental conditions become more favorable for tropical diseases and pathogenic vectors. The hotter and dryer conditions lead to increased severity of forest fires as well. The frequency of extreme heat days have already led the White Lemuroid Ringtail possum (Hemibelideus lemuroides) to ecological extinction. Sea turtles have also been taking a toll due to rising temperatures. During incubation of the eggs, the sand temperature determines the gender of the turtle. Initially, the gender ratio was being skewed toward the females, but the sand temperatures have increased to the point where the eggs cook and fail to hatch. Deglaciation of polar ice caps has led to rising sea levels, estimated at 3.2 mm/year. The increased sea levels flood urban areas, particularly on the coast. This also affects erosion of cays found in the ocean, and has actually led to the extinction of the Bramble Cay melomys (Melomys rubicola) in 2016.

Increased ocean temperatures leads to higher frequency of ENSO events, where upwelling is reduced in the Eastern Pacific Ocean and decreases productivity and plankton biomass. This then impacts species higher in the food chain. Coral bleaching events have directly impacted the Great Barrier Reef. Corals have a unique symbiotic relationship with zooxanthellae, but the increased heat response causes the corals to expel them, leaving the coral bleach-white, and this can lead to coral death. The Great Barrier Reef is composed of vast coral reef systems, and coral bleaching directly impacts the structure of the ecosystem. Some reefs impacted are Orpheus Island and Mission Beach. The increased global bleaching events put these unique ecosystems at risk, sometimes to the point where they are unrecoverable.

Changes to weather patterns have also impacted the coasts of northern Australia. There has been frequent releases of sand plumes near the mouth of rivers. This release of sand and mud settles on the coast and smothers sea grass, an essential food source for dugongs and sea turtles. This has also led to the death of mangroves on the Gulf of Carpentaria. In the recent decade, there has been an increased frequency and intensity of cyclones. The rising sea temperature has contributed to the intensity of cyclones, as storm cells gain their energy from warm coastal waters. There has been 10 cyclones since 2005 that have hit the Great Barrier Reef. Daydream Island, a resort off the coast of Queensland, was destroyed by Cyclone Debbie several months ago. In 2009, Cyclone Hamish, a category 5 cyclone, ran parallel across the Great Barrier Reef and caused substantial damage to the reefs and even caused an oil spill off the Sunshine Coast. Storms also destroy cays, which are prime nesting habitats for seabirds.

Rising atmospheric CO2 concentration leads to a lower nitrogen to carbon ratio, and this causes koalas to intake more eucalyptus leaves to get adequate nitrogen for metabolic processes. The ocean is also a major carbon sink, and dissolution of carbon dioxide has led to ocean acidification. The decreasing pH may cause long-term potential damage to coral reefs and their development because of decreased rate of precipitation of bicarbonates in ocean water.

The Great Barrier Reef has lost 50% of coral in the last 30 years: 50% of this is from increased cyclone intensity, 40% is due to Crown-of-Thorns Starfish outbreaks, and 10% is from the rising ocean temperatures. It is apparent that climate change is impacting the Great Barrier Reef on all fronts, but the question is: can we do something about this?

Ecologists across the globe often have differing views about the most effective way to intervene. In recent years, there has been a dramatic shift in perspective among scientists regarding what the most effective and, more importantly, most realistic approach to preservation is. Malcom Turner, a biologist and manager of field operations for the Great Barrier Reef Heritage Area, explained this shift in perspective as the adoption of a single, key concept: resilience.

According to Turner and many others in his field, the aim of conservation should be to focus on protecting the most resilient areas rather than the most vulnerable areas. This goes against a widely accepted belief that for conservation to be effective, ecosystems must be repaired and returned to their previous state prior to any human impacts. Turner claims that, “in reality, nothing is pristine or untouchable anymore. If you really want to protect something, you must be hands-on”. (Malcolm Turner. Interview.) Turner’s most significant project involving the adoption of this approach has been working to increase the resilience of coral reefs.

As ocean temperatures rise, coral reefs are put under greater stress and are, thus, at a higher risk of bleaching. Even a temperature change of 2 degrees Celsius can cause massive damage to a healthy reef. Unlike other marine animals, corals are unable to relocate and simply migrate to a cooler area when their surrounding temperatures rise. In addition, corals are limited in the areas they can colonize because they require very specific living conditions in order to thrive, which include a shallow substrate to build on and adequate sunlight exposure. As a result, Turner’s project involved accepting that the water temperatures will rise and, thus, working to increase the resilience of the corals this will impact.

The figure to the right illustrates the mechanism of increasing resilience of reef systems. If the condition of the reef (shown by the green line) deteriorates to the point where it crosses the resilience threshold (represented by the white dotted line), it will no longer be able to bounce back and recover. This means that either a single bleaching event will go on for long enough or bleaching events will be so frequent that the corals will not be able to recover and the reef as a system will die. Rather than attempting to reduce coral bleaching events that are caused by a variety of complex reasons, reducing the resilience threshold of the reef instead can allow the opportunity for it to rebound naturally. Reef systems experience a loss of resilience when external factors lead to shifts in ecosystem functions, a reduction in species diversity, and a loss or reduction of productivity in the system. Examples of key external factors are water pollution, global climate change, and commercial or recreational fishing. (Turner. Interview.) While focusing on reducing these external factors could improve resilience, another method could be to identify and research hotspots for resilience: areas where corals are naturally more resilient and bounce back from bleaching events more quickly and effectively. Examples of corals found to be naturally more resilient are those located in cooler currents, areas of upwelling, and areas in deeper water. (Turner. Interview.) By choosing to concentrate on understanding and preserving these more resilient areas, scientists like Turner believe they can make the most meaningful impacts on coral reefs as well as other habitats under stress to protect them from the threats of climate change.

Image 1: Example of coral bleaching.

Image 2: Cyclone records along Great Barrier Reef.

Reef Ecologic and the Reef Rescue Project

By: Peggy Mullin and Caleigh Sewell

We sat down, ready for our first day of active learning on Magnetic Island. We had been promised a lecture on algal-dominated coral reefs, and Dr. Andrew Skeat arrived to Bungalow Bay right on time to share his information. He began with a simple question: “Do you think you can make a difference on the reef?” The gathered students had mixed responses about the effectiveness of their efforts, from both direct and indirect perspectives.

Next up was a video; a production put together by a group of students from our USA neighbors, Virginia Tech, last summer. The video was an impressive compilation and described in simple terms how algae comes to dominate a reef. When a colony of coral becomes stressed, it ejects its symbiotic microalgae into the water column, resulting in a loss of color or “bleaching.” This “bleaching” is not immediately indicative of coral death, but rather a sign of significant stress. After these symbiotes are ejected, the coral colony has a short period of time (which varies from species to species) during which it can resume a healthy state and re-accept its symbiotic algae.

(Watch the video below!)

http://http://blogs.lt.vt.edu/ResearchBlog/2017/06/21/today-we-helped-resort-the-great-barrier-reef-tomorrow-you-can-too/

However, if the coral’s environmental conditions do not become restored within the range of health for that species, the individual coral polyps will die and the organism will be unable to live on. At this point, the reef ecosystem crosses the threshold to an alternative stable state; algae becomes dominant on the skeletal reef structure and is allowed to overgrow, outcompeting other colonizers for space and overtaking the once-vibrant reef.

Andrew explained that coral bleaching is a natural and regular process in the marine environment; what is different now, however, is that the intensity and frequency of coral bleaching events has increased to unprecedented levels in recent years. Some of the most notable examples are the mass bleaching events which struck the northern end of the Great Barrier Reef in 2015 and 2016. There are many possible reasons for this increase, but the most universally accepted reason is a combination of several environmental pressures, including: poor water quality, climate change, increased frequency and intensity of extreme weather events, and Crown-of-Thorns sea star outbreaks.

On the left, a ‘healthy’ reef ecosystem. On the right, an algal-dominated ecosystem.

So what to do about this algal-dominated alternative stable state? Many examples of this state can be seen just off the coast of Magnetic Island, especially in Geoffrey Bay. The organization Andrew represents, Reef Ecologic, aims to both inform the public about this problem and to involve citizens and tourists in management efforts for reef health. For our purposes, this meant that we would be spending the day surveying the algal-dominated reef, defining a transect area, and physically removing macroalgae in the hopes of freeing up complex substrate for possible settlement by new live coral polyps.

Around 10:00 am, we headed over to the southern part of the island to grab wetsuits and then made our way to Geoffrey Bay where we would be snorkeling for the day. From there we divided into two groups, one lead by Brett Flemming and the other lead by Andrew. Brett’s group went on a snorkel trail to explore the reef a bit while Andrew’s group removed seaweed from the nearshore corals. This task required several materials and prior knowledge to begin: a 4 x 4 meter quadrat to mark the area where we would be removing seaweed, two seaweed collection bags, gloves, and scrapers. Andrew explained that we would set up the quadrat in an area with a lot of seaweed growth.

Then two people would hold the seaweed bags while their partners would dive down and remove seaweed. In order to remove the seaweed from the coral, you could either grab the seaweed and twist/yank it off or you could use the scraper to get a cleaner removal. After Andrew explained the process, we divided the tasks and headed out into the water. Part of the experiment was to see how much seaweed we could collect in a given amount of time, to determine the productivity of the process. The first group was given 15 minutes to remove seaweed and the second group was given 10 minutes (we were running low on time). After our time was up, we returned to shore and weighed both bags, removed the seaweed, weighed the empty bags, and subtracted that weight from the total weight. The first group collected approximately 8 kilos and the second group collected approximately 14 kilos. Some factors that explain why our group (the second group) collected so much more seaweed (in less time) was because we went second so we had some time to practice snorkeling and duck diving before the seaweed removal. Also, we initially divided into groups based on experience and ability and our group was the group with more experienced snorkelers.

One student poses with her ‘catch’!

Bags of collected macroalgae

The next task was to separate the seaweed into two piles: seaweed with the holdfast and seaweed without the holdfast. The holdfast is the hard, rock-like area on the bottom of the seaweed that attached the seaweed to the coral. The reason we sorted them was because if the holdfast was still connected to the seaweed then we know the seaweed was completely removed and will no longer grow in that area. If the holdfast wasn’t connected to the seaweed, then its base is still attached to the coral somewhere and will continue to grow. The results from separating the seaweed and weighing the pile with the holdfast were a little inconclusive because they weighed about the same as when we weighed all the seaweed together. This is most likely because the seaweed gathered a lot of sand in the sorting process, which added a fair amount of weight to the seaweed. After taking all of our measurements, all of the seaweed was gathered and taken to a local compost area.

One team of collectors poses with their bags!

Since we were such a small group and didn’t spend much time removing seaweed, the actual impact of our efforts on the coral reef were minute. But the point of the activity was not to save the reef in one day, it was to bring awareness to the issue and show how easy it is to do small, beneficial tasks. This activity was also beneficial to Andrew because now he knows that he could easily take volunteer groups out on the reef and do the same thing we did for longer amounts of time. Through collective effort and awareness, more people will be inclined to do their part to save the reef, whether it’s directly removing seaweed so the coral can grow, or using less energy and fuel to slow the effects of climate change.

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