This is a Tambja verconis sea slug. Many species of colorful sea slug are native to the cold New Zealand waters. This photo was taken at the Poor Knights Islands on a scuba trip with Dive! Tutukaka. 

Scuba Diving in AU and NZ: Experiencing Vulnerability

The considerable limit of global warming on conservation

In February 2017, the majority of the Great Barrier Reef was placed on red alert for coral bleaching as temperatures in Australia reached a scorching 47°C (116°F).

According to the Intergovernmental Panel on Climate Change (IPCC), Earth’s atmosphere is currently over 400 parts per million carbon dioxide and rising. Land temperature, ocean temperature, sea level, atmospheric methane and nitrous oxide are all at their highest points in recorded history and rising (IPCC AR5). Following the 2016 Framework Convention on Climate Change, 197 parties signed the Paris Agreement stating that global climate change would be kept below 2°C in the next century. So far, little international effort has been taken to achieve this mission and many of the signing parties have not ratified the document.

Global climate change is objectively occurring and is severely negatively impacting our oceans primarily by increasing temperature and through a process known as ocean acidification. 

In an effort to see the underwater wonders of the world before they disappear, I was fortunate to participate in two ecotourism scuba diving trips along the East Australian Current (EAC). Relative to other forms of ecotourism. there is something truly overwhelming about scuba diving. For a brief moment, woman becomes fish. The slow descent into the deep is exhilarating; your heart races and breath quickens as you realize the world above is fading from view. Then, all at once the fear recedes and there is an overwhelming sense of oneness with the tactile world around you and the ecological past of the ocean. Before you is the beginning of life on earth, seemingly thriving as it has done for millions of years.  Yet, despite the appearance of unity, it is the duty of the ecologist, conservationist, and informed ecotourist to look closer.

This image was creates by Tilburg et al. 2001 and shows the current connecting New Zealand and Australia across the Tasman Sea. 

My first dive was at Poor Knights Islands off of the coast of the North Island of New Zealand in the North Cape Eddy (labeled NCE in the figure to the left) of the EAC with Dive! Tutukaka. According to the New Zealand Department of Conservation, the Poor Knights Islands marine reserve is one of 44 national marine reserves protected under the Reserves Act of 1977. The Poor Knights Island marine reserve is home to a unique collection of endemic cold water coral reef species and tropical fish swept up by the EAC along the Australian coast and taken across the Tasman sea.

In Australia, I participated in a live-aboard dive trip on the Great Barrier Reef off the coast of Queensland near Cairns with Ocean Quest. As the world’s largest coral reef system, the Great Barrier Reef comprises 2900 coral reefs and expands over 14 degrees of latitude. In 1981, the Great Barrier Reef was named a UNESCO World Heritage Site. Presently, the reef is managed for multiple use by the Great Barrier Reef Marine Park Authority (GBRMPA) of the Australian government. The GBRMPA estimates that 54,000 full time positions are supported by the Great Barrier Reef commercial industries, including ecotourism and scuba diving, making the reef a significant natural, historical, and economic site.

My experiences in New Zealand and Australia were drastically different. At Poor Knights Island in New Zealand, we were the only boat going out that day departing from a tiny village in a rural part of the North Island. It was the end of winter and the cold water made diving unpopular. By the time I got to the Great Barrier Reef in Australia several weeks later, the seasons were changing; Spring and the busy tourist season were beginning to ramp up. There were constantly other boats around and our dive trip was mostly full. Due to these seasonal differences, I did not get a complete picture of the regulation required to manage the Poor Knights Islands marine reserve. 

In contrast, visiting the Great Barrier Reef was a production. It seemed like every other building in Cairns was a dive shop promoting trips to an "undisturbed" part of the reef. Despite these claims, 80 percent of all tourism occurs in about 7 percent of the total region. GBRMPA helps regulate ecotourism on the Great Barrier Reef by requiring all companies apply for permits and by limiting the number of people on the reef. GBRMPA also has its own Eco Certification Program which enables businesses, such as the one I dove with, to extend their permit for up to 15 years if they meet certain environmental protection and sustainability criteria. The GBRMPA is working hard to bridge the gap between the economic dependence on the reef and environmental conservation. 

According to the GBRMPA, many businesses are also taking additional steps to protect the reef such as:

  • calculating and reducing their carbon emissions
  • trialling alternative energy sources such as biofuels
  • becoming climate action certified through Ecotourism Australia
  • offsetting the emissions created by their business.

Ocean Quest, the company I dove with, also selected dive sites where we swam along side tall reef walls instead of swimming over the reef. This significantly decreases the likelihood of damaging the reef with a flipper and helps keep some parts of the reef undisturbed. 

In general, scuba diving indirectly helps conserve the environment. In Australia, considering 54,000 jobs are supported by the Great Barrier Reef alone, there is a huge economic incentive to protect the reef for future generations and ensure it is one of the top dive sites in the world. The economy of Queensland heavily relies on the reef which creates a common respect for preservation. Scuba diving also helps to educate divers about the environment and provides a firsthand look at environmental degradation. 

In my opinion, the most important conservation contribution of scuba diving is its ability to build a community of people who love nature and want to protect it. During my dive with Dive! Tutukaka, the whole boat took a detour to fish a piece of trash out of the water. They exemplified the principle that one should leave each place cleaner than he or she found it. And when we spotted a couple of Bryde's whales, no one was more excited than the dive instructors, because the more time you spend in nature the more you appreciate when something truely special happens.

This image was created by the National Academies of Sciences Engineering and Medicine and shows the chemical balance between different compounds and how they can lead to ocean acidification. 

However, any positive effect of ecotourism on conservation in the water is limited externally by global warming. In particular, coral reefs are most heavily affected by ocean acidification. Ocean acidification is the process by which pH is lowered (which means acidity increases) and H+ (proton) concentration is increased primarily due to increased levels of dissolved carbon dioxide. Ocean acidification harms the majority of marine life but most significantly impacts marine calcifiers. Coral reefs are made by marine calcifiers and depend heavily upon the stability and health of their calcium structures. The two figures summarize the effects of ocean acidification and introduce the basic chemistry behind the process.

As shown in the image above, the ocean and air are in equilibrium with one another. The ratio of dissolved CO2 between the two media will always remain approximately constant.  Therefore, increasing the concentration of CO2 in the air will proportionately increase the concentration of CO2 in the water. In the water, the concentration of carbon dioxide is then in equilibrium with the concentration of carbonic acid. When the concentration of CO2 in the water increases, this increases the concentration of carbonic acid, which then dissociates into bicarbonate and H+ to increase acidity. Additionally, the increase in H+ concentration (meaning increase in acidity and decrease in pH) changes the equilibrium between calcium carbonate (found in shells, corals, mollusks, etc.), hydrogen, and bicarbonate and drives the equilibrium away from calcium carbonate towards bicarbonate. The decrease in calcium carbonate greatly impedes marine calcifiers’ ability to build and maintain calcium structures.

Even though both of the sites I visited are heavily protected and monitored, the marine ecosystems’ greatest threat occurs on land beyond the boundaries of the marine reserve. Herein lies the most fundamental weakness of using ecotourism as an strategy for conservation: ecotourism is a small-scale solution. It is successful only at mitigating local issues or protecting nearby land. Climate change is a global problem that can only be solved by unprecedented international cooperation.

Additionally, scuba diving may also have internal limitations to conservation. According to Reef Resilience, tourism can negatively impact reefs by causing:

  • Breakage of coral colonies and tissue damage from direct contact such as walking, touching, kicking, standing, or gear contact
  • Breakage or overturning of coral colonies and tissue damage from boat anchors
  • Changes in marine life behavior from feeding or harassment by humans
  • Water pollution
  • Invasive species
  • Trash and debris deposited in the marine environment

In general, scuba diving can potentially be more harmful for the reefs than snorkeling by allowing closer access to the underwater structures. Some researchers additionally speculate that the experience level of the diver changes how likely they are to harm a reef by changing how well they can control their bodies in the water. However, some preliminary findings contradict this observation and indicate that nationality may have a greater impact on frequency of reef damage than other factors such as diver experience and ability. The correlation between nationality and reef damage suggests that changing socialization and improving education about the environment may be one of the most important steps to help protect the reefs from harm. 

The internal limitation of human use on conservation efforts is pervasive throughout ecotourism. However, there are some intervention tactics such as educating tourists and strategically selecting sites for ecotourism that can help reduce human impact. As described in the next Feature on Elm Wildlife Tours, some companies have found a productive balance between human use, conservation, and ecotourism. 

Resources

Tilburg, Charles E., Harley E. Hurlburt, James J. O'brien, and Jay F. Shriver. "The Dynamics of the East Australian Current System: The Tasman Front, the East Auckland Current, and the East Cape Current." Journal of Physical Oceanography 31.10 (2001): 2917-943. Web.