Penn State NASA

Module 7: Ocean Acidification, Red Tides, and Monster Jellyfish


Module 7: Ocean Acidification, Red Tides, and Monster Jellyfish


There is one definite advantage of being over the age of forty. If you were lucky enough as a kid, you had the opportunity to snorkel or dive in a place like the Florida Keys or the Bahamas when coral reefs were healthy and diverse, colorful, and teeming with life. There are very few places on Earth where this is the case today. Tragically, the large majority of reefs are in a profound state of decline, with limited growth of new coral, and overgrowth by slimy green or brown films of algae. Piles of coral debris are commonplace. The water is often muddy, and the plethora of life has departed. Reefs are no longer magical places. There is absolutely no argument about it, the decline in coral reefs is human inflicted. To this point, the largest culprit is probably pollution, but that will change in coming decades. Enter Ocean Acidification, a process that has already begun, tied to our excessive CO2 emissions, and one that will accelerate soon. Corals cannot grow once the pH drops below a certain level, and if we don't act fast, that level will approach by mid-century. Reefs have survived the two largest mass extinctions the Earth has faced, but they may not survive the mass extinction humans are causing.

Ecosystems, such as reefs, are governed by a delicate balance of interactions between animals and plants. Yin and Yang. If that balance is upset even slightly and one part of the ecosystem is favored at the expense of others, havoc can break out. The recent surge in harmful algal blooms along many coasts and the outbreaks of massive jellyfish in the western Pacific Ocean are signals of Yin or Yang, but not both. Our oceans are getting out of whack.

In the latter part of Module 6, we learned about changes in circulation and health of the oceans that are predicted to occur with climate change. In this module and Modules 8-11, we continue to address the impacts of climate change on natural systems. These changes are very much central to the issue of sustainability of the planet and its populations. "Sustainability" has a variety of definitions, and, in particular, the meaning for environmentalists is substantially different from the meaning for businesses. Regardless of where you might be coming from, sustainability means the preservation of society and our way of life. Most directly, we are concerned with maintaining the needs of people today and in the future, and this very much hinges, as we will see in this module, on sustaining the life support systems of the planet.

Global warming and an array of environmental changes resulting from human activities are already causing profound impacts on organisms across the spectrum of the marine food chain. Warming of the ocean and subtle changes in its chemistry are combining with pollution and overfishing to alter the habitat of many marine creatures. In the near future, these habitats look to be further impacted, and potentially destroyed, with possibly devastating biological and economic consequences, including very negative impacts on people. The goal of this module is to learn about three very different but equally significant impacts of climate change and human activity on life in the ocean: ocean acidification, red tides, and blooms of jellyfish.

To set the stage, watch the Award Winning video Sea Change, produced by Craig Welch.

Video: Craig Welch on "Sea Change" in Indonesia (2:32)

Click here for a transcript of the Craig Welch on "Sea Change" in Indonesia video.

Here in the Coral Triangle in Malaysia, Thailand, Indonesia, Papua New Guinea, this part of the world relies heavily on coral reefs and fish that will be affected by ocean acidification for its food. So, we decided to find a community that relies on ocean fish for its protein more than some others. We wound up in this village of former sea gypsies in the South Sulawesi region of Indonesia. It is a stark and amazing way to live, and an incredible place to work as a journalist. The first thing you notice, of course, is that people here live in houses built on stilts above the water. But the next thing you notice, right away, is that everything here is loud, between the wind and the waves and the coughing diesel engines. People here are just used to constant shouting. It’s hard to explain how far removed this place is from the Western world. Just getting here from Seattle took six flights and a three-hour boat ride. We stayed on nearby Hoga Island, at a mostly empty research station, where monitor lizards fought over kitchen scraps and the walking paths were frequented by banded sea crates, a deadly type of ocean snake. Our translator Immon connected us with a boatman, and every day we paid that boatman, Duda, to take us to the stilt village to visit with his neighbors. Duda, like most villagers, never let an opportunity on the water pass without attempting to catch some fish. Talking to some of the more senior villagers, such as Ambelia, required working with multiple translators. The poverty at times was overwhelming. We met a widow who made her living getting paid to collect dead coral and to stack it below people's homes for support. The everyday risks were sometimes hard to ignore. We saw adults who had lost limbs to dynamite fishing accidents. Adults and children alike daily traverse crumbling boardwalks. Some of the homes were connected to these boardwalks by a single flimsy, treacherous log. Our attempts to cross provided villagers no end of amusement. But the Sama people, often referred to as Bajau, were open to us from the start. They shared their homes and their lives without question. No matter what happens with climate change in ocean acidification, it's clear that the people who live here don't have many options. They will continue to go out on the water and fish every day, and the women will go to the marketplace and sell that fish wherever they can, because, for the moment at least, they don't appear to have any other options.