The Complexities of Climate Change: ongoing studies to determine mankind's impact

The complexity of global warming and its effects are highlighted in journal articles cited by SeaWeb in its latest Marine Science Review (issue #359). The challenge to scientists in determining the long-term effects is how best to correlate a myriad of artificially introduced components that can either increase or even decrease atmospheric and ocean temperatures.

A study in Nature Geoscience examines the complexities behind the El Nino-Southern Oscillation (ENSO) which begins in the tropical Pacific but whose effects extend worldwide. Predicting the frequency and extant of this oscillation has been a challenge even in the best (aka "al naturale") of circumstances. By interjecting man-made factors, the predictability becomes even more difficult. But it is clear that a strong ENSO raises temperatures along the equator, changing wind patterns that impact temperature gradients between surface and deep water layers both at the equator and beyond.

Another study in Nature Geoscience examined issues related to atmospheric aerosols - particles and gases in the atmosphere that have the ability to actually lower temperatures (an extreme example of this would be the extended "winter" that doomed the dinosaurs brought on by ejecta from a meteorite impact). With man-made pollutants, like smog, sometimes both effects - heating and cooling - are at work due to the nature of what is being thrown into the air. This can make it challenging for scientists to determine the end net result and for those who have proposed the use of man-made atmospheric aerosols to moderate temperature, called radiation management, the results are questionable. One fact is known: atmospheric aerosols ultimately weaken the ozone layer, as we had over the Arctic, which increases temperatures.

There were two studies in Toxicon that examined the increase of Ciguatera, a fish poisoning that occurs with the ingestion of algal toxins. As it works its way up the food chain, the effect accumulates and becomes magnified. Human consumption of infected fish can produce some nasty gastrointestinal and even neurological effects. One study, focused on the Caribbean, and showed that the incidence of ciguatera was highest where high and relatively consistent sea surface temperatures (SST) occurred. In contrast, another study in the South Pacific showed that there is a temperature threshold over which ciguatera prevalence is dampened, but determining where and when this dampening effect occurs is challenging due to the oscillation of ocean currents in the area.

And lastly, a study in Climate Policy reminded us all of where the impacts of climate change will fall on human populations. Equatorial, developing countries - in Africa, the Indian subcontinent, Latin America, and small island states - will feel the greatest effects, affecting subsistence-level economies. And this will have to be taken into consideration when establishing international policies. The industrial world, existing in colder latitudes, has produced over 66% of the global greenhouse gases, but its equatorial neighbors will experience over 75% of the effects within this century.

Climate ecology, like many of the natural forces from evolution to the birth of the universe, is an incredibly complex system unto itself. This makes the study and outcomes of man-made intrusions a very difficult one to forecast. But there is no doubt that mankind is having an impact. I receive 20 to 30 summaries on climate change studies each month from SeaWeb - the data is there, the research is ongoing, and the reality of climate change should be a worldwide concern.

China's Finless Porpoise: dwindling population faces extinction in Yangtze River

China's Yangtze River has been described as the "Asian Amazon" and, as seems to befall many large rivers in growing nations, it has seen its share of perils from urban development, commercial use, and industrial pollution. Unfortunately, many of the river's inhabitants pay the price - including the river's dwindling population of freshwater cetaceans.

The Baiji - a freshwater river dolphin with an unusual, elongated jaw/beak that roamed the Yangtze for tens of thousands of years - was declared extinct in 2007, eliminated from the planet in a matter of a few decades.

And now another rare dolphin species is facing a similar fate. As reported in the BBC Earth News, a new study published in the Marine Biology journal, says that the river's remaining population of finless porpoises are headed for extinction. The finless porpoise (so named because it lacks a dorsal fin) lives in the Yangtze, Yellow Sea, and South China Sea; and according to the study, there are genetic differences between the various populations. This would indicate that there is no co-mingling between the groups and this can add to their inability to withstand adverse changes to one group's environment.

This type of isolation and loss of mixing of the DNA gene pool is also what threatens land animal populations, like some of the wolf packs in the north central United States.

With everything from human waste and industrial chemical pollution, boat traffic, and commercial fishing taking place in the Yangtze River, the rapidly declining freshwater population of the finless porpoise - numbering less than 1,000 when last estimated in 2006 - will not survive without strong action on the part of the Chinese government.

The only hope is for a fundamental change in attitude in China regarding its aquatic natural resources. And there is some evidence of that which could produce results, hopefully before it is all too late.

While a major producer of CO2 emissions and the greatest exporter of seafood of any country, China is also realizing the environmental impact its economic growth is having on itself. The country is making sizable investments in alternative energy and, according to the Seafood Choices operational arm of SeaWeb, China's seafood distributors are beginning to show some interest in sustainability. Seafood Choices is holding seminars with seafood exporters in advance of a Sustainable Seafood Forum to be held in China this November.

Whether all of this will produce changes that will come in time to save the finless porpoise remains questionable at best. It is unfortunate that humans seem to be a reactionary species, responding to a tragedy that might spell a better future for some but leaving victims - like the Biaji and the finless porpoise - as reminders of what we could have done if only for a little foresight.

Read about the finless porpoise in BBC Earth News.
Read about SeaWeb/Seafood Choices progress in China.

Ocean Acidification: SeaWeb brings bring scientists and commercial fisheries to the table

With many environmental issues, real quantifiable progress is often attained when scientists and commercial interests can sit down and objectively discuss the situation. SeaWeb.org, through its Seafood Choices Alliance, realizes this and has been taking steps to get what can seem like disparate interests to sit down at the same table to discuss the reality of ocean acidification.

Ocean acidification is when the oceans become more acidic from the absorption of increased CO2 in the atmosphere. This increase in the water's acidity levels impacts a variety of corals, shellfish, and other animals that rely on the use of calcium in building shells or other supporting structures - a process that is severely weakened by the more acidic water.

SeaWeb has conducted two workshop meetings - one in Portland, Oregon and another recently held in St. Petersburg, Florida - between scientists and commercial fishing leaders to discuss what the latest data says about the current and future status of ocean acidification, and what it means not only for the marine species but for the commercial fishermen and aquaculture companies.

"It is good for various and even opposing stakeholders of a public resource to sit down and talk. At least we can understand the investment each of us has in our finite fisheries and oceans," said Bobby Aylesworth, chairman of the Board of the Southeastern Fisheries Association, about the workshops. "Hopefully we find some common ground to grow from."

According to SeaWeb, one of the ways that scientists hope to collaborate with the seafood industry is through the sharing of data. Ocean acidification is not something that anyone can hide from, so by sharing data drawn from water quality tests taken at hatcheries and nurseries, combined with ongoing scientific studies by local scientists; all interested parties can have a better idea as to what changes are taking place within their own particular region of commercial concern.

There is already documented evidence of the impact of ocean acidification on sealife, so it behooves commercial industry to work with scientists - rather than to oppose or worse yet, buy-off scientists - to get an accurate picture of the issue. Nothing grabs the attention of policy and decision makers regarding an environmental threat than when a commercial enterprise is put at risk. When may be thought of as a bit esoteric suddenly becomes very real.

Read about SeaWeb in Action.

Coral Reefs vs. Poisonous Seaweed: overfishing gives dangerous seaweed an edge

Regarding coral reefs, it has been said that when water conditions are less than optimal and algae is allowed to run rampant - often the result of runoff and pollutants high in nitrogen - then corals can be pushed out or overtaken. A recent study, reported by SeaWeb, cites the danger to coral reefs from species of seaweed that are capable of poisoning the coral. The seaweed is normally kept in check by feeding fish, but when overfishing reduces the population of these important herbivores, then the corals are at risk.

Overfishing Allows Seaweed to Flourish, Killing Corals

Overfishing of herbivorous fish is allowing seaweed species (such as this green seaweed Chlorodesmis fastigiati, center) to thrive, killing corals with which they come into contact. Mark Hay

Researchers have found that several species of common seaweed contain chemicals that kill corals. In the Proceedings of the National Academy of Sciences, Douglas Rasher and Mark Hay of the Georgia Institute of Technology in Atlanta report that five of seven seaweed species caused bleaching, declines in photosynthesis and death of coral tissues when they came into direct contact with Porites [stony] corals off the Caribbean coast of Panama. Three of eight seaweed species had similar effects on Porites corals off Fiji.

The researchers noted that only the areas of the coral that came into direct contact with the seaweed were affected. Attempts to replicate the effect with plastic seaweed models did not produce the same results. However, when extracts from seaweed tissue were embedded in gel strips and placed on the corals, the results almost precisely replicated those from the seaweeds themselves, suggesting strongly that chemicals within the seaweeds were responsible for the damage.

The researchers note that when seaweeds were placed on corals in a marine protected area off Fiji, herbivorous fish that were prevalent within the area rapidly consumed them. However, when placed on an adjacent reef where fishing took place only 1,000 feet (more than 300 meters) away, the seaweeds were consumed far more slowly, if at all. They write that their study shows that in healthy reef systems, coral are protected from the impacts of seaweeds, and that even relatively small amount of fishing of species that graze on those seaweeds could have potentially disastrous effects on coral reefs.

Source: Rasher, D.B., and M.E. Hay. 2010. Chemically rich seaweeds poison corals when not controlled by herbivores. Proceedings of the National Academy of Sciences.

Contact: Mark Hay, Georgia Institute of Technology. E-mail: mark.hay@biology.gatech.edu

This Winter's Extreme Weather: climate change defined by macro-weather patterns

With some extreme winter weather taking place in some parts of the world, discussions about global warming would seem to fall on deaf ears. It can be challenging to gain the attention of a U.S. senator regarding warming ocean temperatures when he or she is shoveling several feet of snow to get to the U.S. capitol!

In United States alone, we have had some flip-flopping of "normal" weather patterns: heavy rains in southern California, record snow levels in the northeast, and a cold snap in Florida that has caused the deaths of over 100 manatees and triggered an extensive coral bleaching event. Even with an unusual warm spell in Vancouver, British Columbia as the Winter Olympics are about to begin, it doesn't sound much like global warming, does it?

However, one must look beyond micro-weather patterns and look at the big picture, at annual or decadal trends, and even longer, to determine what is a natural cycle or an anomaly or a man-made trend.

As an example, NASA's Goddard Institute for Space Studies recently declared 2009 to be the second warmest year on record, next to 2005. This first decade of the 21st century has been the warmest on record, warmer than the previous decade which was the former record holder. With changes in macro-weather patterns over a long period of time, there are disruptions to the typical wind, temperature, and ocean current patterns. In the Pacific Northwest, changing climate conditions are being considered responsible for steadily increasing wave height over the past several decades, posing greater flooding and erosion potential. Ironically, these major weather disruptions can manifest themselves regionally in ways that would seem to run counter to the idea of global warming.

One seasonal weather event that occurs in the Pacific is the El Nino - a change in the usual sea temperature patterns that warms the Pacific and disrupts weather patterns across much of North and South America. Research that has studied the El Nino over several centuries have shown that it has been occurring more frequently, with over 40% of the extreme events taking place in the 20th century, with 30% of those occurring after 1940. There is an El Nino in place right now and is considered the source of much of the current abnormal weather patterns in the North America.

There are some scientists who propose that all of this represents a normal macro-weather pattern, that this is all nature's doing and not man-made. But as research continues, we are beginning to see that the rate of change seems to be much greater than from any other previously recorded or extrapolated natural cycle - another accelerant would appear to be at work here. Hence, the issue of man's impact through CO2 and other greenhouse gas emissions and the use of fossil fuels.

Opponents of global warming have characterized it in various ways, from a natural-occurring event to a massive global conspiracy by maniacal scientists. While I don't buy into the Machiavellian plots, I would propose that if all the research were to ultimately point to a natural shift, I for one would choose not to simply sit back and enjoy the ride, proclaiming there's nothing we can do and watch ecosystems shift and species (including homo sapiens) disappear in many parts of the world. I just can't sit on my hands.

However, having reviewed the continuing stream of research studies, my inclination is that man-made activities have been the primary cause behind climate change. We did it and we can do something about it.

Read SeaWeb article on recent cold temperatures, El Nino, and northeast Pacific wave height.

The Arctic Permafrost: a ticking time bomb of greenhouse gases

After having had the opportunity to travel through a portion of the Northwest Passage, above the Arctic Circle, documenting evidence of climate change for the marine research organization InMER, I became more interested in what is happening to this region and the implications. There are some serious issues beyond what is most often portrayed in the news: the threatened polar bear.

In the recent issue of SeaWeb's Marine Science Review #290: Climate and Climate Change, several articles and abstracts outline studies made regarding the effects of rising temperatures on the permafrost that forms the primary ground cover in the region. Permafrost is, in essence, a frozen soil layer. The upper or active portion of the layer supports flora with shallow root structures - different types of moss and lichen abound and bushes or trees do not grow there.

But also trapped in that frozen layer is a considerable amount of organic carbon and methane and as the temperature increases, those potential greenhouse gases can be released. In terms of greenhouse gas emissions, it makes the permafrost a ticking time bomb.

The SeaWeb review sited two articles: "Vulnerability of permafrost carbon to climate change: Implications for the global carbon cycle" (BioScience 58[8], 2008) and "Soil microbial respiration in arctic soil does not acclimate to temperature" (Ecology Letters 11[10], 2008). Really exciting, attention-grabbing titles, I know, and they're very heavy on the academic/scientific gobbledygook but what it boils down to is that with even a slight increase in temperature, the permafrost experiences an increase in soil decomposition that releases the trapped organic carbon and methane. And there is a considerable amount held in that frozen soil.

It's another example of the "cascade effect" where one change - an increase in temperature - causes a myriad of other changes, with some of these changes feeding back into the original issue and exacerbating the problem.

The polar bear can generate well-deserved public sympathy and hopefully provide impetus to address the problem of climate change. But it's a multi-faceted problem with potential land mines right under our feet.

Marine Protected Areas: scientists studying the impacts

The continuing efforts to establish marine protected areas (MPA) or reserves worldwide has been an important issue with many conservation and scientific groups for obvious reasons. Activities ranging from overfishing to pollution have needed to be addressed because of the negative impact they have on marine ecosystems and marine life populations. The juggling act has always been in trying to meet the needs or at least compromise with the various stakeholders: commercial fishing, recreational activities, conservationists, scientists, and more.

Challenging as it is, MPAs continue to be established and now a new challenge facing scientists is the careful monitoring of these areas to see what effects - good or bad - the MPA may be having. I was reading interesting information from a SeaWeb.org Marine Science Review (Marine Protected Areas & Reserves #288). Worldwide, there is a considerable amount of research taking place regarding MPAs. Some of the issues they are studying have to do with bio-dispersion - the movement of marine species within a given area. We humans may define an area as "protected" but marine species don't read the fine print and may not stay within safe borders. Depending on the size, sex, and bio-density, a species that moves into harvesting areas, outside an MPA's borders, could be severely impacted. On the other hand, species of less commercial value could profligate within the MPA and perhaps upset the overall ecosystem - one example I read concerned increased populations of parrotfish which consume coral.

While the overall concept of marine protected areas and reserves seems to make environmental sense, scientists are hard at work developing new methodologies and research methods to be able to properly monitor the long term consequences of our efforts to preserve and protect our oceanic resources.