Greetings, eco-wise viewers, to this week’s episode of Planet Earth: Our Loving Home, where we’ll present the final segment of our two-part series on the harmful algal blooms, known as HABs, that are injuring coastal ecosystems around the globe, with a focus on the threat to marine animals caused by domoic acid. Between 2002 and 2003 in Southern California, USA over 1,000 sea lions and 50 dolphins succumbed to this neurotoxin.

For expert insight on this issue we’ll hear once again from Dr. Vera Trainer, a supervisory oceanographer at the National Oceanic and Atmospheric Administration’s Northwest Fisheries Science Center in Seattle, Washington, USA, who has conducted HAB research for many years and Dr. Bill Cochlan, a biological oceanographer at the Romberg Tiburon Center for Environmental Studies, a part of the San Francisco State University system, in Tiburon, California, USA.

Dr. Cochlan has also done extensive work on the issue of harmful algal blooms. The tiny marine organisms known as phytoplankton play a pivotal role in global carbon circulation, being responsible for 50% of all photosynthetic activity on Earth, and emitting vast amounts of oxygen into the atmosphere.

However, some types of phytoplankton cause HABs, which wreak havoc on aquatic environments. Approximately 300 species of microalgae are known to form algal blooms. And almost a fourth of these species can generate toxins. As a result of toxin transfer through the food chain, HABs may debilitate or kill animals near or at the top of the chain.

Today, we’ll begin with a discussion of the breeding grounds for the algae called Pseudo-nitzschia, which is found in coastal waters throughout the world and produces deadly domoic acid.

There are a number of factors that could spur the growth of an algae bloom, much like what other plants need to grow. If you look at your garden in the winter versus the summer, you'll notice that your plants are starting to come out of the earth in the springtime as the days get longer, as the days get warmer, as more sunlight is present.

For any phytoplankton bloom, you have to have sunlight, because they’re autotrophic. They’re not actually plants, but they’re very, very similar to plants. Of course they need a sufficient amount of CO2, because they are photosynthetic and they need nutrients.

Pseudo-nitzschia can bloom efficiently when small amounts of iron and copper are available in the water. Road runoff and animal manure that end up in the oceans can be sources of these elements.

The work that we’ve been doing in the laboratory over the past few years suggests that the production of domoic acid is related to the micronutrient availability, in particular iron and copper. That toxin binds both metals very well, and laboratory experiments have shown that when we change the metal availability, we can make the cell produce more or less of the toxin. So we think that that’s what the metabolic role of the toxin really is.

You can have blooms of Pseudo-nitzschia when there are very, very low nutrients. So you don’t necessarily have this linkage between a high nutrient load in an environment and this species. And it may in fact have something to do with your nutrients you’d put on your houseplants like nitrogen and phosphorus, and of course silicon, because it’s a diatom. But what makes it a little different with this cell is that it has specific requirements for trace elements, or trace nutrients. And these are things like iron and copper.

One of the tools that was thought to be useful for the mitigation of climate change was ocean fertilization. You may have heard about some of these ocean fertilization experiments that were happening in the outer ocean, where iron was being dumped to cause phytoplankton blooms to occur.

These phytoplankton blooms then assimilate the carbon dioxide, which in ways is increasing the warming. So what happens when iron is dumped into the ocean, Pseudo-nitzschia is one of the organisms that can bloom. And so these companies that were promoting these experiments, they were saying, "Oh yes, Pseudo- nitzschia were there, but they weren’t toxic." But, we, our team, has shown that that’s not the case.

The massive amounts of hazardous manure and organic matter generated by factory farms as well as effluents from industrial agriculture operations stimulate the production of HABs, with studies showing that nitrogen and ammonium accelerate the growth of some types of Pseudo-nitzschia.

Let me start with whether agricultural runoff spurs these algal blooms, or enhances these blooms. We do know that certain algal blooms are enhanced by the presence of these human-derived nutrients. Some species of Pseudo-nitzschia, producing higher quantities of toxin, grow under urea or ammonium, which tend to be more human-derived sources of this nitrogenous nutrient. We have an example of such a bloom very close to here in Sequim Bay, where we had one of the first domoic acid closures in Puget Sound that we think was due to human-derived sources of nutrients.

You really do have to be careful in making sure our sewage from our animals and from humans is properly discharged and treated. Because it will have an effect on not just the amount of phytoplankton, but the types of phytoplankton. Even the different ratios of nutrients can impact which phytoplankton species will proliferate.

Research has linked climate change with the spread of HABs, including blooms of Pseudo-nitzschia.

Increased red tides, or harmful algal blooms, might be a consequence of global warming. We know that these cells do well when temperatures are higher, phytoplankton cells per se.

Warming of the oceans could be having an effect. It could also be the fact that more and more of the world’s population lives right on the coast, and also uses marine resources to support themselves. So, more and more aquaculture, and with so much of the population interacting with the ocean, this could be exasperating harmful algae blooms.

In March 2011, six sea lions were found dead and 175 tons of sardines all perished at once in Southern California’s Redondo Beach’s King Harbor. It is thought domoic acid may have played a role in harming the wildlife.

Once all the fish went into Redondo (Beach’s) (King) Harbor, and the fish still have to breathe the oxygen out of the water through their gills. There were so many fish there and there wasn't a lot of exchange. It wasn't a mixed zone, because they all got into one corner of the harbor. Then they started to suffocate.

Oceanic dead zones, where fish and other marine life cannot survive, are created by the condition of “hypoxia” or reduced dissolved oxygen content.

Any phytoplankton species, once they run out of nutrients and once they start to die, if there are a large enough concentration, they can cause these dead zones. The dead zone like off Mississippi, which is very, very large. It's larger than the state of New Jersey. Those phytoplankton are fueled by excess nutrients coming down the Mississippi.

These are nutrients that are not used by the farmers, and then the runoff goes into the river, and makes it down to the Gulf of Mexico. And they fuel massive blooms of phytoplankton. But eventually those phytoplankton will die. And As the phytoplankton die, they're decomposed by the bacteria, and that causes the massive dead zones.

The harmful algal blooms, phytoplankton blooms will deplete, once they are dying, and sinking to the bottom of the ocean, they will remove oxygen from the water. So that by definition is what the dead zone is, but that’s not necessary a harmful algal species causing that dead zone. It’s the phytoplankton per se, the assemblage of marine photosynthesizing plants that are blooming and then dying and sinking, and taking away the oxygen from the surface waters.

The Intergovernmental Oceanographic Commission of the United Nations Educational, Scientific and Cultural Organization (UNESCO) operates a global HAB program for scientific research and mitigation. In Washington State, USA, the Olympic Region Harmful Algal Bloom Program regularly monitors the ocean and issues an alarm when a HAB occurs.

In nature the cells are rather easy to monitor using a microscope. They have very distinctive, overlapping chains. Here's the scanning electron micrograph of the Pseudo-nitzschia cells. So we have folks through the Olympic Region Harmful Algal Bloom Program on the outer coast who are doing weekly monitoring of the water with the intent to protect human health. So we've established these threshold levels. If they see cells at a certain number they will then monitor for toxin both in the algae themselves or in shellfish on the coast.

In the long term, reducing nutrient inflows is one of the best ways to prevent HABs. Dr. Cochlan highlights the importance of raising awareness among schoolchildren on this topic.

The Seto inland sea law in Japan is a great example of when you change the amount of pollutant going into an area, how will that impact the ecology of that area? So in this case, when Seto inland's law came into effect, the Japanese authorities saw a rapid decline in the number of red tides each year. So, there's where we see the linkage between you decrease some of your pollutant sources, and we seem to have less red tides. That's the sort of evidence we have.

The way we're going to probably decrease harmful algal blooms is through education. We're pleased that the public is taking interest in how ecology can affect them. Of course we have a personal relationship when we see people getting ill with consuming marine resources. So more and more schoolchildren and curricula are discussing and teaching their students about marine ecology and about phytoplankton.

How can we as individuals help reduce growth of harmful algal blooms so that marine life can thrive in our oceans? Following the organic, plant-based diet is the quickest and simplest way, and is something that we can all do very easily. Vegan organic farming enormously benefits the environment and public health and eliminates fertilizers, animal manure and other pollutants that induce the growth of HABs.

Finally, our sincere appreciation Drs. Vera Trainer and Bill Cochlan, for giving us your perspectives on harmful algal blooms and their severe impact on our vulnerable marine ecosystems. May your important research work in this area soon help minimize the number of such blooms in coastal waters.

For more details on the experts featured today, please visit the following websites:
Dr. Bill Cochlan
Dr. Vera Trainer

Amiable viewers, thank you for joining us on today’s program. May the light and love of Heaven forever be with us all.