Tag Archives: GlobalWarming

Predicting Marine Populations with Phytoplankton

View of Earth from space. Photo from Wikimedia Commons.

Did you know that the ocean is predicted to warm over 4°C  the next 100 years? There’s certainly more than meets the eye when it comes to understanding the effects of global warming, and knowing how ecosystems change in response to changes in temperature can help make our efforts more focused and accurate.

As a recent PhD graduate from the University of British Columbia, Dr. Joey Bernhardt is already making waves in the science community. Her most recent paper describes the use of phytoplankton to analyze growth rates among species under different temperature conditions. Most of the study’s work actually occurred just last September, and we were lucky enough to be able to meet Dr. Bernhardt to explore the bigger picture issues she’s addressing.

What’s so special about phytoplankton?

Green swirls of phytoplankton in the Baltic Sea. Photo from Wikimedia Commons.

To debunk a common misconception: not all of the oxygen we breathe comes from trees. In reality, nearly 50% of the world’s oxygen supply is produced by phytoplankton. What’s more, phytoplankton serve as the basis of marine food webs, so it’s no surprise that they were the main subjects used in Dr. Bernhardt’s study. These remarkable organisms can actually help us make predictions about species populations in the context of global warming.

What issues are being addressed?

2070-2100 global warming predictions map. Photo from Wikimedia Commons.

One of the most pressing issues in our global warming narrative surrounds how temperature changes affect species population. While it’s easy to measure population growth rates in the controlled conditions of a lab, Dr. Bernhardt explores whether we can apply these results to the unpredictable, fluctuating temperatures of the outdoor environment.

If we were to disregard the fact that in nature temperatures fluctuate, we will ultimately make inaccurate population predictions. To generate a more realistic sample, Dr. Bernhardt collected phytoplankton off the coast of Vancouver Island and placed them in lab incubators that mimic a natural environment using a variety of temperature settings.

To gain a better understanding of the methodology behind Dr. Bernhardt’s study, check out our video:

https://youtu.be/F5rC4PLMsds

Why should I care?

When a species find themselves in an environment outside of their normal temperature range, they will either die off or relocate to more habitable areas. This now presents an entirely new problem since it’s not always easy for the communities that rely on these populations to pack up and move as well. From an economic standpoint, there are whole industries built upon the reliance that these populations will return, year after year.

The Future of Global Economic and Climate Change Issues

These experiments allow us to see the range of temperatures at which a species can persist. We can then pair this with the knowledge of how temperatures around the globe will shift over time in order to build more sustainable communities.

We take a deeper look into the applications of this technology in our podcast:

Group 213-5: Danny Israel, Christy Lau, Christina Rayos

The Fall of Sea Stars

1986-014-01: Sunflower seastar

1986-014-01: Sunflower seastar” by August Rode is licensed under CC BY-SA 2.0

Once an abundant species of sea star, the sunflower sea stars have become harder to find on the West Coast of North America. A recent study co-led by the University of California, Davis, and Cornell University claims that the combination of ocean-warming and an infectious wasting disease has led to the declined population of these large sea stars.

The sunflower sea star is one of the largest sea star species, they can grow as big as manhole covers. Commonly found in the northwest Pacific, they were once regularly found from Southern California to Alaska and some of the largest sunflower sea stars could be found in Puget Sound, British Columbia and Alaska.

In 2013 and 2014, a disease called sea star wasting syndrome affected around 40 different species of sea stars, including the sunflower sea star, to die off along the North American Pacific coast. Symptoms of the disease would be lesions and tissue decay, which the body structure of the sea star would start to breakdown. For example, their arms may twist and fall off and the sea stars would become limp. Eventually, the sea star would disintegrate and melt away into a white, mushy blob and no longer be a sea star. It is unclear where this disease originated from but researchers believe ocean-warming might be the reason why this disease continues to affect the sea stars and why the sea star population is not recovering fast enough.

Dying sea star

Dying sea star” by Oregon State University is licensed under CC BY-SA 2.0

Ocean-warming is an effect of global warming. The ocean absorbs excess heat from the atmosphere which contains greenhouse gas emissions, which leads to rising ocean temperatures. Increasing ocean temperature can affect many marine species and ecosystems. Warming of the oceans have been linked to the increase and spread of diseases of marine species.

The sunflower sea star species has been detrimentally affected by sea star wasting syndrome. The study conducted by Dr. Harvell and her colleagues collected data over eleven years to show how the population of sea stars have diminished due to this disease. In addition, scientists also found that the ocean water has warmed almost 4 oC within a four-year span in some areas. Results of the study showed the population crash of sunflower sea stars from Southern California to Alaska whilst tracking patterns of unusual warming in the Pacific Ocean. The sunflower sea star is shown to be highly susceptible to this wasting disease because they do not have a complex immune system. As a result, the data showed an 80 to 100% decline over the period of the study.

Sunflower Star Imperiled by Sea Star Wasting Epidemic” by Hakai Institute

If the sunflower sea star dies off, this should be an important indicator of the effects of ocean-warming and its impact on marine ecosystems. Sunflower sea stars are voracious predators in the deep and shallow waters of the northwest Pacific, and if these sea stars were to go away we could see an unbalanced ecosystem in our waters.

– Katherine Lam

Global Warming and Mountain living species Extinction. No place to live!

Scientists believe that the global temperature will continue to rise for future decades due to climate change and global warming, which will impact the whole ecosystem severely. One big issue that scientists found in recent years is called “Elevational Range Shift”. Each species that lives in a different range and altitude of mountains, together form a balance in mountain ecosystem. As the temperature continuously increase, many species, especially those living in the mid and high elevation of mountains, seek to escape from the warming original habitats and move towards higher ground. However, the living space in mountaintops is limited. What will happen to those creatures that have already lived at the highest levels and cannot go any higher? The only ending is the extension. In recent several years, more evidence have shown that species’ geographic range shift had arose and constituted an elevational extinction to species that live in mountains.

In November 2018, Dr Benjamin Freeman, from the University of British Columbia, published an article showing evidence about impacts of recent temperature warming on high-elevation birds species abundance declination and extinction in Peruvian Andes Mountains. Peruvian Andes is a tropical mountain located in the western edge of South America, with an average height of about 4,000m and host abundant types of species. Tropical species, especially birds, born and live within one particulate section of woods and don’t migrate.

A scarlet-breasted bird lives at high elevations on the Cerro de Pantiacolla in Peru. Source: BBC News

“It is only got a little bit warmer in the tropics and tropical animals seen to live a bit higher now than they used to,” told by Dr. Freeman to BBC News report.

The research team conducted a survey in 2017 of bird species that lived on a mountain peak by using same methods and at same time of year as a pervious survey carried out in 1985. They compared the results and found that the average living range had shifted upwards of the slope and most bird species that are found at the highest elevation had already declined in population and range significantly. Of the 16 species of tropical birds that had been recorded living at high elevation of the study area in previous survey, 8 had disappeared in the new survey in 2017.

Comparative species richness patterns for recent and historical. Source: PLOS

In contrast, scientists found that low elevation living bird species of the mountain get benefits from climate change by expanding their habitats range as they shift their upper living limits upslope. But current increasing in abundance still cannot guarantee that these birds will not face to the problem of run out of habitats.

What about the non-mobile species, like plants? Scientists believe that plants may be unable to shift according to the data showing that about 88% plant species show weak to no evidence of range shift. The main reason is due to plants’ dispersal limitation. Plant need other species, such as birds, or external force like wind to disperse seeds, which may not be quickly enough to keep peace with climate change.

In conclusion, the escalator to extinction will be even worse in the future if temperature continuously rising. “The way to deal with it is to maintain protected habitat corridors that stretch across large elevational gradients.” told by Dr. Freeman to BBC News.

– Jingyi Cheng