LIAO Yifei 廖一菲 ZHENG Ce 郑策
Introduction
Our group members were all interested in the topic of the Sea and Ocean, especially a wonderful animal in the sea——coral.
Coral is an ecologically important but often overlooked animal. We found that more and more corals are becoming unhealthy and even dying, which also shows a natural state of contamination.
As a habitat for many creatures in the sea, corals play an important role in protecting biodiversity. At the same time, coral also affects the carbon cycle through photosynthesis, calcification, etc., and it is also a piece of important evidence to record the changes in the marine environment.
Corals are always colorful and colorful in our impression, but this is not the case now. Actually, the original coral is white, and its beautiful color comes from the symbiotic algae in the body. These algae provide nutrients to the coral through photosynthesis. If they die or leave the coral, the coral will lose nutrients and bleach.
And these algae need to live in a suitable environment. With the increase of sea temperature and other issues, the number of algae symbiotic on corals is decreasing, which further aggravates coral bleaching.
We hope to start with a small animal species and look for data in different aspects, such as temperature changes, human pollution, biological invasion, etc., to explore the impact of the environment on coral bleaching, and to call on more people to pay attention to the ocean and ecology.
Dataset
Main dataset: coral average bleaching rate
From the beginning, we found a dataset on the average bleaching rate for the whole world.This has helped us establish an initial understanding of the coral bleaching problem. It’s a large dataset with the coral bleaching rate for each measurement point, and the latitude and longitude of that measurement point, as well as some climatic elements associated with bleaching ( Depth,SST,SSTA,DHW… ).
To understand what is in this table, we first looked up what the abbreviations in the table header stood for. For instance,
- SST – Sea Surface Temperature
- DHW – Degree Heating Weeks
Then we found the parameters that we thought might be relevant to the bleaching rate, and classified their data types.
DHW
In bleaching dataset, we mainly explored the relationship between bleaching and temperature. But it only have the temperature of that location at that moment, we want to find data on temperature change over time. And finally we find this one. It records the historical temperature of each coral observation site.
link: coralreefwatch.noaa.gov/product/50km/index.php
link: coralreefwatch.noaa.gov/product/vs/map.php
Plastic emissions
figshare.com/articles/dataset/River_plastic_emissions_to_the_world_s_oceans/4725541
Plastics are one of the most important pollutants in the oceans. When it comes to man-made impacts on corals, plastic pollution is the first thing that comes to our mind. So we search for data on plastic pollution flowing into the ocean in order to find if there is a relationship between plastics and coral bleaching.
Important parameters：Latitude, longitude, Emission
Atlantic Hurricane
www.kaggle.com/noaa/hurricane-database
When we searched for information about the Atlantic Ocean in 2005, we found that 2005 was also was a hurricane-prone year. Is there a relationship between bleaching and hurricanes? We looked for hurricane data.
Coral Species
Unfortunately, we found no well-integrated coral species distribution data for the time being. Therefore we tried to find data on coral species in each region in paper.
Analyze & Visualize data
Q1: Where are the bleaching corals？
Faced with a huge coral bleaching dataset with more than 30 parameters, we decided to start with the simplest geographic location to understand the dataset as a whole. We want to know where all the bleaching corals are distributed in the world’s oceans, and where the situation is more severe. Therefore, we put the bleaching rate into a world map by its longitude and latitude, with the size of the points responding to the high or low percentage.
Bleaching corals are found close to land and are more severe in Southeast Asia, the Great Barrier Reef and the Caribbean. However, this is very relevant to coral distribution and does not suggest that close to land is responsible for the high rate of bleaching.
Q2: When are the corals bleached？
We drew the following graph with the year as the independent variable and the average of the annual bleaching rate as the dependent variable to see the change over time.
Also, we added the ocean as another independent variable. The color represents the average bleaching rate.
Finding
Atlantic in 2005 and Indian in 2016 had the most severe bleaching.
Q3:Are there any different bleaching reasons in different oceans?
We zoom in from each year to each day. The data is separated by oceans and you can obviously see that different oceans have different coral bleaching times. We wanted to find if the coral bleaching rates in each ocean followed some rules, but unfortunately we did not find it in this dataset. We then decided to turn to various factors that could be related to bleaching and looked for more data under each factor to support our analysis.
Q4: How does temperature affect coral？
In this coral bleaching dataset, the parameters related to temperature are the most numerous, including SSTA, SSTA Frequency, SSTA DHW, Temperature, TSA, TSA Frequency, and TSA DHW. We choose temperature as our first research direction.
DHW
“Based on research at CRW, when the heat stress reaches 4 degree C-weeks, you can expect to see significant coral bleaching, especially in more sensitive species. When heat stress reaches 8 degree C-weeks or higher, you would likely see severe, widespread bleaching and significant mortality.”
NOAA Coral Reef Watch (CRW) uses DHW as an indicator for coral bleaching event warning. We think it might be an important parameter that affect corals, so we started to try find the relationship between DHW and the bleaching rate.
Every 5 percentage points of bleaching rate data is a group. Its color represents the high or low whitening rate, and the area represents the number of data in this group as a percentage of the total number.
Finding
There are more data points with high bleaching rate when DHW>4. This means that when DHW is high, it is more likely to cause coral bleaching.
Since the information expressed in this diagram is too complex, we try to only show how many the high bleaching rate (>50%) points are in different DHW situation to visualize this finding in a simpler diagram.
El Niño
EI Nino is the equatorial climate variation in the Pacific. It causes the warming of the ocean surface or above-average sea surface temperatures.We think that it may have an influence on coral bleaching, so we find another dataset that represents El Niño to see if the time of El Niño occurrence and the time of coral bleaching are related.
From the graph above, we can see that 2016 had the most severe El Niño, which is the same as the highest average coral bleaching rate year. Because the ocean with the highest bleaching rate in 2016 was the Indian Ocean, we compared DHW maps with coral bleaching maps.
Finding
EI Nino is one of the main reasons that cause coral bleaching in Indian Ocean, 2016.
Coral Species
In the picture below, we find that for the corals of different oceans, they have different sensitivity to high sea surface temperatures. This might be caused by the different species of corals covering in different oceans. Red Sea and Arabian Sea have more variation in sea surface temperature and higher average temperature, but the bleaching rate is not so high. The coral species living there should have a strong adaptation to high temperatures.
We did not find any data sets on the global distribution of coral species online, but we did search for “super corals” in the Red Sea and Arabian Sea. They can better adapt to the global warming oceans and are considered by scientists as a hope to restore coral cover.
Finding
Coral species in the Red Sea and Arabian Sea have higher heat tolerance.
Q5: How does hurricane affect coral？
2005 was the year with the highest bleaching rate in the Atlantic Ocean and also the hurricane season. Hurricanes are similar to coral bleaching in that they are also caused by high ocean temperatures. We collected hurricane data from 1851 to 2014 to help us analyze. We first plotted the trends of annual Sea Surface Temperature Anomaly (SSTA) and the number of hurricanes in the Atlantic, confirming that 2005 was a year of high SSTA and frequent hurricanes.
The years shared with coral bleaching data were filtered and their trends were found to be highly correlated.
We think that hurricanes and coral bleaching might have some connection.Then we searched for papers related to hurricanes and corals and concluded the following relationships.
By comparing the temperature monitoring data of coral observation sites with the hurricane data, it can be seen that when the hurricane with weak wind passes by the coral area, the ocean surface temperature will be reduced, and the coral bleaching warning is lowered from Alert Level 1 to Bleaching Watch level.
Finding
Not all hurricane is do harm to the coral. Small hurricane can reduce the SST to mitigate
coral bleaching.
Q6: How do human activities affect coral？
This part of data process is dominated by supporting analysis and less visualization content. This is because although there are studies showing that these anthropogenic factors contribute to coral bleaching, the data we collected cannot effectively visualize these findings for the time being. We feel that human activities have influenced natural factors such as ocean temperature, water quality, and fish thus causing coral bleaching. This influence process is more indirect than natural factors.
Plastic
Southeast Asia has higher plastic emissions and greater coral bleaching rates.
Fishery
“The RRSEA project found that over 85% of Malaysian coral reefs are threatened by human activities. Destructive fishing and overfishing were the main threats, affecting 68% and 56% of the reefs, respectively. Coastal development and sedimentation from upland areas affect approximately 23% of Malaysia’s reefs, respectively.”
CO2 Emissions
Malaysia has high CO2 emissions, and it is surrounded by high rates of coral bleaching.
Storytelling
Draft
Story summary:
Bleaching Overview
Common Causes
Through the analysis of the data, we found that there are some common causes of coral bleaching all over the world, such as SSTA DHW (Sea Surface Temperature Abnormal Degree heating weeks), we put it in a separate location to let everyone see this more clearly importance of factors.
The Atlantic Ocean
Also, when we zoom in to a certain ocean, we can see some different correlations in the data.For example, for the Atlantic Ocean, the coral bleaching rate in 2005 was very high, and at almost the same time, the Atlantic Ocean ushered in the hurricane season. By comparing the number of hurricanes recorded in the Atlantic Ocean and the coral bleaching rate, we found a relatively close association.
At the same time, considering the reasons, hurricanes are also related to temperature: higher temperatures are prone to hurricanes, and some small hurricanes can reduce the ocean temperature, which will slow down coral bleaching in the area, but large hurricanes will bring more corals. big damage.
The Indian Ocean
For the Indian Ocean, In 2016, it had the highest rate of coral bleaching, mainly because of the warmer temperatures caused by the strong El Niño current. We can see from the comparison chart.
We found large differences in the distribution of coral bleaching in southwestern Indonesia, with lower bleaching rates in its northwest and higher bleaching rates in its southeast. When we connect some data, we find that there are some man-made reasons – we put the number of plastic emissions in the estuary. Visualize and find that the amount of emissions corresponds exactly to the level of bleaching rate.
The Pacific Ocean
“On average one COTS can consume 13 square meters of reef per year. During population spikes, clusters of COTS eat living coral polyps faster than the coral can grow and reproduce. “
For the Pacific Ocean, Australia’s Great Barrier Reef is an area with severe coral bleaching. When we searched for information, we found that there are a lot of corals that are being damaged by a creature – the crown of thorns starfish（COTS）. Divers are also spontaneously helping to collect and kill them.
The Red sea and Arabian Gulf
For the Red Sea and Arabian Gulf, studies have shown that corals in this area are more heat-tolerant than corals in other places, and have a certain ability to adapt to the temperature. Scientists are studying whether the findings can be applied to corals worldwide to improve their ability to withstand global warming.
Super Coral are species of coral that have survived harsh temperature and environmental conditions and may help existing reefs recover and rebound, if we invest in them.
Key insights from data
- Atlantic in 2005 and Indian in 2016 had the most severe bleaching.
- There are more data points with high bleaching rate when DHW>4. This means that when DHW is high, it is more likely to cause coral bleaching.
- EI Nino is one of the main reasons that cause coral bleaching in Indian Ocean, 2016.
- Coral bleaching rates and the number of hurricanes in the Atlantic show correlation. But not all hurricane is do harm to the coral. Small hurricane can reduce the SST to mitigate coral bleaching.
- Coral species in the Red Sea and Arabian Sea have higher heat tolerance. They may help existing reefs recover and rebound
- Crown-of-thorns starfish outbreaks cause massive coral bleaching, and they have no natural predators, relying on human intervention to reduce the impact on corals.
- Human activities such as plastics, fishing and CO2 emissions affect corals by affecting their habitat
Our design
Design Idea
To do an AR experience by Hololens placed in the aquarium allow viewers to see not only the corals here, but also the current state of all corals in the world.
And through interaction you can explore the reasons why corals bleach, and at the end you can donate to coral conservation and grow your own AR corals in the aquarium.
Relevance
Because we want to…
- let more people know what corals around the world are suffering. Many people know that corals are bleaching and probably know that it’s related to global warming, but there are actually more reasons that are also causing corals to turn white.
- And encourage people to join coral conservation programs and help plant coral, so that little goes a long way!
Touch point
Hololens in aquarium or sea tank exhibition
Design scenario & interaction
