Happy Canada Day everyone! Last night we went into town to view the town's fireworks display- quite the show! There seems to be something uniquely Canadian about watching fireworks on June 30 while standing on a patch of snow. We stayed in town until quite late- I think we missed the darkest period of the night because by the time we were on our way back to the CNSC it seemed as though the run was rising again, or perhaps it was just setting..difficult to tell sometimes.
Instead of a highway dotted with cities, the metacommunity we are studying is a rock bluff along the coast of Hudson Bay that is covered in small rock pools; zooplankton being the inhabitants of each pool. Each pool possesses its own unique set of characteristics; some like the salinity (saltiness) of the pools may vary with factors like global environmental and climate change. Yes, this means that in an age where the environment dominates personal and political agendas, it may come as a small comfort that some of the world’s tiniest organisms are acting as watchmen, poised to tell us about changes in our environment. Through previous research we have found that salinity is one of the main environmental conditions that determine which species of zooplankton are found in which pool. There are certain species that are found in very saline pools and other species that are found in only freshwater pools. Other species seem to tolerate a wider range of salinity and are found in pools right across the bluff. And the really cool thing? Both salinity and therefore the zooplankton can be completely different between two pools separated by as little as a few centimetres. So here is what I want to know:
1. Do the communities of species present in the rock pools change as pools become saltier?
2. If the communities do change, is this impacted by a pool’s position relative to other pools?
Basically for the second question, I’m asking if the way a community responds to environmental change is influenced by the potential for organisms to enter a community from other nearby communities.
But why is this important? Well because it can tell us a lot about how organisms move from place to place which is essential for understanding or making predictions about many other processes in nature. As well the Churchill rock pools are a unique system in Canada’s north; they have relatively simple zooplankton communities which makes it easier to identify and count all of the species and they are in an area likely to feel increasing impacts of environmental change. Another cool fact is that work of this particular nature on rock pools is occurring in only a few other places around the world- Jamaica, Africa and Finland to name some.
So here is a simplified breakdown of our methods...
So this blog post is a special edition and really should be titled- "Amanda explains zooplankton communities on Da Bluff." Ingrid has challenged me to give a brief explanation of my project on the blog for all the followers back home, so here is my attempt. So please "bear" with me...hahaha.
As children, many of us spent time imagining different ways of travel- flight, tunnelling through the ground, riding on the back of an elephant. Ecologists too spend their days envisioning how the tiniest of organisms get from place to place. Zooplankton are aquatic organisms, only the biggest of which can be seen with the naked eye, and yet they may help researchers understand how small organisms disperse from one location to another and how environmental changes may cause their movement. To better understand this we need a way to think about communities of plants, animals, insects and other organisms that allow us to see connections between them. Metacommunities are communities that are linked to each other; think of them as cities connected by 400 series highways versus cities or towns joined only by gravel roads, train tracks or stretches of water. For example, it tends to take less time and effort to drive straight on the 401 west from Toronto to Guelph then it does to take the train from Winnipeg to Churchill, MB (yes A LOT less time). This means that the interchange of people between Toronto and Guelph may be significantly higher on a daily basis than between Winnipeg and Churchill. You will have witnessed this if you are a daily commuter within the Greater Toronto Area. If you wanted to do a study on the community of people living in Churchill, you probably wouldn’t look at people living in Winnipeg. However you might very well study those that live in Guelph to get a better idea of who is coming into and out of Toronto.
This can be applied to an ecological angle as well. When scientists study metacommunity dynamics they are essentially studying how and why organisms “commute” from one community to another. So, metacommunities allow us to think of the inhabitants of one area in terms of the inhabitants of nearby and connected areas. Does easy access between one community and another influence what organisms are found in a community? Or is it more about the environment at a certain site? These are two of the key questions that I am addressing with my project up here in Churchill.
Instead of a highway dotted with cities, the metacommunity we are studying is a rock bluff along the coast of Hudson Bay that is covered in small rock pools; zooplankton being the inhabitants of each pool. Each pool possesses its own unique set of characteristics; some like the salinity (saltiness) of the pools may vary with factors like global environmental and climate change. Yes, this means that in an age where the environment dominates personal and political agendas, it may come as a small comfort that some of the world’s tiniest organisms are acting as watchmen, poised to tell us about changes in our environment. Through previous research we have found that salinity is one of the main environmental conditions that determine which species of zooplankton are found in which pool. There are certain species that are found in very saline pools and other species that are found in only freshwater pools. Other species seem to tolerate a wider range of salinity and are found in pools right across the bluff. And the really cool thing? Both salinity and therefore the zooplankton can be completely different between two pools separated by as little as a few centimetres. So here is what I want to know:
1. Do the communities of species present in the rock pools change as pools become saltier?
2. If the communities do change, is this impacted by a pool’s position relative to other pools?
Basically for the second question, I’m asking if the way a community responds to environmental change is influenced by the potential for organisms to enter a community from other nearby communities.
But why is this important? Well because it can tell us a lot about how organisms move from place to place which is essential for understanding or making predictions about many other processes in nature. As well the Churchill rock pools are a unique system in Canada’s north; they have relatively simple zooplankton communities which makes it easier to identify and count all of the species and they are in an area likely to feel increasing impacts of environmental change. Another cool fact is that work of this particular nature on rock pools is occurring in only a few other places around the world- Jamaica, Africa and Finland to name some.
So here is a simplified breakdown of our methods...
Firstly our bluff looks something like this: (aerial pictures coming soon!)
We have labelled and taken dimensions and GPS coordinates for over 60 pools on the bluff. From there we assigned pools to different experimental categories. We have several pools that are very salty and are acting as saline "controls"- which means we do not manipulate them, as well as pools acting as
freshwater controls. The remaining pools are classified as being near to saline controls or farther away. At three points in the summer we begin to add salt to the non-control pools to make them more salty and watch as the communities change over time. We use a piece of equipment that measures a whole slew of environmental variables including salinity to get an idea of the environmental conditions of each pool. We then take a sample of the zooplankton living in each pool using a special net. We take note if there are differences in the changes we see between the pools that are close to the salty controls and the pools that are farther away.
freshwater controls. The remaining pools are classified as being near to saline controls or farther away. At three points in the summer we begin to add salt to the non-control pools to make them more salty and watch as the communities change over time. We use a piece of equipment that measures a whole slew of environmental variables including salinity to get an idea of the environmental conditions of each pool. We then take a sample of the zooplankton living in each pool using a special net. We take note if there are differences in the changes we see between the pools that are close to the salty controls and the pools that are farther away.Finally we also record weather data for each day as well as changes in the depth of all the pools. This will help us to see if seasonal changes or things like precipitation or evaporation have an impact on our experiment. To measure evaporation from our site we have set up a "pan evaporation system." This is a large rectangle filled with a specific volume of water that we record water loss from. And that in essence is the project!
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