I went out to Peggy's Cove (NS) yesterday with a group of 27 grade 7 students from a private school here in Halifax. The kids were doing projects on different species or habitats in the intertidal zone. The intertidal zone is the area of shoreline that exists between the high tide line and low tide line. It is solely populated with marine organisms. Although, you sometimes get some terrestrial beasts that stray into the zone at low tide (eg: birds, dear, mink). So, I was there to lend my expertise to the students. Usually, Diego and I do this every year. It is something we really enjoy and feel is important! Unfortunately, Diego couldn't make it this year so the kids didn't get their interactive tide lecture... : ( Maybe next year!
One of the things I talked about was intertidal zonation (see pic).This is generally described as the distinct organization of plants and animals into bands that represent different zones within the intertidal area. The zonation is caused by environmental as well as biological interactions.
For example, plants and animals that live in the high zone are exposed to air longer than those in the low zone and need to withstand extreme heat (summer) and cold (winter) as well as drying out. However, those in the low zone are covered by water more often so don't need to deal with the problems of air as much but they are exposed to subtidal (below the tide) predators more often than the high zone. The students also got to see the large tidepools that are present in the granite rocks of that area. Tidepools are depressions in the rock that contain water, regardless of the time of tide. They are scattered at all levels of the intertidal and they act as a refuge for organisms that cannot tolerate the physiological stress of being exposed to extreme environmental conditions when the tide is out. Depending on the height on the shore the tidepools can be very different...they too are zoned. Here is a photo of me working in a large low zone tidepool near Peggy's Cove. I worked in tidepools for my honours thesis, as part of my undergraduate degree.
Unfortunately for us, they day wasn't as nice/calm as in the tidepool pic...we had fog, rain and wind so it was cold, wet and rough...which meant that we couldn't get close to the low zone at all! Regardless, the students had lots of fun but many, including myself, left chilled and ready for a warm drink! Lots of pictures were taken and I hope to get my hands on them so I can post a few!
Have a good weekend!