I use my text as a resource, and utilize credible sources on the Internet to give my students multiple sources of text, and this assignment helps with that.
This webquest will have students analyzing the text from http://oceanmotion.org/html/background/western-boundary-currents.htm. Take a look at that text to see if it fits your curriculum. I find it a nice resource to compare eastern and western boundary currents, which in the gyre are very different and have different distributions of life. In Florida, our standard reads students must "explain the distribution of life in our oceans due to waves, tides, and currents", and I think this resource starts that classroom learning atmosphere for currents. Some of the questions on the webquest are "right there" style (or lower level) while some of the questions require the students to infer from the reading an answer (higher level).
There are many ways to incorporate this into your lesson:
1. Have the students work independently on this as you circulate the room
2. Have the students work in pairs on this as you circulate the room
3. Assign as homework
4. This requires a little work on your part, but possible: Correlate the webquest questions to each paragraph the answer is found in on the website before making copies/giving this to students. Then, the teacher could read the webquest questions and then the text paragraph by paragraph to the students, stopping and allowing time for students to find and write answers. That may be a good strategy for a lower lexile group of readers.
This download includes an answer key, as well as the website text in a printable version (in case a student is without means to access the website in class).