Argyle Creek Lesson Plan
Time: 2-3 hours.
Location: In field at Argyle Creek.
Handout: Map of creek showing zones, an example of detailed zone map indicating diversity, areas to write data for 3 activities, outline of the lesson, a good quote, future possible research ideas to think about.
Equipment: Rain gear, knee or hip wading boots, and a pencil. You will also need one of each of the following for each group of 3-4: clipboards, shovels, and sieves (large mesh, 2-4 mm holes).
A scanned copy of the handout used for the 2000 MIZ field lesson can be found here .
Part I exercise: Familiarization with habitat
Lecture: Describe large scale observations of the creek:
Saltwater creek always flowing. Similar to floating docks in that it is a sub tidal habitat, but with a huge tidal influence: differences include highly variable temperature, directional and bi-directional flow with large daily velocity changes, depth changes (unlike floating docks), substrate differences, including type of surface substrate as well as having an infaunal area.
Physical parameters and variation within those parameters: Water velocity, water depth, temperature, sediment composition.
Patches: We made zones and within zones, edges vs. middle, faunal patches.
Walk through the zones: Spend 20 minutes walking along side the creek, stopping at each zone and giving a mini lecture using field to point out these various aspects: variability particular to zone and within a zone, reason the zone is demarcated as a zone. Tell them to begin to observe the diversity and remember vast number of different taxa found at the creek.
Part II exercise: Diversity within a zone
Exercise: Already described large scale diversity, especially of easy to observe physical aspects and fauna. Now focus on patches within zones: explain epifaunal, cryptofaunal and infaunal designations, and have participants compare the species composition of those surfaces on rocks between 2 zones.
Equipment: Pencil, handout, shovel, sieve.
Handout: Handout is a list of key species to focus on and document in which zone the species is found. Change zones and repeat. Zone pairs 1&3; 2&1; 3&4; 4&2 (because zones 2 and 3 are similar). Spend 20 min per zone. Afterward gather in groups and discuss size variation, and abundance between zones.
Focus animals: Limpets, anemones, Semibalanus and Balanus barnacles, terebellid worms, chitons, clams, brittlestars, gastropods.
Activity: Observation of patchiness of animal distribution, abundance, size, and location. Group together 4-6 people per zone and collectively document where focus species occur: epifaunally, cryptofaunally or infaunally.
Summary: Have groups announce what they found, and where. For example, for a focus species go through the four zones and have people shout out or raise hands if they found the animal in the zone and if it was small big abundant or not etc.
Part III exercise: Observation of activities of fauna
Exercise 1: Observation of feeding, color morphs (protection), locomotion. Most animals at Argyle are sessile filter feeders whose feeding and locomotion are easy to observe because they are sessile. Observe other methods of feeding, competitive interactions and locomotion.
Handout: Provide spaces that relate to varying spatial scales on the sheet (1 mm, 1 cm, 10 cm). Have people stay in place, watch for animals, and record the appropriate scale on which each organism interacts with its environment. This applies also to sessile organisms that move body parts, e.g. serpulid worms that move the tentacles for feeding. Do this in Zones 2 or 3. Watch for about 10 minutes.
Focus animals: Clams, terebellid worms, hermit crabs, sculpin, Hemigrapsus crabs, limpets.
Some about scale of locomotion:
Exercise 2: Have people stand downstream (as to not create ripples in surface making visibility low) and break mussel on a rock and observe activity of crabs, hermit crabs, sculpin. While in activity note the color morphs of Hemigrapsus and hypothesize reasons for varying colors: selection pressure white of oyster bed vs. brown of pebbles; near molting color variation.
- Clams - siphons open and close, 1 cm
- Terebellidae -move feather duster in and out, 1 cm
- Hermit crabs - fight over shells, 10 cm
- Sculpin swim 30-50+ cm
- Hemigrapsus- walk around 30 cm
- Limpets walk or lift shell - 1 cm or 1 mm
Questions: Have participants defend their choices for spatial scales of locomotion for particular animals. Do these decisions depend on the time scale considered? For example, a clam closing its valves occurs over 1 cm or several mm, but what about a clam burrowing? Again the point is to answer the question how much of the substrate habitat does an animal see? Did large clawed porcelain crabs attack the mussel? Why not? Is it valid to call a clam closing its valves locomotion? Over what time and spatial scale can you say these organisms move, given your 5 min. observation?
How much of the substrate do animals actually see then? Do crabs only run over the same territory, while limpets graze over lots of territory?
Part IV exercise: Big picture view of habitat and phylum diversity
Exercise: Phylum scavenger hunt.
Handout: List of organisms to find in a scavenger hunt, and spaces to write zones in which organisms are found. Have individuals look separately. Focus animals include all four zones. The Scavenger hunt ends when first person finds all organisms and the judges verify.
Discussion: Recap the vast diversity discovered and general trends noted.
Further topics to discuss:
Discuss future human impact given the lack of understanding of what "marine research preserve" means as far as collecting and trespassing, use of land by trespassers, possible increased human interaction given the new boat dock being installed, and lack of signs marking the habitat as a marine protected area.
Would a sign indicating uniqueness and scientific value of the site, as well as a description of the rules of a "marine research preserve" be beneficial or have no impact or a detrimental impact to the site?