Window on Marine Life: Jaltemba Bay Tide pools

 by Tara A. Spears 

One of the favorite activities along the Riviera Nayarit is strolling the gorgeous beaches. But most people stay on the sand and miss out on a remarkable phenomenon, the Pacific Ocean tide pools.  It’s worth the extra exertion to climb the rocky outcroppings at either end of the Jaltemba Bay to view the tide pools that contain a wealth of marine critters. Tide pools are a unique and brutal habitat where the ocean meets the land.

This tidal zone is continually shaped by the actions of sun, wind, water, and rock. The sun bears down, heating exposed surfaces and organisms, ocean breezes blow and contribute to the wave action, erosion, and drying of exposed plants and animals; the ever changing water level requires tide pool inhabitants to have adaptive characteristics; and the rocks are etched by the force of the pounding tides constantly approaching and receding.   If you want a perfect spot to meditate or just enjoy the natural beauty of the tropical ocean, sitting beside a tide pool is a guaranteed de-stressor.

Motivated by my favorite two budding biologists, Anna and Isabella and I visited the tide pools numerous times during the last week. In the rocky outcroppings, portions of the shoreline are regularly covered and uncovered by the water movements of the tides. In order to survive, tide pool organisms must prevent being washed away by the tidal waves, keep from drying out in the sunlight of low tide, and avoid being eaten.  Life is tough for plants and animals that live in tide pools, one of the most daunting environments for sea life!  I had told the girls that we might see starfish, crabs, small fish, anemones, urchins, barnacles, or other sea plants in a tide pool so we knew what to look for. Fortunately, we did identify several types of marine life.

Tide pools can be subdivided in four zones: the splash zone, high tide, mid-tide, and low tide areas. Waves that bring in much-needed nutrients and moisture can also carry unprotected animals out to sea. An additional characteristic of the tide pool environment is the constantly changing salinity (salt concentration.) Animals living in the tide pools must be able to tolerate wide salinity variations.

Due to the logistics of exploring with young children, we primarily studied the splash and high tide zones. In the splash zone, which is the area above the high tide water line and mainly depends on sea spray and mist for water coverage,  live lichen and barnacles.  We located cute little fish that were silver with black stripes besides several types of snails, crabs, and urchins.  All of these species are adapted to withstand long periods of exposure.

At the high tide pools, the area of intertidal that is covered by most high tides, we found many barnacles, limpets and chitons- all animals with superior sticking adaptations and hard protective shells.  The array of colors and textures of these sessile arthropods is fascinating. Another wonder that was plentiful are the anemone that live in colonies. The anemones are squishy and wet when out of the water but open into a concise and beautiful flower-like patch when submerged.

The next time you walk the Jaltemba Bay beach, don’t miss out on the treasures that live in the rocky tide pools. As my granddaughter, Anna, so accurately observed, “It’s really special!”